Managing complications of procedural sedation and analgesia

Significant adverse events are uncommon with procedural sedation and analgesia, but minor adverse events (those requiring limited or no intervention) occur in up to 20% of patients. Adverse events are more likely if multiple sedatives are used, or if the sedative effects of the drug(s) outlast the stimulating procedure. The risk of adverse events is minimised by careful patient selection, cautious dose titration and close monitoring, but staff involved in the delivery or monitoring of procedural sedation and analgesia must be alert to any complication and prepared to manage it.

Sedation can lead to adverse respiratory events such as impaired ventilation, apnoea or hypoxia, despite cautious dose titration. These adverse events usually respond to basic airway opening manoeuvres, supplemental oxygen and brief bag-mask ventilation. Manage postprocedural opioid-induced ventilatory impairment according to the advice outlined here.

Cardiovascular depression is usually dose related and most often seen with midazolam or propofol. The risk of cardiovascular depression can be minimised by cautious dose titration and administration of intravenous fluids for patients who are hypovolaemic (eg after trauma).

Ketamine is associated with a higher incidence of postprocedural vomiting (approximately 10%) than other drugs used for procedural sedation and analgesia, but does not increase the risk of pulmonary aspiration. Ketamine can also cause postprocedural agitation. This can usually be managed in a calm, low-stimulation environment, but occasionally specific treatment may be required (eg a low dose of a benzodiazepine); see local protocols. Ketamine-induced laryngospasm is rare and seems to be associated with ketamine’s peak effect. It is usually responsive to bag-mask ventilation using 100% oxygen.