Sedation During Flexible Bronchoscopy: What is needed? (2006)

For most patients, bronchoscopy is associated with anxiety and fear of pain and breathing difficulties.1 There is a large demand for sedation with endoscopy.2 The British Thoracic Society Guidelines state that combining the amnesic effects of a benzodiazepine with the analgesic and antitussive effects of a narcotic is rational.3 Various sedative medication such as diazepam, midazolam, temazepam, lorazepam, morphine, fentanyl, hydrocodone have been used either singly or in combination in patients undergoing bronchoscopy.3–8 Midazolam is preferred over diazepam and is used by many during flexible bronchoscopy.3 It has a rapid onset of action and duration of action a brief in healthy individuals.3 Fentanyl is a potent short acting opioid in low doses, which has a greater analgesic potency than morphine with a rapid onset and limited duration of action.9 Hydrocodone is a codeine derivative, which has been widely used for cough since 1923.10,11 It is assumed to have a greater antitussive activity than codeine but less than morphine.12 Hydrocodone is much cheaper than alfentanyl.7 The untoward effects of benzodiazepines and opioids include respiratory and myocardial depression, hypotension, and bronchospasm.9 When used together these drugs may act synergistically warranting caution and careful monitoring during the procedure.9 Significant hypoxemia may sometimes occur during flexible bronchoscopy despite the use of supplemental oxygen. Upper airway obstruction has been shown to be the dominant cause of hypoxemia during flexible bronchoscopy and this is successfully managed with nasopharyngeal tube insertion.4 Other strategies that may need to be implemented to manage hypoxemia include oxygen supplementation with intratracheal catheter, administration of sedation reversal medication, removal of the bronchoscope, bag and mask ventilation and rarely endotracheal intubation and ventilation.13 Therefore, the bronchoscopy suite should be well equipped to deal with such untoward situations. The combination of a benzodiazepine and an opioid has been shown to be effective and safe for the purposes of sedation during bronchoscopy.7 This approach using a combination of hydrocodone and midazolam in incremental doses has recently been shown in a randomized, double blind, placebo controlled trial to markedly reduce cough during flexible bronchoscopy without causing significant desaturation when compared with midazolam and placebo.7 Patient satisfaction is also good with combined use of midazolam and hydrocodone.14 The midazolam dose requirement has been shown to be significantly higher in patients with stem cell transplantation and in some selected patients with HIV and drug abuse.15 Recently, it has been reported that there is an increase in sedative drug requirement with time for both midazolam and fentanyl after lung transplantation, which is significantly higher in patients with cystic fibrosis.16 Propofol has been suggested as an useful alternative in those patients with cystic fibrosis in whom adequate sedation to facilitate flexible bronchoscopy is not achieved with usual dosages of midazolam and fentanyl.16 In the April 2006 issue of the Journal, Diaz-Fuentes et al17 compared the sedative drug requirements during flexible bronchoscopy in patients with and without substance abuse. The authors report that patients with drug abuse need higher doses of sedation during flexible bronchoscopy, which confirms the findings of another recent study.15,17 Rab-Khan et al6 have also reported the requirement of a high midazolam dose (mean 38.6 mg) in HIV patients who were also intravenous drug abusers. The use of combined midazolam and opiate may significantly reduce the requirement of midazolam during flexible bronchoscopy in these patient population.15 This information is important for the bronchoscopist and the anesthetic and nursing staff for optimal use of sedative drugs. After having discussed all these details of potential sedation, the important question has to be asked—Do we really need sedation or is it just a play field for the bronchoscopist and the anesthetist? No doubt that flexible bronchoscopy can be performed without sedation.18–20 In a randomized, single blind, prospective controlled study, the nonsedation group received airway topical anesthesia whereas the sedation group received topical anesthesia and intravenous sedation with propofol.19 The patients in the sedation group had significantly less cough, pain and sense of asphyxiation.19 Global tolerance to the procedure was also significantly better in patients who received sedation.19 In the April 2006 issue of the Journal, Ruiz Lopez et al21 report results of bronchoscopy performed under only local anesthesia without sedation. Tolerance to bronchoscopy in this study was lower when compared with literature.21 Older patients showed better tolerance to bronchoscopy.21 Patients with solitary pulmonary nodule or pneumonia showed a lack of tolerance to the procedure.21 This paper also shows that not all patients need sedation during bronchoscopy. May be we should ask the patient himself whether he or she would prefer to have sedation or not. Our opinion is that sedation should be offered to all patients undergoing flexible bronchoscopy. Complications related to sedation do occur during bronchoscopy, therefore, the patients should be adequately monitored and the bronchoscopy suite adequately equipped. The sedative drug requirements are different in different patient groups and hence the doses need to be tailored to the individual patient. It is also possible for bronchoscopy to be performed without sedation—just ask the patient!