Subcutaneous buffered lidocaine for intravenous cannulation: is there a role in emergency medicine?

To prospectively evaluate whether subcutaneous buffered lidocaine (SQBL) significantly reduces the pain or adversely affects the success rate of i.v. cannulation (IVC) in adult ED patients.

A convenience sample of patients > or=18 years old requiring IVC in a regional military ED were prospectively randomized to receive SQBL, SQ normal saline with 0.9% benzyl alcohol (SQNS), or no pretreatment (NPTx), prior to IVC with an 18-gauge angiocatheter. SQ infiltration was accomplished using a 27-gauge insulin syringe. Investigators and patients were blinded to SQBL and SQNS in the pretreatment groups. The number of attempts at IVC was recorded for each patient. A 100-mm visual analog pain scale (VAPS) was used to record pain scores for both SQ infiltration and IVC. Comparisons of the mean numbers of attempts to achieve IVC and of the VAPS scores were accomplished by analysis of variance followed by Duncan's multiple range test if significance was found.

A total of 103 patients (SQBL-34, SQNS-30, and NPTx-39) were enrolled between November 15, 1996, and June 13, 1997. There were no significant differences among the groups in either the mean number of attempts (SQBL=1.35, 95% CI+/-0.260; SQNS=1.13, 95% CI +/-0.124; and NPTx=1.28, 95% CI+/-0.203) (p= 0.367) or the success rate on the first attempt (SQBL =79.4%, SQNS=86.7%, NPTx=79.5%) (p=0.533). The median VAPS score of IVC without pretreatment (21 mm, 95% CI+/-7.97) was greater than that for SQBL infiltration alone (10 mm, 95% CI+/-9.11), SQNS infiltration alone (9 mm, 95% CI+/-7.37), and IVC after SQBL (6 mm, 95% CI+/-9.18) (p < 0.009 for each group). SQNS infiltration had no significant effect on the VAPS score of subsequent IVC (20 mm, 95% CI+/-10.5) compared with IVC without pretreatment (21 mm).

SQBL significantly reduced the pain, while not adversely affecting the success rate, of IVC in adult patients in the ED.