Comparison of Changes in Arterial Blood Gases during Endoscopic Thyroidectomy, Laparoscopic Cholecystectomy and Gynecologic Laparoscopic Surgery / 대한마취과학회지

BACKGROUND: Because laparoscopic surgery has many advantages compared with conventional methods, it has recently been applied to not only intraabdominal or intrathoracic surgery but also thyroidectomy. It is possible that arterial blood gases and hemodynamic variables can be changed by patient position and insufflation of pressurized CO2 into extraperitoneal or intraperitoneal space, so we examined the changes in arterial blood gases, end tidal CO2 (P(ET)CO2) and hemodynamic variables during an endoscopic thyroidectomy with extraperitoneal CO2 insufflation, laparoscopic cholecystectomy and gynecologic laparoscopic surgery with intraperitoneal CO2 insufflation under N2O, enflurane inhalational general anesthesia. METHODS: Forty ASA class I or II patients were included in this study, endoscopic thyroidectomy group (n = 10), laparoscopic cholecystectomy group (n = 18), gynecologic laparoscopic surgery group (n = 12). All patients were underwent controlled mechanical ventilation (tidal volume: 10 ml/kg, respiratory rate: 12/min) and the ventilator mode was fixed in this volume and rate until the end of the operation. The position of patients during the endoscopic thyroidectomy and laparoscopic cholecystectomy were under 5 degree reverse Trendelenburg position, whereas the gynecologic laparoscopic surgery was under a 10 degree head-down lithotomy position. Variables were measured before CO2 insufflation (10 minute after induction), 10, 20 and 30 minutes after CO2 insufflation and 40 minutes after CO2 deflation. RESULTS: PaCO2 and P(ET)CO2 were significantly increased during CO2 insufflation compared with preinsufflation values in all groups, but the magnitude of increases of PaCO2 and PETCO2 was not significantly different among the three groups. The mean magnitude of increases of PaCO2 at 10 minutes after CO2 insufflation were as follows: gynecologic laparoscopic surgery (6.21 +/- 2.0 mmHg), endoscopic thyroidectomy (5.07 +/ 2.3 mmHg), and laparoscopic cholecystectomy (5.01 +/- 2.2 mmHg). CONCLUSIONS: We concluded that PaCO2 and P(ET)CO2 were significantly increased during CO2 insufflation compared with the preinsufflation values in all groups, but the magnitude of increases of PaCO2 and P(ET)CO2 was not significantly influenced by CO2 insufflation site and patient position.

Interaction between Mivacurium and Nitroglycerin / 대한마취과학회지

BACKGROUND: The neuromuscular blocking effects of a nondepolarizing neuromuscular blocker (NDNM) during a nitroglycerin (NTG) infusion were significantly potentiated and prolonged. NTG reduced the requirement of a NDNM in surgical patients. We investigated the influence of a NTG single bolus injection on a mivacurium nuromuscular blockade. METHODS: We studied 36 adult surgical patients, ASA physical status I or II, between 15 and 53 years old. Neuromuscular monitoring was measured by TOF-GUARD (Biometer Co., Denmark). Anesthesia was induced by thiopental sodium 3-5 mg/kg and fentanyl 3 microgram/kg, and maintained with 3 L/min N2O, 2 L/min O2 and 1 vol.% isoflurane. Patients were randomly assigned to 3 groups: 1) Control group (mivacurium 0.16 mg/kg), 2) N100 group (mivacurium 0.16 mg/kg, NTG 100 microgram), 3) N200 group (mivacurium 0.16 mg/kg, NTG 200 microgram). We measured the train-of-four (TOF) response from the beginning of recovery to the complete regaining of muscle twitch. RESULTS: NTG produced a prolongation of the neuromuscular blocking effect by mivacurium. T1 (contro group: 12.1 +/- 0.5, N100 group: 15.8 +/- 0.4 and N200 group: 11.6 +/- 0.4 min), T25 (16.4 +/- 0.4, 20.5 +/- 0.5 and 14.9 +/- 1.0 min), T75 (22.5 +/- 0.9, 29.4 +/- 0.7 and 20.1 +/- 1.0 min), T95 (27.3 +/- 0.6, 39.6 +/- 0.7 and 24.6 +/- 1.5 min) and the recovery index (6.1 +/- 0.6, 9.0 +/- 0.4 and 5.3 +/- 0.7 min) were significantly prolonged in the N100 and N200 groups (P < 0.05). CONCLUSION: These results suggest that a NTG bolus injection prolonged the neuromuscular blocking effect of mivacurium, dose relatively.

Estimate of the Degree of Difficulty in Endotracheal Intubation in Patients with Obstructive Sleep Apnea Syndrome / 대한마취과학회지

BACKGROUND: Tracheal intubation may be difficult in many patients with sleep apnea syndrome because of anatomical abnormalities in their upper airway. METHODS: For 30 patients with obstructive sleep apnea syndrome, we evaluated two classifications; Samsoon-Young and Cormack-Lehane, and five airway examinations; interincisors' distance on mouth opening (DI), angle on cervico-occipital extension (ACO), thyromental distance (TD), and existence of edentulous with atrophic mandible and prominent maxillary incisor. RESULTS: 20 patients (67%) belonged to class III or IV according to the Samsoon-Young classification and 22 patients (73%) to grade III or IV according to the Cormack-Lehane classification. The incidence rate for DI less than 40 mm, ACO less than 160o, TD less than 60 mm, atrophic mandible and prominent maxillary incisor were 30%, 37%, 50%, 13% and 27% respectively. CONCLUSIONS: According to our results, we concluded that most patients with obstructive sleep apnea syndrome are difficult for anesthesiologists to intubate. Therefore, we suggest that anesthesiologists must prepare variable methods for ventilation if there is any suspicion of difficult intubation in those patients.