EQUINE | Proceedings
EQUINE | Proceedings
aesthesia . The volume of published research on colic has dramatically increased . Research seminars , such as the international colic symposium allow dissemination of novel information and promote discussion on all aspects relating to colic in the horse
Major advances have been made in knowledge of the pathophysiological mechanisms involved with various forms of colic , surgical and anaesthetic techniques and pre- and postoperative critical care of colic patients .
There have been significant improvements in inhalant and injectable anaesthetic agents , improved monitoring is available and positive inotropic drugs and ventilators are routinely used as part of the anaesthetic routine . Additionally , an increase in the pleasure horse population has seen more horses being regarded as pets and companion animals , more likely to be eligible for surgical treatment . In some regions like the United Kingdom and the Scandinavian countries a greater proportion of the equine population is insured and therefore more clients are prepared to pay for expensive colic surgery .
Accurate knowledge of post-operative survival rates for specific forms of colic is an important tool for the clinician , when discussing treatment options with the owner of the horse . It is an important factor in the decisionmaking process in the management of horses with colic as it helps to provide owners with evidence-based information regarding survival following surgery .
Moreover , identification of the specific factors that are significantly associated with prognosis following surgical treatment of colic allows clinicians and owners to make informed decisions regarding the management of individual horses . However , it must be recognized that these key prognostic indicators for survival and survival patterns following surgery , differ between the various types of colic ( Archer and Proudman 1996 ; Traub-Dargatz et al . 2001 ; Kaneene et al . 1997 ).
Outcome Measures
Outcome can be defined in different ways . A simple system is based on the time of survival following surgery and defines a surgical success as a horse walking out of the recovery room after surgery , short term survival as a horse surviving at least to the time of discharge from the hospital , and long term survival as the horse surviving a defined period after leaving the hospital . Variable long term survival times reported in the literature .
The types of studies assessing survival of horses following colic surgery can also vary . Retrospective studies are useful but have a number of limitations . Data may not have been collected on variables of interest , records may be incomplete and valuable data may be missing . Prospective studies are time-consuming and more expensive to perform but the data obtained can be more useful . Study design can often be improved over that of a retrospective study , as potentially issues detrimental to useful data collection can be addressed prior to the initiation of the study .
Standard statistical methods can be used for survival analysis such as percentages , proportions , and the comparison between groups of horses . However , these methods cannot investigate effects of other parameters on survival . Therefore more sophisticated statistical methods are utilised using logistic regression and longitudinal studies . The methods include Kaplan-Maier plots , which allow graphical representation of survival and Cox proportional hazards models , which permit looking at the association of specific parameters with survival time . However , a direct comparison of the results from different studies remains difficult due to differences in inclusion criteria and variation in categorisation of cases .
The results presented below are mainly from UK studies in the UK most of which were conducted at the University of Liverpool ’ s School of Veterinary Medicine .
32 • Equine Health Update •