Green et al
Purpose
● To define guidelines for patient selection, administration, monitoring, and recovery for ED dissociative sedation.
Definition of Dissociative Sedation
● A trancelike cataleptic state induced by the dissociative agent ketamine, characterized by profound analgesia and amnesia, with retention of protective airway
reflexes, spontaneous respirations, and cardiopulmonary stability.
Characteristics of the Ketamine “Dissociative State”
● Dissociation: After administration of ketamine, the patient passes into a fugue state or trance. The eyes may remain open, but the patient does not respond.
● Catalepsy: Normal or slightly enhanced muscle tone is maintained. On occasion, the patient may move or be moved into a position that is self-maintaining.
Occasional muscular clonus may be observed.
● Analgesia: Analgesia is typically substantial or complete.
● Amnesia: Total amnesia is typical.
● Maintenance of airway reflexes: Upper airway reflexes remain intact and may be slightly exaggerated. Intubation is unnecessary, but occasional repositioning
of the head may be necessary for optimal airway patency. Suctioning of hypersalivation may occasionally be necessary.
● Cardiovascular stability: Blood pressure and pulse rate are not decreased and typically are mildly increased.
● Nystagmus: Nystagmus is typical.
Indications
● Short, painful procedures, especially those requiring immobilization (eg, facial laceration, burn debridement, fracture reduction, abscess incision and drainage,
central line placement, tube thoracostomy).
● Examinations judged likely to produce excessive emotional disturbance (eg, pediatric sexual assault examination).
Contraindications: Absolute (Risks Essentially Always Outweigh Benefits)
● Age younger than 3 months (higher risk of airway complications)
● Known or suspected schizophrenia, even if currently stable or controlled with medications (can exacerbate condition)
Contraindications: Relative (Risks May Outweigh Benefits)
● Major procedures stimulating the posterior pharynx (eg, endoscopy) increase the risk of laryngospasm, whereas typical minor ED oropharyngeal procedures
do not.
● History of airway instability, tracheal surgery, or tracheal stenosis (presumed higher risk of airway complications)
● Active pulmonary infection or disease, including upper respiratory infection or asthma (higher risk of laryngospasm)
● Known or suspected cardiovascular disease, including angina, heart failure, or hypertension (exacerbation caused by sympathomimetic properties of ketamine).
Avoid ketamine in patients who are already hypertensive and in older adults with risk factors for coronary artery disease.
● Central nervous system masses, abnormalities, or hydrocephalus (increased intracranial pressure with ketamine)
● Glaucoma or acute globe injury (increased intraocular pressure with ketamine)
● Porphyria, thyroid disorder, or thyroid medication (enhanced sympathomimetic effect)
Personnel
● Dissociative sedation is a 2-person procedure, one (eg, nurse) to monitor the patient and one (eg, physician) to perform the procedure. Both must be
knowledgeable about the unique characteristics of ketamine.
Presedation
● Perform a standard presedation assessment.
● Educate accompanying family about the unique characteristics of the dissociative state if they will be present during the procedure or recovery.
● Frame the dissociative encounter as a positive experience. Consider encouraging adults and older children to “plan” specific, pleasant dream topics in advance
of sedation (believed to decrease unpleasant recovery reactions). Emphasize, especially to school-aged children and teenagers, that ketamine delivers sufficient
analgesia, so there will be no pain.
Ketamine Administration: General
● Ketamine is not administered until the physician is ready to begin the procedure because onset of dissociation typically occurs rapidly.
● Ketamine is initially administered as a single IV loading dose or IMinjection. There is no apparent benefit from attempts to titrate to effect.
● In settings in which IV access can be obtained with minimal upset, the IV route is preferable because recovery is faster and there is less emesis.
● The IM route is especially useful when IV access cannot be consistently obtained with minimal upset, and for patients who are uncooperative or combative
(eg, the mentally disabled).
● IV access is unnecessary for children receiving IM ketamine. Because unpleasant recovery reactions are more common in adults, IV access is desirable in these
patients to permit rapid treatment of these reactions, should they occur.
Ketamine Administration: IV Route
● Administer a loading dose of 1.5 to 2.0 mg/kg IV in children or 1.0 mg/kg IV in adults, with this dose administered during 30 to 60 seconds.More rapid
administration produces high central nervous system levels and has been associated with respiratory depression or apnea.
● Additional incremental doses of ketamine may be administered (0.5 to 1.0 mg/kg) if initial sedation is inadequate or if repeated doses are necessary to
accomplish a longer procedure.
Purpose
● To define guidelines for patient selection, administration, monitoring, and recovery for ED dissociative sedation.
Definition of Dissociative Sedation
● A trancelike cataleptic state induced by the dissociative agent ketamine, characterized by profound analgesia and amnesia, with retention of protective airway
reflexes, spontaneous respirations, and cardiopulmonary stability.
Characteristics of the Ketamine “Dissociative State”
● Dissociation: After administration of ketamine, the patient passes into a fugue state or trance. The eyes may remain open, but the patient does not respond.
● Catalepsy: Normal or slightly enhanced muscle tone is maintained. On occasion, the patient may move or be moved into a position that is self-maintaining.
Occasional muscular clonus may be observed.
● Analgesia: Analgesia is typically substantial or complete.
● Amnesia: Total amnesia is typical.
● Maintenance of airway reflexes: Upper airway reflexes remain intact and may be slightly exaggerated. Intubation is unnecessary, but occasional repositioning
of the head may be necessary for optimal airway patency. Suctioning of hypersalivation may occasionally be necessary.
● Cardiovascular stability: Blood pressure and pulse rate are not decreased and typically are mildly increased.
● Nystagmus: Nystagmus is typical.
Indications
● Short, painful procedures, especially those requiring immobilization (eg, facial laceration, burn debridement, fracture reduction, abscess incision and drainage,
central line placement, tube thoracostomy).
● Examinations judged likely to produce excessive emotional disturbance (eg, pediatric sexual assault examination).
Contraindications: Absolute (Risks Essentially Always Outweigh Benefits)
● Age younger than 3 months (higher risk of airway complications)
● Known or suspected schizophrenia, even if currently stable or controlled with medications (can exacerbate condition)
Contraindications: Relative (Risks May Outweigh Benefits)
● Major procedures stimulating the posterior pharynx (eg, endoscopy) increase the risk of laryngospasm, whereas typical minor ED oropharyngeal procedures
do not.
● History of airway instability, tracheal surgery, or tracheal stenosis (presumed higher risk of airway complications)
● Active pulmonary infection or disease, including upper respiratory infection or asthma (higher risk of laryngospasm)
● Known or suspected cardiovascular disease, including angina, heart failure, or hypertension (exacerbation caused by sympathomimetic properties of ketamine).
Avoid ketamine in patients who are already hypertensive and in older adults with risk factors for coronary artery disease.
● Central nervous system masses, abnormalities, or hydrocephalus (increased intracranial pressure with ketamine)
● Glaucoma or acute globe injury (increased intraocular pressure with ketamine)
● Porphyria, thyroid disorder, or thyroid medication (enhanced sympathomimetic effect)
Personnel
● Dissociative sedation is a 2-person procedure, one (eg, nurse) to monitor the patient and one (eg, physician) to perform the procedure. Both must be
knowledgeable about the unique characteristics of ketamine.
Presedation
● Perform a standard presedation assessment.
● Educate accompanying family about the unique characteristics of the dissociative state if they will be present during the procedure or recovery.
● Frame the dissociative encounter as a positive experience. Consider encouraging adults and older children to “plan” specific, pleasant dream topics in advance
of sedation (believed to decrease unpleasant recovery reactions). Emphasize, especially to school-aged children and teenagers, that ketamine delivers sufficient
analgesia, so there will be no pain.
Ketamine Administration: General
● Ketamine is not administered until the physician is ready to begin the procedure because onset of dissociation typically occurs rapidly.
● Ketamine is initially administered as a single IV loading dose or IMinjection. There is no apparent benefit from attempts to titrate to effect.
● In settings in which IV access can be obtained with minimal upset, the IV route is preferable because recovery is faster and there is less emesis.
● The IM route is especially useful when IV access cannot be consistently obtained with minimal upset, and for patients who are uncooperative or combative
(eg, the mentally disabled).
● IV access is unnecessary for children receiving IM ketamine. Because unpleasant recovery reactions are more common in adults, IV access is desirable in these
patients to permit rapid treatment of these reactions, should they occur.
Ketamine Administration: IV Route
● Administer a loading dose of 1.5 to 2.0 mg/kg IV in children or 1.0 mg/kg IV in adults, with this dose administered during 30 to 60 seconds.More rapid
administration produces high central nervous system levels and has been associated with respiratory depression or apnea.
● Additional incremental doses of ketamine may be administered (0.5 to 1.0 mg/kg) if initial sedation is inadequate or if repeated doses are necessary to
accomplish a longer procedure.
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