CFRN cheat sheet

Dalton's law: total pressure is the sum of partial pressures; at altitude, lower barometric pressure reduces inspired PO2 even when FiO2 is unchanged.

Alveolar gas equation: PAO2 = FiO2(PB - PH2O) - (PaCO2 / R), with R approximately 0.8.

Arterial oxygen content: CaO2 = (1.34 x Hgb x SaO2) + (0.003 x PaO2); dissolved oxygen is a small fraction at sea level.

Boyle's law: at constant temperature, gas volume is inversely proportional to pressure; trapped gas expands as cabin altitude increases.

Henry's law: dissolved gas is proportional to partial pressure; rapid ascent can cause nitrogen bubbles and decompression sickness.

Cabin altitude in pressurized transport is typically 6,000-8,000 ft; loss of pressurization requires supplemental oxygen and descent.

Positive-pressure ventilation raises intrathoracic pressure, lowers venous return, and can worsen hypotension in hypovolemia.

+Gz acceleration causes blood pooling and reduced cerebral perfusion; anti-G maneuvers and suit use counter it.

Primary survey ABCDE: airway, breathing, circulation, disability, exposure; correct life threats before secondary survey.

Shock index = HR / SBP; an adult value greater than 0.9 suggests occult shock.

Adult hypotension is often a late sign; traumatic brain injury requires avoiding SBP below 90 mm Hg and hypoxia.

Parkland formula: 4 mL/kg/%TBSA lactated Ringer's in 24 hours; half is given in the first 8 hours from burn time.

Pediatric hypotension: SBP below 70 + (2 x age in years) for ages 1-10; infants below 70 mm Hg.

Endotracheal tube cuff pressure target is 20-30 cm H2O; recheck at altitude because cuff volume expands.

Stroke thrombolysis window is up to 3-4.5 hours from last known well; check glucose and contraindications.

Capnography confirms endotracheal tube placement and monitors ventilation during transport.

Crew resource management skills include briefing, shared mental model, closed-loop communication, assertiveness, and debriefing.

Sterile cockpit: no nonessential conversation during takeoff, landing, and critical flight phases.

Safety management system four pillars: safety policy, risk management, assurance, and promotion.

Just culture distinguishes human error from reckless behavior and supports nonpunitive reporting.

Go/no-go decision includes weather, aircraft, crew, patient, terrain, and alternate options.

Hand hygiene and PPE are used; an N95 respirator is required for airborne precautions when indicated.

Noise above 85 dB risks hearing damage; use hearing protection and limit exposure.

Checklists reduce omission errors; read-do or do-verify formats are used.

Pressurized aircraft maintain a cabin altitude; unpressurized flight above 10,000 ft generally requires supplemental oxygen per regulations.

Oxygen cylinder duration in minutes is approximately cylinder capacity in liters divided by flow in liters per minute; add reserve and altitude correction.

Secure medical equipment for turbulence with approved restraints; unsecured items become projectiles.

Lithium-ion spare batteries travel in the cabin, terminals are protected, and state-of-charge limits are followed.

Electromagnetic interference from radios or phones can disrupt monitors and pumps; maintain distance and use approved devices.

Landing zone commonly is at least 100 x 100 ft in daylight and larger at night; clear debris and mark the approach path.

Weight and balance includes patient, crew, fuel, and equipment; center of gravity must remain within limits.

Ventilator tidal volume and alarms must be verified at altitude because gas density and pressure change.

Informed consent requires capacity, information, and voluntariness; an emergency exception applies to life threats.

Refusal of care: assess capacity, document risks and alternatives, and consult medical control per protocol.

HIPAA permits disclosures for treatment, payment, and operations; use the minimum necessary protected health information.

EMTALA requires stabilization and appropriate transfer with an accepting physician and qualified transport.

SBAR means Situation, Background, Assessment, Recommendation; it is used for structured handoffs.

Scope of practice is set by state law, licensure, and medical director protocols.

Mandatory reporting includes suspected child or elder abuse and specified communicable diseases per jurisdiction.

Documentation includes objective findings, times, interventions, and response; late entries are labeled.