Toxicology & OB

Poisons and Overdose

Drug Overdose and Poisoning Emergencies

Overview

Toxicology is the study of poisonous or harmful substances and their effects on the body. A poison is any substance capable of causing injury, illness, or death after entering the body and producing harmful chemical effects. Even a relatively small amount of some substances may cause serious poisoning.

A drug is generally a substance used for therapeutic or medical purposes, although it can also become harmful when taken incorrectly or in excessive amounts. Toxins are poisonous substances that originate from living sources such as plants, animals, or bacteria.

An overdose occurs when a person takes an excessive or dangerous amount of a medication or drug, resulting in potentially serious or life-threatening effects. An overdose may involve a prescription medication, an over-the-counter drug, or an illegal substance. It may happen accidentally or intentionally.

Toxic exposures may affect different numbers of people depending on the event. A small incident may involve only one or several patients, while larger chemical releases may expose hundreds or thousands of individuals. In some circumstances, widespread exposure may affect entire regions or populations.

Common Types of Toxicologic Emergencies

Accidental Poisoning

Unintentional poisoning occurs when a harmful substance is taken or encountered accidentally. Although these incidents are not always fatal, they can produce serious medical emergencies.

Children and older adults are particularly vulnerable. Young children may swallow medications or chemicals because they do not recognize the danger. Older adults may accidentally take excessive amounts of medication because of multiple prescriptions, complicated medication schedules, memory problems, or confusion.

Other accidental toxic exposures may result from:

Substance-Related Overdose

Alcohol, stimulants, sedatives, opioids, and other substances that affect mood or consciousness can result in poisoning or overdose when taken in dangerous amounts.

Patients under the influence of drugs or alcohol may experience altered judgment, confusion, agitation, or unusual behavior. Their condition and behavior can change rapidly, so EMS personnel should continue to monitor both the patient’s medical condition and scene safety.

Deliberate Poisoning

Intentional poisoning may involve a person deliberately exposing themselves or another person to a harmful substance. Intentional overdoses may occur as part of self-harm or a suicide attempt, while poisoning another individual may occur in criminal or other deliberate circumstances.

Regardless of the reason for the exposure, treatment should focus on the patient’s immediate medical needs while also addressing any psychological or emotional concerns that may be present.

Routes of Toxic Exposure

Poisons and drugs can enter the body through several different pathways. Determining the route of exposure can help identify the substance involved and guide appropriate emergency treatment.

The four major routes are:

Ingestion

Ingestion occurs when a toxic substance, medication, or drug is swallowed. The substance travels from the mouth through the esophagus and into the stomach, where it may be absorbed through the stomach or intestinal lining. Because absorption takes time, symptoms may sometimes be delayed after the exposure.

Common examples include:

Management depends on the substance involved, the amount taken, the patient’s condition, and the time since exposure. Treatment may include supportive care, continuous monitoring, consultation with poison-control or medical personnel, and substance-specific therapy. Activated charcoal may be appropriate for certain ingestions when specifically indicated, but it is not suitable for every type of poisoning.

Inhalation

Inhalation poisoning occurs when a person breathes a toxic gas, vapor, smoke, or aerosol into the lungs. The substance may pass through the alveoli and enter the bloodstream, allowing toxic effects to develop quickly.

Examples of inhaled toxins include:

Initial care usually involves removing the patient from the contaminated environment when it is safe to do so and providing appropriate airway and breathing support. Oxygen may be administered when indicated. Certain exposures, such as severe carbon monoxide poisoning, may require specialized treatment such as hyperbaric oxygen therapy.

Injection

Injection occurs when a toxic substance enters the body through a break in the skin. This may happen through a needle or another penetrating object, or through the bite or sting of a venomous animal or insect.

Injected substances may enter the body through:

This route can be especially dangerous because the substance may reach the bloodstream quickly and produce rapid or severe effects. Needle use can also create additional risks, including infection, bloodborne disease transmission, and accidental needlestick injuries to healthcare providers or responders.

Examples include injected illicit substances such as heroin or fentanyl, as well as venom introduced through snake bites, insect stings, or other animal exposures.

Absorption

Absorption occurs when a medication, chemical, or toxic substance enters the body through the skin or mucous membranes. Before producing systemic effects, the substance must pass through epithelial tissues and enter the bloodstream.

Common examples include:

Treatment begins by stopping further exposure whenever it can be done safely. Contaminated clothing or medication patches may need to be removed, and chemicals on the skin may require appropriate decontamination according to the substance involved.

Responders should wear proper personal protective equipment (PPE) when caring for patients with possible skin contamination. Some toxic substances can also expose rescuers through direct contact.

Substance Misuse

Drugs of abuse are substances used to alter mood, perception, behavior, or consciousness, often for recreational purposes. Some are legal medications or substances, while others are illegal. Any of them may cause serious illness when misused, taken in excessive amounts, or combined with other substances.

Cannabis

Cannabis is a psychoactive substance that may be used for medical or recreational purposes. Its effects can vary depending on the amount consumed, the route of administration, the concentration of active ingredients, and whether other substances were also used.

Possible effects include:

Cannabis may be inhaled, swallowed in edible products, or consumed in other forms. Most patients require supportive care and observation, but significant symptoms may require further medical evaluation and transport.

Stimulants

Stimulants increase activity within the central nervous system (CNS). They range from commonly used substances such as caffeine to prescription medications and illicit drugs such as cocaine and methamphetamine.

Stimulant toxicity may produce:

Serious stimulant toxicity may cause severe agitation, seizures, abnormal heart rhythms, hyperthermia, or cardiovascular complications. Management focuses on the airway, breathing, and circulation, continuous monitoring, rapid transport when indicated, and treatment according to local EMS protocols.

Patients with severe agitation may present a danger to themselves or others. Responders should prioritize scene safety and use approved de-escalation, medication, or restraint procedures only when clinically necessary and permitted by protocol.

Sedative and Barbiturate Overdose

Sedatives are substances that decrease activity in the central nervous system. They may be prescribed for conditions such as anxiety, sleep disorders, or seizures. Examples include barbiturates, benzodiazepines, and other sedating medications.

An overdose may cause:

Management focuses on maintaining the airway, breathing, and circulation. Patients with significant respiratory depression may require assisted ventilation or advanced airway management. Continuous monitoring, supportive care, and prompt transport are important for severe sedative overdoses.

Hallucinogenic Drugs

Hallucinogens are psychoactive substances that can change a person’s perception, thoughts, emotions, and awareness of the environment. They may cause hallucinations, in which a person sees, hears, or feels things that are not actually present.

Hallucinogens are generally grouped into two categories:

The effects of these substances can vary considerably depending on the drug, dose, and individual. Possible effects include altered sensory perception, changes in mood, distorted awareness of time, abnormal pain perception, and changes in body temperature.

Patients under the influence of hallucinogens may behave unpredictably and can become frightened, confused, agitated, or detached from reality. Management should focus on maintaining a calm and safe environment while assessing the patient’s airway, breathing, circulation, and mental status.

Physical restraint should only be considered when necessary to protect the patient or others and should follow approved EMS protocols. Patients with severe symptoms, altered consciousness, or significant behavioral changes may require prompt transport and continued monitoring.

Opioid Drugs

Opioids are powerful medications and substances that reduce pain by acting on opioid receptors in the nervous system. They may be prescribed for pain relief, but they also have a significant potential for misuse, dependence, and overdose.

Examples include prescription medications such as oxycodone and codeine, as well as illicit or illegally manufactured substances such as heroin and fentanyl.

An opioid overdose commonly produces depression of the central nervous system and respiratory drive. Typical findings may include:

Immediate care should focus on the airway, breathing, and circulation. Assisted ventilation is especially important when respirations are inadequate.

Naloxone is an opioid antagonist that can temporarily reverse opioid-induced respiratory and central nervous system depression. It should be administered according to local EMS protocols when opioid overdose is suspected.

Naloxone may wear off before the opioid has completely left the patient’s system. Because of this, symptoms of overdose can return after an initial improvement. Continued observation, monitoring, and transport for further medical evaluation are therefore important.

After naloxone administration, some patients may become confused, agitated, or experience symptoms of acute opioid withdrawal. Responders should maintain a safe environment and continue monitoring the patient.

Patients with opioid misuse may also have additional medical concerns that should be considered during assessment, including infections, poor nutrition, injection-related complications, or other coexisting health problems.

Inhalant Abuse

Inhalants, sometimes called huffing agents, are chemical vapors that are deliberately breathed in to produce a brief feeling of euphoria or intoxication. These substances are especially dangerous because many are inexpensive and readily available in products such as aerosol sprays, paints, glues, and other household or hardware-store chemicals.

Excessive exposure to hydrocarbons and similar inhalants can cause severe effects on the heart, brain, lungs, and nervous system. Serious complications may include seizures, abnormal behavior, loss of consciousness, and cardiovascular collapse.

Patients exposed to inhalants should be monitored closely because their condition can deteriorate rapidly. Important concerns include maintaining the airway, supporting breathing and circulation, and arranging prompt transport when serious symptoms are present.

Alcohol Intoxication and Withdrawal

Alcohol is a commonly used psychoactive substance that depresses activity in the central nervous system (CNS). Excessive or long-term alcohol use can result in dependence and may contribute to numerous medical, behavioral, and trauma-related emergencies.

Signs and symptoms of alcohol intoxication may include:

Because intoxication can resemble other serious medical problems, providers should not automatically assume that altered mental status is caused only by alcohol. Trauma, low blood glucose, stroke, drug use, or other medical conditions should also be considered.

Long-term excessive alcohol use may damage multiple organs and can contribute to liver disease, cardiovascular problems, pancreatitis, immune-system dysfunction, and nutritional deficiencies.

Severe Alcohol Withdrawal

A person who has developed physical dependence on alcohol may experience withdrawal after suddenly stopping or significantly reducing alcohol intake.

Delirium tremens (DTs) is a severe and potentially life-threatening form of alcohol withdrawal. Possible findings include:

Patients showing signs of severe alcohol withdrawal require prompt medical evaluation and close monitoring.

Toxic Exposure Emergencies

Patients with suspected poisoning or hazardous-substance exposure require careful attention to scene safety. Responders should first identify potential dangers before approaching or treating the patient.

Appropriate personal protective equipment (PPE) should be used whenever chemical contamination is possible. Without adequate protection, EMS personnel may become secondary victims through inhalation, skin contact, or contaminated clothing and equipment.

Important priorities include:

Carbon Monoxide Poisoning

Carbon monoxide (CO) is a colorless, odorless, and tasteless gas produced by incomplete combustion. Exposure commonly occurs from fires, faulty heaters, generators, vehicle exhaust, or other fuel-burning equipment used in poorly ventilated areas.

Carbon monoxide binds strongly to hemoglobin, reducing the blood’s ability to carry and deliver oxygen to body tissues. Significant exposure can therefore cause severe tissue hypoxia even when a pulse oximeter appears normal.

Possible signs and symptoms include:

Treatment begins with removing the patient from the contaminated environment when it is safe to do so and administering high-concentration oxygen as indicated. Severe cases may require specialized treatment, including hyperbaric oxygen therapy, depending on the patient’s condition and medical direction.

Pulse Oximetry and Carbon Monoxide

Standard SpO₂ monitors estimate how much hemoglobin is carrying oxygen, but they cannot reliably distinguish oxyhemoglobin from carboxyhemoglobin. Because of this, a patient with carbon monoxide poisoning may display a normal or falsely reassuring oxygen saturation reading even while significant tissue hypoxia is occurring.

For suspected carbon monoxide exposure, assessment should be based on the history of exposure, clinical findings, and appropriate diagnostic testing, rather than pulse oximetry alone.

Chlorine Gas Exposure

Chlorine gas poisoning may occur when certain household cleaning products are mixed improperly. Combining bleach with acids or ammonia-containing products can release dangerous irritating gases. Exposure may also occur during industrial leaks or other hazardous-material incidents involving multiple patients.

Chlorine primarily irritates the eyes, respiratory tract, and mucous membranes. The severity of symptoms depends on the concentration of the gas and the duration of exposure.

Possible findings include:

Severe exposures may result in pulmonary edema, hypoxia, altered mental status, or loss of consciousness.

Treatment focuses on removing the patient from the contaminated environment when safe, providing airway and breathing support, administering oxygen when indicated, and arranging prompt transport for significant exposures.

Cyanide Toxicity

Cyanide is a rapidly acting poison that prevents body cells from effectively using oxygen. It may be produced when certain synthetic materials containing carbon and nitrogen burn, making it a concern during structure fires, particularly in enclosed spaces.

Cyanide may also be encountered in certain industrial settings and some naturally occurring substances. Because it interferes with cellular oxygen use, severe exposure can cause rapid deterioration even when oxygen is present in the bloodstream.

Patients may develop:

Management includes aggressive supportive care, oxygen administration, rapid transport, and specific antidotal treatment when available and indicated.

Caustic Chemical Exposure

Acids and alkalis are corrosive substances capable of causing significant chemical burns to the mouth, esophagus, stomach, skin, and eyes.

Examples of acids include hydrochloric acid, sulfuric acid, and acetic acid, while common alkaline substances may include lye, ammonia, drain cleaners, and certain household cleaning products.

Ingestion may cause:

Vomiting should not be induced after a caustic ingestion, because bringing the chemical back through the esophagus may produce additional tissue injury. Treatment focuses on airway assessment, supportive care, consultation with appropriate medical or poison-control resources, and prompt transport.

Organophosphate Poisoning

Organophosphates are chemicals commonly associated with certain pesticides and agricultural products. They interfere with normal nerve signaling by causing excessive accumulation of acetylcholine.

Exposure may occur through inhalation, ingestion, or absorption through the skin. Patients may develop excessive secretions, sweating, vomiting, diarrhea, pinpoint pupils, muscle weakness, slowed heart rate, breathing difficulty, or seizures.

Responder safety is especially important because contaminated clothing or chemicals on the patient’s skin can cause secondary exposure.

Important priorities include:

Toxic Plant Exposure

Many plants contain substances capable of producing irritation, allergic reactions, gastrointestinal symptoms, neurologic effects, or other forms of poisoning. Serious or fatal poisoning is uncommon, but severe reactions can occur depending on the plant and amount of exposure.

Children are particularly vulnerable because they may accidentally eat berries, leaves, or other attractive plant material.

Examples of potentially toxic plants include:

Plant exposure may cause skin irritation, painful rashes, vomiting, mouth irritation, or allergic reactions. Severe allergic responses may progress to anaphylaxis.

Treatment varies according to the plant, route of exposure, and symptoms. Unknown plants should never be eaten, and suspected ingestion should be evaluated with appropriate medical or poison-control guidance.

Medication Poisoning and Overdose

Medication overdoses are among the more common toxicologic emergencies encountered by EMS. They may occur accidentally or intentionally and can involve prescription medications, over-the-counter products, or multiple substances taken together.

Unintentional overdose may result from:

Older adults may be at increased risk because they often take several medications and may have difficulty remembering when or how much medication has already been taken.

Medications can become harmful when they are taken incorrectly or in excessive amounts.

Cardiovascular Medications

Overdoses involving cardiac medications can be especially dangerous because these drugs directly influence heart rate, cardiac rhythm, blood pressure, and circulation. Common cardiovascular medications include nitroglycerin, digoxin, beta-blockers such as metoprolol, and ACE inhibitors such as lisinopril.

Depending on the medication involved, an overdose may cause significant changes in heart rhythm, pulse rate, blood pressure, or level of consciousness. Severe toxicity can lead to poor circulation, shock, or other life-threatening complications.

Patients with suspected cardiac medication overdose may require:

Psychiatric Medications

Psychiatric medications are prescribed to manage conditions involving mood, behavior, anxiety, psychosis, and other mental health concerns. Examples include antidepressants, antipsychotics, mood stabilizers, and anti-anxiety medications.

An overdose may occur accidentally or intentionally. EMS providers should assess the situation carefully without automatically assuming the reason for the overdose.

Effects vary according to the specific medication but may include:

Management should focus on supportive care, continuous monitoring, identification of the medication involved, and rapid transport when significant toxicity is suspected.

Over-the-Counter Pain Medications

Medications available without a prescription can still cause severe poisoning when taken in excessive amounts. Common examples include acetaminophen, aspirin and other salicylates, and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.

Acetaminophen and aspirin overdoses may occur accidentally or intentionally and can be especially concerning in children and adolescents. Although early symptoms may sometimes appear mild, serious internal injury can develop.

Important considerations include:

Activated charcoal may be considered for certain recent ingestions when specifically indicated and when the patient’s airway can be safely protected. Its use should follow poison-control guidance, medical direction, and local EMS protocols.

How Activated Charcoal Works

Adsorption is the process in which substances attach to the surface of another material. Activated charcoal can bind certain drugs or toxins within the gastrointestinal tract, reducing the amount that is absorbed into the bloodstream.

Activated charcoal does not work for every poison, so it should only be used when appropriate for the substance involved.

Prehospital Management of Overdose

Patients with suspected overdose should first receive a systematic assessment with emphasis on scene safety and the ABCs—airway, breathing, and circulation.

If the patient has an altered mental status, providers should consider both poisoning and other possible medical causes. Airway support, oxygenation, ventilation, circulation, and glucose assessment should be provided according to the patient’s condition and local protocols.

Important prehospital priorities include:

Whenever possible, obtain information about what was taken, how much was taken, when it was taken, how it was taken, and whether any other substances were involved. This information can help guide treatment and prepare the receiving hospital for continued care.

Special Considerations for Vulnerable Patients

Certain age groups require additional attention when evaluating suspected poisoning or overdose because the causes, risks, and clinical presentation may differ.

Pediatric Patients

Young children, particularly those between 1 and 3 years of age, are at increased risk for accidental ingestion. Their natural curiosity may lead them to swallow medications, household chemicals, poisonous plants, or other harmful substances that are within reach.

Common concerns include:

Teenagers and young adults may also be exposed to toxic substances through experimentation, recreational drug use, or intentional misuse.

Older Adult Patients

Older adults may experience poisoning or overdose because they frequently take several medications for chronic medical conditions. Complex dosing schedules, medication interactions, memory difficulties, and long-term use of pain medications may increase the risk of accidental overdose.

Some older patients may have been using opioid pain medications for an extended period and may have developed physical dependence. When naloxone is given to an opioid-dependent patient, rapid reversal may produce withdrawal symptoms, pain, anxiety, agitation, or distress.

Naloxone should therefore be administered according to the patient’s respiratory status and local EMS protocols, with the primary goal of restoring adequate ventilation.

Patient Documentation and Handoff Communication

Accurate documentation is especially important when caring for patients with suspected poisoning or overdose. Information provided to the receiving hospital should clearly describe what the patient reported, what responders observed, and what evidence was discovered at the scene.

Important information may include:

Patients who intentionally use drugs may sometimes provide incomplete or inaccurate information, while others may be confused or have an altered perception because of intoxication. EMS personnel should therefore combine the patient’s history with physical findings and available scene information.

Protecting Patient Confidentiality

Medical information should be handled confidentially and shared only with individuals who are legally authorized or directly involved in the patient’s care.

Family members and other individuals do not automatically have permission to receive detailed medical information about an adult patient. Information provided to law enforcement should also follow applicable privacy laws, agency policies, patient consent requirements, and legally authorized requests.

Responders should:

Transport and Continued Care

A patient with a suspected significant overdose or poisoning may initially appear stable while serious toxic effects are still developing internally. Some substances produce delayed symptoms, so a normal appearance at the scene does not always rule out a dangerous exposure.

Prehospital priorities include:

The overall goal is to protect both the patient and the responder, provide appropriate supportive care, and ensure that the receiving medical team has accurate information to continue treatment.

Organophosphate Toxicity

Overview

Organophosphate poisoning is an important toxicologic emergency that EMS providers may encounter, particularly in agricultural, industrial, or household settings. These chemicals can produce severe effects on the nervous system and may become life-threatening without rapid recognition, decontamination, and treatment.

Key Facts
How Organophosphates Affect the Body

The nervous system uses acetylcholine to transmit signals between nerve cells and between nerves and certain muscles or organs. Normally, after acetylcholine delivers its message, the enzyme acetylcholinesterase breaks it down so that stimulation stops.

Organophosphates inhibit acetylcholinesterase. As a result, acetylcholine accumulates at nerve endings and continues stimulating receptors throughout the body.

This excessive stimulation affects the central nervous system, respiratory system, cardiovascular system, gastrointestinal tract, glands, and skeletal muscles. Severe poisoning can lead to respiratory failure, seizures, profound weakness, and cardiovascular complications.

Signs and Symptoms

Symptoms may develop rapidly after a significant exposure. The exact presentation depends on the substance, dose, route of exposure, and duration of contact.

Common findings include:

A helpful way to recognize the cholinergic effects is through the pattern of increased secretions, gastrointestinal activity, pinpoint pupils, and respiratory compromise.

Assessment and Emergency Management

Responder safety comes first because organophosphates can contaminate rescuers through direct contact with the patient’s skin, clothing, secretions, or the chemical itself. Appropriate personal protective equipment (PPE) should be used before contact with a contaminated patient.

Decontamination

Contaminated clothing should be carefully removed when appropriate and isolated according to hazardous-material procedures. The patient’s exposed skin should be thoroughly decontaminated with appropriate methods, commonly including soap and water when indicated.

Decontamination should occur before placing a heavily contaminated patient or contaminated equipment inside the ambulance whenever circumstances allow.

Airway and Breathing

Organophosphate poisoning can produce large amounts of respiratory secretions, bronchospasm, muscle weakness, and respiratory depression.

Important priorities include:

Circulation and Monitoring

Cardiovascular status should be monitored closely because patients may develop bradycardia, hypotension, or abnormal cardiac rhythms.

Obtain vascular access when indicated and continuously reassess the patient’s vital signs, cardiac rhythm, mental status, and response to treatment.

Antidotal Therapy

Two important medications used in significant organophosphate poisoning are:

Medication doses and repeat administration should follow current EMS protocols, poison-control guidance, and medical direction, because patients with severe poisoning may require repeated or substantial antidotal therapy.

Transport and Hospital Notification

Patients with suspected significant organophosphate poisoning require prompt transport to an appropriate medical facility after lifesaving interventions and necessary decontamination have begun.

Notify the receiving hospital early so personnel can prepare appropriate decontamination resources, respiratory support, antidotes, and critical-care treatment before the patient arrives.

Gynecologic Conditions & Emergencies

Gynecologic Emergencies

Overview

Gynecologic emergencies involve conditions affecting the female reproductive system. Some may cause severe pain, significant bleeding, infection, or other complications that require urgent medical evaluation. Even conditions that are not immediately life-threatening can have important long-term effects on reproductive and overall health.

Anatomy and Physiology

External Reproductive Structures

The external genital structures are collectively known as the vulva and include several important anatomical features:

Internal Reproductive Structures

The internal reproductive organs include:

Common Gynecologic Conditions

An imperforate hymen is a congenital condition in which hymenal tissue completely covers the vaginal opening. It may not be recognized until puberty, when menstrual blood is unable to leave the vagina normally.

Possible findings include:

An imperforate hymen develops during fetal development and is not caused by sexual activity or sexual abuse.

Menstruation, also called a menstrual period or menses, is the periodic shedding of the uterine lining when pregnancy has not occurred. Menstrual fluid contains blood, mucus, and endometrial tissue.

Cycle length varies from person to person. Hormonal changes during the cycle can produce temporary physical and emotional symptoms such as:

The amount and duration of menstrual bleeding also vary among individuals.

The ovarian cycle describes the changes occurring in the ovaries during the menstrual cycle.

The follicular phase begins on the first day of menstruation and continues until ovulation. During this time, ovarian follicles develop under the influence of reproductive hormones.

Ovulation occurs when a mature ovarian follicle releases an oocyte. The timing varies depending on the length of the individual’s menstrual cycle and does not always occur on exactly the same day each month.

Normally, one dominant follicle completes maturation and releases an oocyte, while other developing follicles regress.

The luteal phase begins after ovulation and continues until the next menstrual period if pregnancy does not occur. The remaining follicular tissue forms the corpus luteum, which produces hormones that help support the uterine lining.

Uterine Cycle

The uterine cycle describes changes occurring within the endometrium, or inner lining of the uterus.

During the proliferative phase, estrogen stimulates the endometrium to rebuild and become thicker following menstruation. This prepares the uterus for the possibility of implantation.

The secretory phase occurs after ovulation. Progesterone helps make the endometrium more suitable for implantation and supports it if pregnancy occurs.

If fertilization and implantation do not occur, estrogen and progesterone levels decrease. The uterine lining then breaks down and is shed during the next menstrual period.

Menarche is the first menstrual period and represents an important stage of reproductive development during puberty.

The age of menarche varies considerably and may be influenced by:

Menopause is reached when a person has gone 12 consecutive months without a menstrual period because ovarian reproductive function has naturally declined. It most commonly occurs during middle age.

The transition leading up to menopause is called perimenopause. During this period, menstrual cycles may become irregular and symptoms may develop as hormone levels fluctuate.

Possible symptoms include:

Falling estrogen levels after menopause are also associated with increased risk of bone loss and osteoporosis. Cardiovascular risk also changes with aging and the menopausal transition.

Pregnancy remains possible during perimenopause while ovulation is still occurring, but natural pregnancy does not occur after menopause has been established.

Premenstrual syndrome (PMS) refers to recurring physical and emotional symptoms that develop during the luteal phase, usually before menstruation, and improve shortly after menstrual bleeding begins.

Symptoms may include:

The severity of PMS varies widely. Stress, sleep patterns, diet, alcohol use, and other health factors may influence symptoms.

Mittelschmerz is pelvic or lower abdominal discomfort associated with ovulation. It generally occurs around the middle of the menstrual cycle.

Typical characteristics include:

Mittelschmerz is usually self-limited, but severe, persistent, or unusual pelvic pain should be evaluated for other possible causes.

Amenorrhea refers to the absence of menstrual periods. It may occur normally during pregnancy, breastfeeding, or after menopause, but it can also result from medical or lifestyle factors.

Possible causes include:

The underlying cause should be determined when amenorrhea is unexpected or persistent.

Urgent Conditions

Gynecologic Trauma

The genital and reproductive organs contain an extensive blood supply. Trauma to these structures can therefore result in significant bleeding, pain, and potentially serious injury.

Possible causes include:

Important considerations include:

Prehospital care should prioritize airway, breathing, circulation, control of external bleeding when possible, treatment for shock, patient privacy, and prompt transport when significant injury is suspected.

Vaginal Bleeding

Dysmenorrhea refers to painful menstrual cramping. It may occur as a normal part of menstruation or may result from an underlying gynecologic condition.

Primary Dysmenorrhea

Primary dysmenorrhea occurs with otherwise normal menstrual cycles. Cramping may begin shortly before or at the start of menstrual bleeding and is usually most intense during the first 1–2 days before gradually improving.

Common findings include:

Secondary Dysmenorrhea

Secondary dysmenorrhea is menstrual pain caused by an underlying pelvic or reproductive disorder. Unlike primary dysmenorrhea, discomfort may begin before menstruation, continue throughout the menstrual period, and persist afterward.

Possible causes include conditions such as endometriosis, uterine fibroids, pelvic inflammatory disease, or other structural abnormalities.

Abnormal Uterine Bleeding

Abnormal uterine bleeding describes menstrual bleeding that differs from a person’s usual pattern in amount, timing, frequency, or duration. Causes may include hormonal changes, reproductive disorders, medications, pregnancy-related conditions, or systemic illness.

Patterns may include:

Because abnormal bleeding has many possible causes, assessment should consider the patient’s age, pregnancy possibility, menstrual history, medications, associated pain, and amount of blood loss.

Ectopic Pregnancy

An ectopic pregnancy occurs when a fertilized egg implants outside the uterine cavity. Most ectopic pregnancies develop within a fallopian tube.

As the pregnancy grows, the surrounding tissue may be unable to expand sufficiently. Rupture can result in severe internal bleeding, shock, and a life-threatening emergency.

Risk may be increased by:

Early symptoms may be mild and localized, but pain can worsen as the condition progresses.

Common findings include:

The classic presentation includes amenorrhea, vaginal bleeding, and abdominal or pelvic pain, although not every patient will have all three findings.

A ruptured ectopic pregnancy is a medical emergency requiring rapid recognition, treatment for shock, and immediate transport.

Endometritis is inflammation or infection of the inner lining of the uterus, known as the endometrium. It may occur after childbirth, miscarriage, abortion, or certain procedures involving the uterus.

Possible symptoms include:

Patients showing signs of serious infection or systemic illness require prompt medical evaluation.

Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus, commonly involving structures within the pelvis.

Symptoms vary widely. Some patients experience severe discomfort, while others have few or no symptoms.

Possible findings include:

Endometriosis can affect fertility and may significantly interfere with daily activities when symptoms are severe.

Pelvic inflammatory disease (PID) is an infection involving the upper female reproductive tract, including the uterus, fallopian tubes, and sometimes the ovaries. It frequently develops when bacteria spread upward from the vagina or cervix.

Symptoms may include:

If infection spreads higher into the abdomen, discomfort may occasionally extend toward the right upper abdomen.

Complications of untreated PID can include:

Risk is associated with exposure to sexually transmitted infections, previous PID, and other factors that allow bacteria to enter the upper reproductive tract.

Vaginitis is inflammation or irritation of the vagina. It may result from infection, changes in normal vaginal bacteria, chemical irritation, or other causes.

Common symptoms include:

Some patients may have few or no noticeable symptoms.

Vulvovaginal Candidiasis

A vaginal yeast infection occurs when Candida organisms grow excessively within the vagina.

Factors that may increase the likelihood of yeast overgrowth include:

Typical symptoms may include:

Bacterial vaginosis (BV) develops when the normal balance of vaginal bacteria becomes disrupted, allowing certain bacteria to multiply excessively. Gardnerella vaginalis is one organism commonly associated with this condition.

Possible symptoms include:

Many patients have no symptoms at all.

Bacterial vaginosis can sometimes be confused with a yeast infection, but the two conditions have different causes and require different treatments. BV can also be associated with complications during pregnancy and may increase susceptibility to certain reproductive-tract infections.

Bartholin Gland Abscess

A Bartholin gland abscess develops when a Bartholin gland duct becomes blocked and infected, allowing fluid and pus to collect near the vaginal opening. The Bartholin glands normally produce mucus that helps lubricate the vaginal area.

Common findings include:

An ovarian cyst is a fluid-filled sac that forms on or within an ovary. Ovarian cysts are common, and many are functional, benign, and resolve without treatment.

Functional cysts develop as part of the normal ovarian cycle. They form when changes involving a follicle or corpus luteum result in temporary fluid accumulation.

A follicular cyst develops when a follicle does not rupture and release an oocyte during ovulation. Instead, the follicle continues to enlarge and fill with fluid. Many resolve naturally within several weeks or months.

After ovulation, the empty follicle normally becomes the corpus luteum. If the opening seals and fluid or blood accumulates inside, a corpus luteum cyst may form.

Most ovarian cysts cause few symptoms, but larger or complicated cysts may produce:

Polycystic ovary syndrome (PCOS) is a hormonal disorder involving abnormal ovulation and increased androgen activity. Despite the name, a patient does not necessarily have multiple large ovarian cysts.

Possible features include:

Ovarian torsion occurs when an ovary twists around the tissues and blood vessels that support it. An enlarged ovary or ovarian mass can increase the risk of twisting.

This is an urgent gynecologic condition because interruption of the ovarian blood supply can lead to tissue damage.

Typical findings include:

The pain may occasionally come and go if the ovary twists and partially untwists. Suspected ovarian torsion requires prompt hospital evaluation and surgical consultation.

Tubo-Ovarian Abscess

A tubo-ovarian abscess (TOA) is a collection of infected material involving the fallopian tube, ovary, or nearby pelvic structures. It most commonly develops as a complication of pelvic inflammatory disease.

Possible symptoms include:

A ruptured abscess can spread infection throughout the abdominal cavity and may result in sepsis, making rapid evaluation essential.

Ruptured Ovarian Cyst

An ovarian cyst may occasionally rupture and release fluid or blood into the pelvic cavity. Some ruptures produce only mild discomfort, while others cause significant bleeding.

Possible findings include:

Significant pain, syncope, hypotension, or signs of internal bleeding should be treated as an emergency.

Pelvic Organ Prolapse

Uterine prolapse occurs when weakened pelvic-floor muscles and supportive tissues allow the uterus to descend downward into the vaginal canal.

Risk may increase with:

Symptoms may include pelvic pressure, low back discomfort, urinary problems, vaginal irritation, or the sensation that something is protruding from the vagina.

Toxic Shock Syndrome

Toxic shock syndrome (TSS) is a rare but potentially life-threatening illness caused by toxins produced by certain strains of Staphylococcus aureus or group A Streptococcus.

TSS can occur in both men and women. Menstrual-associated cases have historically been linked with tampon use, although other infections, wounds, surgical sites, and skin infections may also lead to the condition.

Early findings may include:

As the condition progresses, patients may develop severe hypotension, shock, organ dysfunction, altered mental status, or respiratory distress.

TSS requires rapid recognition, supportive treatment, and immediate transport.

Sexually Transmitted and Related Infections

Bacterial vaginosis (BV) occurs when the normal balance of bacteria in the vagina is disrupted and certain bacterial species become more abundant. BV is associated with sexual activity but is not classified as a sexually transmitted infection.

Possible symptoms include:

Many patients experience no symptoms. During pregnancy, BV has been associated with an increased risk of certain pregnancy complications.

Chancroid is a sexually transmitted bacterial infection caused by Haemophilus ducreyi. It is uncommon in many regions but remains important because genital sores can increase susceptibility to transmission of other infections.

Common findings include:

Chancroid is treatable with appropriate antibiotics.

Chlamydia is a common sexually transmitted infection caused by Chlamydia trachomatis. Many infected individuals have no symptoms, allowing the infection to spread without being recognized.

When symptoms occur, they may include:

Rectal infection may cause pain, discharge, or bleeding.

Untreated infection can spread into the upper reproductive tract and contribute to pelvic inflammatory disease, infertility, chronic pelvic pain, and increased risk of ectopic pregnancy.

Cytomegalovirus (CMV) is a common virus belonging to the herpesvirus family. After infection, CMV remains in the body for life and may become inactive for long periods.

Most healthy people have mild symptoms or none at all. When illness develops, symptoms may resemble mononucleosis and include:

People with weakened immune systems are at greater risk of severe CMV disease, which may affect the lungs, liver, eyes, gastrointestinal tract, or nervous system.

CMV infection during pregnancy can also be transmitted to the fetus. Congenital CMV may cause complications such as hearing loss, vision problems, developmental concerns, poor growth, jaundice, or enlargement of the liver and spleen.

Genital Herpes

Genital herpes is a viral infection caused by the herpes simplex virus (HSV). It can affect the genital area, buttocks, anus, or surrounding skin. After infection, the virus remains in the body and may become active again, producing recurrent outbreaks.

Both major HSV types can cause genital infection:

During an outbreak, a patient may initially experience tingling, itching, burning, or tenderness in the affected area. Small bumps or fluid-filled blisters may then develop and eventually form painful sores.

Other possible symptoms include:

Lesions usually heal without significant scarring. Recurrent outbreaks are often shorter and less severe than the initial episode.

Gonococcal Infection

Gonorrhea is a sexually transmitted bacterial infection caused by Neisseria gonorrhoeae. It commonly affects the cervix and urethra but may also infect the rectum, throat, or eyes.

Many infected people, particularly women, may have mild symptoms or no symptoms at all.

Possible findings include:

Rectal Infection

Rectal gonorrhea may cause:

Throat Infection

Gonococcal infection of the throat is often mild or asymptomatic but may produce sore throat, difficulty swallowing, or swollen lymph nodes.

In uncommon cases, gonorrhea can spread through the bloodstream. Disseminated gonococcal infection may cause fever, joint pain, skin lesions, or other systemic complications.

Human Papillomavirus and Genital Warts

Genital warts, also known as condylomata acuminata, are caused by certain types of human papillomavirus (HPV).

HPV includes many different viral types. Some primarily cause genital warts, while certain high-risk types are associated with cancers of the:

Genital warts may be small and difficult to notice or may grow into larger clusters. During pregnancy, extensive lesions may occasionally enlarge and interfere with the genital or birth canal.

Rarely, HPV acquired around birth may contribute to recurrent respiratory papillomatosis, in which wart-like growths develop within the airway.

Syphilis

Syphilis is a bacterial sexually transmitted infection caused by Treponema pallidum. Without treatment, it can progress through several clinical stages and eventually affect multiple organ systems.

Primary Syphilis

The primary stage commonly produces a chancre, which is typically a firm, round, and painless ulcer at the site where the bacteria entered the body.

The sore may appear on the:

The lesion may heal without treatment, but the infection remains in the body.

Secondary Syphilis

Secondary syphilis develops after the initial infection and may produce a widespread rash, including involvement of the palms of the hands and soles of the feet.

Additional symptoms may include:

Symptoms may disappear even without treatment, but the infection can progress into a latent stage.

Latent and Late Syphilis

During the latent stage, there may be no noticeable symptoms. Untreated infection can eventually damage the nervous system, cardiovascular system, eyes, bones, and other organs.

Serious late complications may include neurologic impairment, vision problems, sensory changes, and cardiovascular disease.

Syphilis During Pregnancy

Untreated maternal syphilis can be transmitted to the fetus and may lead to miscarriage, stillbirth, neonatal illness, or congenital syphilis. Early screening and treatment during pregnancy significantly reduce these risks.

Trichomoniasis is a sexually transmitted infection caused by the parasite Trichomonas vaginalis. Many infected individuals have few or no symptoms.

When symptoms occur, they may include:

Symptoms can develop days to weeks after exposure. Untreated infection during pregnancy has been associated with an increased risk of certain pregnancy complications, including premature delivery and low birth weight.

Sexual Assault

Sexual assault can cause significant physical and psychological trauma. EMS care should be patient-centered, respectful, and focused on safety, immediate medical needs, and preserving the patient’s choices whenever possible.

A patient may appear frightened, withdrawn, confused, angry, quiet, or emotionally numb. These reactions vary widely and should not be used to judge whether an assault occurred.

Important principles include:

Drug-Facilitated Sexual Assault

Alcohol and other substances may contribute to impaired judgment, reduced awareness, sedation, memory loss, or inability to give consent.

Substances sometimes associated with drug-facilitated assault include:

Patients with suspected intoxication require assessment of the airway, breathing, circulation, mental status, and possible co-ingestion of other substances.

Vaginal or Rectal Foreign Bodies

Foreign objects retained in the vagina or rectum may cause pain, bleeding, infection, or internal injury.

Possible complications include:

EMS providers should generally avoid attempting removal of deeply embedded or difficult objects unless an immediate life-threatening problem requires intervention and local protocol permits it. The patient should be transported for appropriate medical evaluation and removal.

Prehospital Care for Gynecologic Emergencies

Gynecologic Trauma

Treatment begins with the usual priorities of airway, breathing, and circulation.

Important measures include:

Internal vaginal or pelvic bleeding may be difficult to assess in the field, so providers should watch carefully for tachycardia, hypotension, pallor, weakness, altered mental status, and other signs of shock.

Abnormal Vaginal Bleeding

When vaginal bleeding is not caused by obvious trauma, prehospital treatment is generally supportive.

Assess:

Provide supportive care, vascular access, and fluid therapy when indicated by the patient’s condition and local protocol.

Suspected Ectopic Pregnancy

Any patient of reproductive potential who presents with abdominal or pelvic pain and vaginal bleeding should be assessed for possible pregnancy-related complications, including ectopic pregnancy.

A ruptured ectopic pregnancy can cause severe internal hemorrhage even when visible vaginal bleeding is minimal.

Prehospital priorities include:

Do not attempt invasive vaginal procedures in the prehospital setting.

Endometritis

Endometritis is usually treated with antibiotics and supportive medical care after evaluation at the hospital.

EMS treatment focuses on:

Severe uterine infection can progress to sepsis or septic shock, particularly following childbirth, miscarriage, or uterine procedures.

Endometriosis Care

Prehospital treatment for endometriosis is primarily based on the patient’s symptoms.

Care may include:

Severe or unusual pain should receive further medical evaluation.

Pelvic Inflammatory Disease Care

Definitive treatment of pelvic inflammatory disease (PID) usually requires antibiotics after medical evaluation.

Prehospital care is generally supportive and may include:

Prompt treatment is important because untreated PID can lead to chronic pelvic pain, infertility, tubo-ovarian abscess, and an increased risk of ectopic pregnancy.

Vaginal Inflammation

Vaginitis refers to inflammation or irritation of the vagina. Depending on the cause, untreated infection may contribute to complications such as pelvic inflammatory disease or pregnancy-related problems.

Prehospital management is mainly supportive. Assess the patient’s symptoms, provide comfort, maintain privacy, and arrange medical evaluation when needed.

Bacterial vaginosis, often associated with an overgrowth of organisms such as Gardnerella vaginalis, occurs when the normal balance of vaginal bacteria becomes disrupted.

Many patients are not acutely ill, but evaluation is still appropriate. Treatment usually involves prescription medication after medical assessment.

Prehospital care focuses on:

A Bartholin gland abscess develops when a blocked Bartholin duct becomes infected and fills with pus. Patients may experience significant pain, swelling, difficulty walking or sitting, and discomfort during intercourse.

Definitive treatment may involve drainage of the abscess and, when appropriate, antibiotic therapy.

EMS care is generally supportive and includes pain assessment, comfort measures, and transport when symptoms are severe or systemic infection is suspected.

Ovarian and Pelvic Emergencies

Ruptured Ovarian Cyst, Ovarian Torsion, and Tubo-Ovarian Abscess

These conditions may produce severe pelvic or abdominal pain and sometimes internal bleeding or infection. Their presentation can resemble ectopic pregnancy and other serious abdominal emergencies.

Prehospital priorities include:

Severe pain, syncope, hypotension, fever, guarding, or signs of significant hemorrhage should increase concern for a serious pelvic emergency.

Uterine prolapse occurs when weakened pelvic-support structures allow the uterus to descend into or through the vaginal canal.

Prehospital care is aimed at protecting the exposed tissue and keeping the patient comfortable.

Important measures include:

Definitive treatment requires evaluation by a gynecologic specialist and may involve surgical or nonsurgical management.

Toxic shock syndrome (TSS) is a rare but potentially life-threatening illness caused by bacterial toxins. Patients can deteriorate rapidly and develop severe hypotension, organ dysfunction, and shock.

Possible findings include:

Prehospital treatment focuses on:

Definitive hospital care generally includes IV fluids, antibiotics, treatment of the source of infection, and intensive supportive care when necessary.

Sexually Transmitted Infections

Patients with suspected sexually transmitted infections usually do not require extensive prehospital intervention unless serious complications are present.

EMS care should emphasize:

Care After Sexual Assault

Sexual assault patients require both medical care and trauma-informed emotional support. The patient’s safety, dignity, privacy, and choices should remain central throughout the encounter.

When possible, patients may be offered a provider of their preferred gender, but this should not delay urgent medical treatment.

Important principles include:

Preserving Potential Evidence

EMS providers are generally responsible for preserving, rather than collecting, forensic evidence unless specifically trained and authorized.

When practical and with the patient’s cooperation:

A patient may want to bathe, change clothes, urinate, rinse their mouth, or perform other hygiene activities after an assault. Explain that these actions may reduce available forensic evidence, but the patient’s medical needs, consent, and autonomy should be respected.

Detailed documentation should be objective and factual. Record relevant statements in the patient’s own words when appropriate and avoid including personal opinions or assumptions.

Vaginal Foreign Objects

Foreign objects inside the vagina may cause pain, bleeding, infection, or internal injury. Removal attempts can sometimes worsen trauma or cause additional bleeding.

Prehospital management includes:

Additioanal Assessment of Vaginal Bleeding

When evaluating vaginal bleeding, determine whether the patient is using pads, tampons, menstrual cups, or other menstrual products and ask how frequently they have needed to change them.

Important questions include:

The number and degree of saturation of menstrual products can help estimate the severity and rate of bleeding, but fixed milliliter estimates for individual pads or tampons are unreliable. Clinical assessment should focus on the patient’s symptoms, vital signs, perfusion, and overall condition.

Medications & Drug Therapy

Fundamentals of Pharmacology

Medication Safety

Medication administration is an important part of emergency medical care. When used correctly, medications can relieve symptoms, treat specific conditions, and improve a patient’s overall status. However, administering the wrong medication, dose, or route can cause serious or even life-threatening complications.

Because of these risks, EMS providers must understand the medications within their scope of practice, including their uses, effects, contraindications, doses, and routes of administration.

Pharmacology is the branch of medicine concerned with drugs, including their uses, actions, and effects on the body.

A medication is a substance or combination of substances used to prevent, manage, or treat illness and symptoms.

A drug is any substance that produces a physiological or biochemical change in the body after it is absorbed.

Medications Used in Emergency Care

Medications used in emergency medicine are primarily intended to treat acute conditions and immediate symptoms. Unlike many medications prescribed for long-term disease management, EMS medications are often selected because they act quickly and produce measurable changes in the patient’s condition.

The effectiveness of an emergency medication may be evaluated by monitoring:

Medication Forms

Medications are available in several physical forms. The form of a medication often influences its route of administration, absorption, onset of action, and effectiveness.

Solid Medications

Capsules

Capsules contain powdered, granular, or liquid medication enclosed within a dissolvable shell. After the capsule is swallowed, the outer covering breaks down in the gastrointestinal tract, allowing the medication to be released and absorbed.

Examples may include certain formulations of acetaminophen, ibuprofen, and diphenhydramine.

Tablets

Tablets are compressed solid medications designed to dissolve or break apart after administration. Most are swallowed, although some tablets are intended for sublingual, buccal, or other specialized routes.

Examples include aspirin and certain antacid medications.

Powders

Some medications are stored as dry powders because they remain more stable in that form. Before administration, they may need to be mixed or reconstituted with an appropriate solution.

Examples include certain preparations of:

Liquid Medications

Enteral Liquids

Enteral medications enter the body through the gastrointestinal tract, most commonly by swallowing.

Examples include:

After ingestion, the medication is absorbed through the digestive tract.

Parenteral Medications

Parenteral medications are administered by routes that bypass the gastrointestinal tract. This commonly includes injection routes such as:

Examples of medications commonly available in injectable forms include fentanyl and adenosine.

Inhaled Medications

Inhaled medications may be delivered as a gas, aerosol, or fine mist. The medication enters the respiratory tract and is absorbed through the airway or alveolar surfaces.

Examples include:

Inhaled medications can act rapidly because of the large surface area and extensive blood supply within the lungs.

Medication Naming System

A medication may be identified by several different names.

Chemical Name

The chemical name describes the drug’s molecular or chemical composition. It is mainly used in scientific or pharmaceutical settings and is generally not the name most commonly used during routine patient care.

Generic Name

The generic, or nonproprietary, name is the standardized name of the medication. It is not owned by a particular manufacturer and is often the preferred name in clinical practice.

Brand Name

The brand, or proprietary, name is assigned by a manufacturer for marketing purposes. The same generic medication may be sold under several different brand names.

Example

Understanding a Drug Profile

A medication’s drug profile describes the information needed to determine when and how the drug should be administered safely.

Pharmacodynamics

Pharmacodynamics describes what a drug does to the body.

After reaching its target tissues, a medication may interact with receptors, enzymes, or other cellular structures and produce physiological changes. The effects of a medication can vary depending on factors such as:

Pharmacokinetics describes what the body does to a drug.

It includes the processes of:

The route by which a medication is administered strongly influences these processes.

An indication is a medical condition, symptom, or clinical finding that provides a reason for giving a particular medication.

For example:

An indication does not automatically mean a medication should be given; providers must still check for contraindications and follow the appropriate protocol.

The therapeutic effect is the intended beneficial response produced by a medication.

Examples include:

Providers should reassess the patient after medication administration to determine whether the intended response occurred.

A side effect is an additional effect that occurs along with the medication’s intended therapeutic action.

Side effects may be predictable and relatively mild. Depending on the medication, they may include:

A medication may still be appropriate when the expected benefit outweighs its known side effects.

An adverse effect is an undesirable or potentially harmful reaction to a medication. Adverse reactions may range from mild symptoms to severe emergencies.

Examples include:

Patients should be monitored after medication administration so that adverse reactions can be recognized and treated promptly.

A contraindication is a condition or circumstance in which a medication should not be administered because the potential harm may outweigh the expected benefit.

Examples may include:

Contraindications may be absolute or relative, depending on the medication and clinical situation.

Medication Dose

The dose is the amount of medication administered to a patient.

The appropriate dose may depend on:

Some medications are administered as a fixed dose, while others are calculated according to body weight or clinical response.

A medication must reach an effective concentration to produce its desired therapeutic action, but excessive amounts can increase the risk of toxicity and adverse effects.

Routes of Administration

The route of administration describes how a medication enters the patient’s body.

Common routes include:

The chosen route affects the medication’s speed of absorption, onset of action, and duration of effect.

Prescription and Over-the-Counter Medications

Some medications require a healthcare provider’s prescription, while others can be purchased over the counter (OTC) without a prescription.

EMS medications are administered under established medical direction and local protocols. Before giving any medication, providers should verify:

When uncertainty exists, EMS personnel should follow local protocols and contact medical direction before administration.