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Abstract Laparoscopy is a well established surgical practice for diagnosis and minor surgical treatment. Recently the technique has been used for more major surgical procedures such as cholecystectomies (Gabbott et al,1992). The advantages 0:’ shorter hospital stay and more rapid return to normal activities are combined with less pain associated with the small limited incisions and less post-operative ileus compared with the traditional open cholecystectomy, There is unquestionable benefit to the patient and significant cost saving (Grevitt et al, 1991). These advantage are regulatly emphasized and explain the increasing Success of laparoscopy, now proposed for many surgical procedures, This contrasts with the silence surrounding the incidence of complications, which vary from minor to major and sometimes result in fatalities, Complications are mostly due to traumatic lIlJunes sustained during blined trocar insertion, and physiologic changes a~sociated with patient positioning and pneumoperitoneum creation, This makes monitoring of patients during laparoscopic cholecystectomy an essential work allthrough the procedure (Cunningham and Brull, 1993). This study was done on one hundred and twenty patients subjected to elective cholecystectomy operations. All patients were clinically free apart from their surgical problems, they were all class land II according to ASA classification. Patients with respiratory, cardio vascular diseases or with clinical or laboratory evidence of liver disease were excluded from the study. Patients were classified into 2 equal groups. Group I : Patients subjected to laparoscopic cholecystectomy. Group II : Patients subjected to opened cholecystectomy. All patients were between 40-60 years. Informed consent was taken from every patient before surgery. All patients were visited the day before operation, a full history was taken. followed by full clinical examination.The routine laboratory investigations were done for every patients. Premedication was in the form of Pethedine Img/kg I.M. and Atropine 1 mg. J.V., 1/2 an hour and 10 minutes respectively before induction of anesthesia. Before induction of anaesthesia an intravenous cannula was inserted in every patient and 1. V. infusion of ringer solution was started, then radial artery canulation was performed after negative Allen’s test to detennine the adequecy of collateral ulnar artery flow. Pre-Oxygenation was done for 3 minutes through a face mask, then . anaesthesia was induced with a sleep dose. of thiopentone 2.5% followed by succinylcholine lmg/kg. The patients were-ventilated with for 1 - 2 minutes followed by direct vision, oral endotracheal intubation using a cuffed tube after spraying the larynx with 10% xylocaine spray. Nasogastric tube were placed in all patients after induction, before start of surgery; Anaesthesia was maintained using halothane I% in 100% 02’ Muscle relaxation was achieved by pancuronium 0.08 mg/kg as initial bolus dose, and the lungs was ventilated using automatic ventilator. Monitoring Was As Follows: Monitoring of C.V.S. 1- Heart rate (H.R.) 2- Systolic blood pressure (S.B.P.) and Diastolic blood pressure (D.B.P) .. 3- Mean blood pressure (M.B.P) ’= SA.P _DAP/3 + DAP. 4- E.C~.G monitor using lead II. Monitoring of respiratory system: 1- Respiratory rate (R.R) and tidal valume (fixed after steady ventilation). 2- O2 saturation using pulse oximeter. 3- End-tidal CO2 using capnograph. 4- Arterial blood gases. 5- PaCOz- PEtCOZ was calculated. , Monitoring of temperature during operations: Intra-operative temperature monitoring was accomplished using the core temperature probes of the alburry monitor. Munitoring for all previous parameters was done and recorded at the following times: 1-15 minutes after a stable PEtC02 has been achieved during mechanical ventilation and before C02 insufflation or skin incision (T I)’ 2- 15 minutes after C02 insufflation in laparoscopic group or starting of skin incision in opended group (T2)’ 3- 15 minutes after the reading number 2 (T3)’ 4- 15 minutes after the reading number 3 (T4). 5- Immediately before C02 deflation in laparoscopic group or closure of skin incision in opened group (T5)’ 6- 15 minutes after C02 deflation and before reversal of the muscle relaxants in both groups (T6) 7- 30 rnintues after complete reversal of muscle relaxants and full recovery of patients (T7)’ In the present study, in group II (opened cholecystectomy), there were minimal haemodynamic changes in the form of DROP in blood pressure and decrease in H.R .. In group I (laparoscopic cholecystectomy), there were statistically significant haemodynarnic changes in the form of increase in heart rate and rise in blood pressure. These changes occured in all readings (T2, T3, T4, r;T6 and T7) compared with control value (T}). In the present study, it was found that the decrease in Pa02 intraoperatively in both groups were statistically significant but the levels of Pa02 were above the hypoxaemic level all through the intra-operative period and oxygen saturation (S~Oz) was above 99% in both groups, which was sufficient for patient oxygenation. However mean value ofPaOz postoperatively was (81.23 ± 0.90) in group I with SaOz (95.15 ± 0.27). Only two out ufsixtypatients (3.33%) in group I were hypoxic and they needed Oz therepy in the form of mask oxygen. PaOz were less than 60 mm Hg and SaOz less than 90% in the two cases. In group II (post-operatively) PaOz was (70.05 ± 0.75) with SaOz (90.60 ± 0.35). nine out of sixty patients (15%) in group II were hypoxic and needed oxygen therapy in the form of mask oxygen. PaOz were less than 60 mm Hg and Sa02 were less than 90% in all hypoxic cases. In the present study, it was found that PaC02 and PEtC02 increased simultaneously with the start of CO2 insufflation in group I. The maximum values were noted just before CO2 deflation. PaCOz and PEtCOZ slightly decreased after COz deflation but did not return to the control values (before COz insufflation). In group I, PaC02-PEtCOZ gradient was typically within the normal range (3 - 5 mm Hg) before CO2 insufflation after start of CO2 insufflation, the value increased reaching the maxinun value just before CO2 deflation. The small change in (PaC01-PEtC02) gradient demonstrated in this study does not affect the validity of PEtCO2 as a measure of PaCOz in the clinical setting during laparoscopic cholecystectomy (Tawfik et al., 1993). In group II PaCOZ and PEtCOZ did not change greatly throughout the course of the procedure. PaCOZ-PEtCOZ gradient was within the normal range (3-5 mm Hg) throughout the course of the procedure indicating the validity PEtCOZ of to assess the adeqnacy of ventilation in all opened operations. pH DROP was statistically highly significant in both groups in all readings compared with the control value in each group. However the difference in mean values of pH between the two groups were statistically highly significant in T3, T4, T5 T6 and T7· pH was lower in group 1. In the present study, it was found that the decrease in CT. in both groups were significant. The decrease was higher in group II compared with group I. In group II, the incidence of hypothermia was 6/60 (10%) companed with 4/60 (6.67%) in group 1. In conclusion, these results highlight the fact that laparoscopy induces significant cardio-respiratory changes even in healthy patients and creates increases of systolic blood pressure, diastolic blood pressure, mean blood pressure, heart rate, arterial carbon dioxide tension and end-tidal carbon dioxide. Hemodynamic changes has been explained to be due to reflex sympathetic stimulation and release of humoral factors such as (catecholamines, prostaglandin, the reninangiotensin system and vasopressin leading to increase in systemic vascular resistance (S.V.R.) immediatly after start of pneumoperitoneum (Joris et al., 1993). Respiratory changes in laparoscopic group was attributed to absorption of C02 from peritoneal cavity and impairment of ventilation by mechanical factors such as abdominal distention, trendelenburg position of patients and mechanical ventilation (Joris et ai; 1993, Lewis et aL, 1972). Although these cardio - respiratory changes may not be hazardons in healthy patients it may cause serious complications in patients with compromised cardiovascular and respiratory system functions, which mandate stricte monitoring allthrough the procedure. In these patients post - operative benefits of laparoscopy should be balanced against intra-operative risk. ’Also the small change in (PaC02 - PEtC02) gradient demonstrated in this study does not affect the validity of PEtC02 as a measure of PaC02 in the clinical setting during laparoscopic cholecystectomy. |