OBJECTIVE: Percutaneous dilatational tracheostomy (PDT) is a commonly performed method in neurocritical care, and its safety has been proven in numerous studies. Nevertheless, data regarding the application in patients with acute brain injury and poor respiratory function are poor. The purpose of this study was to evaluate the incidence of hypoxemia and hypercapnia during PDT in those patients.
METHODS: In a retrospective analysis, we acquired data from 54 patients with an acute brain injury (ABI) and a reduced PaO2/FiO2 ratio (PaO2/FiO2 < 300 mm Hg). In all cases, blood gas analyses before, during, and approximately 12 hours after PDT were available. We reviewed the patients' ventilator settings, results of gas exchange, and radiographic signs of acute respiratory distress syndrome (ARDS). Patients with ARDS were defined using the Berlin criteria.
RESULTS: We observed 2 cases (3.6%) of intraoperative hypoxemia (PaO2 < 60 mm Hg) and 4 cases (7.4%) of intraoperative hypercapnia (PaCO2 > 55 mm Hg). Twenty patients fulfilled the Berlin criteria for ARDS. While mean PaO2 did not differ significantly between ARDS and non-ARDS patients, intraoperative hypoxemia only occurred in the ARDS group (2/20). Mean PaCO2 was similar in the ARDS and non-ARDS groups, and cases of hypercapnia were apparent in both groups. The mean PaO2/FiO2 ratio of all patients improved from 229.1 mm Hg before PDT to 255.3 mm Hg.
CONCLUSIONS: Regarding the intraoperative gas exchange, indication of PDT in patients with ABI and ARDS should be considered carefully. However, PDT in ABI patients with reduced PaO2/FiO2 ratio alone appears to be a safe procedure.