Ojective To evaluate the effect of nasal cannula apneic oxygenation technique on duration of non-hypoxic apnea during tracheal intubation after inducting general anesthesia among severe obstructive sleep apnea hypopnea syndrome (OSAHS) patients.
Methods Eighty patients with OSAHS, 62 males and 18 females, aged 18-56 years, BMI 30-42 kg/m2, falling into ASA physical status Ⅰ or Ⅱ, Mallampati grade Ⅰ-Ⅲ, were scheduled for elective uvulopalatopharyngoplasty, were divided into 2 groups (n = 40) by random number table method: nasal cannula apneic oxygenation group (group N) and control group (group C). A simulated prolonged intubation was performed to determine the duration of non-hypoxic apnea after all patients underwent standard intravenous induction. After patients lost consciousness in group N, nasopharyngeal catheters were placed to confirm mask ventilation, muscle relaxants were given, and laryngoscope was placed to expose glottis structure after satisfactory muscle relaxations. Meantime 15 L/min humidified pure oxygen were given through nasopharyngeal catheters. Patients in group C were induced routine anesthesia, then laryngoscope was inserted to expose glottis structure after satisfactory muscle relaxations. Value of CETO2 when mask ventilation was stopped, minimum value of SpO2 after stopping mask ventilation, and value of PETCO2 when ventilation began after intubation were recorded. Duration of non-hypoxic apnea safety time,the time from intubation to SpO2 value reached 100% were recorded as well. The incidence of tracheal intubation related complications such as nasal bleeding, tooth injury, sore throat, hoarseness and oropharyngeal bleeding were recorded at 24 h after operation.
Results Compared with group C, there was no significant difference in the value of CETO2 when mask ventilation was stopped in group N. And the minimum value of SpO2 after stopping mask ventilation was significantly increased (P < 0.05), PETCO2 value when ventilation began after intubation increased significantly (P < 0.05), the duration of non-hypoxic apnea safety time was prolonged (P < 0.05), and the time from intubation to SpO2 value reached 100% was shorter in group N (P < 0.05). There was no statistically significant difference between two groups of complications related to tracheal intubation, such as nasal bleeding, tooth injury, sore throat, hoarseness, and oropharyngeal bleeding.
Conclusion In severe OSAHS patients, nasal cannula apneic oxygenation technique can significantly increase the safe apneic duration during induction of anesthesia. |
