In this episode of Critical Levels, Zach sits down with Dr. Anna-Maria Carvalho, a Royal College–certified emergency physician with a subspecialty in aviation medicine, to unpack what really happens when someone asks, "Is there a medical professional on board?"

From the physiology of flying at 36,000 feet to the realities of managing cardiac arrest in a cramped aircraft cabin, this episode tackles the fears, logistics, and practical considerations of in-flight medical emergencies—especially for paramedics, nurses, and physicians who may be called upon to help.

✈️ What We Cover

🫁 The Physiology of Flight

• Why cabin altitude means we're all mildly hypoxic (normal sats ~92–93%)

• How hypoxia increases heart rate, blood pressure, and sympathetic tone

• Why alcohol hits harder in the air

• Why tomato juice tastes better at altitude

• The risk of DVTs and who's most vulnerable

• Barotrauma, ear pain, and when a perforated eardrum can occur

🚨 In-Flight Medical Emergencies

• Incidence: ~1 in 600 flights

• Most common categories:

  • Neurologic

  • Cardiac

  • Respiratory

  • Gastrointestinal

• The realities of flying with chronic disease

• Why more emergencies are happening as more people travel

🧰 What's in the Emergency Medical Kit?

• AED (separate from the medical kit)

• Oxygen & Ambu bag

• Oral airways (intubation equipment varies by airline)

• IV supplies (limited fluids, but enough for medication administration)

• Medications: epinephrine, steroids, bronchodilators, benzodiazepines, antipsychotics, glucose agents, and more

• BP cuff (palpated pressures only—too noisy to auscultate!)

• Pulse oximeter (remember: 93% can be normal)

📡 Ground-Based Medical Support

• Most airlines consult 24/7 emergency physicians on the ground

• Volunteers don't make diversion decisions—the captain does

• Diversions involve significant operational and logistical consequences

• In-flight volunteers are there to assess, stabilize, and communicate

🫀 Cardiac Arrest at 36,000 Feet

• Move to a bulkhead/galley if possible

• Call for additional medical volunteers

• Early AED use

• CPR until ROSC, exhaustion, or medical futility

• Diversion decisions are collaborative and situational

⚖️ The Legal Question

• Good Samaritan protections apply

• Act within scope

• No gross negligence or willful misconduct

• No one has ever been successfully sued for assisting with an in-flight medical emergency

• You are not responsible for diversion decisions

🕊️ When Death Occurs In Flight

• Resuscitation attempts may cease when appropriate

• Diversion is not automatic

• Flight crew are trained to manage these situations professionally and discreetly

🔑 Key Takeaways

• You already have the skills.

• The environment is different—but the fundamentals are the same.

• Recognizing sick vs. not sick is incredibly valuable.

• Most in-flight volunteer diagnoses are ultimately confirmed in hospital.

• About 60% of passengers improve with basic stabilization.

• You are protected when acting in good faith and within scope.

If you've ever hesitated to answer that overhead call, this episode may change your perspective.