Hyperventilation

Hyperventilation results from a significant decrease in carbon dioxide content in the blood that, left untreated, can result in incapacitation.


Introduction

Introduction

Aeromedical and Human Factors Disclaimer

Aeromedical and Human Factors Disclaimer

WARNING:
All aeromedical topics are GENERALIZED.
Always consult with a doctor or physician to understand your specific situation


Possible Causes of Hyperventilation

Possible Causes of Hyperventilation
  • Hyperventilation
    Encyclopedia Britannica, Hyperventilation
  • Hyperventilation is an abnormal increase in the volume of air breathed in and out of the lungs [Figure 1]
    • Stress
    • Panic
    • Anxiety
    • Hypoxia
    • Decreased carbon dioxide in blood
    • Under conditions of stress and anxiety, a person's body reacts automatically to such stimuli, whether the danger be imaginary or real
    • One of these automatic reactions is a marked increase in breathing rate, which results in a significant decrease in the carbon dioxide content of the blood, which is necessary to regulate the breathing process automatically
  • Hyperventilation
    Encyclopedia Britannica, Hyperventilation

Hyperventilation Symptoms

Hyperventilation Symptoms
  • As hyperventilation "blows off" excessive carbon dioxide from the body, a pilot can experience symptoms of:
    • Lightheadedness
    • Nausea
    • Suffocation
    • Drowsiness
    • Tingling in the extremities
    • Coolness
    • Dry mouth
    • Blurred vision
    • Rapid pulse and breathing rate
  • Early symptoms of hyperventilation are similar to those of hypoxia and some to ordinary airsickness
    • Symptoms of both are not unique, and several can occur at the same time
      • Therefore, if a pilot is using an oxygen system when experiencing symptoms, the oxygen regulator should immediately be set to deliver 100%, and the system should be checked to ensure that it has been functioning effectively before giving attention to the rate and depth of breathing
  • Symptoms can easily cause confusion and panic, which only aggravates the problem by further increasing anxiety and, thus, the breathing rate

Effects of Hyperventilation

Effects of Hyperventilation
  • First and foremost, hyperventilation can be a significant distraction to the safe operation of the aircraft
  • Incapacitation can eventually result from a lack of coordination, disorientation, and painful muscle spasms
    • Eventually, unconsciousness can occur

Recovering from Hyperventilation

Recovering from Hyperventilation
  • The symptoms of hyperventilation subside within a few minutes after the rate and depth of breathing are consciously brought back under control
  • The buildup of carbon dioxide in the body can be hastened by talking loudly or controlled breathing in and out of a paper bag held over the nose and mouth
    • This method does not force you to breathe carbon dioxide but instead forces you to think about your breathing rate
      • This method may increase carbon dioxide levels too quickly, leaving it as a last resort
    • Recovery will occur within a few minutes
  • Remove the cause of stress, panic, or anxiety as able
    • If the source is an emergency that must be dealt with immediately, take a moment and remember your emergency procedure training
  • If incapacitation occurs, then the body will naturally recover from the situation and slow the breathing rate

Hyperventilation Case Studies

Hyperventilation Case Studies
  • NTSB Identification: ATL90LA025 The National Transportation Safety Board determines the probable cause(s) of this accident to be: Pilot's temporary physical condition (possible hyperventilation or anxiety attack). Soft terrain in the emergency landing was considered to be a related factor
  • NTSB Identification: DEN82DA125 The National Transportation Safety Board determines the probable cause(s) of this accident to be: Physical impairment (other organic problem of the pilot in command
  • NTSB Identification: MIA78DLA01 The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilot in command's misjudgment of distance and speed and physical impairment from hyperventilation

Private Pilot (Airplane) Human Factors Airman Certification Standards

Private Pilot (Airplane) Human Factors Airman Certification Standards

Private Pilot (Airplane) Human Factors Knowledge:

The applicant demonstrates an understanding of:

Private Pilot (Airplane) Human Factors Risk Management:

The applicant demonstrates the ability to identify, assess and mitigate risks encompassing:

  • PA.I.H.R1:

    Aeromedical and physiological issues.

  • PA.I.H.R2:

    Hazardous attitudes.

  • PA.I.H.R3:

    Distractions, task prioritization, loss of situational awareness, or disorientation.

  • PA.I.H.R4:

    Confirmation and expectation bias.

Private Pilot (Airplane) Human Factors Skills:

The applicant exhibits the skills to:


Hyperventilation Knowledge Quiz

Hyperventilation Knowledge Quiz

Conclusion

Conclusion
  • Hyperventilation is simply a matter of breathing too rapidly
  • It is seldom completely incapacitating, but it does produce one or more of the symptoms that are disturbing, if not alarming, to the uninformed pilot
  • Hyperventilation can look just like hypoxia, depending on the symptoms displayed, and has resulted in numerous fatal accidents
  • Understand the symptoms and how you will recognize them in yourself and your passengers, along with the appropriate recovery method
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References

References