Relatively light general anesthesia is more effective than fluid expansion in reducing the severity of epinephrine-induced hypotension during functional endoscopic sinus surgery.

BACKGROUND: Epinephrine infiltration of the nasal mucosa causes hypotension during functional endoscopic sinus surgery (FESS) under general anesthesia. A prospective randomized-controlled study was designed to determine whether relatively light general anesthesia is superior to fluid expansion in reducing epinephrine-induced hypotension during FESS. METHODS: Ninety patients undergoing elective FESS under general anesthesia were randomly assigned to three groups with 30 patients in each. Each patient received local infiltration with adrenaline-containing (5 microg/ml) lidocaine (1%, 4 ml) under different conditions. For Group I, anesthesia was maintained with propofol 2 microg/ml and rimifentanil 2 ng/ml by TCI. Group II (control group) and Group III received propofol 4 microg/ml and rimifentanil 4 ng/ml, respectively. In Groups I and II, fluid expansion was performed with hetastarch 5 ml/kg within 20 minutes; hetastarch 10 ml/kg was used in Group III. Mean arterial pressure (MAP) and heart rate (HR) were recorded at 30-second-intervals for 5 minutes after the beginning of local infiltration. Simultaneously, the lowest and the highest MAP were recorded to calculate the mean maximum increase or decrease percent in MAP for all patients in each group. Data analysis was performed by chi(2) test, one-way analysis of variance, or one-way analysis of covariance. RESULTS: Hemodynamic changes, particularly a decrease in MAP accompanied by an increase in HR at 1.5 minutes (P < 0.05), were observed in all groups. The mean maximum decrease in MAP below baseline was 14% in Group I, 24% in Group III and 26% in Group II. There were statistically significant differences between Group I and Groups II and III (P < 0.05). The mean maximum increase in MAP above baseline was 9% in Group I, 6% in Group III and 2% in Group II. CONCLUSION: Relatively light general anesthesia can reduce the severity of epinephrine-induced hypotension more effectively than fluid expansion during FESS under general anesthesia.

Hemodynamic changes due to infiltration of the scalp with epinephrine-containing lidocaine solution: a hypotensive episode before craniotomy.

Epinephrine-containing lidocaine solution is commonly infiltrated on the scalp before craniotomy. But the hemodynamic changes caused by epinephrine-containing lidocaine solution have been less intensely studied. A prospective randomized double blind control study was designed to observe hemodynamic changes caused by epinephrine-containing lidocaine solution in neurosurgical operations under general anesthesia. One hundred twenty patients undergoing scheduled craniotomy were allocated randomly to 4 groups. All the patients received 1% lidocaine 16 mL with different dose (concentration) epinephrine: group 1 with 40 microg (2.5 microg/mL); group 2 with 80 microg (5 microg/mL); group 3 with 160 microg (10 microg/mL); and group 4 (control group) without epinephrine. mean arterial pressure (MAP) and heart rate were recorded at 30-second interval in 5 minutes after the beginning of local infiltration. In group 1, group 2, and group 3, the lowest MAP and the highest MAP during this period also were recorded. Bleeding was assessed after raising the craniotomy flap. Compared with the baseline, significant hemodynamic changes, particularly decrease in MAP with increase in heart rate at 1.5 minutes after the beginning of local infiltration, were observed in group 1, group 2, and group 3 (P<0.001), but not in group 4. The highest MAP increased significantly compared with the baseline in group 3 (P<0.05), but not in group 1 or group 2. Epinephrine-containing lidocaine solution reduced bleeding significantly (P<0.01). Infiltration with epinephrine-containing lidocaine solution elicits temporary but significant hemodynamic changes including hypotension before craniotomy. Commonly clinically used concentrations of epinephrine (2.5 to 10 microg/mL) can reduce the bleeding on the scalp.