The lumbar spine includes five vertebrae (L1 to L5) that comprise the lower part of the spine and connect to the pelvis.1 The lumbar vertebrae are larger and thicker than the other spinal vertebrae and support most of the body’s weight.2 As such, lumbar strain can occur from pushing or pulling heavy weights or from sports that require twisting of the lower back.3 Conservative treatments for lumbar pain include rest, over-the-counter pain relievers and physical therapy. For patients who do not respond to such treatments, surgery may be required. Different types of back surgery include a diskectomy, the removal of the herniated portion of a disk, and spinal fusion, which connects bones in the spine and relieves pain by adding stability.4 Surgery on the lumbar spine is performed with either general or local anesthesia.
Spinal anesthesia (SA) is a type of local anesthetic that is injected into the cerebrospinal fluid to numb the nerves and block sensation below the site of injection.5 SA has been shown to be as effective as general anesthesia for this type of surgery and is typically associated with better patient outcomes, due to the decrease in intraoperative blood loss and postoperative pain.6 Attari et al. found that, somewhat predictably, patient satisfaction is higher in lumbar disk surgery patients receiving SA than in those receiving general anesthesia.5
Nevertheless, general anesthesia is sometimes preferred and is often used in operations lasting longer than three hours.7 The most common general anesthesia techniques are inhalation anesthesia, in which the patient inhales an anesthetic agent such as nitrous oxide, and total intravenous anesthesia (TIVA), in which an anesthetic, typically propofol, is administered intravenously without the use of inhalation agents.8
Meng et al. sought to evaluate the differences in patient recovery in male patients undergoing lumbar surgery depending on the type of general anesthesia they received. Previous studies have shown that women given TIVA recovered quicker, but patient sex, according to the authors, is an independent factor in postoperative recovery, necessitating research that can analyze male and female patients separately. 80 male patients undergoing transforaminal lumbar interbody fusion (TLIF) – a common surgical approach for lumbar disc herniation – were randomly assigned to two groups, one of which received the anesthetic sevoflurane via inhalation while the other received TIVA. Each patient was given a quality of recovery (QoR) score, based on his levels of physical comfort, emotional state, and physical independence before and after surgery. While the QoR scores were similar between the two groups, the inhalation anesthesia group reported significantly less postoperative pain than the TIVA group. Postoperative nausea and vomiting were higher in the inhalation group, though not significantly.
Interestingly, the latest development in anesthesia for TLIF is the use of liposomal bupivacaine, which recently received FDA approval to be expanded for use in pediatric patients.9 Some research suggests that this local anesthetic reduces the length of the operation and hospital stay, though conflicting results have also been found.10 The drug consists of the anesthetic bupivacaine encapsulated in a phospholipid compartment that prolongs the drug’s half-life and allows for bupivacaine to more effectively reach its target, voltage-gated sodium ion channels. These biochemical properties result in significant physiological outcomes: Kim et al. report that TLIF patients given liposomal bupivacaine report significantly less pain than those receiving nonliposomal local anesthetic.11
References
1. Spine Structure & Function: Parts & Segments, Spine Problems, Spine Health. Cleveland
Clinic https://my.clevelandclinic.org/health/articles/10040-spine-structure-and-function.
2. Lumbar Spine: What It Is, Anatomy & Disorders. Cleveland Clinic
https://my.clevelandclinic.org/health/articles/22396-lumbar-spine.
3. Lumbar Strain. https://www.hopkinsmedicine.org/health/conditions-and-diseases/lumbar-strain-weight-lifters-back.
4. Back surgery: When is it a good idea? Mayo Clinic https://www.mayoclinic.org/diseases- conditions/back-pain/in-depth/back-surgery/art-20048274.
5. Attari, M. A., Mirhosseini, S. A., Honarmand, A. & Safavi, M. R. Spinal anesthesia versus general anesthesia for elective lumbar spine surgery: A randomized clinical trial. J. Res. Med. Sci. Off. J. Isfahan Univ. Med. Sci. 16, 524–529 (2011), PMID: 22091269
6. Rodgers, A. et al. Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials. BMJ 321, 1493 (2000), https://doi.org/10.1136/bmj.321.7275.1493
7. Pierce, J. T. et al. Efficiency of spinal anesthesia versus general anesthesia for lumbar spinal surgery: a retrospective analysis of 544 patients. Local Reg. Anesth. 10, 91–98 (2017), https://doi.org/10.2147/LRA.S141233
8. Miller, A. L., Theodore, D. & Widrich, J. Inhalational Anesthetic. in StatPearls (StatPearls Publishing, 2022).
9. Inc, P. P. Pacira Announces FDA Approval of Supplemental New Drug Application for EXPAREL® (bupivacaine liposome injectable suspension) in Pediatric Patients. GlobeNewswire News Room https://www.globenewswire.com/news-release/2021/03/22/2197275/0/en/Pacira-Announces-FDA-Approval-of-Supplemental-New-Drug-Application-for-EXPAREL-bupivacaine-liposome-injectable-suspension-in-Pediatric-Patients.html (2021).
10. Keeping Patients Awake During Spine Surgery is Cutting Recovery Time in Half | UC San Francisco. https://www.ucsf.edu/news/2019/03/413446/spine-surgery-while-patients-are-awake-speeds-healing.
11. Kim, J. et al. The Role of Liposomal Bupivacaine in Reduction of Postoperative Pain After Transforaminal Lumbar Interbody Fusion: A Clinical Study. World Neurosurg. 91, 460–467 (2016), https://doi.org/10.1016/j.wneu.2016.04.058