Heating of infusion fluids through heated breathing circuits

BACKGROUND: Hypothermia is a common physiological condition that occurs during surgical operations. The goal of this experiment is to measure the temperature of the fluids flowing through heated breathing circuits with respect to changes in infusion speed. METHODS: The infusion pump was connected to the intravenous inlet of a heated breathing circuit with two 50 cm extension lines connected to the outlet. Fluids were injected through the heated breathing circuit at 100, 200, 300, 400, 500, 600, and 700 ml/h, with measurement of the fluid temperature immediately after transit (OP 20), 70 cm after transit (OP 70), and 120 cm after transit (OP 120). RESULTS: The mean fluid temperatures at OP 20, OP 70, and OP 120 were 40.7 ± 4.8℃, 35.1 ± 3.22℃, and 31.7 ± 2.5℃, respectively. CONCLUSIONS: The heated breathing circuit was effective to heat the fluid. After passing out the heated breathing circuit, the temperature of the fluid continuously reduced. A length of 70 cm can be used to efficiently supply heated fluid to the patient. From this experiment, it is expected that supplying heated fluid to a patient using the heated breathing circuit will help maintain the patient's body temperature.

Effects of thiopental sodium, ketamine, and propofol on the onset time of rocuronium in children

BACKGROUND: In emergency condition, failure in securing airway is a common and serious reason of pediatric death. Rapid intubation is required to minimize physiologic complication in children due to airway failure. Rapid loss of consciousness and rapid onset of neuromuscular blocking agent are necessary for the rapid sequence intubation. In this study, we compared the effects of thiopental sodium, ketamine, and propofol (drugs commonly used to induce anesthesia in children) on the onset time of rocuronium. We also compared the effects of these anesthesia induction drugs on intubation condition and their duration of action. METHODS: A total of 89 patients undergoing various elective surgeries were enrolled and allocated to the following three groups according to the anesthesia induction drug: 1) Group T, thiopental sodium; 2) Group P, propofol; and 3) Group K, ketamine. After loss of consciousness, neuromuscular monitoring was performed and rocurunium 0.6 mg/kg was administered. Onset time and duration of action of rocuronium were measured. Intubation condition was recorded with a tracheal intubation scoring system. Hemodynamic changes were observed before induction until 5 min after endotracheal intubation. RESULTS: The onset time of rocuronium in group K (39.9 s) was significantly faster than that in group T (61.7 s) or group P (50.7 s). There was no significant difference in duration of action of rocuronium or intubation condition among the three groups. CONCLUSIONS: Ketamine can decrease the onset time of rocuronium significantly compared to thiopental sodium or propofol.