Systemic Effects of Peritoneal Instillation of a Polyethylene Polymer Based Obstetrical Lubricant in Cows

Abstract

Incidence of dystocia in well managed herds has declined due to better selection of bulls that have proven 'calving ease' scores, However, obstetrical complications remain an important reason for veterinary services on many farms, Instillation of copious volumes of obstetrical lubricant is advocated to protect the delicate tissues of the cow's reproductive tract, Another important consideration is the need to distend the uterus such that additional space becomes available in which to manipulate the fetus, If attempts at manipulation are unsuccessful, then an experienced clinician may be able to resolve the problem by fetotomy. However, if a uterine laceration is present, or if a cesarean section becomes necessary, then the lubricant may enter the peritoneal cavity. This is especially likely during a standing flank cesarean section where complete exteriorization of the incised portion of the uterus does not always occur. A common obstetrical lubricant consists of a polyethylene polymer (PEP) in a dispersing agent base that, when mixed with water to the appropriate consistency, forms a 1-2% (w/v) solution. Effects of this PEP-based lubricanton the peritoneal cavity, and potential for toxicity, are not known. Thus, some surgeons express concern about prior use of large volumes of liquid obstetrical lubricant. However, the principal investigator counters that if copious volumes are not used, then far more cows will require surgery.

This project was designed to simulate accidental contamination of the peritoneal cavity during a cesarean section (approx. 1.0 liter), and to determine what effects, if any, a PEP-based lubricant may have on the bovine peritoneal cavity. The hypothesis was that a mild, transient peritonitis would result; that no fibrin deposition would occur; and that no systemic effects would occur. Peritonitis is a serious disease that, if not treated early and actively, can be fatal. The fibrin deposited on damaged or irritated tissues often results in adhesions which can lead to rumenal atony, intestinal blockage and abdominal pain. The proposal entailed serial abdominocentesis followed by euthanasia at two weeks to investigate the possibility of adhesions. The Ohio State University Institutional Laboratory Animal Care and Use Committee (ILACUC) required that a preliminary study be conducted on rodents.