General Anesthesia

1. Introduction

Vertebral lumbar surgery can be performed under both general anesthesia (GA) and spinal anesthesia (SA). Each has possible advantages and complications in the perioperative period ^[1]. In particular, SA does not require airway device placement for intraoperative sedation and analgesia; however, it could be associated with patient discomfort and intraoperative patient movements ^[2]. Moreover, fear of neuraxial damage caused by either local anesthetic toxicity or direct damage with an associated prolonged hospital length of stay (LOS) may discourage its use ^[3].

According to a systematic review and meta-analysis published in 2016 ^[4], patients undergoing lumbar spine surgery under SA required less analgesia in post-anesthesia care units and had less nausea and vomiting (PONV) in the first postoperative day, but no difference in intraoperative hypotension, bradycardia, blood loss, and surgical time was reported.

Given the above, a clear benefit from SA during lumbar spine surgery remains unproven. Furthermore, relevant clinical outcomes remain unexplored.

2. Study Selection and Data Retrieval

Bibliographic search results are shown in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) diagram (Figure 1). Notably, three RCTs did not report quantitative data. Two papers were excluded because, despite our best efforts, we were not able to retrieve the full text ^[5][6], in one case ^[7] the paper did not contain any variable of interest and the authors were not able to provide any missing information.

Figure 1. The PRISMA flowchart.

Eleven studies counting a total of 896 patients entered the quantitative and qualitative analysis ^{[8][9][10][11][12][13][14][15][16][17][18]}. All controversies were solved by discussion and the third reviewer was not required.

We asked all the corresponding authors for missing data, and five of them replied to our query. Only two of them, nevertheless, provided part of the missing data required ^{[10][11][12][13][14][15][16][17][18]}.

Additional records were identified by checking the reference lists of included studies.

3. Study Characteristics

Among the 896 patients, half (449; 50.12%) underwent GA, while the remainder underwent SA (447; 49.88%). The characteristics of included studies are shown in Table 1 and Table S2.

Table 1. Study characteristics.

ASA-PS: ASA Physical Status, F: females, GA: General Anesthesia, SA: Spinal Anesthesia, PACU: Post-Anesthesia Care Unit, PO: Post-Operative, NR: Not Reported.

There were concerns of bias in ten studies, where one study was evaluated at high risk of bias ^[17] (Figure 2).

Figure 2. Summary of bias evaluated by the Risk of Bias 2 Tool. R: Bias arising from the randomization process, D: Bias due to deviations from intended interventions, Mi: Bias due to missing outcome data, Me: Bias in measurement of the outcome, S: Bias in the selection of the reported result, and O: Overall risk of bias. Green “+”: Low risk of bias, Yellow “?”: Some concerns, Red “-”: High risk of bias.

The entry is from 10.3390/jcm10010102