Efficacy of self-made breathing circuit joint for intermittent positive pressure ventilation in patients with central airway obstruction undergoing interventional fiberoptic bronchoscopy

Abstract

Objective To evaluate the efficacy of self-made breathing circuit joint for intermittent positive pressure ventilation (IPPV) in patients with central airway obstruction undergoing interventional fiberoptic bronchoscopy (FOB). Methods Sixty-two patients of both sexes with central airway obstruction requiring tracheal intubation, aged 60-80 yr, with body mass index of 20-26 kg/m2, of American Society of Anesthesiologists physical status Ⅲ or Ⅳ and Medical Research Council dyspnea scale grade Ⅲ or Ⅳ, undergoing interventional FOB under general anesthesia, were divided into 2 groups (n=31 each) using a random number table: high frequency jet ventilation (HFJV) group and IPPV group.The patients were tracheally intubated after induction of general anesthesia.The self-made breathing circuit joint was connected, then the anesthesia machine was connected to perform IPPV, and the ventilator settings were adjusted to maintain the end-tidal pressure of carbon dioxide 35-45 mmHg in group IPPV, and HFJV was used in group HFJV.Before induction (baseline), at 10, 20, 30 and 40 min after start of operation, and at the end of operation, arterial blood samples were collected for blood gas analysis, the pH value, arterial oxygen partial pressure, and arterial carbon dioxide partial pressure were recorded.The development of hypercapnia was recorded. Results Hyoxemia was not found in the two groups.The incidence of hypercapnia was 74%, and in addition the incidence of severe hypercapnia was 10% in group HFJV.The incidence of hypercapnia was 16%, and all the patients presented with permissive hypercapnia in group IPPV.Compared with group HFJV, the incidence of hypercapnia was significantly decreased, and the pH value and arterial oxygen partial pressure were increased, and arterial carbon dioxide partial pressure was decreased from 10 min after start of operation to the end of operation in group IPPV (P<0.05). Conclusion The self-made breathing circuit joint provides better efficacy than HFJV when used for IPPV in the patients with central airway obstruction undergoing interventional FOB. Key words: Intermittent positive-pressure ventilation; Bronchoscopy; Airway obstruction