Inflation Pressure, Gastric Insufflation and Rapid Sequence Induction

Abstract

Manual inflation of the lungs should be avoided (before tracheal intubation) when rapid sequence induction is performed. This teaching is applied to all patients at risk from the dangers of a full stomach, particularly in obstetric practice. Unless hypoxia supervenes, manual ventilation is contraindicated on two grounds. First, if cricoid pressure has been inadequately applied (a not uncommon situation (Howells et al., 1983)), silent regurgitation may occur and gastric contents be forced into the lungs. Second, and more importantly, it has been stated that manual inflation of the lungs can lead to gaseous distension of the stomach and further predispose to vomiting or regurgitation, or both (Snow, 1963). With the use of adequate preoxygenation and a rapidly-acting depolarizing neuromuscular blocking agent, manual ventilation of the lungs before intubation is not usually required. Under certain circumstances, however, the patient's oxygen reserves may be insufficient as, for example, during failed or delayed intubation-particularly when the oxygen reserves are decreased (low FRC) (Nunn, 1977), or when oxygen consumption is increased as during pregnancy (Archer and Marx, 1974), thyrotoxicosis or fever. Similarly, when suxamethonium is contraindicated, the speed of onset of a non-depolarizing agent may be adequate to allow intubation before the exhaustion of the oxygen reserves. Recently, the "priming" principle has been described (Gergis et al., 1983; Foldes, 1984; Miller, 1985; Schwarz et al., 1985). A nondepolarizing agent is used as an alternative to suxamethonium when this agent is contraindicated for rapid sequence induction. The principle E. G.

Emergency Neurological Life Support: Airway, Ventilation, and Sedation

“…However, the time to desaturation following pre-oxygenation is shorter in apneic infants compared to older children (<100 s), and a modified RSI technique with gentle pressure-limited mask ventilation (10-12 cm H2O) and 100 % oxygen may be used to avoid hypoxemia [119,120]. This technique may also limit hypercarbia and keep small airways open without the risk of gastric inflation and related morbidity [121][122][123]. Cricoid pressure is routinely applied despite questionable evidence that it improves clinical outcomes [123][124][125].…”

Cardiac Arrest Resuscitation

“…However, the original studies that demonstrated these findings used much higher tidal volumes than those currently recommended. 66,67 More recent data now show that cricoid pressure hampers the placement of both supraglottic and endotracheal airways. Cricoid pressure impairs both laryngeal mask airway placement and subsequent ventilation.…”

Challenges and Advances in Intubation: Airway Evaluation and Controversies with Intubation

“…60 This report, however, differs from the results of two studies (a cadaver study and a clinical study) that documented decreased gastric insufflation with air during mask ventilation when cricoid pressure was applied. 61,62 This raises the question or whether or not studies with mask ventilation can be applied to endotracheal intubation and what effect, if any, cricoid pressure has on preventing gastric aspiration during endotracheal intubation. A literature review of 241 articles dealing with cricoid pressure concluded there was little evidence to support the view that cricoid pressure decreases the risk for aspiration.…”