As a physician—and life being what it is—you need to be prepared for anything. Regardless of your specialty, you may be called on to assist during the event of a medical emergency. With this in mind, here are five life-threatening clinical conditions you may encounter in your medical career, and treatment steps you should follow if you are the first point of care.

Pneumothorax

Pneumothorax, or collapsed lung, is a medical emergency that requires immediate transport to the emergency department. More than 50% of cases are primary spontaneous pneumothorax and not caused by trauma. Instead, they’re usually caused by the rupture of blebs. According to one study, the lifespan risk of spontaneous pneumothorax occurrence among lifelong heavily smoking men is approximately 12%—compared with only 0.1% among never-smokers.

Secondary spontaneous pneumothorax occurs in those with chronic obstructive pulmonary disease, as well as parenchymal lung diseases. Traumatic pneumothorax, on the other hand, results from chest trauma, such as rib fracture. Pneumothorax can also be iatrogenic, resulting from biopsies, thoracentesis, and central lines.

Tension pneumothorax is life-threatening and may be fatal. Caused by mechanical ventilation or simple pneumothorax that does not seal after a penetrating or blunt chest trauma or failed central venous cannulation, tension pneumothorax occurs when the injury to the lung or chest wall allows air into but not out of the pleural space. Air accumulates and compressing the lung, shifting the mediastinum, compressing the contralateral lung, and increasing intrathoracic pressure, which decreases venous return to the heart and causes shock.

Symptoms of pneumothorax range from mild to life-threatening. The most common include chest pain ipsilateral to the dropped lung, and shortness of breath.

Of note, pleurodesis refers to a procedure that uses medicine to artificially obliterate the pleural space.

Although mortality from primary spontaneous pneumothorax is low—less than 1%—this is because most people who experience it are young. Mortality is going up due to advanced lung disease and increased physiologic reserves.

Sudden cardiac death

Sudden cardiac death (SCD) is defined as cardiac arrest within 1 hour of clinical onset of symptoms. The prodrome for SCD is fatigue, palpitations, chest pain, and other nonspecific complaints. Now, here’s a fact that should keep you on your toes: Up to 45% of people who’ve experienced SCD had been seen by a physician within 4 weeks prior to death, with 75% unrelated to cardiovascular complaints. In other words, SCD could darken the door of your practice even if you don’t treat cardiovascular issues.

The window of treatment for SCD is limited because ventricular fibrillation becomes quickly irreversible. Chances of survival after an out-of-hospital SCD are < 12%. Of note, chest compressions can double or triple the chances of survival. So, if you’re the first point of care, call for help and start compressing.

Implantable cardioverter-defibrillators that detect and treat ventricular fibrillation have radically enhanced the treatment of SCD. However, these devices need to be implanted before the onset of SCD.

Poisoning

Millions of poisonings are reported to Poison Control each year, with many deaths resulting. If you find someone passed out near a car, furnace, fire, or unventilated area, then poisoning should be an immediate concern. However, a person with poisoning can also appear in the office with complaints that seemingly came out of the blue.

Poisons take on many forms—including chemicals, carbon monoxide gas, foods, drugs, paints, and pesticides—with an even more diverse range of symptoms, such as abdominal pain, cough, confusion, difficulty breathing, dizziness, seizures, loss of bladder control, fever, and headache.

If you suspect poisoning, call for immediate help. Next, remember your first aid training: ABCDE (airway, breathing, circulation, disability, and exposure). Clear the airway of vomit if needed, and keep the person rolled to the left side to prevent aspiration until help arrives.

Stroke

For a physician who doesn’t encounter stroke regularly, it can be difficult to immediately recognize the symptoms. To help distinguish stroke, the FAST test from the National Stroke Association may be helpful.

Keep in mind that the patient has mere hours to receive clot-busting tissue plasminogen activator (tPA). Thus, take exact note of when you first saw the patient, and ask others when the patient first began to display symptoms.

Heat stroke

After a person has been exposed to heat without taking in enough water, the body loses its ability to cool by sweating. In younger people, heat stroke is often exertional. However, in young children, older people, or those with chronic illness, heat stroke can be nonexertional. Heat stroke happens when the body temperature rises to ≥105°F , and is preceded by heat exhaustion or symptoms including nausea, vomiting, headache, muscle cramps, and fatigue. Neurological symptoms of heat stroke can include irritability, delusions, hallucinations, coma, and seizures.

If you suspect heat stroke, call for help immediately. Before help arrives, you can apply ice packs to the patient’s neck, groin, and armpits. You can also mist the patient in front of a fan, sponge them with cold water, or place them in a cool shower. Also, try to have the patient drink water, if possible. Be prepared to perform CPR in case of loss of consciousness.

This story is contributed by Naveed Saleh and is a part of our Global Content Initiative, where we feature selected stories from our Global network which we believe would be most useful and informative to our doctor members.