Ketamine for Acute Pain Management and Sedation

Abstract

Topic Ketamine is beneficial in clinical settings ranging from procedural sedation to the treatment of chronic pain. This article describes the clinical benefits of ketamine for treatment of acute pain and for sedation of patients undergoing mechanical ventilation. Clinical Relevance Ketamine causes analgesic and amnestic effects by noncompetitive inhibition of the N-methyl-D-aspartate receptor and activation of the opioid μ and κ receptors. Unlike other sedatives, ketamine provides analgesia and amnesia without causing hypotension or respiratory depression. Several studies have elucidated the clinical benefits of ketamine. The use of ketamine has extended beyond critical care areas such as the operating room and intensive care units. Nurses must be familiar with optimal clinical scenarios, monitoring parameters, and contraindications of ketamine. Purpose To highlight the clinical utility and pharmacological properties of ketamine through a literature review. Current studies of ketamine in acute pain and sedation management are summarized. Content Covered This narrative review describes pharmacological properties, dosing strategies, adminis­tration considerations, and adverse effects of ketamine.

Acute pain in the critically ill patient: revisiting the literature

“…Ketamine is a drug that induces sedation and analgesia mediated by inhibition of N-methyl-D-aspartate (NMDA) receptors and activation of µ-type opioid receptors. It can cause tachycardia and hypertension, with minimal central depressant effect, but attention is required to its dissociative effects described in the literature 43 . The latest pain management consensus (2018) recommends the use of ketamine as an adjunct drug to the use of opioids for the management of PO pain in critically ill patients 5 .…”

“…In addition, publications on the adjuvant use of sub-anesthetic doses (~0.1mg/kg/h) in the management of mechanical ventilation 44 and its use in the control of opioid-induced hyperalgesia 43 have been increasing. In a recent systematic review in the surgical setting, the use of ketamine was well tolerated and significantly reduced the consumption of opioids and other analgesics in general PO patients, including in orthopedic procedures 45 .…”

Postoperative Pain Management

“…71 Typical infusion regimens range from 0.02 to 0.1 mg/kg/h (any dosage below <0.25 mg/kg/h is considered sub-anesthetic), and at these dosages, side-effects are uncommon. 83,84 Longer infusions (24-72 h) are safe and show increased benefit over shorter infusions. Infusions should be typically administered in collaboration with the hospital Pain Service or Anesthesia colleagues and should be considered in patients with challenging to manage postoperative pain refractory to opioid management, after major noncardiac surgery (i.e., spine, thoracotomies), and those with a history of chronic pain or opioid tolerance.…”