Effects of vasopressors on circulation in the porcine abdominal island flap model.

BACKGROUND: During reconstructive surgical procedures, systemic vasopressors are frequently used to maintain normal blood pressure. However, questions have arisen regarding the pharmacologic effects of vasopressors on flap circulation. Many plastic surgeons have expressed concern about the possibility of impaired flap circulation caused by the vasoconstrictive effect of the drugs. However, the opposing argument exists that the increase in mean arterial pressure from vasoactive agents may improve flap perfusion. The purpose of this study was to evaluate the effect of commonly used vasopressors on flap circulation. METHODS: The vertical rectus abdominis myocutaneous (VRAM) island flap was raised in five female pigs (38.2∼40.7 kg). Hemodynamic parameters were measured continuously by a carotid arterial catheter. A bi-directional transonic vascular doppler flow probe and Laser Doppler perfusion monitor (LDPM) unit were applied to record the continuous change in pedicle artery flow and microvascular perfusion following intravenous administration of dopamine (3, 5, 10µg/kg/minute), dobutamine (1.25, 2.5, 5µg/kg/minute), and norepinephrine (0.05, 0.1, 0.2µg/kg/minute). RESULTS: Both microvascular perfusion and pedicle flow were generally proportional to the mean arterial pressure, and all three vasopressors improved flap perfusion and pedicle flow without deleterious effects. Norepinephrine showed the highest microvascular perfusion and dobutamine showed the highest pedicle flow rate. The mean blood pressure was the only statistically significant factor to affect both microvascular perfusion and pedicle flow (p < 0.0001). CONCLUSION: Our results strongly suggest that the foremost three vasopressors can be used for flap surgery without deterioration, and that the maintenance of adequate systemic blood pressure is crucial for good flap circulation.

Corrigendum: Occurrence bilateral bronchospasm consequently after unilateral bronchospasm (Korean J Anesthesiol 2013 December 65(6 Suppl): S28-S29).

[This corrects the article on p. S28 in vol. 65, PMID: 24478860.].

The effect of ketamine on the separation anxiety and emergence agitation in children undergoing brief ophthalmic surgery under desflurane general anesthesia.

BACKGROUND: Emergence agitation (EA) frequently occurs after desflurane anesthesia in children. Ketamine, because of its sedative and analgesic properties, might be useful for the management of separation anxiety and EA. We investigated the preventive effect of ketamine on separation anxiety and EA after desflurane anesthesia in children for brief ophthalmic surgery. METHODS: Sixty children, ranging in age from 2-8 years old, undergoing brief ophthalmic surgery were randomly allocated to one of the 3 groups: group C received normal saline, group K1.0 received ketamine 1.0 mg/kg intravenously before entering the operating room, or group K0.5 received ketamine 0.5 mg/kg 10 min before the end of the surgery. Before induction, the separation anxiety score was evaluated. Extubation time, post-anesthesia care unit stay time, postoperative nausea and vomiting, emergence agitation, and pain were assessed. RESULTS: The group K1.0 had a lower separation anxiety score compared with groups K0.5 and C. Extubation time in group K0.5 was significantly prolonged compared with groups K1.0 and C. The incidence of EA and the modified Children's Hospital of Eastern Ontario Pain Scale were significantly lower in group K1.0 and group K0.5 compared to group C, but there was no significant difference between groups K1.0 and K0.5. CONCLUSIONS: In children undergoing brief ophthalmic surgery with desflurane anesthesia, ketamine 1.0 mg/kg administered before entering the operating room reduced separation anxiety, postoperative pain, and incidence of EA without delay in recovery.

Effect of fentanyl on hemodynamic changes connected with a thigh tourniquet during knee arthroscopic surgery.

BACKGROUND: The use of a tourniquet can produce pain and increase in blood pressure. It is known that fentanyl reduces central sensitization, however its effect on blood pressure increase due to tourniquet is unknown. So we investigated the effect of fentanyl on tourniquet-induced changes of mean arterial blood pressure (MBP), heart rate (HR), and cardiac index (CI). METHODS: ASA physical status I and II, who were scheduled for knee arthroscopic surgery using a tourniquet, were assigned into control (n = 30) and fentanyl group (n = 30). Anesthesia was maintained with enflurane, N2O and O2. Fentanyl was injected 1.5 ug/kg at 10 min before inflation of the tourniquet in the fentanyl group. Changes of the MBP, HR, CI were measured before and 10, 20, 30, 40, 50, 60 min after inflation of the tourniquet. RESULTS: There were no differences in the baseline values. MBP was increased at 40, 50, 60 min in the control group. At 60 min, MBP was lower in the fentanyl than the control group. HR was decreased at 10 min in the fentanyl group. CI was decreased in all groups after tourniquet inflation. At 60 min, CI was more decreased in the control than the fentanyl group. CONCLUSIONS: Fentanyl injection prior to tourniquet inflation can attenuate the tourniquet induced hemodynamic changes in the knee arthroscopic surgery patients.