Pressure support ventilation versus spontaneous ventilation in infants undergoing brachial plexus exploration: a comparative study

Abstract

Background General anesthesia and muscle relaxants have the potential to decrease or even abolish action potentials, interfering with surgical nerve exploration. Prolonged surgeries in spontaneously breathing infants lead to muscle fatigue, shallow breathing, and CO 2 accumulation. This randomized study aimed to evaluate the efficiency of pressure support ventilation (PSV) in infants undergoing brachial plexus exploration without muscle relaxants in maintaining normal end-tidal CO 2 (EtCO 2 ) and hemodynamics. Patients and methods After the approval of the ethical committee in Kasr Al Ainy University Hospital, and parents' consent, 16 ASA I and II infants (4-12 months) were allocated randomly to two main groups. In group I, PSV was used from the start. In group II, spontaneous ventilation was started, followed by switch to PSV once fatigue occurred; group II was subdivided into group IIa (spontaneous ventilation) and group IIb (PSV). Recorded variables included tidal volume, EtCO 2 , oxygen saturation, respiratory rate (RR), heart rate (HR), blood pressure, and arterial blood sample analysis. Results Systolic and diastolic blood pressure and HR were higher in group IIa than group I ( P = 0.0047, 0.0135, and 0.3575, respectively). EtCO 2 and RR were also higher ( P V t was higher in group I ( P = 0.0092). Comparing groups IIa and IIb, systolic and diastolic blood pressure, HR, RR, EtCO 2, and PaCO 2 were significantly higher in group IIa ( P V t was higher in group IIb ( P = 0.0053). Conclusion PSV in infants undergoing prolonged surgery without muscle relaxants is efficient in maintaining normal EtCO 2 and hemodynamics through avoidance of fatigue and maintaining normal V t .