Comparison of Changes in Carbon Dioxide Absorption during Transperitoneal Laparoscopic Surgery and Intraperitoneal Laparoscopic Surgery / 대한마취과학회지

BACKGROUND: Transperitoneal laparoscopy for renal surgery is now a common procedure. Previous studies have suggested that retroperitoneal laparoscopy is associated with greater carbon dioxide absorption. We compared carbon dioxide absorption and hemodynamic variables in patients undergoing transperitoneal laparoscopy for renal or adrenal surgery with that of patients undergoing intraperitoneal laparoscopy for colon surgery. METHODS: Thirty two patients undergoing laparoscopic surgery were divided into laparoscopic renal surgery group (n = 16) and laparoscopic colon surgery group (n = 16). We measured hemodynamic changes and arterial blood gases before CO2 insufflation, 10 minutes, 70 minutes after insufflation and 30 minutes after exsufflation in each groups. RESULTS: There was no significant difference in carbon dioxide absorption in patients who underwent transperitoneal laparoscopy compared to intraperitoneal laparoscopy at any interval. CONCLUSIONS: In contrast to previous reports, our study suggests that transperitoneal laparoscopy is not associated with greater carbon dioxide absorption compared to intraperitoneal laparoscopy.

Clinical Study of the Duration of CO2 Absorption of ROK and USA-produced Soda Lime and Their Re-use Time after Being Exhausted / 대한마취과학회지

BACKGROUND: In a circle system, gas that is to be reused is cleared of carbon dioxide by passing through a canister containing a chemical CO2 absorbent. In anesthesia textbooks the utilization time of carbon dioxide is nearly always specified to last about 5 hours. The soda lime used was noted to regenerate its efficiency for CO2 absorption after being exhausted. Two different types of soda lime (a ROK product and USA product) were analyzed in patients for their duration of carbon dioxide absorption from the anesthetic closed circle system and re-use time after being exhausted. METHODS: General inhalation anesthesia was performed using a PhysioFlex anesthesia machine. To determine the duration of carbon dioxide absorption by soda lime and the re-use time after being exhausted, twenty seven (ROK; 20 and USA; 7) and fifty (ROK; 22 and USA; 28) adult patients were studied. Duration of CO2 absorption was determined as the time for the inspired CO2 concentration to reach 0.5%. The color change of ethyl violet in soda lime was observed throughout the study. Duration of CO2 absorption was compared by unpaired t-test. Re-use time of each group was analysed by simple regression; p less than 0.05 was considered significant. RESULTS: Duration of CO2 absorption was 2.67 +/- 2.12 hrs for the ROK product and 9.52 +/- 0.68 hrs of USA product, and they were different significantly (P < 0.05). Regression equations of ROK- and USA-products werey (min) = 5.761x + 45.701 (r2 = 0.0438, P = 0.3496, x means day after being exhausted) and y = 0.6x + 33.179 (r2 = 0.0158, P = 0.5233) respectively. A color change of ethyl violet in ROK soda lime was not observed throughout the chemical reaction. CONCLUSIONS: From the above results we suggest that ROK soda lime is not effective yet to use for CO2 absorption in clinical anesthesia. It is marked shorter than that of the USA soda lime. A color change of ethyl violet was not observed throughout the chemical absorption reaction in ROK soda lime. Re-use time of both soda limes were not related with the duration after being exhausted.

Comparative Effects of Propofol vs Enflurane on Cardiopulmonary Change during Transthoracic Endoscopic Sympathectomy / 대한마취과학회지

BACKGROUND: Respiratory function and pulmonary gas exchange are affected in thoracoscopic procedures where a pneumothorax is introduced using CO2. Carbon dioxide absorption into the blood during thoracoscopic surgery using intrathoracic carbon dioxide insufflation may lead to respiratory acidosis, increased ventilation requirements, and possible serious cardiovascular compromise. In the present study, the effects of propofol on pulmonary gas exchange were compared with those of enflurane in patients undergoing transthoracic endoscopic sympathectomy (TES) during standard tube ventilation with CO2 insufflation to the surgical side in a prospective randomised manner. METHODS: Sixteen patients with ASA physical status I were divided randomly into enflurane or propofol groups. After induction of anesthesia, patients were ventilated in the same mode in each group. Heart rate and mean arterial pressure were checked and blood gas analyses were performed at 3 time points: 10 min after induction of anesthesia (stage 1), 10 min after CO2 insufflation to the surgical side (stage 2), 10 min after CO2 desufflation from the surgical side (stage 3) under two lung ventilation during TES. RESULTS: Arterial oxygen tension (PaO2) did not differ significantly between enflurane and propofol groups and showed no difference among each stage. PaCO2 and end-tidal CO2 (PetCO2) increased significantly at stage 2 compared to stage 1 and then decreased significantly at stage 3 compared to stage 2 (P < 0.05). There were no significant changes in the mean arterial pressure throughout the procedure with CO2 insufflation in both groups, whereas heart rate was significantly lower in the propofol group than in the enflurane group (P < 0.05) at each stage. CONCLUSIONS: This study demonstrates that pulmonary gas exchange in patients with TES using standard tube ventilation with CO2 insufflation to the surgical side is not affected by choice of anesthesia.

The Effect of the Body Position and CO2 Gas Insufflation on Airway Pressure and Compliance in Normal Subjects during Laparoscopy or Pelviscopy / 대한마취과학회지

BACKGROUND: Laparoscopic and pelviscopic techniques have rapidly increased in recent years. Laparoscopy or pelviscopy require carbon dioxide (CO2) insufflation and Trendelenburg or reverse-Trendelenburg position for operational convenience. Many studies were done about the effects of laparoscopic procedures. But simultaneous comparisons of end-tidal CO2 tension (PETCO2), peak airway pressure (Ppeak), plateau pressure (Pplat) and respiratory compliance (Cdyn), between Trendelenburg and reverse-Trendelenburg position are rare. We compared the airway pressure and compliance between the two positions during laparoscopic surgery. METHOD: Eighty patients were divided into 2 groups: for 10o reverse-Trendelenburg position (n=40, Group R) and 10o Trendelenburg position (n=40, Group T). Abdominal pressure was maintained at 10 mmHg by a CO2 insufflator, and minute ventilation was controlled with a constant tidal volume and fixed respiratory rate. We observed the change of PETCO2, Ppeak, Pplat, and Cdyn at 1 minutes before CO2 insufflation (control value), 2 min after position change, 5, 20, 30, 60 minutes after CO2 insufflation, 2 min after CO2 removal, and 2 min after operation. RESULT: PETCO2, Ppeak, and Pplat were increased and Cdyn was decreased significantly after pneumoperitoneum compared with the control in group R. PETCO2, Ppeak, and Pplat were increased significantly under the Trendelenburg compared with the reverse-Trendelenburg, and Cdyn was decreased significantly in Trendelenburg compared with reverse-Trendelenburg. CONCLUSION: PETCO2, Ppeak, Pplat, and Cdyn impedances increased more under the Trendelenburg after pneumoperitoneum compared with reverse-Trendelenburg. We should pay more attention to patient with pulmonary disease, obesity, and old age under the Trendelenburg than reverse-Trendelenburg position.