Kyung-Cheon Lee

Acid–base alterations during laparoscopic abdominal surgery: a comparison with laparotomy

BACKGROUND Carbon dioxide insufflation during laparoscopic surgery results in an acid-base imbalance. The purpose of this study was to investigate the effect of pneumoperitoneum on the acid-base status using Stewarts approach. METHODS Thirty patients undergoing abdominal surgery were allocated to the laparotomy group (n=15) or the laparoscopy group (n=15). The acid-base parameters were measured 10 min after the induction (T1), 40 min after opening the peritoneum or pneumoperitoneum according to the group (T2), at the end of the surgery (T3), and 1 h after the surgery (T4). RESULTS There were no significant differences in the standard base excess (SBE), strong ion gap, or anion gap between the two groups. In both groups, the SBE decreased at T2, T3, and T4 compared with baseline value. At T3 and T4 in the laparotomy group, the apparent strong ion difference (SIDa) and pH were decreased whereas the lactate and chloride were increased compared with their baseline values. At T2 in the laparoscopy group, the pH was decreased whereas Pa(CO(2)) was increased compared with their baseline values. CONCLUSIONS The decrease in the pH during the pneumoperitoneum was affected by the increase in Pa(CO(2)), which promptly returned to a normal value after the desufflation. On the other hand, the decrease in the pH after laparotomy was affected by the metabolic factors, which persisted an hour after the surgery.

The optimal bolus dose of alfentanil for tracheal intubation during sevoflurane induction without neuromuscular blockade in day-case anaesthesia

Background: The purpose of this study was to determine the optimal bolus dose of alfentanil required to provide successful intubating conditions following inhalation induction of anaesthesia using 5% sevoflurane and 60% nitrous oxide without neuromuscular blockade in adult day‐case anaesthesia.

The effect of sequential compression device on hypotension in the sitting position during shoulder arthroscopy; a comparison with elastic stocking

BACKGROUND The sitting position under general anesthesia is associated with hemodynamic instability. The purpose of this study was to compare the efficacy of a sequential compression device (SCD) with that of elastic stockings (ES) in reducing the incidence of hypotension and other hemodynamic instability in the sitting position during shoulder arthroscopy. METHODS Fifty-one patients undergoing shoulder arthroscopy were randomly assigned into one of three groups to receive no treatment (control group, n = 17), SCD (SCD group, n = 17) or ES (ES group, n = 17). Hemodynamic variables were measured 5 min after induction of anesthesia (baseline values), and every 1 min from 1 to 5 min after raising the patient to a 70degrees sitting position (T1-5) with the beach-chair. RESULTS The incidences of hypotension (proportion, 95% CI) were 12/17 (0.71, 0.47-0.87), 5/16 (0.31, 0.14-0.56) and 7/15 (0.47, 0.25-0.70) in the control, SCD and ES group, respectively. The incidence was significantly lower in the SCD group than that in the control group (P = 0.038). At 1 min after sitting position, mean arterial pressure in the control group was significantly lower than that in the SCD group and it was significantly decreased from the baseline value. CONCLUSIONS SCD could significantly reduce the incidence of hypotension with less hemodynamic instability in the sitting position during shoulder arthroscopy. Although the incidence of hypotension was decreased with the elastic stocking, there was no statistical significance.

Reperfusion Pulmonary Edema after Pulmonary Endarterectomy

Pulmonary artery thromboendarterectomy is a potentially curative procedure in chronic, major vessel thromboembolic pulmonary hypertension. However, persistent pulmonary hypertension and unrelenting reperfusion edema have serious complications, often requiring prolonged mechanical ventilation. A 50-year-old man who was diagnosed with a thromboembolism in both pulmonary arteries underwent a bilateral pulmonary endarterectomy. He received O2-isoflurane-fentanyl anesthesia. When the lungs were reperfused with CPB weaning, massive hemorrhage occurred in the left lung. After the operation, the patient was taken to the intensive care unit. Mechanical ventilation was performed immediately and then both inhaled NO and i.v. furosemide therapies were administered. The patient was discharged from ICU 15 days postoperation.

The effect of heating insufflation gas on acid-base alterations and core temperature during laparoscopic major abdominal surgery

Background Carbon dioxide (CO2) has different biophysical properties under different thermal conditions, which may affect its rate of absorption in the blood and the related adverse events. The present study was aimed to investigate the effects of heating of CO2 on acid-base balance using Stewarts physiochemical approach, and body temperature during laparoscopy. Methods Thirty adult patients undergoing laparoscopic major abdominal surgery were randomized to receive either room temperature CO2 (control group, n = 15) or heated CO2 (heated group, n = 15). The acid-base parameters were measured 10 min after the induction of anesthesia (T1), 40 min after pneumoperitoneum (T2), at the end of surgery (T3) and 1 h after surgery (T4). Body temperature was measured at 15-min intervals until the end of the surgery. Results There were no significant differences in pH, PaCO2, the apparent strong ion difference, the strong ion gap, bicarbonate ion, or lactate between two groups throughout the whole investigation period. At T2, pH was decreased whereas PaCO2 was increased in both groups compared with T1 but these changes were not significantly different. Body temperatures in the heated group were significantly higher than those in the control group from 30 to 90 min after pneumoperitoneum. Conclusions The heating of insufflating CO2 did not affect changes in the acid-base status and PaCO2 in patients undergoing laparoscopic abdominal surgery when the ventilator was set to maintain constant end-tidal CO2. However, the heated CO2 reduced the decrease in the core body temperature 30 min after the pneumoperitoneum.

Target-Controlled Infusion of Remifentanil for Laryngeal Mask Airway Insertion during Sevoflurane Induction in Adults

OBJECTIVE: This randomized, double-blind study investigated the suitable target effect-site concentration of remifentanil for laryngeal mask airway (LMA) insertion during inhalation induction with sevoflurane. METHODS: Patients aged 18 – 60 years were randomly assigned to one of three groups receiving infusions of normal saline (control group), or infusions with target effect-site remifentanil concentrations of either 1 ng/ml (R1 group) or 2 ng/ml (R2 group), 1 min after the induction of anaesthesia with sevoflurane. LMA insertion was attempted 2 min after induction. Insertion conditions were graded using a six-variable, three-point scale (excellent, intermediate or poor). RESULTS: A total of 102 patients were included. The proportion of patients ranked as excellent for the LMA insertion was significantly higher in groups R1 and R2 compared with the control group. The incidence of apnoea was significantly more frequent in the R2 group than in the control or R1 groups. CONCLUSIONS: Compared with 1 ng/ml remifentanil or normal saline, target-controlled infusion of 2 ng/ml remifentanil significantly improved the LMA insertion conditions during sevoflurane inhalational induction, although apnoeic episodes were more frequently observed.

The clinical effective dose of rocuronium for lightwand tracheal intubation after induction with alfentanil, propofol, and low concentrations of sevoflurane

Background The aim of this study was to determine the clinical effective dose of rocuronium for tracheal intubation using a lightwand after induction with propofol, alfentanil, and a low concentration of sevoflurane. Methods Twenty-eight adults scheduled to undergo elective surgery lasting less than one hour were enrolled in this study. All patients received alfentanil (10 µg/kg) and propofol (1.5 mg/kg) for the induction of anesthesia. Tracheal intubation using a lightwand was attempted 3 minutes after administering rocuronium and mask ventilation with 2 vol% of sevoflurane. The initial rocuronium dose was 0.5 mg/kg. The rocuronium dose for consecutive patients, determined by Dixons up-and-down method, was increased or decreased by 0.05 mg/kg according to the result of the previous patient. The mean arterial pressure and heart rate were recorded before induction, 1 min before intubation, 1 and 2 min after intubation. Results The 50% clinical effective dose (cED50) of rocuronium for tracheal intubation using a lightwand was 0.20 ± 0.05 mg/kg according to Dixons up and down method. Isotonic regression revealed the cED50 and cED95 (95% confidence intervals) to be 0.20 mg/kg (0.10-0.3 mg/kg) and 0.35 mg/kg (0.16-0.49 mg/kg), respectively. Conclusions The cED50 and cED95 of rocuronium for tracheal intubation using the lightwand were 0.20 mg/kg and 0.35 mg/kg, respectively, after induction with alfentanil, propofol, and a low concentration of sevoflurane.