*9.2.1 Respiratory depression*

Both benzodiazepine and opioids may cause respiratory depression by blocking their receptors in brain and brainstem which may lead to hypoxia and CO2 retention. Therefore, continues capnography monitoring is extremely important during endoscopic procedures. Drop in oxygen saturation on pulse oximetry is a late sign of respiratory depression especially if patients on supplemental oxygen. Patient stimulation and reversing the sedative agents should be considered to treat respiratory depression. Naloxone (1–2 mcg/kg intravenous) reverses both analgesic and respiratory depressant effect of the opioids, the dose can be repeated every 3 minutes with maximum dose 0.1 mg/kg. Naloxone has short half life (60–90 minutes), therefore patients should be observed at least for 2 hours after administration of naloxone to guarantee that re-sedation does not occur. Flumazenil (0.01 mg/Kg I.V) is a benzodiazepine antidote and useful to reverse both sedative and respiratory depressant effect of benzodiazepine. The half life of flumazenil is 40–80 minutes, therefore patients should be monitored for 2 hours after administration of flumazenil to ensure re-sedation does not occur [19–21].

### *9.2.2 Air way obstruction*

Laryngospasm and bronchospasm are the most common cause of airway obstruction.
