This retrospective review of rapid sequence intubation (RSI) of patients with non-traumatic coma by Mobile Intensive Care Ambulance (MICA) paramedics in Ambulance Victoria, incorporated examination of electronic patient care records for all cases where Suxamethonium was administered between January 2008 and June 2011.
Inclusion criteria were all adult (≥15 years) patients with a Glasgow Coma Score (GCS) ≤9 who underwent RSI for presumed non-traumatic intracranial pathology. Patients undergoing RSI for suspected traumatic brain injury (TBI), drug overdose, coma due to non-neurological causes, return of spontaneous circulation (ROSC) post cardiac arrest, and those transported by air ambulance were excluded from analysis.
A total of 1 152 patients underwent RSI and road transportation during the study period. Cases that were excluded comprised: 263 TBI, 194 drug overdose, 134 post cardiac arrest, and 10 miscellaneous (hypothermia, airway burns, near drowning and suspected liver failure).
In the remaining 551 patients, MICA paramedics achieved an RSI success rate of 97.5% based on a maximum of two attempts at intubation. A total of 360 older (≥60 years) and 191 younger (15–59 years) patients underwent RSI. Mean pre RSI systolic blood pressure (SBP) was significantly higher in older patients (168 versus 153 mmHg, p <0.001). Mean decrease in SBP post RSI was greater in the older rather than the younger patients, although the difference was not statistically significant (20 mmHg versus 16 mmHg, p=0.074).
Intubation was unsuccessful in five younger and seven older patients, of whom 11 were managed adequately with bag-valve-mask (BVM) ventilation and arrived at hospital with SpO2 >97%. The remaining case was an older patient who arrived at hospital with SpO2 88% despite BVM ventilation. No patient required a surgical airway.
Cardiac arrest occurred during or immediately following RSI in four patients (0.7%), all of whom subsequently achieved ROSC. Asystole occurred immediately post RSI drug administration in three patients, all of whom achieved ROSC after intravenous atropine and two minutes of CPR. In one of these patients, asystole occurred after oesophageal intubation was recognised and the endotracheal tube was removed. The fourth patient experienced isolated episodes of ventricular fibrillation pre and post RSI, with successful restoration of sinus rhythm after defibrillation on both occasions.
The authors acknowledge the limitations associated with retrospective case review, including the potential for data not primarily collected for a specific research study to be inaccurate. The study did not examine clinical outcomes in this group, although a recent randomised control of paramedic RSI for TBI in Ambulance Victoria demonstrated improved neurological outcomes in the RSI group.
It is suggested that future research should investigate clinical outcomes following RSI in non-traumatic coma and aim to identify the optimal RSI approach in this subset of patients.
The authors conclude that the procedural success rate achieved by MICA paramedics compares favourably with data from physician-led aeromedical services, and that paramedic RSI has a comparatively higher success rate when compared with non-pharmacological or sedation only approaches.
This paper adds to the growing body of evidence that RSI delivered by appropriately educated paramedics with robust clinical governance and regular procedural exposure is both safe and feasible in a range of clinical scenarios.