Effects of inspired gas content during respiratory arrest and cardiopulmonary resuscitation

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8 Scopus citations


Mouth-to-mouth and bag-valve-mask ventilation have been an indispensable part of cardiopulmonary resuscitation (CPR). However, only recently have the effects of different tidal volumes on arterial oxygenation been reported for mouth-to-mouth and bag-valve-mask ventilation. Currently recommended tidal volumes (10-15 mL/kg) are associated with an increased risk of gastric inflation because they produce high peak inspiratory pressures. An animal model of ventilation with an unprotected airway showed that a smaller tidal volume (6 mL/kg) is as effective as a larger tidal volume (12 mL/kg) in maintaining SaO2 at >96%. However, a smaller tidal volume with exhaled gas ventilation produced a mean SaO2 of 48%, which is ineffective. Ventilation gas mixtures have been studied in models of cardiac arrest and CPR. One study showed that ventilation with air during 6 mins of CPR resulted in a return of spontaneous circulation in 10 of 12 animals compared with only 5 of 12 animals ventilated with exhaled gas (p < .04). Arterial and mixed-venous PO2 were significantly higher, and PCO2 was significantly lower in the air ventilation group. Investigations of the cardiovascular effects of mouth-to-mouth ventilation during CPR suggest that there are adverse effects during low blood flow states. However, mouth-to-mouth ventilation during respiratory arrest is lifesaving and should continue to be taught and emphasized in basic life support courses.

Original languageEnglish (US)
JournalCritical Care Medicine
Issue number11 SUPPL.
Publication statusPublished - 2000



  • Acidosis
  • Artificial ventilation
  • Bag-valve-mask ventilation
  • Cardiac arrest
  • Cardiopulmonary resuscitation
  • Hypercarbia
  • Hypoxemia
  • Mouth-to-mouth ventilation
  • Ventilation

ASJC Scopus subject areas

  • Critical Care and Intensive Care Medicine

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