CTRN cheat sheet

Glasgow Coma Scale sums eye (1–4), verbal (1–5), and motor (1–6) scores; total range 3–15, and GCS ≤8 indicates the airway is not protected.

Mean arterial pressure = (SBP + 2 × DBP) ÷ 3; a MAP ≥65 mmHg is the usual adult perfusion target.

Shock index = heart rate ÷ systolic blood pressure; normal is 0.5–0.7, and a value >0.9 suggests occult hypoperfusion.

Cushing triad - hypertension with widened pulse pressure, bradycardia, and irregular respirations - signals rising intracranial pressure.

Capillary refill longer than 2 seconds, mottling, and cool extremities are markers of poor peripheral perfusion.

End-tidal CO2 of 35–45 mmHg is normal; a sudden fall toward zero suggests esophageal intubation or circuit disconnection.

AVPU (Alert, Verbal, Pain, Unresponsive) is a rapid consciousness screen; any response below Alert requires full GCS scoring.

Pulse pressure (SBP minus DBP) narrowing below 30 mmHg is an early indicator of hypovolemia.

Blood glucose is measured in any altered mental status; hypoglycemia is defined as <70 mg/dL.

Arterial oxygen content CaO2 = (1.34 × hemoglobin × SaO2) + (0.003 × PaO2); oxygen delivery DO2 = cardiac output × CaO2 × 10.

PaO2/FiO2 ratio: normal about 400–500; <300 defines mild ARDS, <200 moderate, and <100 severe.

Lung-protective ventilation uses tidal volume 6 mL/kg predicted body weight with plateau pressure kept <30 cmH2O.

Endotracheal tube cuff pressure is maintained at 20–30 cmH2O to prevent mucosal ischemia and air leak.

In children, uncuffed ETT internal diameter ≈ (age in years ÷ 4) + 4; cuffed ≈ (age ÷ 4) + 3.5.

Suction pressure should not exceed 120–150 mmHg in adults or 80–100 mmHg in children, with each pass limited to about 10 seconds.

Minute ventilation = respiratory rate × tidal volume; normal adult minute ventilation is roughly 5–8 L/min.

A nasopharyngeal airway is contraindicated when basilar skull fracture is suspected (raccoon eyes, Battle sign, CSF rhinorrhea).

An oropharyngeal airway is sized from the corner of the mouth to the angle of the mandible.

The four shock categories are hypovolemic, cardiogenic, distributive, and obstructive; treatment priorities differ by category.

Hemorrhagic shock classes by blood loss: I <15%, II 15–30%, III 30–40%, IV >40%; class III is where hypotension typically appears.

Isotonic crystalloid bolus is 500–1000 mL in adults and 20 mL/kg in children, with reassessment after each bolus.

Norepinephrine is the first-line vasopressor for septic shock, titrated to a MAP ≥65 mmHg.

Serum lactate >2 mmol/L indicates tissue hypoperfusion; values >4 mmol/L correlate with higher mortality.

Dobutamine is the inotrope used for low cardiac output with adequate or elevated filling pressures.

Permissive hypotension (SBP 80–90 mmHg) is acceptable in bleeding trauma without brain injury until hemorrhage control.

Urine output targets are 0.5 mL/kg/hr in adults and 1 mL/kg/hr in children.

Central venous pressure correlates poorly with fluid responsiveness; dynamic measures such as pulse pressure variation are preferred.

Adult Rule of Nines: head 9%, each arm 9%, anterior trunk 18%, posterior trunk 18%, each leg 18%, perineum 1%.

Parkland formula: 4 mL × weight (kg) × %TBSA of lactated Ringer's over 24 hours; half is given in the first 8 hours from injury time.

Tension pneumothorax is treated with immediate needle decompression - 2nd intercostal space midclavicular or 5th intercostal space anterior axillary line - then tube thoracostomy.

A tourniquet is placed 2–3 inches proximal to the wound, never directly over a joint, and the application time must be recorded.

Severe hypothermia is core temperature <28°C; handle the patient gently because the myocardium is irritable and prone to fibrillation.

Exertional heat stroke is core temperature >40°C with CNS dysfunction and requires immediate cold-water immersion.

Frostbite is rewarmed rapidly in water at 37–39°C; rubbing with snow or walking on the affected foot worsens injury.

In traumatic brain injury maintain SBP ≥110 mmHg and avoid hypoxia; hyperventilation to PaCO2 30–35 mmHg is reserved for impending herniation.

Intravenous thrombolysis for ischemic stroke is generally given within 4.5 hours of onset; mechanical thrombectomy may extend to 24 hours in selected patients.

A 12-lead ECG is obtained and interpreted within 10 minutes for suspected acute coronary syndrome.

Status epilepticus is treated first with a benzodiazepine, then levetiracetam, fosphenytoin, or valproate.

In DKA, insulin is withheld when serum potassium is <3.3 mEq/L until potassium is repleted.

Hypoglycemia (<70 mg/dL) is treated with IV dextrose, or IM glucagon 1 mg when no vascular access exists.

Naloxone reverses opioid-induced respiratory depression; titrate to adequate ventilation rather than full arousal.

Septic shock bundles include broad-spectrum antibiotics within 1 hour and 30 mL/kg crystalloid for hypotension or lactate ≥4 mmol/L.

For suspected raised intracranial pressure, elevate the head of bed 30 degrees, keep the head midline, and avoid hypoxia and hypotension.

In severe asthma add ipratropium and systemic corticosteroids to albuterol; IV magnesium sulfate is an adjunct for poor response.

Oxygen cylinder duration (minutes) = (gauge pressure in psi × cylinder factor) ÷ flow in L/min; E-cylinder factor 0.28, M-cylinder 3.14.

A full E cylinder holds about 660 L at 2200 psi; plan a reserve of at least 30 minutes beyond the planned transport time.

Boyle's law: gas expands as altitude rises, so pneumothoraces, airway cuffs, and air splints must be monitored during air transport.

Cabin altitude in most air medical aircraft is maintained at 6000–8000 feet, lowering PaO2 and requiring increased FiO2.

A landing zone should be at least 100 ft × 100 ft, clear of wires and obstructions, with approach only from the direction signaled by the crew.

Never approach the tail rotor; approach a helicopter only after eye contact and a signal from the pilot or crew.

I-PASS handoff covers Illness severity, Patient summary, Action list, Situation awareness, and Synthesis by receiver.

CAMTS is the accreditation body that sets standards for medical transport services, including equipment and crew configuration.

SBAR structures communication into Situation, Background, Assessment, and Recommendation.

EMTALA requires a medical screening examination and stabilization before transfer; the transferring facility retains responsibility until the receiving facility accepts.

Documentation records objective findings, times, interventions, and the patient's response in chronological order.

Against-medical-advice refusal requires documented decision-making capacity, risk explanation, a signed refusal, and notification per protocol.

Closed-loop communication requires the receiver to repeat back the order and the sender to confirm it.

Chain-of-custody documentation is required for forensic evidence such as bullets, clothing, or personal items.

Protected health information may be shared under HIPAA only for treatment, payment, operations, or as required by law.