Has intravenous lidocaine improved the outcome in horses following surgical management of small intestinal lesions in a UK hospital population?

Abstract

BackgroundPerioperative lidocaine treatment is commonly used in horses that undergo surgical treatment of colic, to prevent or treat postoperative ileus and reduce the effects of intestinal ischaemia-reperfusion injury. However, its clinical efficacy has not been evaluated in a large population of horses undergoing small intestinal surgery. The aim of the current study was to evaluate whether systemic lidocaine administration reduced the prevalence, volume and duration of postoperative reflux and improved rates of survival following surgical treatment of small intestinal lesions. Data were collected as a part of two prospective studies investigating postoperative survival of surgical colic patients admitted to a UK equine referral hospital during the periods 2004–2006 and 2012–2014. Kaplan-Meier plots of cumulative probability of survival and the log-rank test were used to compare survival between horses that did or did not receive lidocaine. The Wilcoxon rank-sum test was used to compare the total reflux volume and duration of reflux between the groups. A multivariable Cox proportional hazards model was used to identify pre- and intraoperative risk factors for non-survival.ResultsData from 318 horses were included in the final analysis. The overall prevalence of postoperative reflux was 24.5 %. This was significantly higher (34.8 %) in horses admitted in 2012–2014 compared to the 2004–2006 cohort (16.7). Perioperative lidocaine treatment had no effect on total reflux volume, duration of reflux or rates of postoperative survival nor was it a risk factor associated with altered postoperative survival. Variables identified to be associated with increased risk of postoperative mortality included packed cell volume on admission (hazard ratio [HR] 1.03 95 %, 95 % confidence interval [CI] 1.004–1.06, p = 0.024), heart rate on admission (HR 1.014, 95 % CI 1.004–1.024, p =0.008) and duration of surgery (HR 1.007, 95 % CI 1.002–1.01, p = 0.008).ConclusionsLidocaine therapy had no effect on the prevalence of postoperative reflux, total reflux volume and duration of reflux nor did it have any effect on postoperative survival in horses undergoing surgical management of small intestinal disease for treatment of colic. There is a need for a well-designed multicentre, prospective randomised controlled trial to fully investigate the efficacy of lidocaine across different hospital populations.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-016-0784-7) contains supplementary material, which is available to authorized users.

Chronic gastric impaction and dilatation in horses: Clinical signs, diagnosis, treatment options and pathologic findings – A case series

“…1.3 mg/kg in 500 ml NaCl for a 30 min infusion) also promotes gastrointestinal motility by suppressing local sympathetic nerves (Malone et al 2006, Okamura et al 2009). However, a recent study showed that lidocaine therapy had no effect on the prevalence of postoperative reflux (Salem et al 2016). Side effects include fasciculations and collapse (Malone et al 2006, Okamura et al 2009).…”

Post‐operative reflux – a surgeon's perspective

“…Also, this increased rate of POR was noted recently in a report from a single hospital over a 10‐year span and an explanation could not be offered (Salem et al . ). Granted, more specific inclusion criteria and improvements in record keeping could explain this apparent trend ( Fig ), but the role of surgery and related effects on intestinal function ( Fig ) warrant close consideration.…”

“…A more recent study demonstrated that lidocaine did not affect the prevalence of post‐operative reflux, total reflux volume, duration of reflux and post‐operative survival after small intestinal surgery (Salem et al . ). That lidocaine has anti‐inflammatory effects in equine small intestine is unlikely (Cook ; Grosche et al .…”

“…A true prophylactic role for lidocaine is unknown, because it imparted no apparent benefit to horses that received it intraoperatively in one study, although a favourable response was evident in the same study when horses received it post-operatively (Torfs et al 2009). A more recent study demonstrated that lidocaine did not affect the prevalence of post-operative reflux, total reflux volume, duration of reflux and post-operative survival after small intestinal surgery (Salem et al 2016b). That lidocaine has anti-inflammatory effects in equine small intestine is unlikely (Cook 2012;Grosche et al 2014;Bauck et al 2015), although visceral analgesic effects cannot be discounted, based on improved pain scores when combined with flunixin meglumine (Cook et al 2008).…”

Perioperative pain management in horses

“…); however, a more recent study found no effect of lidocaine administration on total reflux volume or duration, or on post‐operative survival (Salem et al . ).…”