Periprocedural Polypharmacy in Lumbar Fusions Performed Under Spinal Anesthesia Compared With General Anesthesia

Spinal Anesthesia Reduces Perioperative Polypharmacy and Opioid Burden in Patients Over 65 Who Undergo Transforaminal Lumbar Interbody Fusion

BACKGROUND

Polypharmacy and opioid administration are thought to increase the risk of postoperative cognitive dysfunction and delirium in elderly patients. Spinal anesthesia (SA) holds potential to reduce perioperative polypharmacy in spine surgery. As more geriatric patients undergo spine surgery, understanding how SA can reduce polypharmacy and opioid administration is warranted. We aim to compare the perioperative polypharmacy and dose of administered opioids in patients ≥65 years who undergo transforaminal lumbar interbody fusion (TLIF) under SA versus general anesthesia (GA).

METHODS

A retrospective analysis of 200 patients receiving a single-surgeon TLIF procedure at a single academic center (2014-2021) was performed. Patients underwent the procedure with SA (n = 120) or GA (n = 80). Demographic, procedural, and medication data were extracted from the medical record. Opioid consumption was quantified as morphine milligram equivalents (MME). Statistical analyses included χ2 or Student's t-test.

RESULTS

Patients receiving SA were administered 7.45 medications on average versus 12.7 for GA patients (P < 0.001). Average perioperative opioid consumption was 5.17 MME and 20.2 MME in SA and GA patients, respectively (P < 0.001). The number of patients receiving antiemetics and opioids remained comparable postoperatively, with a mean of 32.2 MME in the GA group versus 27.5 MME in the SA group (P = 0.14). Antiemetics were administered less often as a prophylactic in the SA group (32%) versus 86% in the GA group (P < 0.001).

CONCLUSIONS

SA reduces perioperative polypharmacy in patients ≥65 years undergoing TLIF procedures. Further research is necessary to determine if this reduction correlates to a decrease the incidence of postoperative cognitive dysfunction and delirium.

Comparative outcomes of awake spine surgery under spinal versus general anesthesia: a comprehensive systematic review and meta-analysis

BACKGROUND

Awake surgery, under spinal anesthesia (SA), is an alternative to surgery under general anesthesia (GA), in neurological and spine surgery. In the literature, there seem to be some evidence supporting benefits associated with the use of this anesthetic modality, as compared to GA. Currently, there is a notable lack of updated and comprehensive review addressing the complications associated with both awake SA and GA in spine surgery. We hence aimed to perform a systematic review of the literature and meta-analysis on the topic.

METHODS

A systematic search was conducted to identify studies that assessed SA in spine surgery from database inception to April 14, 2023, in PubMed, Medline, Embase, and Cochrane databases. Outcomes of interest included estimated blood loss, length of hospital stay, operative time, and overall complications. Meta-analysis was conducted using random effects models.

RESULTS

In total, 38 studies that assessed 7820 patients were included. The majority of the operations that were treated with SA were single-level lumbar cases. Awake patients had significantly shorter lengths of hospital stay (Mean difference (MD): - 0.40 days; 95% CI - 0.64 to - 0.17) and operative time (MD: - 19.17 min; 95% CI - 29.68 to - 8.65) compared to patients under GA. The overall complication rate was significantly higher in patients under GA than SA (RR, 0.59 [95% CI 0.47-0.74]). Patients under GA had significantly higher rates of postoperative nausea/vomiting RR, 0.60 [95% CI 0.39-0.90]) and urinary retention (RR, 0.61 [95% CI 0.37-0.99]).

CONCLUSIONS

Patients undergoing awake spine surgery under SA had significantly shorter operations and hospital stays, and fewer rates of postoperative nausea and urinary retention as compared to GA. In summary, awake spine surgery offers a valid alternative to GA and added benefits in terms of postsurgical complications, while being associated with relatively low morbidity.

General Versus Nongeneral Anesthesia for Spinal Surgery: A Comparative National Analysis of Reimbursement Trends Over 10 Years

BACKGROUND AND OBJECTIVES

Nongeneral anesthesia (non-GA) spine surgery is growing in popularity and has facilitated earlier postoperative recovery, reduced cost, and fewer complications compared with spine surgery under general anesthesia (GA). Changes in reimbursement policies have been demonstrated to correlate with clinical practice; however, they have yet to be studied for GA vs non-GA spine procedures. We aimed to investigate trends in physician reimbursement for GA vs non-GA spine surgery in the United States.

METHODS

We queried the ACS-NSQIP for GA and non-GA (regional, epidural, spinal, and anesthesia care/intravenous sedation) spine surgeries during 2011-2020. Work relative value units per operative hour (wRVUs/h) were retrieved for decompression or stabilization of the cervical, thoracic, and lumbar spine. Propensity score matching (1:1) was performed using all baseline variables.

RESULTS

We included 474 706 patients who underwent spine decompression or stabilization procedures. GA was used in 472 248 operations, whereas 2458 operations were non-GA. The proportion of non-GA spine operations significantly increased during the study period. Operative times ( P < .001) and length of stays ( P < .001) were shorter in non-GA when compared with GA procedures. Non-GA lumbar procedures had significantly higher wRVUs/h when compared with the same procedures performed under GA (decompression; P < .001 and stabilization; P = .039). However, the same could not be said about cervicothoracic procedures. Lumbar decompression surgeries using non-GA witnessed significant yearly increase in wRVUs/h ( P < .01) contrary to GA ( P = .72). Physician reimbursement remained stable for procedures of the cervical or thoracic spine regardless of the anesthesia.

CONCLUSION

Non-GA lumbar decompressions and stabilizations are associated with higher and increasing reimbursement trends (wRVUs/h) compared with those under GA. Reimbursement for cervical and thoracic surgeries was equal regardless of the type of anesthesia and being relatively stable during the study period. The adoption of a non-GA technique relative to the GA increased significantly during the study period.

The Relationship of Spinal Anesthesia Dosing Based on Thecal Sac Area to Anesthetic Failure in Lumbar Surgery

BACKGROUND AND OBJECTIVES

Greater thecal sac volumes are associated with an increased risk of spinal anesthesia (SA) failure. The thecal sac cross-sectional area accurately predicts thecal sac volume. The thecal sac area may be used to adjust the dose and prevent anesthetic failure. We aim to assess the rate of SA failure in a prospective cohort of lumbar surgery patients who receive an individualized dose of bupivacaine based on preoperative measurement of their thecal sac area.

METHODS

A total of 80 patients prospectively received lumbar spine surgery under SA at a single academic center (2022-2023). Before surgery, the cross-sectional area of the thecal sac was measured at the planned level of SA injection using T2-weighted MRI. Patients with an area <175 mm2, equal to or between 175 and 225 mm2, and >225 mm2 received an SA injection of 15, 20, or 25 mg of 0.5% isobaric bupivacaine, respectively. Instances of anesthetic failure and adverse outcomes were noted. Incidence of SA failure was compared with a retrospectively obtained control cohort of 250 patients (2019-2022) who received the standard 15 mg of bupivacaine.

RESULTS

No patients in the individualized dose cohort experienced failure of SA compared with 14 patients (5.6%) who experienced failure in the control cohort (P = .0259). The average thecal sac area was 187.49 mm2, and a total 28 patients received 15 mg of bupivacaine, 42 patients received 20 mg of bupivacaine, and 10 patients received 25 mg of bupivacaine. None of the patients experienced any adverse outcomes associated with SA. Patients in the individualized dose cohort and control cohort were comparable and had a similar distribution of lumbar procedures and comorbidities.

CONCLUSION

Adjusting the dose of SA according to thecal sac area significantly reduces the rate of SA failure in patients undergoing lumbar spine surgery.

TL1A promotes the postoperative cognitive dysfunction in mice through NLRP3-mediated A1 differentiation of astrocytes

AIM

We investigated the mechanism, whereby tumor necrosis factor-like ligand 1A (TL1A) mediates the A1 differentiation of astrocytes in postoperative cognitive dysfunction (POCD).

METHODS

The cognitive and behavioral abilities of mice were assessed by Morris water maze and open field tests, while the levels of key A1 and A2 astrocyte factors were detected by RT-qPCR. Immunohistochemical (IHC) staining was used to examine the expression of GFAP, western blot was used to assay the levels of related proteins, and enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory cytokines.

RESULTS

The results showed that TL1A could promote the progression of cognitive dysfunction in mice. Astrocytes differentiated into A1 phenotype, while unobvious changes were noted in astrocyte A2 biomarkers. Knockout of NLRP3 or intervention with NLRP3 inhibitor could inhibit the effect of TL1A, improving the cognitive dysfunction and suppressing the A1 differentiation.

CONCLUSION

Our results demonstrate that TL1A plays an important role in POCD in mice, which promotes the A1 differentiation of astrocytes through NLRP3, thereby exacerbating the progression of cognitive dysfunction.

Spinal anesthesia in elective lumbar spinal surgery

Spinal anesthesia (SA) is gaining recognition as a safe and efficacious regional alternative to general anesthesia for elective lumbar surgery. However, unfamiliarity with management issues related to its use has limited the adoption of awake spine surgery, despite its benefits. Few centers in the United States routinely offer SA for elective lumbar surgery, and a comprehensive workflow to standardize SA for lumbar surgery is lacking. In this article, we examine recent literature on the use of SA in lumbar surgery, review the experience of our institution with SA in lumbar surgery, and provide a cohesive outline to streamline the implementation of SA from the perspective of the anesthesiologist. We review the critical features of SA in contemporary lumbar surgery, including selection of patients, methods of SA, intraoperative sedation, and management of several important technical considerations. We aimed to flatten the learning curve to improve the availability and accessibility of the technique for eligible patients.

Awake Spinal Fusion Is Associated with Reduced Length of Stay, Opioid Use, and Time to Ambulation Compared to General Anesthesia: A Matched Cohort Study

OBJECTIVE

There is increasing interest in performing awake spinal fusion under spinal anesthesia (SA). Evidence supporting SA has been positive, albeit limited. The authors set out to investigate the effects of SA versus general anesthesia (GA) for spinal fusion procedures on length of stay (LOS), opioid use, time to ambulation (TTA), and procedure duration.

METHODS

The authors performed a retrospective review of a single surgeon's patients who underwent lumbar fusions under SA versus GA from June of 2020 to June of 2022. SA patients were compared to demographically matched GA counterparts undergoing comparable procedures. Analyzed outcomes include operative time, opioid usage in morphine milligram equivalents, TTA, and LOS.

RESULTS

Ten SA patients were matched to 10 GA counterparts. The cohort had a mean age of 66.77, a mean body mass index of 27.73 kg/m2, and a median American Society of Anesthesiologists Physical Status Score of 3.00. LOS was lower in SA versus GA patients (12.87 vs. 50.79 hours, P = 0.001). Opioid utilization was reduced in SA versus GA patients (10.76 vs. 31.43 morphine milligram equivalents, P = 0.006). TTA was reduced in SA versus GA patients (7.22 vs. 29.87 hours, P = 0.022). Procedure duration was not significantly reduced in SA patients compared to GA patients (139.3 vs. 188.2 minutes, P = 0.089).

CONCLUSIONS

These preliminary retrospective results suggest the use of SA rather than GA for lumbar fusions is associated with reduced hospital LOS, reduced opioid utilization, and reduced TTA. Future randomized prospective studies are warranted to determine if SA usage truly leads to these beneficial outcomes.