Ketamine has become an important agent in non-operating room anesthesia (NORA), a practice area that includes procedural sedation and anesthesia delivered in locations such as radiology suites, endoscopy units, interventional cardiology labs, and emergency departments. The unique pharmacologic profile of ketamine distinguishes it from other sedative and anesthetic agents and provides several benefits when administering anesthesia outside the traditional operating room environment.
As a dissociative anesthetic, ketamine produces a functional and electrophysiological separation between the thalamocortical and limbic systems, resulting in profound analgesia, amnesia, and sedation while often preserving spontaneous respiration and protective airway reflexes. This combination makes ketamine especially valuable in NORA settings, where procedures may be painful but relatively short and where maintaining cardiorespiratory stability is essential, as access to critical care resources are limited in the event of a catastrophic medical event. Unlike many commonly used sedatives, ketamine does not cause significant dose-dependent respiratory depression, reducing the risk of hypoventilation or apnea during procedures performed in remote locations.
Hemodynamic stability is another major advantage of ketamine in non-operating room anesthesia. Through sympathetic nervous system stimulation, ketamine typically increases heart rate, blood pressure, and cardiac output. This property contrasts with agents such as propofol or benzodiazepines, which frequently cause hypotension. In patients with limited physiological reserve, hypovolemia, or trauma, ketamine’s cardiovascular effects can help maintain perfusion during sedation. However, in patients with depleted catecholamine stores or severe cardiac disease, these effects may be blunted or undesirable, requiring careful patient selection and monitoring.
Additionally, ketamine’s analgesic properties reduce or potentially eliminate the need for adjunctive opioids, thereby minimizing opioid-related adverse effects such as respiratory depression, nausea, and ileus. Ketamine’s versatility allows it to be used alone or in combination with other agents, such as low-dose benzodiazepines or propofol, to balance sedation depth and minimize adverse effects.
However, ketamine use in NORA requires an understanding of its limitations and potential side effects. Emergence phenomena, including vivid dreams, hallucinations, and agitation, can occur during recovery, particularly in adults. While these effects are usually self-limited, they may be distressing and can complicate post-procedural care. Hypersalivation and increased airway secretions are additional concerns, particularly in settings where suction or airway intervention may be less readily available. Antisialagogues and careful dosing strategies are often employed to mitigate these risks.
The expanding role of NORA has underscored the importance of agents that provide reliable sedation with a wide margin of safety. Ketamine’s predictable pharmacokinetics, multiple routes of administration, and preservation of respiratory drive have contributed to its growing use in these settings. Its applicability across diverse patient populations, including pediatric, trauma, and hemodynamically unstable patients, further reinforces its value.