Summary of findings for the main comparison. Risk of transient neurological symptoms with spinal lidocaine compared to other local anaesthetic in adults undergoing surgery.

Risk of transient neurological symptoms (TNS) with spinal lidocaine compared to other local anaesthetics in adults undergoing surgerya
Patient or population: adult undergoing surgery Settings: hospital or ambulatory surgery setting (Belgium, Brazil, Canada, Denmark, Egypt, Finland, Iran, Italy, Lebanon, Nepal, the Netherlands, Norway, Spain, Switzerland, Turkey, USA) Intervention: spinal lidocaine Comparison: other local anaesthetics as indicated
Outcomes	Anticipated absolute effectsb (95% CI)		Relative effect (95 CI)	№ of participants (studies)	Quality of the evidence (GRADE)	Comments
	Risk with lidocaine	Risk difference with the other local anaesthetic
Presence of any TNS –lidocaine vs bupivacaine Follow‐up: range 1–30 days	210 per 1000	176 fewer per 1000 (191 fewer to 151 fewer)	RR 0.16 (0.09 to 0.28)	1220 (12 RCTs)	⊕⊕⊕⊝ Moderatec	Bupivacaine probably reduced the risk of TNS compared to lidocaine.
Presence of any TNS – lidocaine vs 2‐chloroprocaine Follow‐up: range 1–7 days	106 per 1000	97 fewer per 1000 (105 fewer to 54 more)	RR 0.09 (0.01 to 1.51)	94 (2 RCTs)	⊕⊕⊝⊝ Lowc,d	2‐chloroprocaine may have resulted in no difference in the risk of TNS compared to lidocaine.
Presence of any TNS – lidocaine vs levobupivacaine Follow‐up: range 2–7 days	183 per 1000	159 fewer per 1000 (180 fewer to 57 fewer)	RR 0.13 (0.02 to 0.69)	120 (2 RCTs)	⊕⊕⊝⊝ Lowe,f	Levobupivacaine may have reduced the risk of TNS compared to lidocaine.
Presence of any TNS – lidocaine vs mepivacaine Follow‐up: range 1–5 days	95 per 1000	1 more per 1000 (78 fewer to 457 more)	RR 1.01 (0.18 to 5.82)	274 (4 RCTs)	⊕⊝⊝⊝ Very lowd,e,f	Mepivacaine may have resulted in no difference in the risk of TNS compared to lidocaine but the evidence was very uncertain.
Presence of any TNS – lidocaine vs prilocaine Follow‐up: range 1–5 days	127 per 1000	104 fewer per 1000 (118 fewer to 65 fewer)	RR 0.18 (0.07 to 0.49)	429 (4 RCTs)	⊕⊕⊕⊝ Moderatec	Prilocaine probably reduced the risk of TNS compared to lidocaine.
Presence of any TNS – lidocaine vs procaine Follow‐up: range 2–3 days	292 per 1000	251 fewer per 1000 (281 fewer to 140 fewer)	RR 0.14 (0.04 to 0.52)	130 (2 RCTs)	⊕⊕⊕⊝ Moderatef	Procaine probably reduced the risk of TNS compared to lidocaine.
Presence of any TNS – lidocaine vs ropivacaine Follow‐up: range 2–7 days	200 per 1000	180 fewer per 1000 (198 fewer to 44 fewer)	RR 0.10 (0.01 to 0.78)	90 (2 RCTs)	⊕⊕⊝⊝ Lowc,e	Ropivacaine may have reduced the risk of TNS compared to lidocaine.
CI: confidence interval; TNS: transient neurological symptoms; RCT: randomized controlled trial; RR: risk ratio.
GRADE Working Group grades of evidence High quality: further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: we are very uncertain about the estimate.

^a'Summary of findings' table is based on pair‐wise meta‐analysis (Figure 1). Results of the network meta‐analysis are presented in Table 3; Table 4; Table 5 and Figure 2; Figure 3; Figure 4; Figure 5; Figure 6; Figure 7.
 ^bThe risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
 ^cDowngraded one level due to limitations in the design and implementation.
 ^dDowngraded one level due to high probability of publication bias.
 ^eDowngraded one level due to imprecision of results.
 ^fDowngraded one level due to unexplained heterogeneity or inconsistency of results.