Anesthesia Management of Patients with Spinal Cord Injury
Spinal cord injury (SCI) is a serious condition that can involve severe neurological dysfunction and organ complications [1]. To maximize the chance of survival and sensorimotor recovery, surgery should occur within 24 hours of the initial injury [2]. Accordingly, anesthesia providers must work quickly, which limits the time they can spend analyzing integral spinal cord injury-related considerations. These factors include autoregulation, hemodynamic stability, and airway management, among other factors [1].
The pre-operative evaluation is essential for identifying and addressing several of the difficulties commonly exhibited by SCI patients. The first priority for physicians is airway management [3]. Intubation can be difficult to achieve without promoting further injury [3]. Consequently, physicians should take extreme care to avoid causing too much motion in the spine, particularly at the atlantooccipital junction [3]. Spinal immobilization is critical for preventing further injury [3]. Physicians can achieve immobilization by strapping a taut cervical collar with supportive blocks, as well as a firm backboard, onto a patient [3]. If unexpected airway complications occur, weaning strategies may be inadequate and later reintubation or tracheostomy may be necessary [1].
After airway establishment, physicians should obtain a detailed medical history when possible and conduct an evaluation [2]. The focus should be on acquiring information concerning the state of the patient’s airway, cardiorespiratory, and neurological systems [2]. To determine the location of the injury, thin-section computed tomographic assessments can be highly effective [1]. Tomographic assessments also contribute to the anesthesia provider’s understanding of the patient’s airway by demonstrating how the patient’s injury may interact with the airway system [1]. Once the care team has received as much information as possible without jeopardizing the patient’s survival, surgery can occur.
There are some general guidelines that anesthesiologists can follow to create the ideal regimen for their patients. Patients who are unstable or exhibit hypovolemia should not be induced until they are adequately stabilized [3]. Once a patient has been cleared for induction, the main priority is limiting the length of time a patient exhibits systemic hypotension [1, 4]. Hypotension can occur after induction with propofol, benzodiazepines, or barbiturates [5]. Despite its hypotensive properties, a propofol-based total intravenous anesthetic (TIVA) has its advantages, such as rapid awakening, facilitated neurological assessments, and diminished interference with neuromonitoring [2]. Another concern is hyperkalemia [2]. To avoid it, patients should not receive succinylcholine for three days to 6-9 months following SCI [2]. Multi-drug regimens can avoid harmful complications [5]. For instance, propofol administered with ketamine can balance the latter’s ability to increase axial pressure [5].
Closely monitoring a patient’s spinal cord can help inform anesthesiologists which anesthetic agents are most appropriate [1, 5]. Monitoring can be either invasive or noninvasive; both have been beneficial in different cases [1]. However, invasive monitoring may be more effective in tracking intravascular volume during fluid therapy [1]. Central venous pressure (CVP) catheters should be used to administer vasoactive drugs and monitor CVP, while arterial catheters are crucial for tracking arterial blood gas and blood pressure [3]. Being attentive to evoked potentials (EPs) can help physicians monitor whether a patient has neurological deficits, but the uncertain interaction between EPs and anesthetics hinders the accuracy of this method [3].
Unfortunately, there is no singular anesthetic technique that repeatedly produces the best results across patients [1]. Despite this lack of consensus, the aforementioned recommendations are essential to keep in mind when developing an anesthesia regimen for spinal cord injury patients.
References
[1] O. Akyol et al., “Anesthesia for Traumatic Spine Injury,” in Textbook of Neuroanesthesia and Neurocritical Care, vol. II. H. Prabhakar and Z. Ali, 1st ed., Singapore, Singapore: Springer, 2019, ch. 16, sec. 1-3, pp. 225-231.
[2] J. Ko and T. Chan, “Anaesthesia for major spinal surgery,” Anaesthesia & Intensive Care Medicine, vol. 22, no. 1, p. 6-12, January 2021. [Online]. Available: https://doi.org/10.1016/j.mpaic.2020.11.008.
[3] A. Omi and K. Satomi, “Anesthetic Management of Spinal Cord Injury (Unstable Cervical Spine),” in Neuroanesthesia and Cerebrospinal Protection. H. Uchino, K. Ushijima, and Y. Ikeda, 1st ed., Tokyo, Japan, Springer, 2015, ch. 35, sec. 1-3, pp. 405-414.
[4] T. Mingir et al., “Approach to Patients with Neurotrauma and Thoracic Trauma and Anesthesia Management with Current Guidelines -1,” European Archive of Medical Research, vol. 35, no. 2, p. 102-110, November 2019. [Online]. Available: https://doi.org/10.4274/eamr.galenos.2019.76476.
[5] F. P. Bao, H. G. Zhang, and S. M. Zhu, “Anesthetic considerations for patients with acute cervical spinal cord injury,” Neural Regeneration Research, vol. 12, no. 3, p. 499-504, January 2017. [Online]. Available: https://doi.org/10.4103/1673-5374.202916.