Intracuff alkalinized lidocaine to prevent postoperative airway complications: A meta-analysis

Table 1 Characteristics of the included trials

Trial	Country	Age (yr)	Male/ Female	Sample size	ASA status	Surgery	Intervention/comparator	Outcomes
Rizvanović et al[31], 2019	Bosnia and Herzegovina	49.4 (18-65)	44/46	90	I, II, III	Elective surgery	1 Alkalinized 2% lidocaine; 2 0.9% saline; 3 Air	IPOST
Nath et al[32], 2018	USA	52 (18-80)	73/127	200	I, II, III	NR	1 Alkalinized 2% lidocaine; 2 0.9% saline	IPC
Gaur et al[24], 2017	Arabia	44.62 (18-65)	51/49	100	I, II	NR	1 Alkalinized 2% lidocaine; 2 Air	IPOST
Suma et al[25], 2015	India	37.66 (18-65)	NR	200	I, II	Elective orthopedic, spine, and general surgery	1 Alkalinized 2% lidocaine; 2 Air	VAS of POST
Navarro et al[26], 2012	Brazil	NR (≥ 18)	13/37	50	I, II	Elective gynecological, orthopedic, or plastic surgery	1 Alkalinized 4% lidocaine; 2 0.9% saline	IPC, IPH, IPOST
Shroff and Patil[27], 2009	UK	36.71 (18-60)	51/99	150	I, II	NR	1 Alkalinized 2% lidocaine; 2 0.9% saline 3 Air	IPC, IPH
Navarro et al[28], 2007	Brazil	45.15 (18-65)	NR	50	I, II	Gynecological surgery or plastic surgery	1 Alkalinized 2% lidocaine; 2 Air	IPOST
Estebe et al[29], 2005	USA	47.67 ( ≥ 18)	13/47	60	I, II	Thyroidectomy surgery	1 Alkalinized 2% lidocaine (8.4%NaHCO3); 2 Alkalinized 2% lidocaine (1.4%NaHCO3); 3 Air	IPC, IPH, VAS of POST
Estebe et al[33], 2004	UK	49.67 ( ≥ 18)	39/21	60	I, II, III	Lumbar spinal surgery	1 Alkalinized 2% lidocaine (lubricated with sterile water); 2 Alkalinized 2% lidocaine (lubricated with water-soluble gel); 3 Air	IPC, IPH, VAS of POST
Estebe et al[34], 2002	USA	46.5 ( ≥ 18)	27/23	50	I, II, III	Lumbar spinal surgery	1 Alkalinized 2% lidocaine; 2 2% Lidocaine; 3 Air	IPC, IPH, VAS of POST
Navarro et al[35], 1997	USA	40.15 (NR)	18/88	106	I, II, III	NR	1 Alkalinized 2% Lidocaine; 2 Air	IPOST, VAS of POST
D’Aragon et al[30], 2013	Canada	41.8 ( ≥ 18)	0/59	59	I, II	Elective gynecological surgery	1 Alkalinized 2% lidocaine; 2 0.9% saline	IPC

IPC: Incidence of post-extubation cough; IPH: Incidence of postoperative hoarseness; POST: Postoperative sore throat; IPOST: Incidence of postoperative sore throat; VAS: Visual analogue scale; NR: Not reported.

Table 2 Sensitivity analyses: The effect of potential biases on primary and secondary outcomes

Potential bias or limitations excluded	IPC RR (95%CI), I2	IPH RR (95%CI), I2	IPOST within 24 h RR (95%CI), I2	VAS of POST at 1 h RR (95%CI), I2	VAS of POST at 24 h RR (95% CI), I2
Overall	0.38 (0.23, 0.63), 82%	0.38 (0.21, 0.69), 74%	0.19 (0.09, 0.41), 0%	-18.30 (-22.79, -13.82), 73%	-14.86 (-15.75, -13.98), 43%
Only females	0.33 (0.20, 0.52), 69%	NE	NE
Cuff prefilling	0.35 (0.19, 0.63), 85%	NE	NE	-17.59 (-18.69, -16.49), 77%	-14.81 (-17.22, -12.41), 54%
A high risk of bias	NE	NE	0.19 (0.08, 0.48), 0%	-18.45 (-25.61, -11.29), 77%	-14.37 (-18.31, -10.43), 56%

IPC: Incidence of post-extubation cough; IPH: Incidence of postoperative hoarseness; POST: Postoperative sore throat; IPOST: Incidence of postoperative sore throat; VAS: Visual analogue scale; CI: Confidence interval; NE: Not estimable; RR: Relative risk.