Safety of ketamine in Australia ventilated ICU spitalized patients with Dr. Tom Niccol: In Australian and New Zealand, mechanically ventilated patients account for about 35% of all adult patients admitted to the intensive care unit (ICU). In addition to treating the primary illness, international clinical practice guidelines emphasise five critical domains in the management of ventilated patients. These are pain assessment and management, sedation and agitation prevention, delirium assessment and treatment, rehabilitation and mobilisation, and minimising sleep disruption. Discover even more info at Dr. Tom Niccol.
Mechanically ventilated patients account for about one-third of all admissions to the intensive care unit (ICU). Ketamine has been conditionally recommended to aid with analgesia in such patients, with low quality of evidence available to support this recommendation. We aimed to perform a narrative scoping review of the current knowledge of the use of ketamine, with a specific focus on mechanically ventilated ICU patients.
One study compared an S-ketamine anaesthesia of a bolus of 1–3 mg/kg followed by infusion of 2–4 mg/kg/h versus sufentanil infusion. Five of the studies reported that racemic or S-ketamine reduced the inflammatory response after surgery as measured by plasma/serum IL-6 concentrations. This response was most pronounced in the early (within 6 hours) postoperative period. It is possible that this anti-inflammatory effect of ketamine may provide some benefit to mechanically ventilated ICU patients.
Methods: We searched MEDLINE and EMBASE for relevant articles. Bibliographies of retrieved articles were examined for references of potential relevance. We included studies that described the use of ketamine for postoperative and emergency department management of pain and in the critically unwell, mechanically ventilated population.
The recommended dose for ICU sedation is 1 mg/kg/h. Recommended doses for analgesia in mechanically ventilated patients are an intravenous bolus of 0.5 mg/kg followed by an infusion of 1–2 μg/kg/min (0.06–0.12 mg/kg/h). 3 For the purposes of this review, a low dose intravenous bolus of ketamine is considered < 1 mg/kg and low dose intravenous infusion may be a median dose of ≤ 0.3 mg/kg/h aligned with international studies of the use of ketamine as an adjunct for analgesia and sedation.
Results: There are few randomised controlled trials evaluating ketamine's utility in the ICU. The evidence is predominantly retrospective and observational in nature and the results are heterogeneous. Available evidence is summarised in a descriptive manner, with a division made between high dose and low dose ketamine. Ketamine's pharmacology and use as an analgesic agent outside of the ICU is briefly discussed, followed by evidence for use in the ICU setting, with particular emphasis on analgesia, sedation and intubation. Finally, data on adverse effects including delirium, coma, haemodynamic adverse effects, raised intracranial pressure, hypersalivation and laryngospasm are presented.
Raised intracranial pressure: Early observational studies suggested ketamine was associated with raised ICP in patients with space-occupying lesions 71, 72 and there were concerns with its use in traumatic and non-traumatic brain injury. However, to address these concerns, there have been several small randomised controlled trials of ketamine combined with midazolam versus narcotic combined with midazolam. Low dose. There are no studies using low dose ketamine to study its effects on raised ICP.
Conclusions: Ketamine is used in mechanically ventilated ICU patients with several potentially positive clinical effects. However, it has a significant side effect profile, which may limit its use in these patients. The role of low dose ketamine infusion in mechanically ventilated ICU patients is not well studied and requires investigation in high quality, prospective randomised trials.