The call comes over your radio: “Rescue 12, respond with Engine 8 to male injured in a motorcycle crash 12 miles west of Route 7. More details to follow.”
You and your partner get into the ambulance and head toward the area. As you’re driving, your partner recalls that there’s a motocross track somewhere near Route 7. She also recalls that there are no paved roads around the area.
“Rescue 12, the patient is located approximately 14 miles east of Route 7. The patient is a male injured in a motocross race and is reported to have severe lower extremity injuries. He’s conscious and breathing.” Dispatch provides the name of a cross street where an off-duty police officer will meet you.
“Understood,” your partner responds. “Will you please place a helicopter on standby?”
You drive for about 20 minutes until you reach the off-duty officer at the rendezvous point. You follow his car and drive another 27 minutes until you reach the patient.
The 31-year-old male is found on the ground next to his motorcycle. He appears to be in pain and is wearing full protective gear that includes a helmet, jacket and pants. Both of his lower extremities are obviously deformed. A bystander reports that the patient had landed a 20–30 foot jump on his motorcycle.
You introduce yourself and begin an examination. He’s awake and his airway is intact. You remove the jacket and note equal chest rise and fall, breath sounds bilaterally present and no chest deformity.
The patient is fully exposed and you note that the skin is warm and dry and there’s no external hemorrhage. Your partner places a large bore peripheral IV and is in the process of starting another. She reports that the heart rate is 120, blood pressure is 134/76, and oxygen saturation (SpO2) is 99% on room air.
On secondary survey, you note trauma to the left lower extremity, which is shortened, and the thigh, which has a deformity. There’s no dorsalis pedis (DP) or posterior tibial (PT) pulse and the foot is cool and mottled. The right lower extremity is medially rotated at the hip. Additionally, there’s an open fracture of the leg with bone exposed. The DP and PT pulses are strong and this extremity is warm and pink.
You and your partner immediately recognize there’s most likely a left femur fracture that needs to be reduced emergently to restore perfusion to the extremity. Given the extent of injuries and the current location, your partner calls to launch the helicopter as you get the traction splint from your bag.
You attach the splint and attempt traction but the patient is in too much pain and yells for you to stop. You administer 100 mcg of fentanyl IV and try again, but the patient won’t tolerate the reduction attempt. This occurs four more times; you’ve given a total of 400 mcg of fentanyl. You call medical command but the physician recommends more fentanyl as needed and that the fracture needs to be reduced emergently.
You administer another 200 mcg of fentanyl and attempt reduction again, but the patient still can’t tolerate the pain. Twelve minutes after the request to launch the helicopter, it lands and the crew joins you at the patient’s side.
The flight crew takes a report and examines the patient. The vital signs are still normal with the exception of an elevated heart rate, which is thought to be due to pain.
The flight nurse gets a vial of ketamine from his medication box. He draws up 1 mg/kg (100 mg) and gives it over 60 seconds. Immediately, the patient relaxes. The heart rate elevates slightly, the respiratory rate remains normal, the EtCO2 is normal and the SpO2 is normal. Traction is placed and the femur fracture is reduced within seconds.
The left leg is reassessed and the DP and PT pulses are now strong. The skin is pink and warm and the mottled appearance has resolved. The patient is flown to a trauma center for further evaluation and management. He’s found to have multiple lower extremity fractures and requires operative intervention. He’s hospitalized for several days and discharged home to receive physical and occupational therapy.
Ketamine works as an N-methyl-D-aspartate receptor antagonist. Clinically, it functions as a dissociative anesthetic. Depending on the dose, however, it can be used as an adjunct to psychotherapy, to treat depression and posttraumatic stress disorder, acute and chronic pain, as a primary agent for procedural sedation, and as an induction agent for rapid sequence intubation (RSI).1 The use of ketamine is becoming ubiquitous in EDs, and its safety and efficacy is well documented in the literature.2–6,9,10
Prehospital use of ketamine isn’t uncommon. This is true especially in countries with physician presence in the field.7,8
In the prehospital setting, ketamine has three uses: 1) procedural sedation, 2) control of agitation, and 3) management of acute pain. It’s important to understand that the dose and route for each indication will vary.
For procedural sedation, ketamine is administered in an IV dose of 1 mg/kg over 60 seconds. If sedation is required for a prolonged period of time, half doses can be repeated as needed.9,10 Transient respiratory depression and apnea have been reported when ketamine is pushed rapidly, so it’s recommended to administer the dose over 60 seconds.
Adverse effects of ketamine are rare but include transient respiratory depression or apnea, transient laryngospasm and recovery agitation.2 These adverse effects are managed by tactile stimulation provoking a response from the patient, bag-valve mask ventilation or endotracheal intubation as needed and benzodiazepines, respectively.
The sedative effects of ketamine will last 10–15 minutes. Ketamine inhibits the reuptake of catecholamines, which may result in increased blood pressure, heart rate and myocardial oxygen demand. This may be advantageous in certain situations, but one must use caution in patients with known coronary artery disease.2
It’s vital for EMS providers to have a strong foundation of knowledge regarding life- and limb-saving procedures and medications. Ketamine is a wonderful addition to the prehospital clinician’s armamentarium, and will continue to grow in popularity as a medication for procedural sedation, acute pain management and controlling agitation in the field. As ketamine begins to find its way onto more ground units in the U.S., we must have open discussion on its use, and understand its indications and contraindications.
1. Radvansky B, Puri S, Sifonios A, et al. Ketamine—A narrative review of its uses in medicine. Am J Ther. 2016;23(6):e1414–e1426.
2. Green SM, Krauss B. Clinical practice guideline for emergency department ketamine dissociative sedation in children. Ann Emerg Med. 2004;44(5):460–471.
3. Green SM, Roback MG, Krauss B, et al. Predictors of emesis and recovery agitation with emergency department ketamine sedation: an individual-patient data meta-analysis of 8,282 children. Ann Emerg Med. 2009;54(2):171–180.
4. American College of Emergency Physicians. Clinical policy: Procedural sedation and analgesia in the emergency department. Ann Emerg Med. 2005;45(2):177–196.
5. Green SM, Rothrock SG, Lynch EL, et al. Intramuscular ketamine for pediatric sedation in the emergency department: Safety profile with 1,022 cases. Ann Emerg Med. 1998;31(6):688–697.
6. Newton A, Fitton L. Intravenous ketamine for adult procedural sedation in the emergency department: A prospective cohort study. Emerg Med J. 2008;25(8):498–501.
7. Bredmose P, Lockey D, Grier G, et al. Prehospital use of ketamine for analgesia and procedural sedation. Emerg Med J. 2009;26(1):62–64
8. Hayward M, Regan L, Glasheen J, et al. Review of agents employed by an Australian aeromedical prehospital and retrieval service. Emerg Med Australas. 2016;28(3):329–334.
9. Strayer RJ, Nelson LS. Adverse events associated with ketamine for procedural sedation in adults. Am J Emerg Med. 2008;26(9):985–1028.
10. Miner JR, Gray RO, Bahr J, et al. Randomized clinical trial of propofol versus ketamine for procedural sedation in the emergency department. Acad Emerg Med. 2010;17(6):604–611.