Is monitored anesthesia care (MAC) for lower limb orthopaedic surgery in cervical cord injured patients adequate?
Abstract
Spinal cord injuries (SCI), involving previously healthy young adults, result from trauma; 37% occur after road accidents, 42% follow falls, 11% are associated with sports and recreational activities, and 3% after assault.1 Respiratory complications are the leading cause of death in the short or long term.1,2 SCI can cause numerous pulmonary complications and special attention to respiratory support can reduce morbidity, length of stay, and mortality.2,3 Anesthesiologists have to encounter the consequences of SCI preoperatively to postoperative period. Management of anesthesia in cervical spinal cord injured patients varies from regional anesthesia, general anesthesia to monitored anesthesia care.
A 25 year old young male patient scheduled for intramedullary nailing for right mid shaft fracture femur after detailed pre anesthetic check-up. Patient had diffuse cord edema from C3-C5 with paraplegia and bowel, bladder involvement after spinal cord trauma 6 weeks back. He was on conservative treatment for cord edema and pain. His sensory level was T11 and crutch field cervical traction was in situ. Patient was hemodynamically stable but had abdomino-thoracic respiration with poor cough reflex although breath holding time was 27 sec. Preoperative investigations were within normal limits. Premedication done with tab. ranitidine 150 mg and alprazolam 0.25 mg at night. The surgery was scheduled under monitored anesthesia care. Injection fentanyl bolus 1 µg/kg IV, Inj. glycopyrrolate 4-8 µg/kg IV was administered and propofol infusion @100-150 µg/kg/min IV was started for first 3-5 min. Propofol infusion @ 25-75 µg/kg/min maintained BIS above 75 and stable hemodynamics throughout the procedure. The procedure lasted for 2 hrs.
The patients with cervical cord injury present with multitude of systemic problems out of which autonomic dysreflexia is of prime concern. Our patient had to undergo surgery on insensate part below the level of injury. Studies have shown that even such surgeries may require anesthesia.3 Fentanyl and propofol were successfully used to prevent the stimuli, and glycopyrrolate was used to prevent reflex bradycardia. Regional anesthesia is technically difficult in such type of patients due to cervical cord immobilization and crutch-field cervical traction in situ. General anesthesia related morbidities4 can be prevented by managing such patients under MAC sedation.
The options in this situation are to give sedation, local anesthesia or no anesthesia. In compliant patients with infrequent mild spasm and no autonomic dysreflexia, ‘no anesthesia’ or only sedation may be an option. Infiltration anesthesia or peripheral nerve blocks may be helpful where some sensation persists. Pain can be alleviated by short acting opiates or the use of N2O inhalation without having to resort to general anesthesia. The presence of an anesthesiologist is mandatory and monitoring should be instituted and venous access secured in case there is an unexpected need for anesthetic intervention. There is no evidence that spinal anesthesia adversely affects or alters neurological deficit in spinal cord injured patients. It can reliably prevent autonomic dysreflexia and spasm. Epidural anesthesia may be used, but is not as reliable as spinal anesthesia in preventing autonomic dysreflexia.5 Supportive treatment with appropriate sedation, is key to the management. Suxamethonium is best avoided from 72 h to 9 months following injury. For short procedures on surface lesions or limbs, spontaneous ventilation is satisfactory, although it should be noted that patients with intercostal paresis will appear to have an obstructed breathing pattern.
Success of MAC depends upon communication with the patient and surgeon. Always be prepared for emergency management of airway.
REFERENCES
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- Winslow C, Rozovsky J. Effect of spinal cord injury on the respiratory system. Am J Phys Med Rehabil 2003;82:803-14. [PubMed]
- Ball PA. Critical care of spinal cord injury. Spine 2001;26:S27-30. [PubMed]
- Fox R, WatlingG. Anaesthesia for patients with chronic spinal cord injury. Current Anaesthesia & Critical Care 2001;12:154-158. [Abstract]
- Kanonidou Z. Anaesthesia for chronic spinal cord lesions. Hippokratia 2006;10:28-31.
