Fitness for Altitude and Diving

Altitude Fitness Assessment - Summit Seekers' Screen

• Core Evaluation:
  • History: Prior altitude illness (AMS, HAPE, HACE), comorbidities (cardiac, pulmonary).
  • Physical Exam: Focus on CVS & RS.
• Key Indicators & Tests (Selective):
  • VO2 max: Aerobic fitness.
  • Spirometry: FEV1, FVC for lung function.
  • ECG/Echo: If cardiac concerns.
  • 📌 HVR (Hypoxic Ventilatory Response) test: Specialized.
• High-Risk Factors:
  • Previous HAPE/HACE.
  • Severe cardiopulmonary disease (Pulmonary HTN, severe COPD).
  • Sickle cell disease.

  ⭐ History of HAPE/HACE significantly ↑ recurrence risk (e.g., HAPE up to 60% at >4500m).

• Contraindications (Absolute/Relative): Unstable cardiac conditions, severe lung disease.

Diving Fitness Assessment - Deep Dive Med Check

Crucial for preventing barotrauma, Decompression Illness (DCI), and other dive-related incidents. Aims to identify conditions exacerbated by hyperbaric environments.

• Key Systems:
  • Cardiovascular: No uncontrolled HTN (>160/100 mmHg), arrhythmias, significant Coronary Artery Disease (CAD), Patent Foramen Ovale (PFO).
  • Respiratory: No active asthma, COPD, bullae/cysts, history of spontaneous pneumothorax. Spirometry FEV1/FVC >70%.
  • ENT: Patent Eustachian tubes, no chronic sinus infections.
  • Neurological: No epilepsy, unexplained Loss Of Consciousness (LOC).
  • Psychological: No severe claustrophobia or panic disorder.
• 📌 Mnemonic: "EARS & LUNGS" - Ears (barotrauma), Airways (asthma), Respiratory (pneumothorax), Sinuses & Lungs (general fitness).

⭐ An absolute contraindication to diving is a history of spontaneous pneumothorax due to high risk of recurrence and tension pneumothorax under pressure.

Contraindications & Special Groups - No-Fly, No-Dive Zones

• Absolute Contraindications (Flying/Diving):
  • Recent Pneumothorax (⚠️ critical)
  • Active, unstable asthma; Severe COPD/bullae
  • Inability to equalize pressure (ears/sinuses)
• Primarily No-Fly (Altitude):
  • Sickle cell disease (unpressurized/hypobaric exposure)
  • Severe pulmonary hypertension
  • Recent CVA/MI (<6 weeks for commercial flights)
• Primarily No-Dive (Diving):
  • Pregnancy (absolute)
  • Uncontrolled epilepsy
  • History of severe/recurrent Decompression Sickness (DCS)
  • Symptomatic Patent Foramen Ovale (PFO)
  • Active psychosis
• Special Groups (Increased Risk):
  • Infants, young children (equalization, susceptibility)
  • Elderly with comorbidities
  • Obesity (↑DCS risk diving)

⭐ A recent spontaneous pneumothorax is an absolute contraindication to air travel for at least 1 week after radiological resolution (BTS guidelines); other guidelines suggest 2-3 weeks.

Prophylaxis & Safe Practices - Altitude & Abyss Armor

• Altitude Acclimatization & Prophylaxis:
  • Gradual Ascent: Key. Limit gain to 300-500m/day above 2500m.
  • 📌 "Climb high, sleep low."
  • Pharmacoprophylaxis (if rapid ascent/prior AMS):
    • Acetazolamide: 125-250mg BD, 1-2 days before, continue for 48h at altitude.
    • Dexamethasone: Alternative if sulfa allergy; or for HACE/HAPE rescue.
  • Hydration, high-carbohydrate diet. Avoid alcohol, sedatives.
• Diving Safety & DCS Prevention:
  • Controlled Ascent: Max 9-18 m/min (or per dive computer).
  • Safety Stops: e.g., 3-5 min at 5m.
  • Dive Planning: Use tables/computers; respect no-decompression limits (NDLs).
  • Fitness: Medical clearance, no acute illness.
  • Buddy System: Never dive alone.

  ⭐ Critical: No flying for 12h (single no-D dive) to 18-24h (multiple/decompression dives) post-diving to prevent DCS.

High‑Yield Points - ⚡ Biggest Takeaways

• Gradual ascent and acetazolamide aid altitude acclimatization, preventing Acute Mountain Sickness (AMS).
• HAPE and HACE are life-threatening; immediate descent and oxygen are critical.
• Absolute diving contraindications: history of spontaneous pneumothorax, epilepsy, severe lung disease.
• Decompression Sickness (DCS) from rapid ascent requires 100% oxygen and recompression.
• Nitrogen narcosis ("Martini effect") impairs judgment at depth; heliox for very deep dives.
• Good cardiorespiratory fitness and normal Pulmonary Function Tests (PFTs) are essential for safe diving.
• Avoid flying for 12-24 hours post-diving to prevent DCS.