Does Arterial Blood Gas (ABG) Provide a Safety Net for Extubation in Surgical Patients?

Background Extubation has always been a critical aspect of anaesthesia. Guidelines and recommendations are in place for achieving successful extubation, but the risk of failure always persists. Through this study, we assess whether arterial blood gas (ABG) values taken intraoperatively help predict extubation success in the operation theatre. Materials and methods This was a prospective observational study for one year of extubated patients whose blood gas values were not within the normal range. The patients of age 18 years and above undergoing high-risk elective and emergency surgeries where at least one intraoperative arterial blood sample was taken for blood gas analysis were included. Apart from parameters of ABG demographic data, urgency and duration of surgery, blood loss, urine output, use of intraoperative fluid(s), and blood product(s) were also observed.  Results Of 578 patients enrolled, 116 patients were extubated based on the predefined extubation criteria. Of these, 24 patients were reintubated within 24 hours. ABG parameters such as partial pressure of arterial oxygen (PaO₂) and serum HCO_3- levels were significantly lower in the reintubated patients compared to non-reintubated patients (p-values of 0.045 and 0.003, respectively). Conclusion This study showed that the PaO₂ <100 mm Hg or ratio of arterial oxygen partial pressure to fractional inspired oxygen (P/F ratio) of less than 200 and an HCO_3- value of less than 18 are plausible ABG parameters to decide extubation in post-surgery patients in OT. PaCO₂, base deficit, and lactate were less reliable parameters for planning extubation.