Ketamine is one of the most thoroughly studied sedation drugs used in children, and its safety record across tens of thousands of pediatric cases is strong. A systematic review covering more than 58,000 children found no deaths and no permanent adverse outcomes, with truly dangerous complications occurring roughly once in every 24,000 sedation encounters.1PubMed. Systematic Review of Pediatric Ketamine in Emergency Department Procedural Sedation: Frequency and Predictors of Adverse Events That does not mean the drug is free of side effects, though. Parents deserve to know what the common reactions look like, which ones are temporary nuisances, and which rare events the medical team is actively watching for.
Why Children Receive Ketamine in the First Place
Ketamine is most commonly used in emergency departments when a child needs a painful or frightening procedure done quickly, such as setting a broken bone, stitching a deep laceration, or draining an abscess.2PubMed Central. Considerations for physicians using ketamine for sedation of children in emergency departments It works differently from most sedatives: instead of putting a child fully to sleep, it produces a trance-like state called dissociative sedation. The child’s eyes may remain open and they may make small movements, but they are disconnected from pain and from awareness of what is happening around them. This state tends to preserve protective airway reflexes and breathing drive better than many alternatives, which is a major reason emergency physicians favor it for children.
Outside the emergency department, ketamine also appears in pediatric anesthesia for surgical procedures and, less commonly, in specialized pain clinics for children with hard-to-treat chronic pain conditions. A small pilot study tested oral ketamine in children with chronic pain, and while some participants saw improvement in pain scores, two experienced dose-limiting side effects including excessive sedation and loss of appetite.3Elsevier / ScienceDirect (The Journal of Pediatrics). Oral Ketamine for Children with Chronic Pain: A Pilot Phase 1 Study The takeaway for parents is that the context matters: a single dose for a 15-minute procedure carries a very different risk profile than repeated doses over days or weeks.
Vomiting and Nausea
If your child receives ketamine, the single most likely side effect is vomiting. Across studies, it happens in roughly 7 to 8 percent of children.4PubMed Central. Predictors of emesis in children undergoing procedural sedation with intramuscular ketamine in a paediatric emergency department That rate is not evenly distributed, though. Older children get hit harder: kids aged eight and above vomit nearly 20 percent of the time, roughly four times the rate of younger children.4PubMed Central. Predictors of emesis in children undergoing procedural sedation with intramuscular ketamine in a paediatric emergency department Cumulative dose also plays a role. One study found the vomiting rate climbed from about 7 percent to 11 percent when the total dose exceeded a certain threshold, though the initial dose did not seem to matter on its own.5Pediatric Emergency Care. Ketamine-Associated Vomiting: Is it Dose-Related?
Vomiting usually occurs during the recovery phase, not while the procedure is happening. It is uncomfortable and can be upsetting for both the child and the parent watching, but it is self-limiting. Medical teams typically position the child on their side during recovery and keep suction equipment nearby as a precaution, because vomiting during sedation carries a small theoretical risk of aspiration. In practice, clinically significant aspiration from ketamine sedation is vanishingly rare.
Heart Rate and Blood Pressure Changes
Ketamine is a sympathomimetic, meaning it stimulates the body’s “fight or flight” system. After a dose, you can expect a noticeable bump in heart rate, systolic blood pressure, and diastolic blood pressure.6Annals of Emergency Medicine. Effect of Ketamine on Intracranial Pressure in Pediatric Patients Assessed by Transcranial Doppler Ultrasound: A Pilot Study For the vast majority of children, this temporary cardiovascular stimulation is harmless and resolves as the drug wears off. It can actually be an advantage when sedating a child who is in pain or mild shock, because the blood pressure support helps maintain circulation.
The cardiovascular effects become a concern mainly in children with certain pre-existing heart conditions. A study comparing ketamine to sevoflurane (an inhaled anesthetic) in children with ventricular septal defects found that the ketamine group showed higher heart rates and arterial pressures along with increased resistance in the blood vessels.7PubMed Central. Comparison of hemodynamic effects of sevoflurane and ketamine as basal anesthesia by a new and direct monitoring during induction in children with ventricular septal defect For a child with a healthy heart, none of this matters. But if your child has a known cardiac condition, the medical team should be aware of it before ketamine is chosen.
Emergence Reactions
This is the side effect that tends to worry parents the most, partly because it can look alarming if you are not expecting it. As ketamine wears off, children pass through a transition period where they may cry, appear confused, seem agitated, or describe unusual visual experiences. A study that carefully tracked the recovery phase in over 700 children found that about 12 percent cried on awakening, roughly 39 percent experienced pleasant altered perceptions (sometimes described as dreaming or floating), and about 2 percent had what the researchers classified as emergence delirium, a brief period of more intense agitation and disorientation.8PubMed. What is the nature of the emergence phenomenon when using intravenous or intramuscular ketamine for paediatric procedural sedation?
The critical reassurance here is that none of these children required active treatment for their emergence reaction, and all but one settled within 20 minutes.8PubMed. What is the nature of the emergence phenomenon when using intravenous or intramuscular ketamine for paediatric procedural sedation? Children generally do not retain distressing memories of the experience afterward. The recovery room should be kept as quiet and calm as possible, and parents are often encouraged to be present and speak softly to their child. Bright lights, loud noises, and excessive stimulation during the wake-up period may make the transition rougher.
For years, some clinicians routinely gave a benzodiazepine such as midazolam alongside ketamine in the hope of preventing these reactions. The evidence on whether this actually helps is surprisingly mixed. One randomized controlled trial found that adding midazolam made no difference in emergence phenomena.9PubMed. Does midazolam alter the clinical effects of intravenous ketamine sedation in children? A double-blind, randomized, controlled, emergency department trial An earlier study did report that midazolam reduced dysphoric reactions and muscular hypertonicity.10Journal of Oral and Maxillofacial Surgery. Intramuscular ketamine, midazolam, and glycopyrrolate for pediatric sedation in the emergency department A broader review noted that reported rates of recovery agitation without midazolam ranged from 0 to 20 percent, while rates with midazolam ranged from 3 to 33 percent, making it hard to argue the benzodiazepine consistently helps.11Annals of Emergency Medicine. Midazolam with ketamine: who benefits? Many emergency departments have moved away from routine co-administration, reserving midazolam for cases where there is a specific reason to use it.
Respiratory Side Effects
Respiratory complications are the side effects that matter most in terms of actual danger, and they are also the reason your child will be closely monitored throughout the procedure. In a study of over 4,200 children, about 2.4 percent had some kind of respiratory adverse event, and roughly 0.9 percent experienced a severe event.12PubMed. Serious adverse events during procedural sedation with ketamine Laryngospasm, a sudden tightening of the vocal cords that briefly blocks the airway, accounted for a significant share of the serious events. It sounds frightening, and it is an emergency, but trained clinicians can typically resolve it in seconds with simple maneuvers like repositioning the airway or applying positive pressure ventilation.
What makes these respiratory events manageable rather than catastrophic is preparation. The American Academy of Pediatrics recommends that any team sedating a child be equipped and trained to rescue the airway if needed, including the ability to suction secretions, provide bag-valve-mask ventilation, and insert an airway device.13Pediatrics. Guidelines for Monitoring and Management of Pediatric Patients Before, During, and After Sedation for Diagnostic and Therapeutic Procedures The systematic review covering nearly 59,000 children found that the pooled rate of truly sentinel outcomes, meaning events like intubation, chest compressions, or aspiration, was about 1 in 24,000 encounters.1PubMed. Systematic Review of Pediatric Ketamine in Emergency Department Procedural Sedation: Frequency and Predictors of Adverse Events To put that in perspective, the risk is far lower than the risk of a serious complication from the underlying injury itself.
Does the Route of Administration Matter
Ketamine can be given intravenously (through an IV) or as an intramuscular injection (a shot into the muscle). The choice affects the side effect profile in ways parents might want to know about. Intramuscular ketamine is associated with more vomiting and a longer recovery time, with one comparison noting that recovery took about 42 minutes longer with the intramuscular route.14Reviews in Clinical Medicine. Comparison between intravenous and intramuscular administration of ketamine in children sedation referred to emergency department The same study noted less observed distress and pain during the procedure itself with the intramuscular route, likely because the IV group required a needle stick to place the line before sedation could begin.
Laryngospasm, the most concerning respiratory complication, was significantly more common with the intramuscular route in one large study. Children who received intramuscular ketamine had roughly five times the odds of laryngospasm compared with the intravenous group.12PubMed. Serious adverse events during procedural sedation with ketamine The reason likely involves dosing precision: intramuscular ketamine is absorbed less predictably, and the initial dose is typically higher to compensate. Intravenous ketamine allows the clinician to give smaller, titrated amounts and watch the child’s response in real time.
That said, the intramuscular route has its place. Some children arrive in the emergency department so distressed that placing an IV is impractical without sedation first, creating a chicken-and-egg problem. A quick intramuscular shot can calm the situation enough to start the procedure or place the IV afterward. The slightly higher risk of certain side effects with the intramuscular route is a known tradeoff that the medical team weighs against the practical reality of the situation.
The Neurodevelopmental Question
This is the area where the science generates the most anxiety among parents, partly because of headlines about brain damage in lab animals. It deserves a careful look rather than a dismissive wave. Animal research has demonstrated that ketamine can cause neuronal cell death in the developing brains of rats and primates, particularly with repeated or prolonged exposures at high doses.15PubMed Central. Potential neurotoxicity of ketamine in the developing rat brain In rats, this cell death was dose-related and time-dependent, meaning higher doses and longer exposures produced more damage.15PubMed Central. Potential neurotoxicity of ketamine in the developing rat brain Another animal study found that neonatal ketamine exposure interfered with how newly formed brain cells integrated into hippocampal circuits, affecting spatial memory performance later in life.16PubMed Central. Ketamine affects the integration of developmentally generated granule neurons in the adult stage
Translating these animal findings to human children is where things get complicated. The doses used in rat studies are often many times higher than what a child receives for a single procedural sedation, and the exposure periods are far longer. A rat pup receiving six injections over hours represents a very different scenario from a child receiving one dose for a 10-minute bone-setting. Still, one small prospective human study in infants who received ketamine anesthesia for laser surgery found that three or more separate ketamine exposures were associated with lower developmental scores on standardized testing, while one or two exposures were not.17PubMed. Repeated exposure to anesthetic ketamine can negatively impact neurodevelopment in infants: a prospective preliminary clinical study The researchers interpreted this as suggesting a threshold effect with repeated exposure.
For a single sedation event in the emergency department, the available evidence does not support a meaningful neurodevelopmental risk. The concern is more relevant for children who might need ketamine anesthesia repeatedly, such as those requiring multiple surgeries during infancy. In those situations, clinicians increasingly weigh the cumulative exposure and may consider alternative anesthetic strategies. A review of the topic framed ketamine as having dual properties in the developing brain: it can be neurotoxic under certain conditions but may also be neuroprotective under others, depending on the dose, duration, and context.18Journal of Neurosurgical Anesthesiology. Dual Effects of Ketamine: Neurotoxicity Versus Neuroprotection in Anesthesia for the Developing Brain
What Monitoring Looks Like During Your Child’s Sedation
If your child is about to receive ketamine, you should expect the team to be checking several things continuously. Standard monitoring includes blood pressure, heart rate, respiratory rate, oxygen saturation (the small clip on the finger), and often end-tidal carbon dioxide, which tracks breathing more sensitively than the oxygen monitor alone.19PubMed Central. Guideline on the Use of Intravenous Ketamine for Procedural Sedation in the Children’s Emergency Department: A Quality Improvement Project These measurements are taken before ketamine is given to establish a baseline, and then continuously or at close intervals throughout the procedure and recovery.
You should also see airway rescue equipment in the room or immediately available. This includes suction for clearing the mouth and throat, a bag-valve mask for assisted breathing, and oral or nasal airways that can help keep the airway open if the child’s muscles relax too much.13Pediatrics. Guidelines for Monitoring and Management of Pediatric Patients Before, During, and After Sedation for Diagnostic and Therapeutic Procedures The presence of this equipment does not mean something is expected to go wrong. It means the team is prepared. If you do not see monitoring equipment or the team seems to be sedating your child without a formal pre-sedation assessment, those are red flags worth asking about.
How Parental Anxiety Fits In
Your own stress level may play a role in how your child experiences the sedation process. Research on emergence delirium in children has found that a child’s preoperative anxiety level correlates with their risk of agitation during recovery, and children tend to absorb anxiety from the adults around them. Parents who are described in the literature as “high monitors,” meaning those who are highly sensitive to perceived threats and tend to amplify them, appear to transmit more anxiety to their children.20British Journal of Anaesthesia. Emergence delirium in children: many questions in the 21st century This does not mean you should blame yourself if your child has a difficult emergence. It means that anything you can do to stay calm, ask your questions beforehand, and project reassurance during the recovery phase may genuinely help.
Practical tips from clinicians include talking to your child in a low, soothing voice during recovery, minimizing bright lights and noise in the area, and avoiding excessive touch or stimulation until the child is clearly awake and oriented. Many emergency departments will allow you to sit beside your child during the wake-up period. Ask the nurse whether this is an option.
Genetic Variation and Side Effect Risk
Not every child processes ketamine at the same speed, and genetics are part of the reason. The enzyme primarily responsible for breaking down ketamine in the liver, called CYP2B6, comes in different genetic variants. People who carry two copies of a specific variant (the *6 allele) clear ketamine from their bloodstream at roughly a third the rate of people with the most common genotype. Those with one copy of the variant fall somewhere in between.21PubMed Central. CYP2B6*6 allele and age substantially reduce steady-state ketamine clearance in chronic pain patients: impact on adverse effects The slower clearance translates to higher drug levels in the blood, and patients with lower clearance experienced more side effects in that study.
This research was conducted in chronic pain patients receiving repeated ketamine doses, not in children undergoing a single procedural sedation. Genetic testing for CYP2B6 is not part of routine care before an emergency ketamine sedation, and it would be impractical to add it. But the finding helps explain why two children of similar age and weight can respond quite differently to the same ketamine dose: one wakes up smoothly in 20 minutes, and another is groggy and nauseous for over an hour. If your child has had a previous difficult experience with ketamine, letting the medical team know may lead them to adjust the dose or choose an alternative.
Rare Complications With Prolonged Use
Most of what parents encounter is a single ketamine dose in an emergency setting, and the side effects discussed above cover that scenario well. But a small number of children receive ketamine infusions lasting days or weeks, typically in intensive care settings for refractory seizures or severe pain. In these situations, a different set of complications can surface. A case report described hemorrhagic cystitis (bleeding and inflammation of the bladder) in a child who received continuous high-dose esketamine infusion for 16 days to treat status epilepticus.22Frontiers in Pediatrics. Hemorrhagic cystitis induced by intravenous esketamine in the treatment of new-onset refractory status epilepticus in children: a case report Bladder toxicity is well known in adults who use ketamine recreationally over long periods, but it is rarely reported in medical settings because medical use is almost always short-term. ICU teams monitoring prolonged ketamine infusions watch for urinary symptoms and adjust the treatment plan if they appear.
When a child’s condition requires sedation or analgesia that might stretch beyond a single dose, clinicians sometimes turn to combination approaches. A mix of ketamine and propofol, sometimes called “ketofol,” has been studied as a way to use lower doses of each drug, potentially reducing the side effects specific to either one.23PubMed Central. Ketamine, propofol, and ketofol use for pediatric sedation Other alternatives include intranasal dexmedetomidine and inhaled nitrous oxide, each with their own tradeoffs. The choice depends on the type of procedure, the child’s medical history, and the resources available at the facility. If you have concerns about ketamine specifically, asking whether an alternative is appropriate for your child’s situation is a reasonable conversation to have with the treating physician.
The Intracranial Pressure Myth
For decades, medical textbooks warned that ketamine raised pressure inside the skull, making it dangerous for children with head injuries or neurological conditions. This belief led many clinicians to avoid ketamine in exactly the patients who might benefit most from its blood-pressure-supporting properties. More recent evidence has challenged this substantially. A study of 143 children with neurologic conditions at risk for elevated intracranial pressure found no significant difference in neurologic events between those who received ketamine as their induction agent and those who did not. Among the subset where intracranial pressure was directly measured before and after, three of the eleven children who received ketamine actually saw their elevated pressure improve.24SpringerLink. Co-administration of Ketamine in Pediatric Patients with Neurologic Conditions at Risk for Intracranial Hypertension The older warnings were based on case reports from the 1970s in patients who were breathing spontaneously without proper ventilation, which can itself raise intracranial pressure regardless of what drug is given. The clinical relevance of this for parents: if a doctor declines to use ketamine for your child solely because of a head injury, the evidence no longer supports that blanket restriction, though the final call always depends on the full clinical picture.