title: Shaken. Not stirred-temperature change and heat loss during delivery of IV fluids
abstract: Microwave-heated intravenous fluids are used in the rewarming of hypothermic patients. OBJECTIVES: To study the effect of both shaking of the microwaved bag and heat loss during delivery. METHODS: Twenty 1-liter normal saline bags were heated individually in a commercial microwave, immediately randomized into a "shaken" or a "non-shaken" group. The temperature of the fluid was recorded initially out of the bag and then at one-minute intervals by a blinded observer as the fluid ran "wideopen" through ambient temperature tubing. RESULTS: No statistically significant temperature difference occurred in any of the measured time intervals between the shaken and the non-shaken bags. Seventy percent of the overall temperature losses occurred in the first three minutes out of the microwave for both groups. CONCLUSIONS: Absence of shaking of the microwaved fluids does not produce "hot spots." Higher initial temperatures out of the bag should be considered as well as warming of the IV tubing.
authors.affiliation: Beth Israel Medical Center, New York, NY.
authors.initials: E
authors.lastname: Fields
authors.initials: C
authors.lastname: Hsu