Efficacy of thracheal extubation-insertion of nasopharyngeal airway for preventing response to extubation under anesthesia in patients with hypertension

Abstract

Objective To evaluate the efficacy of thracheal extubation-insertion of the nasopharyngeal airway for preventing the response to extubation under anesthesia in patients with hypertension. Methods Eighty ASA Ⅱ or Ⅲ patients with hypertension, scheduled for laparoscopic cholecystectomy under general anesthesia were randomly allocated into 2 groups with 40 patients in each group: tracheal tube group (group Ⅰ ) and tracheal tube-nasopharyngeal airway group (group Ⅱ). Anesthesia was induced with midazolam 0.05 mg/kg, sufentanil 0.4 μg/kg, cisatracurium besylate 0.15 mg/kg and propofol 2 mg/kg. The patients were tracheal intubated and mechanically ventilated. Anesthesia was maintained with TCI of propofol (target plasma concentration 3-4 μg/L) and sufentanil (target plasma concentration 0.2-0.4 μg/L). BIS was maintained at 40-50. Target plasma concentrations of propofol and sufentanil were adjusted to 1 μg/L and 0.1 ng/L respectively after operation and the infusion was stopped after recovery of breathing. In group Ⅱ, extubation was performed, and then the nasopharyngeal airway was inserted and oxygen was inhaled by mask, and the airway was removed after recovery of consciousness. In group Ⅰ , extubation was performed after recovery of cousciousness. The SP, DP, HR and SpO_2 were recorded immediately before anesthesia induction (T_0), immediately and 2 min after insertion of the nasopharyngeal airway (T_(1,2)), and immediately and 2 rain after removal of the tube or airway (T_(3,4)). The maximal value of SP (SP_(max)), DP (DP_(max)) and HR (HR_(max)) were also recorded during extubation. The differences in SP (△SP), DP (△DP) and HR (△HR) before and after extubation were calculated. The plasma concentrations of AD and NE were determined. The coughing and restlessness were observed. Results The SP, DP, HR and plasma concentrations of AD and NE were significantly higher at T_(3,4) in group Ⅰ and the SP, DP at T_(1,3,4) and HR at T_(2,3) were significantly lower in group Ⅱ than those at T_0 (P<0.05). The SP, DP, HR and plasma concentrations of AD and NE were significantly lower at T_(2-4) in group Ⅱ than in group Ⅰ (P<0.05). The SP_(max), DP_(max), HR_(max), △SP, ADP and △HR were significantly lower in group Ⅱ than in group Ⅰ (P<0.05). The incidence of coughing and restlessness was obviously lower in group Ⅱ than in group Ⅰ (P<0.05). Conclusion Thracheal extubation-insertion of the nasopharyngeal airway under anesthesia can effectively prevent the patients' response to extubation during emergence from anesthesia. Key words: Nasopharynx; Intubation,intratracheal; Stress; Hypertension