Risk of Harm Associated With Using Rapid Sequence Induction Intubation and Positive Pressure Ventilation in Patients With Hemorrhagic Shock

Based on limited published evidence, physiological principles, clinical experience, and expertise, the author group has developed a consensus statement on the potential for iatrogenic harm with rapid sequence induction (RSI) intubation and positive-pressure ventilation (PPV) on patients in hemorrhagic shock. “In hemorrhagic shock, or any low flow (central hypovolemic) state, it should be noted that RSI and PPV are likely to cause iatrogenic harm by decreasing cardiac output.” The use of RSI and PPV leads to an increased burden of shock due to a decreased cardiac output (CO), which is one of the primary determinants of oxygen delivery (DO₂). The diminishing DO₂ creates a state of systemic hypoxia, the severity of which will determine the magnitude of the shock (shock dose) and a growing deficit of oxygen, referred to as oxygen debt. Rapid accumulation of critical levels of oxygen debt results in coagulopathy and organ dysfunction and failure. Spontaneous respiration induced negative intrathoracic pressure (ITP) provides the pressure differential driving venous return. PPV subsequently increases ITP and thus right atrial pressure. The loss in pressure differential directly decreases CO and DO₂ with a resultant increase in systemic hypoxia.^{1, 2} If RSI and PPV are deemed necessary, prior or parallel resuscitation with blood products is required to mitigate post intervention reduction of DO₂ and the potential for inducing cardiac arrest in the critically shocked patient. Situational Guidance: 1. An important part of the clinical decision-making in a patient with hemorrhagic shock is awareness of the fact that RSI and PPV are likely to decrease CO and worsen the shock state. It is not recommended that RSI and PPV are seen as a first-line standard of care for these patients. 2. The primary management focus in the hemorrhagic shocked patient should be hemorrhage control and resuscitation with blood products of which whole blood (WB) probably represents the best combination of effectiveness and convenience.³ 3. If RSI and PPV are required, every attempt should be made to ensure that resuscitation has been effective enough to enable the patient to withstand the impact of the intervention. As a surrogate for this approach a systolic blood pressure (SBP) of > 100mmHg is recommended.⁴ 4. Aggressive ventilation by “breath stacking,” high ventilatory pressures, positive end-expiratory pressure (PEEP), and high ventilatory rates is likely to further reduce the cardiac output.^5,6 Takeaway Points: • This recommendation reflects the position of the author group and is based on the interpretation of existing evidence applied to physiologic principles, in addition to clinical experience and expertise. It is not intended to be a replacement for clinical judgement in the management of individual patients. • This opinion relates specifically to the resuscitation of patients with hemorrhagic shock and applies to clinical judgment and the balance of risk and benefit to the patient. • In hemorrhage, blood products are recommended for the resuscitation of hemorrhagic shock with WB being considered optimal in the remote damage control resuscitation (RDCR) environment.⁷ • The resuscitation of casualties suffering hemorrhagic shock should begin as soon as blood products and appropriately trained personnel are available. Ideally, resuscitation should not be delayed for more than 30 minutes from the time of injury.^8,9 • It should be noted that spontaneous respiration, inducing negative ITP, is beneficial to the shocked patient. Every effort should be made to retain this driver of venous return and hence CO by using postural airway positioning, intubation without ventilation using short-acting neuromuscular blocking agents (NMBAs) or surgical cricothyroidotomy.