PROSPECTIVE, RANDOMIZED COMPARISON OF THE FLOTEM IIE AND HOTLINE FLUID WARMERS IN ANESTHETIZED ADULTS

Study Objective: To compare the fluid warming capabilities of the Hotl ine and Flotem IIe devices in surgical patients, and whether warming i ntravenous (IV) fluids with the Hotline device resulted in less hypoth ermia and less need for other warming methods compared with the Flotem IIe device. Study Design: Part 1. Prospective, nonrandomized. Part 2. Prospective, randomized. Setting: Teaching hospital, tertiary care ce nter Patients: Part 1. 24 adult patients undergoing elective surgery. Part 2. 49 adult patients scheduled for major elective orthopedic or g ynecologic surgery of greater than 2 hours' duration with general anes thesia. Interventions: Part 1. Insertion of sterile in-line thermistor s along the path of fluids delivered using the Hotline or Flotem devic e. Part 2. Patients were randomly assigned to receive IV fluids via th e Hotline (n = 21) or Flotem IIe (n = 18) warmers. Intervention for co re hypothermia [lower esophageal temperature (Teso) less than 35.5 deg rees C], was with forced air warming. Intervention for postoperative s hivering was with meperidine by a nurse who was blinded to the treatme nt group. Measurements: Part 1. Temperature of infused fluids before a nd after the warmer (T in and T out) and before the fluid entered the patient after insertion of a standard 84 cm extension set having a sto pcock for injection of medications (T distal). Part 2. Tympanic (Ttym) was recorded before induction of anesthesia (baseline) and at 15-minu te intervals after induction. Teso was recorded at 15-minute intervals after induction. The maximum intraoperative Ttym decline from baselin e (Delta Ttym max) was calculated. Main Results: Part 1. Flow rates we re between 1 and 33 ml/min. T out and T distal (mean +/- SEM) of fluid s infused through the Hotline device were warmer compared with those i nfused via the Flotem IIe device (Hotline T out: 35.7 +/- 0.1 degrees C and Hotline T distal: 33.4 +/- 0.2 degrees C vs. Flotem IIe T out: 2 8.9 +/- 0.2 degrees C and Flotem IIe T distal: 28.3 +/- 0.2 degrees C; p < 0.001 between warmers). Part 2. Maximal decrease in Ttym from pre operative baseline (before intervention) was greater in the Flotem IIe compared with the Hotline group (Delta Ttym max = -1.4 +/- 0.1 vs. -0 .9 +/- 0.1 degrees C, p = 0.01). Five patients in the Flotem IIe group required forced air warming for treatment of hypothermia versus none in the Hotline group (p < 0.01). Postoperatively, five patients in the Flotem IIe group required treatment with meperidine for severe shiver ing versus one patient in the Hotline group (p < 0.05). Conclusions: T he Hotline device delivered fluids to the patient at consistently warm er temperatures compared with the Flotem IIe device during actual clin ical conditions. This was asociated with maintenance of near normal co re termperatures throughout the procedure in the Hotline group, and a decreased need for interventions such as forced-air warming and treatm ent for severe shivering.