Drs. Thieman and Fullas are both staff pharmacists at St. Luke’s Regional Medical Center, Sioux City, Iowa.
Caretakers of surgical patients in health systems are sometimes confronted with the dilemma of deciding whether to warm irrigation fluids for intraoperative use in order to prevent the risk of postsurgical hypothermia or to use these fluids at room temperature. Although the jury is still out as far as providing a definitive answer to the question, the majority of published reports support the use of warm irrigation fluids to minimize the risk of hypothermia.
What Causes Hypothermia?
Perioperative hypothermia is an unintentional drop in core body temperature <36ËšC during or immediately following an operation.1 Causes of postoperative hypothermia are numerous and include use of anesthetic agents, exposure of internal organs, ambient environment in the operating room, and the temperature and volume of irrigation fluids.2,3 The contributory role of the temperature of irrigation fluids has not been determined definitively, however. In general, the incidence of hypothermia in patients admitted to general intensive care units is high.2
Use of Irrigation Fluids
It is common practice to use plain irrigation fluids, such as 0.9% sodium chloride and lactated Ringer’s solutions, to wash out debris or unwanted body fluids; antibiotic irrigants, such as aminoglycosides (kanamycin, in particular) and bacitracin to prevent infection; and the vasoconstrictor epinephrine to help control intraoperative bleeding during various surgical procedures. Local antibiotic irrigation has been shown to result in a decrease in the prevalence of postoperative infection when used during peritoneal irrigation, biliary tract surgery, and obstetric procedures.4 Use of topical antibiotic irrigation of orthopedic wounds is also common to prevent infection.5
To Warm Irrigation Fluids or Not
Many studies have been published on the use of irrigation solutions intra operatively during such procedures as laparoscopic surgery, transurethral resection of the prostate (TURP), and orthopedic surgeries. As part of their routine procedures, some health systems tend to warm irrigation fluids to minimize the risk of hypothermia, a common cause of postoperative complications. The outcome of such practice, however, has been contentious. In its published guidelines, the American Society of PeriAnesthesia Nurses (ASPAN) implicates cold irrigants as one of the contributing risk factors for perioperative hypothermia. According to ASPAN and other studies, hypothermia may in turn lead to increased incidence of infections, delayed wound closure, and prolonged hospitalization. 6
Several published papers have reported the association of room temperature irrigation fluids with hypothermia. For example, Winter7 has reported a 63% incidence of hypothermia in patients who underwent TURP with room temperature irrigation fluid, compared with only 20% in patients who received warm irrigation fluid. According to a study by Moore et al,3 laparoscopic irrigation with lactated Ringer’s solution at ambient temperature (20-22 ËšC) or warmed up to 39ËšC for 2 groups of patients, respectively, did not show any difference in the incidence of hypothermia. It was observed, however, that the degree of hypothermia was slightly higher (2ËšC loss of core body temperature) for the group of patients who received room temperature irrigants as compared with a 1ËšC loss in those who were given warm irrigation fluids.
On the other hand, a study by Jaffe et al8 found no correlation between irrigation fluid temperatures and hypothermia in a TURP procedure. The investigators demonstrated that administration of glycine irrigation fluid at room temperature of 70ËšF (21ËšC) and 91.5ËšF (33ËšC), respectively, to 2 groups of surgical TURP patients, did not result in significant differences in core body temperatures between the groups.
A recent study by Okeke9 of 120 TURP patients demonstrated that patients who received isothermic irrigation fluids at 38ËšC had significantly smaller changes in body temperature than those who received them at room temperature. As a result, a higher incidence of cold feeling, shivering, and longer hospital stays was reported for the patients who received room temperature irrigation fluids.
Studies reported in the literature are not clear about a correlation between the temperature of irrigation fluids and postoperative hypothermia that is applicable across all operative procedures. Considering the potential of cold or ambient (room) temperature irrigation fluids to contribute toward postoperative hypothermia, however, warming the fluids might reduce such a risk. Some devices allow inline warming of irrigation fluids, as they are being delivered directly to the irrigation site during surgery.3
From a pharmacy point of view, the effect of elevated temperatures on the integrity of irrigation fluids should be considered. It is very unlikely that warming antibiotic irrigants, such as aminoglycosides, to body temperature for a short time immediately before use would compromise the integrity of the fluids. Crystalloid solutions, such as 0.9% sodium chloride and lactated Ringer’s, are the least likely to be affected, whereas bacitracin irrigation fluids may have a greater chance of degradation, though perhaps not to a significant extent. Each individual irrigation solution has to be evaluated separately for stability. Although more studies on the subject are required, it may be reasonable to recommend warming irrigation fluids to body temperature immediately before use in surgical procedures.
1. Hanata NA, Zimmerman JL. Accidental hypothermia. Crit Care Clin. 1999;15(2):235-249.
2. Kongsayreepong S, Chaibundit C, Chadpaibool J, et al. Predictor of core hypothermia and the surgical intensive care unit. Anesth Analg. 2003; 96(3):826-833.
3. Moore SS, Green CR, Wang FL, et al. The role of irrigation in the development of hypothermia during laparoscopic surgery. Am J Obstet Gynel. 1997;176(3):598-602.
4. Antevil JL, Muldoon MP, Battaglia M, Green R. Intraoperative anaphylactic shock associated with bacitracin irrigation during revision total knee arthroplasty. A case report. J Bone Joint Surg. 2003;85-A(2):339-342.
5. Rosenstein BD, Wilson FC, Funderburk CH. The use of bacitracin irrigation to prevent infection in postoperative skeletal wounds. J Bone Joint Surg. 1989;71(3):427-430.
6. American Society of PeriAnesthesia Nurses. Clinical Guideline for the Prevention of Unplanned Perioperative Hypothermia. www.aspan.org/ClinicalPractice/ClinicalGuidelines/Hypothermia/tabid/3255/Default.aspx. Accessed June 24, 2008.
7. Winter M. Effects of irrigation fluid warming on hypothermia during urologic surgery. Urol Nurs. 1994;14(1):6-8.
8. Jaffe JS, McCullough TC, Harkaway RC, Ginsberg PC. Effects of irrigation fluid temperature on core body temperature during transurethral resection of the prostate. Urology. 2001;57(6):1078-1081.
9. Okeke I. Effect of warm intravenous and irrigation fluids on body temperature during transurethral resection of the prostate gland. BMU Urol. 2007 Sep 18;7:15.