Yes, ketamine is widely used in surgery. It has been a staple of surgical anesthesia since the 1960s and remains on the World Health Organization’s Model List of Essential Medicines as a general anesthetic. What makes ketamine unusual compared to other anesthetics is that it keeps patients breathing on their own and maintains blood pressure, two things most other anesthetics compromise. This combination of safety and versatility has kept ketamine relevant across operating rooms, emergency departments, and battlefield medicine for decades.
How Ketamine Works Differently From Other Anesthetics
Most general anesthetics work by broadly suppressing brain activity. Ketamine takes a different approach. It blocks a specific type of receptor in the brain involved in pain signaling and consciousness. When the receptor opens, ketamine slips inside the channel and physically blocks ions from flowing through, effectively cutting off normal communication between nerve cells. This creates what’s called dissociative anesthesia: rather than being unconscious in the traditional sense, the patient enters a trance-like state where they’re disconnected from pain, their surroundings, and memory of the procedure.
This dissociative mechanism is why ketamine preserves functions that other anesthetics suppress. Patients typically keep breathing spontaneously, maintain their protective airway reflexes (like the gag reflex), and retain muscle tone. The drug also stimulates the cardiovascular system, raising heart rate and blood pressure slightly rather than causing the dangerous drops that agents like propofol can trigger.
Where Ketamine Shines in Surgery
Ketamine isn’t the default anesthetic for routine procedures in well-equipped hospitals. Its real advantages emerge in specific situations where other anesthetics would be risky or impractical.
Emergency and trauma surgery is one of the most important settings. Patients who arrive hemodynamically unstable, meaning their blood pressure is dangerously low from blood loss or shock, can’t safely receive anesthetics that further drop blood pressure. Ketamine’s ability to support cardiovascular function makes it the preferred choice in these cases. For the same reason, it’s ideal for rapid sequence intubation, when a patient needs to be put on a breathing tube quickly without time for elaborate anesthetic planning.
Pediatric surgery is another major use. Children with congenital heart defects, particularly those with cyanotic heart disease, can receive ketamine without worsening the abnormal blood flow patterns in their hearts. Children with neuromuscular disorders who are at risk for malignant hyperthermia (a life-threatening reaction to certain anesthetics) can safely receive ketamine as an alternative. It also works well for pediatric procedures because it can be given as an intramuscular injection, avoiding the need for an IV start in a frightened child.
Patients at risk of bronchospasm, including those with active asthma or upper respiratory infections, benefit from ketamine’s bronchodilating effect. Where other anesthetics might trigger dangerous airway constriction, ketamine actually relaxes and opens the airways.
Ketamine in Battlefield and Remote Medicine
Ketamine’s profile makes it nearly irreplaceable in austere environments. A systematic review of over 2,000 combat casualties receiving ketamine in Afghanistan and Iraq found that its use rose sharply after it was added to the Tactical Combat Casualty Care guidelines in 2012, jumping from 3.9% to 19.8% of analgesic administrations. In one study, it was the most common pain medication given, used in 52% of casualties.
The reasons are practical. Ketamine doesn’t require refrigeration, can be injected into muscle when IV access isn’t available, and won’t cause a trauma patient’s blood pressure to crash. A typical field dose of 50 mg intravenously reduced pain from moderate or severe to mild or none, sometimes after a single dose. Patients given ketamine during tactical evacuation actually showed increased blood pressure compared to those given morphine.
Dosing and Duration
For full surgical anesthesia, the standard intravenous dose is 1 to 4.5 mg/kg, administered over about 60 seconds. An average dose of 2 mg/kg produces roughly 5 to 10 minutes of surgical anesthesia. When given intramuscularly, the dose is higher (6.5 to 13 mg/kg) because absorption is slower, but it provides a longer window of 12 to 30 minutes of anesthesia with effects starting within 3 to 5 minutes.
In children, intramuscular doses of 9 to 13 mg/kg typically produce surgical anesthesia within 3 to 4 minutes. For longer procedures, additional doses or a continuous infusion can extend the effect as needed.
Combining Ketamine With Other Agents
Ketamine is frequently mixed with propofol, a combination nicknamed “ketofol.” The logic is straightforward: propofol causes sedation and lowers blood pressure, while ketamine causes sedation and raises blood pressure. Combined, each drug’s downsides offset the other. The mixture also allows lower doses of both, reducing side effects from either one alone. For procedural sedation, this combination results in less respiratory depression and more stable vital signs than using either drug solo.
Side Effects and Recovery
The most notable side effect of ketamine anesthesia is what happens as it wears off. Some patients experience vivid dreams, hallucinations, agitation, or confusion during emergence. In combat settings, incoherent speech, involuntary limb movements, and hallucinations were the most commonly reported adverse events. These effects are generally short-lived but can be distressing.
Interestingly, low-dose ketamine (well below anesthetic levels) has actually been shown to reduce emergence agitation in children waking up from other anesthetics. In one study of children undergoing dental surgery under sevoflurane anesthesia, adding a small dose of ketamine cut the rate of emergence agitation from 34% to about 17%.
Recovery time is a practical consideration. Ketamine, especially when combined with opioid pain medications, has been linked to longer discharge times after outpatient surgery. In a study of patients undergoing gallbladder removal, higher ketamine doses correlated with delayed discharge. The median time from end of surgery to discharge was about 2.5 hours, but ketamine use was independently associated with pushing that timeline longer. This is one reason ketamine isn’t the first choice for routine outpatient procedures where fast recovery and same-day discharge are priorities.
When Ketamine Is Avoided
Ketamine’s cardiovascular stimulation, normally an advantage, becomes a concern in patients who can’t tolerate increases in heart rate or blood pressure. It’s used cautiously in traumatic brain injury because of ongoing debate about its effects on pressure inside the skull. The drug is metabolized by a specific liver enzyme system, so patients taking medications that inhibit those same enzymes risk toxic ketamine levels. Caution is also warranted when combining ketamine with opioids, benzodiazepines, or other drugs that alter mood and perception, as the effects can compound unpredictably.
Ketamine’s Role in Global Surgery
Perhaps the clearest sign of ketamine’s surgical importance is its inclusion on the WHO’s Model List of Essential Medicines as a 50 mg/mL injectable solution. In low-resource settings where sophisticated anesthesia machines, monitoring equipment, and trained anesthesiologists may not be available, ketamine allows surgery to happen safely. A single provider can administer it by injection, the patient keeps breathing independently, and vital signs tend to remain stable without the intensive monitoring that other anesthetics demand. For millions of surgical patients worldwide, ketamine isn’t just an option. It’s the only viable anesthetic available.