Sedation during Flexible Bronchoscopy in Patients with Pre-Existing Respiratory Failure: Midazolam versus Midazolam plus Alfentanil

Abstract

Background: The use of sedation during flexible bronchoscopy (FB) is undisputed; however, the combination of benzodiazepines and opiates, although reasonable, is suggested to cause hypoventilation, particularly in patients with pre-existing respiratory failure. Objectives: To assess respiratory function during FB. Methods: Transcutaneous PCO₂(PtcCO₂), oxygen saturation, patients’ tolerance, time after FB until recovery and application of drug dosage were assessed in patients receiving either midazolam with alfentanil (n = 15) or midazolam alone (n = 15) for sedation for FB. Results: There were no differences in PtcCO₂ values during FB between the two groups (all p > 0.05). However, PtcCO₂significantly increased over time in both groups (both p < 0.001; RM-ANOVA on ranks). Minimum oxygen saturation (SaO₂) [89 (interquartile range 79.8/92.8) vs. 86 (interquartile range 82.3/87.8)%; p = 0.46] and the duration until recovery, i.e., achieving an ALDRETE score of ≧9 [30 (interquartile range 10/90) vs. 10 (interquartile range 10/105) min; p = 0.68] were comparable for monosedation and combined sedation, respectively. The total amount of midazolam [4.0 (interquartile range 4.0/4.0) vs. 2.0 (interquartile range 2.0/2.0) mg; p < 0.001] was lower in patients receiving combined sedation. Significantly lower scores for pain and asphyxia, and a clear tendency to less nausea and cough were reported by patients receiving combined sedation. Conclusions: Combined sedation during FB produced a comparable degree of desaturation and hypoventilation, and is associated with a comparable time to full recovery compared to monosedation in patients with pre-existing respiratory failure. Importantly, FB using combined sedation is better tolerated by patients despite only 50% midazolam consumption.

Sedation for flexible bronchoscopy: current and emerging evidence

“…When used in combination with midazolam, FOX et al [29] found that these patients had adequate sedation and attenuation of sympathetic responses. DREHER et al [48] compared consecutive patients with stable pre-existing respiratory failure undergoing flexible bronchoscopy receiving midazolam alone or midazolam-alfentanil combination. They did not find any differences in oxygen desaturation or hypoventilation but those in the combination group reported less discomfort.…”

It is time for patients to undergo bronchoscopy without discomfort

“…Over the years, bronchoscopists have used several drugs, alone or in combination, for sedation, but the majority of studies have evaluated benzodiazepines (mainly diazepam and midazolam) and narcotics (mainly opioids, such as fentanyl and alfentanil), or combinations of these [16][17][18][19][20]. The combination of the sedative and amnesic effects of benzodiazepines with the analgesic and the antitussive actions of opioids is able to provide effective conscious sedation [15], and this is probably the most commonly used regimen in bronchoscopy [21], even if there are not many studies that compared the use of a single drug with a combination (and those that did gave controversial results).…”

Safety and Efficacy of Bronchoalveolar Lavage Using a Laryngeal Mask Airway in Cases of Acute Hypoxaemic Respiratory Failure with Diffuse Lung Infiltrates

“…In general, the amount of anaesthetics or analgesics needed to establish an LMA is less than that required for tracheal intubation. Recent studies have also demonstrated the occurrence of alveolar hypoventilation, as estimated by an increase in the partial pressure of carbon dioxide, during FOB under sedation (21,34). In our procedure, mechanical ventilation is immediately applied to maintain the appropriate minute volume if the sedatives suppress the patient's spontaneous breathing.…”