Analgesia after upper abdominal surgery using extradural administration of a fixed dose of buprenorphine in combination with lignocaine given at two infusion rates: a comparative study

Bolus administration of ephedrine and etilefrine induces transient vasodilation just after injection in combined epidural and general anesthesia patients: A randomized clinical study

Hypotension commonly accompanies combined epidural and general anesthesia, and intravenous bolus ephedrine and etilefrine are widely used to correct hypotension. We have noticed that systemic vascular resistance (SVR) transiently decreases just after intravenous bolus administration of these drugs. The goal of the present study was to investigate whether bolus administration of these drugs decrease SVR just after intravenous administration in combined epidural and general anesthesia patients. We investigated 40 patients who were scheduled for elective abdominal surgery. Patients were chosen as subjects if their systolic arterial pressure decreased by 20% or to <100 mmHg at 30 min after the induction of general anesthesia. Baseline hemodynamic values were recorded, and after ephedrine 10 mg injection or etilefrine 2 mg injection (equipotent), the parameters were recorded again at 0.5 min and once each min for the next 5 min thereafter. The 40 patients were enrolled into the ephedrine (n = 20) or etilefrine (n = 20) treatment groups. Patient characteristics were comparable in both groups. After ephedrine injection, SVR decreased significantly at the 1-min time point, whereas after etilefrine injection, SVR decreased significantly at the 0.5- to 2-min time points compared with baseline values. SVR at the 0.5- to 1-min time points was lower in the etilefrine versus the ephedrine group. Both drugs transiently decreased SVR after intravenous injection, but etilefrine decreased SVR much more than ephedrine, indicating that more vasodilation occurred after the injection of etilefrine than after ephedrine. It is thus important to recognize the different characteristics of these drugs.

Does pneumoperitoneum affect perfusion index and pleth variability index in patients receiving combined epidural and general anesthesia?

Plethysmographic variability index (PVI) is a dynamic index used for the purpose of fluid responsiveness in patients, and the effect of pneumoperitoneum on PVI is still unclear. We therefore attempted to determine whether PVI and perfusion index (PI) change before/after pneumoperitoneum in patients receiving combined epidural and general anesthesia, which is a common anesthesia method with intravenous remifentanil. Twenty patients underwent laparoscopic cholecystectomy or colectomy. Immediately before pneumoperitoneum, variables were measured at baseline I and were then measured every min for 5 min after pneumoperitoneum start. Immediately before pneumoperitoneum release, variables were measured at baseline II and were measured every min for 5 min after pneumoperitoneum release. Compared with baseline I values, after pneumoperitoneum start, significant increases occurred in stroke volume variation (SVV) at 1-5 min, and significant decreases occurred in PI at 1-5 min. PVI did not change. Compared with baseline II values, after pneumoperitoneum release, significant increases occurred in PI at 1-5 min, and significant decreases occurred in PVI at 4-5 min and SVV at 1-5 min. In patients receiving combined epidural and general anesthesia, we newly found that PI decreased but PVI remained unchanged with a sufficient dose of remifentanil and epidural anesthesia that can block noxious stimuli and also most sympathetic activity. Furthermore, we reconfirmed that PI increased and PVI decreased upon release of pneumoperitoneum. PI and PVI values must be estimated cautiously during and after pneumoperitoneum.

Vigilance of hemodynamic changes immediately after transferring patients is crucial

PURPOSE

A decrease in blood pressure is sometimes observed when a postsurgical patient is transferred to another bed after recovering from anesthesia. However, the mechanism behind this hypotension has not been completely elucidated. The purpose of this study was to investigate and compare changes in hemodynamic properties for possible causes of hypotension before and after transfer to another bed of postsurgical patients receiving general anesthesia, combined epidural and general anesthesia, or combined spinal and general anesthesia.

METHODS

We studied 69 patients undergoing elective surgery who were randomized to receive anesthesia by one of the three methods. After surgery, the tracheal tube was removed, and each patient was transferred to another bed. Hemodynamic data recorded immediately before and after transfer of the patient to another bed were compared.

RESULTS

After transfer of patients receiving general anesthesia or combined epidural and general anesthesia, systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and cardiac output (CO) decreased; heart rate (HR) and systemic vascular resistance (SVR) did not change. However, after transfer of patients receiving combined spinal and general anesthesia, SAP, DAP, HR, and CO decreased, but SVR did not change.

CONCLUSION

The decrease in blood pressure observed after transfer of a postsurgical patient to another bed after general, combined epidural and general, and combined spinal and general anesthesia was associated with a decrease in CO and no change in SVR, but HR decreased after combined spinal and general anesthesia, whereas it was unchanged after general and combined epidural and general anesthesia. The decrease in blood pressure is assumed to be caused by a decrease in venous return, and several reflexes might participate in this decrease of blood pressure, especially after combined spinal and general anesthesia.

Lidocaine with fentanyl, compared to morphine, marginally improves postoperative epidural analgesia in children

PURPOSE

To compare the epidural administration of fentanyl (1 microg/mL) combined with lidocaine 0.4% to preservative-free morphine for postoperative analgesia and side effects in children undergoing major orthopedic surgery.

METHODS

In a prospective, double-blind study, 30 children, ASA I-II, 2-16-yr-old, were randomly allocated to receive immediately after surgery either epidural F-L (epidural infusion at a rate of 0.1-0.35 mL/kg/hr of 1 microg/mL of fentanyl and lidocaine 0.4%) or epidural M (bolus of 20 microg/kg of morphine in 0.5 mL/kg saline every eight hours). Both groups received 40 mg/kg of iv metamizol (dipyrone) every six hours. In the F-L Group, blood samples were taken on the second and third postoperative day to determine total lidocaine concentrations. Adequacy of analgesia using adapted pediatric pain scales (0-10 score) and side-effects were assessed every eight hours postoperatively.

RESULTS

Resting pain scores were under 4, 95% of the time in the F-L Group and 87% of the time in the M Group (Chi square=4.674, P <0.05). The frequency of complications was very similar in both groups. The F-L Group total plasma lidocaine concentrations were directly related to the dose received, and below the toxic range in all patients.

CONCLUSIONS

Postoperative epidural fentanyl with lidocaine infusion provides slightly better analgesia than conventional bolus administration of epidural morphine. Side-effects or risk of systemic toxicity were not augmented by the addition of lidocaine to epidural opioids.

Analgesia after upper abdominal surgery with extradural buprenorphine with lidocaine

PURPOSE

To determine whether the continuous low thoracic extradural administration of the same dose of lidocaine at low concentration with a high infusion rate or at high concentration with a low infusion rate in combination with a fixed dose of buprenorphine (0.4 mg.day-1) modifies postoperative pain relief.

METHODS

Twenty-eight patients undergoing elective upper abdominal surgery were randomly allocated to one of two groups to receive lidocaine 2%--buprenorphine at a rate of 6.3 ml.hr-1 (2% group, n = 13) or lidocaine 6%-buprenorphine at a rate of 2.1 ml.hr-1 (6% group, n = 15). During suture of the peritoneum, mepivacaine 2% (8 ml) with 0.1 mg (0.5 ml) buprenorphine was infused extradurally. After extubation, the continuous extradural infusion was initiated. Patients were assessed for the level of analgesia with the 10 cm VAS score at rest and with the Prince Henry Pain Scale (PHPS) at 3, 6, 9, 12, 18, and 24 hr postoperatively.

RESULTS

The visual analogue scale (VAS) scores at rest did not differ between the two groups except at 18 hr after surgery. The Prince Henry Pain Scale (PHPS) scores were not different between the two groups postoperatively.

CONCLUSION

There was no difference in analgesia produced by the continuous extradural infusion of lidocaine 2%-buprenorphine at a rate of 6.3 ml.hr-1 and that of lidocaine 6%-buprenorphine at a rate of 2.1 ml.hr-1 following upper abdominal surgery.