Risk Factors for Desaturation in Anesthetic Management During Airway Stenting.

Airway stenting involves a stent being inserted into a stenotic site in the airway. In patients with airway stenosis, the airway is the surgical field; therefore, anesthetic management is challenging, and avoiding hypoxia is important. Limited information is available on the anesthetic management of airway stenting. Risk factors for oxygen desaturation during airway stenting remain unknown. The present study was conducted to retrospectively examine patients who underwent airway stenting during a specific period and identify risk factors associated with oxygen desaturation. We performed univariate and multivariate analyses. The main evaluation items in a multivariate analysis were risk factors for desaturation (SpO2 ≤ 90%). Body mass index, preoperative orthopnea, the stenotic site of the airway, and severity of stenosis were selected for clinical usefulness. We analyzed 302 patients who underwent airway stenting at our hospital between July 2011 and June 2014 under general anesthesia with controlled ventilation. Total intravenous anesthesia with propofol target-controlled infusion and remifentanil was performed. Clinical data were extracted from electronic anesthetic records. The incidence of desaturation (SpO2 ≤ 90%) was 18.5% (56 out of 302 cases). Preoperative orthopnea (OR, 3.06)and stenosis distal to the bronchus (OR, 3.31) were identified as risk factors for desaturation in a multivariate analysis. We herein identified risk factors for desaturation during airway stenting. Anesthetic plans need to be carefully considered for patients with these risk factors.

A Prospective, Randomized Trial Comparing Respiratory Status During Anesthesia for Airway Stenting: Spontaneous Respiration Versus Controlled Ventilation With Muscle Relaxants.

BACKGROUND: Airway stenting is a procedure in which a stent is inserted into a stenotic site of the airway. The safest method of ventilation for airway stenting is controversial. A prospective randomized interventional study was conducted on airway stenting. We conducted this study to investigate whether controlled ventilation with muscle relaxants (MR) during airway stenting reduces the incidence of desaturation events (percutaneous oxygen saturation [SpO2] <95%) in comparison with spontaneous respiration (SP). METHODS: Sixty-four patients were enrolled at our hospital between April 2016 and August 2018, and were randomly assigned to the controlled ventilation with MR group or SP group. For anesthesia, total intravenous anesthesia with propofol target-controlled infusion and remifentanil was performed. In the SP group, SP was maintained. In the MR group, a rigid bronchoscope was inserted after the administration of MR to perform controlled ventilation. The incidence of desaturation events was analyzed by logistic regression adjusted by the preoperative respiratory state and stenotic site of the airway. RESULTS: The incidence of desaturation events in the SP and MR groups was 75.0% (24/32) and 9.7% (3/31), respectively, with an odds ratio of 0.04 (95% confidence interval, 0.01-0.16, reference = SP group; P < .001). In the SP group, the mean intraoperative pH was lower than that in the MR group (7.2 ± 0.1 vs 7.4 ± 0.1, respectively; P < .001). In this group, the mean partial pressure of arterial carbon dioxide (PaCO2) was higher (70.2 ± 17.0 mm Hg vs 40.5 ± 8.0 mm Hg, respectively; P < .001) and the mean partial pressure of oxygen in the arterial blood/fraction of the inspiratory oxygen ratio was lower (263.1 ± 64.2 mm Hg vs 396.4 ± 69.4 mm Hg, respectively; P < .001). CONCLUSIONS: Controlled ventilation with MR during airway stenting reduced the incidence of desaturation events, maintaining a favorable respiratory status.

A Randomized Trial of Respiratory Status during Airway Stenting under General Anesthesia Spontaneous Respiration vs. Controlled Ventilation with Muscle Relaxants.

Airway stenting is a procedure in which a stent is inserted into a stenotic site in the airway. However, the optimal ventilation for airway stenting remains controversial. We have planned a randomized, unblinded controlled study to compare intraoperative respiratory status by dividing patients, who underwent airway stenting, into spontaneous respiration (SP) and controlled ventilation with muscle relaxants (MR) groups. This study started in April 2016. The subjects, patients aged ≥20 years with airway stenosis caused by malignant neoplasms for which airway stenting was scheduled, are randomly allocated to SP and MR groups. Anesthesia management is performed in accordance with the anesthetic methods established in each group to compare parameters of the intraoperative respiratory status. The primary endpoint is the incidence of intraoperative oxygen desaturation events (SpO2 <95). Secondary endpoints are the mean intraoperative P/F ratio, pH, PaCO2, adverse events, and proportion of protocol treatment achievement. Currently, there is no evidence of anesthetic methods affecting airway stenting. Some studies have claimed that muscle relaxants worsen airway stenosis, while others have reported stable anesthetic management of controlled ventilation with muscle relaxants in airway stenting. This study may aid in clarifying anesthetic methods for airway stenting.