Intraoperative patient support and monitoring

Accepted medical and veterinary surgical practice requires assessment of the physiologic status of the animal on a regular basis. Vital time for resuscitation can be lost by failure to notice life threatening physiologic or metabolic problems.

The degree of monitoring sophistication depends on the species, the extent and duration of the surgical procedure, and whether it is a survival or terminal procedure. Monitoring can be qualitative, using the anesthetist's sense of touch, sight and hearing to evaluate the patient; or quantitative, using instruments for periodic measurement of specific vital organ performance.

The anesthetic record provides a detailed account of the course of anesthesia and intraoperative events, Blank record forms are available from the Office of Veterinary Resources. Whether you use one of these forms, or one of your own design, it is important to record data from the pre-operative period, the induction period, the anesthetic/surgical period and the immediate post-operative period. Later measurements may be written on the individual animal's chart.

Support of vital organ functions is an integral part of any surgical protocol. Many devices are available but they may not be practical or applicable for all species.

1. Body temperature - This can be measured via rectal or esophageal thermometers. Every effort should be made to combat hypothermia by use of circulating warm water blankets, warm water bottles, heat lamps, or application of insulating materials such as drapes.
2. Respiratory system support - This can be as simple as appropriate positioning of the animal to ensure an unobstructed airway, endotracheal intubation, or providing supplemental oxygen.
3. Cardiovascular function - A variety of techniques may be used for assessment: capillary refill time, heart rate monitoring, Doppler Flow probes, EKG, palpation of pulse, and use of esophageal or conventional stethoscopes.
4. Cardiovascular support - includes fluid therapy and availability of defibrillators (if necessary) and cardioactive drugs.
5. Hydration Status - Monitoring rate and amount of urine production, as well as subjective assessment of blood loss, and capillary refill time of the oral mucus membranes can indicate adequacy of fluid volume. There are many possible choices for fluid replacement, but normal (0.9%) saline or balanced electrolyte solutions such as lactated Ringer's are common. Intravenous (IV) administered fluid therapy is best for larger animal species, but can be difficult in smaller animals; Subcutaneous (SQ) or Intraperitoneal (IP) fluids may be appropriate for these species. Warming fluids is recommended.

Required Components of a Perioperative Record:

• presurgical body temperature measurements
• periodic heart rate, respiratory rate
• time that drugs or medications were administered
• dosage and route for these drugs or medications
• any noted responses to the drugs or medications
• initials of person who administered drugs

References used for this module:

APPLYING PRINCIPLES OF ASEPTIC SURGERY TO RODENTS. T.C. Cunliffe-Beamer. AWIC Newsletter, Vol. 4, No. 2, Apr-June 1993.

SPECIAL REPORT Guidelines for animal surgery in research and teaching. Brown, M.J., Pearson , P.T., and F.N. Tomson. Am J Vet Res, Vol. 54, No. 9, Sept. 1993.

THE DEA: FOLLOWING ITS "10 COMMANDMENTS", JAVMA, Vol 205, No. 10, Nov. 15, 1994