Dec 02
Anesthesia; fasting, preop 060.31
Anesthetics, Volatile; halothane 100.06
Blood Pressure 160.0
Friesen RH et al: Duration of preoperative fast correlates with arterial blood pressure response to halothane in infants.
Anesth Analg, 95(6):1572-1576, 2002. 19 References
Dept of Anesthesiology, The Children's Hospital, 1056 E. 19th Ave., Denver, CO 80218 (RH Friesen, MD) RO.04 AP0324/114 ©2003
The authors have indicated no affiliation or financial interest with any organization that may impact upon this CME activity.
| Although preoperative fasting guidelines have been developed to optimize patient care, it is difficult to actually control fasting duration in the nonhospitalized preoperative infant and child. Significant hypotension is common during halothane anesthesia in infants and is age related. This study was designed to determine whether the duration of preoperative fasting affects the decrease in blood pressure observed in infants and children during halothane anesthesia. A total of 250 pediatric patients were divided into 5 age groups: term neonates (n=50), 1-6 months (n=50), 6-24 months (n=50), 2-6 years (n=50) and 6-12 years (n=50). Preoperative fasting time was not controlled but recorded by the investigators at the time of anesthetic induction. After anesthetic induction with halothane, end-tidal halothane was maintained at twice minimum alveolar anesthetic concentration (2 MAC) for 10 minutes to allow myocardial uptake. Patients were grouped by |
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duration of preoperative fast (0-4 hours, 4-8 hours, 8-12 hours, and >12 hours). Changes in heart rate (HR), systolic (SAP) and mean (MAP) arterial blood pressure from pre-induction to 2 MAC were compared among fasting groups within each age group.
In the 1-6 month age group, the changes in SAP and MAP were significantly greater in infants fasting 8-12 hours than in those fasting 0-4 hours (SAP, -51 mmHg vs. -31 mmHg, respectively; MAP, -48 mmHg vs. -32 mmHg; P<0.05). No statistically significant differences were noted in the older age group. The results of this study demonstrate that fasting for longer than 8 hours is also associated with a significantly larger decrease in blood pressure during halothane anesthesia in infants. The authors recommend that prolonged fasting should be avoided in infants by adhering to published fasting guidelines. |
(060.31 - Friesen) Discuss the effects of preoperative fasting on arterial blood pressure in infants during halothane anesthesia.
Prolonged preoperative fasting in infants is associated with which of the following during halothane anesthesia?
- an increase in blood pressure
- a decrease in blood pressure
- no changes in blood pressure
- slower induction
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