Sevoflurane in the Acute Phase of Severe Traumatic Brain Injury

Abstract

The aim of the study was to evaluate the usefulness and safety of sevoflurane in patients in the acute phase of severe traumatic brain injury (TBI).Materials and methods. A prospective, randomized, pilot clinical trial was conducted at the Sklifosovsky Research Institute for Emergency Medicine (Moscow) in adults with acute severe TBI, aged 18 years and older, undergoing intensive intracranial pressure (ICP)-guided therapy. To achieve the desired sedative effect, the inhaled anesthetic sevoflurane was administered in the main group, and standard doses of intravenous propofol were administered in the control group. ICP and cerebral oxygen extraction fraction (OEF) were monitored in all patients. Hemodynamic and respiratory support parameters, transcranial Doppler ultrasound scan, brain bioelectrical activity, brain CT scan, laboratory parameters, markers of inflammation, patients' need for sedation and mechanical ventilation, and length of ICU stay were also evaluated.Results. The use of inhalation sedation contributed to the reduction of ICP on day 2 (9.5 mmHg in the sevoflurane group and 17.3 mmHg in the propofol group, P=0.003) and day 3 (10 mmHg and 14.2 mmHg, respectively, P=0.005). BIS monitoring showed no significant difference in depth of sedation between groups on day 2 (60 vs. 48.5, P=0.070) and day 3 (61 vs. 46, P=0.095). Inhalation sedation reduced cerebral OEF on the injury side compared to propofol on day 2 (23.3 vs. 30.2%, P=0.006) and day 3 (22.7 vs. 31.2%, P<0.001). After 24 hours of sedation therapy, there was a significant difference in P/F (PaO₂/FiO₂) ratios between the groups. On days 1, 3, and 7, the sevoflurane group had P/F ratios of 340, 324, and 323 mmHg, while the propofol group had significantly lower ratios of 271, 278, and 275 mmHg (P<0.001). Pneumonia was documented in 9 cases in the sevoflurane group vs. 18 cases in the propofol group (P=0.028), and a similar trend was observed in the total number of infectious complications: 13 vs. 21 cases, respectively (P=0.046).Conclusion. Sevoflurane in the acute phase of severe TBI was not only safe, but also improved several vital functions, including ICP, blood pressure, P/F ratio, and also slowed brain metabolism via reduced oxygen consumption without affecting the depth of sedation according to BIS monitoring data. All of the above suggests that inhalation sedation may improve the prognosis for patient recovery. However, multicenter randomized clinical trials are needed to identify and verify all positive and negative effects of inhalation sedation in this patient  population.