The effect of postoperative hepatic fibrosis factors on morbidity in mitral valve replacement surgery: A single center ten years' experience

Background

Previous studies have shown that hepatic fibrosis indices and rates can be used to predict cardiovascular mortality and morbidity. Our aim with this study was to investigate the effect of aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio and fibrosis-4 (FIB-4) index calculated with ALT, AST, and platelet biomarkers, which are simple, fast, and relatively inexpensive and were used in previous studies to predict cardiovascular disease prognosis, on the prediction of postoperative morbidity and early mortality after mitral valve replacement (MVR) surgery.

Methods

By scanning the hospital electronic health record system, 116 patients who underwent isolated MVR or MVR + tricuspid valve intervention were identified from 178 patients who underwent MVR with the standard sternotomy procedure between 2011 and 2021. The study was completed with 81 of these patients. Patients were divided into AST/ALT <2 (Group 1) and >2 (Group 2). In addition, the same patients were divided into FIB-4 index <3.25 (Group 3) and >3.25 (Group 4), and a total of four groups were formed.

Results

The mean age of Group 2 was significantly higher than Group 1 (P = 0.049). In addition, the mean age of Group 4 was significantly higher than Group 3 (P = 0.003). Postoperative complications did not differ between Groups 1 and 2 (P > 0.05). While noninvasive mechanincal ventilation (NIMV) requirements did not differ between Groups 3 and 4 (P > 0.05), MV duration and intensive care unit stay were significantly longer in Group 4 (P < 0.05).

Conclusion

The AST/ALT ratio, which has been shown to be a predictor of cardiovascular mortality in various studies, was not useful in predicting mortality and morbidity in our study. However, a high FIB-4 index, another hepatic fibrosis index, was found to be associated with increased perioperative bleeding, duration of mechanical ventilation, and cardiac intensive care unit stay, which are important criteria in the prediction of morbidity in cardiovascular surgery.

Fuzzy Logic Preanesthetic Risk Evaluation of Laparoscopic Cholecystectomy Operations

BACKGROUND AND OBJECTIVE

Pre-operative risk classification of patients undergoing anesthesia is an essential interest and has been the focus of many research and categorizations. On the other hand, the ideal categorization system, based on medical doctors' clinical experience and cooperation with other disciplines, has not been developed yet.

METHODS

In this study, 218 consecutive patient undergoing laparoscopic cholecystectomy operations were included. A novel fuzzy logic evaluation model consisting of 270 rules was constructed. Five major (pulmonary, cardiac, diabetes mellitus and renal or liver disease) and three minor criteria (patients' age, cigarette smoking and body mass index) were chosen to be used during high-risk groups determination.

RESULTS

The verification of the success of risk value decision with the proposed novel fuzzy logic algorithm is the main goal of this study. On the other hand, though not essential aim, a statistical consistency check was also included to have a deeper understanding and evaluation of the graphical results. During the statistical analysis the 0-30%, 30-60% and 60-90% risk ranges were found to be in a very strong positive relationship with complication occurrence. In this study, 172, 31, 15 patients were in 0-30, 30-60 and 60-90% risk ranges, respectively. Complication rates were 7/172 (4.07%) in 0-30% range, 3/31 (9.68%) in 30-60% range; and 2/15 (13.33%) in 60-90% range.

CONCLUSIONS

Fuzzy based risk classification model was successfully used to predict medical results for patients undergoing laparoscopic cholecystectomy operations and reliable deductions were reached.

Baseline serum vitamin A and vitamin C levels and their association with disease severity in COVID-19 patients

AIM

We aimed to investigate the association between the serum concentrations of Vitamin A and Vitamin C and the severity of the COVID-19.  Methods: Fifty-three consecutive PCR (+) COVID-19 patients admitted to a dedicated ward were enrolled in this study. Blood samples for serum Vitamin A and C measurements were drawn from all participants upon admission. All subjects underwent thoracic CT imaging prior to hospitalization. CT severity score (CT-SS) was then calculated for determining the extent of pulmonary involvement. A group of healthy volunteers, in whom COVID-19 was ruled out, were assigned to the control group (n=26). These groups were compared by demographic features and serum vitamin A and C levels. The relationship between serum concentrations of these vitamins and pre-defined outcome measures, CT-SS and length of hospitalization (LOH), was also assessed.  Results: In COVID-19 patients, serum Vitamin A (ng/ml, 494±96 vs. 698±93; p<0.001) and Vitamin C (ng/ml, 2961 [1991-31718] vs. 3953 [1385-8779]; p=0.007) levels were significantly lower with respect to healthy controls. According to the results of correlation analyses, there was a significant negative association between Vitamin A level and outcome measures (LOH, r=-0.293; p=0.009 and CT-SS, r=-0.289; p=0.010). The negative correlations between Vitamin C level and those measures were even more prominent (LOH, r=-0.478; p<0.001 and CT-SS, r=-0.734: p<0.001).

CONCLUSION

COVID-19 patients had lower baseline serum Vitamin A and Vitamin C levels as compared to healthy controls. In subjects with COVID-19, Vitamin A and Vitamin C levels were negatively correlated with CT-SS and LOH.

Early Outcomes of a High PaO2/FiO2 Ratio during Cardiopulmonary Bypass

Background: In cardiac surgery, supraphysiological oxygen levels are frequently applied perioperatively. In this study, we examined the postoperative effect of perioperative hyperoxemia in cardiac surgery. Methods: All patients who underwent mitral valve replacement via the standard sternotomy method between 2010 and 2021 were analyzed by scanning the hospital data system. The patients were divided into 2 groups: the hyperoxemic group (partial pressure of oxygen/fraction of inspired oxygen [PaO₂/FiO₂] > 500 mmHg) (Group I) and the normoxemic group (300 mmHg < PaO₂/FiO₂ < 500 mmHg) (Group II) according to the mean of 3 PaO₂/FiO₂ values calculated by using 3 PaO₂ and 3 FiO₂ levels. Postoperative complications, the mechanical ventilation time, the need for noninvasive mechanical ventilator support, the length of intensive care unit (ICU) stay, the hospitalization period, and the mortality rate of the groups were compared. Results: A total of 78 patients were included in the study, and 53 of the patients (67.9%) were female. The mean age of the patients was 58.89±12.60 years. The total mechanical ventilation time was significantly higher in the hyperoxemic group than in Group II (P<0.001) (18.18±12.90 h and 11.45±7.85 h, respectively). The amount of postoperative bleeding was significantly higher in Group I (P=0.003) (539.47±201.74 mL and 417.50±186.93 mL, respectively). The total amount of blood products administered during surgery and ICU stay was higher in Group I (P=0.041) (3.55±1.59 units and 2.87±1.89 units, respectively). Conclusion: We observed that the group with hyperoxemia during cardiopulmonary bypass had a higher amount of postoperative bleeding and the need for transfusion, as well as a longer duration of mechanical ventilation and intensive care.

Comparison of enhanced recovery protocol with conventional care in patients undergoing urogynecological surgery

OBJECTIVE

The impact of enhanced recovery after surgery (ERAS) protocol on postoperative outcomes after urogynecological surgery is yet to be a matter of investigation. This study sought to evaluate this issue by comparing the patients who had conventional or ERAS--guided perioperative care for several clinical end-points including ambulation, length of hospital stay (LOS), readmissions, and postoperative complications.

MATERIALS AND METHODS

A total of 121 patients undergoing pelvic organ prolapse surgery were allocated to two study arms, ERAS protocol (Group E) or conventional care (Group C). Variables reflecting the restoration of appetite and bowel movements, bleeding events, other complications, LOS and readmissions were compared between the groups.

RESULTS

The patients in Group C significantly received a more intensive intravenous fluid treatment compared to Group E (2,760 ± 656 vs. 1,045 ± 218 mL, P < 0.001). Time required for first flatus, first defecation, eating solid food, and ambulation (P < 0.001) were also longer in the former group of patients. Moreover, LOS was significantly reduced when the ERAS protocol was applied (2.5 ± 1.1 vs. 2.0 ± 0.6 days, P < 0.001). On the other hand, the two groups were similar with respect to the frequency of the postoperative complications, including surgical site infections, cardiovascular complications, non-specific abdominal pain, sub-ileus, blood loss and readmission rate.

CONCLUSION

In our sample population, ERAS protocol led to early initiation of oral intake, early recovery of bowel function, early mobilization, and early discharge of patients without compromise in safety concerns after urogynecological surgery.

Effect of the "Recruitment" Maneuver on Respiratory Mechanics in Laparoscopic Sleeve Gastrectomy Surgery

Purpose

LSG surgery is used for surgical treatment of morbid obesity. Obesity, anesthesia, and pneumoperitoneum cause reduced pulmoner functions and a tendency for atelectasis. The alveolar “recruitment” maneuver (RM) keeps airway pressure high, opening alveoli, and increasing arterial oxygenation. The aim of our study is to research the effect on respiratory mechanics and arterial blood gases of performing the RM in LSG surgery.

Materials and Methods

Sixty patients undergoing LSG surgery were divided into two groups (n = 30) Patients in group R had the RM performed 5 min after desufflation with 100% oxygen, 40 cmH₂O pressure for 40 s. Group C had standard mechanical ventilation. Assessments of respiratory mechanics and arterial blood gases were made in the 10th min after induction (T1), 10th min after insufflation (T2), 5th min after desufflation (T3), and 15th min after desufflation (T4). Arterial blood gases were assessed in the 30th min (T5) in the postoperative recovery unit.

Results

In group R, values at T5, PaO₂ were significantly high, while PaCO₂ were significantly low compared with group C. Compliance in both groups reduced with pneumoperitoneum. At T4, the compliance in the recruitment group was higher. In both groups, there was an increase in PIP with pneumoperitoneum and after desufflation this was identified to reduce to levels before pneumoperitoneum.

Conclusion

Adding the RM to PEEP administration for morbidly obese patients undergoing LSG surgery is considered to be effective in improving respiratory mechanics and arterial blood gas values and can be used safely.

Comparison of EtView™ tracheoscopic ventilation tube and video-assisted fiberoptic bronchoscopy during percutaneous dilatational tracheostomy

Fiberoptic bronchoscopy (FOB) via endotracheal tube (ETT) is the most frequent utilized technique for monitoring of percutaneous dilatational tracheostomy (PDT) procedure while maintaining mechanical ventilation. Endoscopic guidance has increased the safety of this procedure; nevertheless, the use of a bronchoscope via ETT potentially may deteriorate ventilation and lead to hypercarbia and/or hypoxia. EtView tracheoscopic ventilation tube (EtView TVT) is a standard endotracheal tube with a camera and light source embedded at the tip. The objectives of this study are to introduce EtView TVT as a monitoring tool during PDT and to compare it with video assisted FOB via ETT. We hypothesized that using EtView TVT during PDT may obtain similar visualization; also may have advantages regarding better mechanical ventilation conditions when compared with video-assisted FOB via ETT. Patients, 18-75 years of age requiring mechanical ventilation scheduled for PDT were randomly allocated into two groups for airway monitorization to guide PDT procedure either with FOB via ETT (Group FOB, n = 12) or EtView TVT (Group EtView, n = 12). After standard anesthesia protocol, alveolar recruitment maneuver was applied and all patients were mechanically ventilated at pressure-controlled ventilation mode with same pressure levels. The primary outcome variable was the reduction in arterial oxygen partial pressure (PaO₂) values during the procedure. Other respiratory variables and the effectiveness (the visualization and identification of relevant airway structures) of two techniques were the secondary outcome variables. Patients in both groups were comparable with respect to demographic characteristics and initial respiratory variables. Visualization and identification of relevant airway structures in any steps of the PDT procedure were also comparable. The decrease in minute ventilation in Group FOB was higher when compared with Group EtView (51 ± 4 % vs. 12 ± 7.3 %, p < 0.05). The decrease in PaO₂ from initial levels during (34 ± 21 % vs. 5 ± 7 % decrease) and after (26 ± 27 % vs. 2.8 ± 16 % decrease) the procedure was higher in Group FOB when compared with Group EtView (p < 0.05). Considering comparable features in monitorization and advantageous features over mechanical ventilation when compared with video bronchoscopy; EtView TVT would be a good alternative for airway monitorization during PDT especially for patients with poor pulmonary reserve.

Evaluation of matrix metalloproteinase, myeloperoxidase, and oxidative damage in mesenteric ischemia-reperfusion injury

BACKGROUND

In this study, we investigated the alterations of matrix metalloproteinase (MMP) and tissue inhibitors of metalloproteinases (TIMPs), acute inflammation, and oxidative damage in the circulatory system and the intestine in response to mesenteric ischemia/reperfusion (I/R).

METHODS

Twenty-one rats were divided randomly into the following three groups (n = 7 in each group): a sham group (CG), an ischemic group (IG), and an I/R group (I/RG). MMP-9, TIMP-1, and myeloperoxidase (MPO) were measured using the enzyme-linked immunosorbent assay method, and lipid peroxidation (quantified as thiobarbituric acid reactive substances (TBARS) content), ischemia-modified albumin, the prooxidant-antioxidant balance (PAB), and ferric-reducing antioxidant power (FRAP) were measured spectrophotometrically. The degree of intestinal injury was evaluated according to the Chiu scoring system.

RESULTS

A significant difference between the mean serum TIMP-1 and MMP-9 levels and the alanine transaminase activity was found among the groups. Compared with the I/RG group a significant difference in the mean tissue MMP-9, MPO, and TBARS levels in addition to the PAB and FRAP was found between the CG and IG groups. The level of MMP-9 also demonstrated a strong, positive, and valid correlation with the TBA-RS levels. A significant morphological change was observed in both the IG and the I/RG groups. The degree of intestinal injury was more severe in the I/R group and was characterized by either villous denudation or villous loss.

CONCLUSIONS

These results suggest that MMP-9, TIMP-1, MPO, and oxidative stress may be important in the intestinal injury development that is induced by acute mesenteric I/R in a rat model. MMP-9 overexpression may increase the extent of intestinal villous loss, particularly when MMP-9 is upregulated by the TBARS present in the intestinal injury.

Comparison of SpO2 values from different fingers of the hands

Pulse oximetry is a frequently used tool in anesthesia practice. Gives valuable information about arterial oxygen content, tissue perfusion and heart beat rate. In this study we aimed to provide the comparison of peripheral capillary hemoglobin oxygen saturation (SpO2) values among every finger of the two hands. Thirty-seven healthy volunteers from operative room stuffs between the ages of 18-30 years were enrolled in the study. They were monitored after 5 min of rest. After their non invasive blood pressure, heart rate, fasting time and body temperature were measured, SpO2 values were obtained from every finger and each of two hands fingers with the same pulse oximetry. All the SpO2 values were obtained after at least 1 min of measurement period. A total of 370 SpO2 measurements from 37 volunteers were obtained. The highest average SpO2 value was measured from right middle finger (98.2 % ± 1.2) and it was statistically significant when compared with right little finger and left middle finger. The second highest average SpO2 value was measured from right thumb and it was statistically significant only when compared with left middle finger (the finger with the lowest average SpO2 value) (p < 0.05). SpO2 measurement from the fingers of the both hands with the pulse oximetry, the right middle finger and right thumb have statistically significant higher value when compared with left middle finger in right-hand dominant volunteers. We assume that right middle finger and right thumb have the most accurate value that reflects the arterial oxygen saturation.

[The influence of airway supporting maneuvers on glottis view in pediatric fiberoptic bronchoscopy]

INTRODUCTION

Flexible fiber optic bronchoscopy is a valuable intervention for evaluation and management of respiratory diseases in both infants, pediatric and adult patients. The aim of this study is to investigate the influence of the airway supporting maneuvers on glottis view during pediatric flexible fiberoptic bronchoscopy.

MATERIALS AND METHODS

In this randomized, controlled, crossover study; patients aged between 0 and 15 years who underwent flexible fiberoptic bronchoscopy procedure having American Society of Anesthesiologists I-II risk score were included. Patients having risk of difficult intubation, intubated or patients with tracheostomy, and patients with reduced neck mobility or having cautions for neck mobility were excluded from this study. After obtaining best glottic view at the neutral position, patients were positioned jaw trust with open mouth, jaw trust with teeth prottution, head tilt chin lift and triple airway maneuvers and best glottis scores were recorded.

RESULTS

Total of 121 pediatric patients, 57 girls and 64 boys, were included in this study. Both jaw trust with open mouth and jaw trust with teeth prottution maneuvers improved the glottis view compared with neutral position (p<0.05), but we did not observe any difference between jaw trust with open mouth and jaw trust with teeth prottution maneuvers (p>0.05). Head tilt chin lift and triple airway maneuvers improved glottis view when compared with both jaw trust with open mouth and jaw trust with teeth prottution maneuvers and neutral position (p<0.05); however we found no differences between head tilt chin lift and triple airway maneuvers (p>0.05).

CONCLUSION

All airway supporting maneuvers improved glottic view during pediatric flexible fiberoptic bronchoscopy; however head tilt chin lift and triple airway maneuvers were found to be the most effective maneuvers.

The evaluation of brain natriuretic peptide changes and difficult airway predictors during perioperative period of pregnancy

AIM

Airway changes, difficult ventilation, and intubation are the leading causes of morbidity and mortality in pregnancy, but no prospective study has evaluated the relationship between airway changes and brain natriuretic peptide (BNP) before and after cesarean section operations. The purpose of this study was to evaluate the relationship between BNP and airway changes in women undergoing delivery and during the postoperative period.

MATERIALS AND METHODS

Included in this prospective study were a total of 35 pregnant females with ASA I physical status who were scheduled for cesarean section under general anesthesia. BNP levels, Mallampati classification, mouth opening, thyromental distance, sternomental distance, and the degree of neck extension were recorded before cesarean section and 24 h after the operation. Laryngeal views were also documented after intubation.

RESULTS

Significant differences in BNP levels, Mallampati classification, mouth opening, thyromental distance, sternomental distance, and the degree of neck extension measurements arose between initial measurements and those measurements made 24 h postoperatively. Pre-delivery Mallampati I, II, III, IV scores of 6, 18, 7, 4 had by 24 h after cesarean section changed to 13, 13, 6, 3, respectively (p < 0.05). Initial BNP levels were 7.59 ± 6.30; postoperative levels were 52.39 ± 48.17. In this study we found a correlation between perioperative BNP levels and difficult intubation parameters.

CONCLUSIONS

Within 24 h postpartum, Mallampati scores changed in 13 patients (30.95 %). Besides the correlation between BNP levels and difficult intubation parameters, we also found significant differences in initial and postoperative BNP values.

Opioid-free total intravenous anesthesia with propofol, dexmedetomidine and lidocaine infusions for laparoscopic cholecystectomy: a prospective, randomized, double-blinded study

BACKGROUND AND OBJECTIVES

Intraoperative use of opioids may be associated with postoperative hyperalgesia and increased analgesic consumption. Side effects due to perioperative use of opioids, such as postoperative nausea and vomiting may delay discharge. We hypothesized that total intravenous anesthesia consisting of lidocaine and dexmedetomidine as an opioid substitute may be an alternative technique for laparoscopic cholecystectomy and would be associated with lower fentanyl requirements in the postoperative period and less incidence of postoperative nausea and vomiting.

METHODS

80 Anesthesiologists I-II adults were scheduled for elective laparoscopic cholecystectomy. Patients were randomly allocated into two groups to have either opioid-free anesthesia with dexmedetomidine, lidocaine, and propofol infusions (Group DL) or opioid-based anesthesia with remifentanil, and propofol infusions (Group RF). All patients received a standard multimodal analgesia regimen. A patient controlled analgesia device was set to deliver IV fentanyl for 6h after surgery. The primary outcome variable was postoperative fentanyl consumption.

RESULTS

Fentanyl consumption at postoperative 2nd hour was statistically significantly less in Group DL, compared with Group RF, which were 75 ± 59 μg and 120 ± 94 μg respectively, while it was comparable at postoperative 6th hour. During anesthesia, there were more hypotensive events in Group RF, while there were more hypertensive events in Group DL, which were both statistically significant. Despite higher recovery times, Group DL had significantly lower pain scores, rescue analgesic and ondansetron need.

CONCLUSION

Opioid-free anesthesia with dexmedetomidine, lidocaine and propofol infusions may be an alternative technique for laparoscopic cholecystectomy especially in patients with high risk for postoperative nausea and vomiting.

Prospective evaluation of the factors effective on morbidity and mortality of the patients having liver resection surgeries

BACKGROUND/AIMS

The objective of this study is to evaluate the factors effective on mortality and morbidity of the patients operated for liver tumor.

METHODOLOGY

Thirty-four patients who were operated for liver tumor between January 1st 2008 and December 31st 2009 in Cerrahpasa Medical Faculty have been included in this study. Patient preoperative, perioperative and postoperative characteristics and the effects of these characteristics on mortality, morbidity and the length of hospital stay were evaluated.

RESULTS

Most common postoperative complications during the study were fever and surgical site infection. Nineteen of the patients with blood loss over 1, 000 mL had the need for postoperative ICU treatment. The presence of concomitant disease, especially diabetes mellitus, liver disease and cardiovascular diseases and more than 2 units transfusion of erythrocyte suspension and fresh frozen plasma were considered related to mortality and morbidity.

CONCLUSIONS

Patient preoperative, perioperative and postoperative characteristics affect patient morbidity and mortality in liver resection surgery. Diagnosing liver tumors early and thus reducing surgical site blood loss and use of blood products will decrease mortality and morbidity ratios after liver surgeries.

An alternative sutureless repair technique with amelogenin for duodenal perforation

BACKGROUND

Among the various sutureless techniques, fibrin glue has proved to be effective in the treatment of peptic ulcer perforation as an alternative to classical suture repair. Albeit rare, a potential disadvantage of fibrin glue use is viral transmission or anaphylaxis. The aim of this study is to introduce a new technique for the closure of duodenal perforation using a novel recombinant enamel protein called amelogenin.

METHODS

In this case-control experimental study, 32 adult male Wistar Albino rats weighing 250-300 g were randomly divided into four groups, each containing 8 rats. Duodenal perforation of 0.2 cm were performed in the postpyloric region in all rats. Each group received primary repair, primary repair with omentoplasty, fibrin glue, and amelogenin, respectively. All animals were killed on the postoperative day five and the bursting pressure measurements, hydroxyproline levels and histopathologic values of the wound site were evaluated.

RESULTS

Bursting pressure levels of the fibrin glue and amelogenin groups were significantly lower than the primary repair and primary repair with omentoplasty groups (P < 0.05) However, no significant difference existed between the fibrin glue and amelogenin groups in this respect (P > 0.05). There was also no statistically significant difference among all groups regarding tissue hydroxyproline levels and histopathologic values (P > 0.05).

CONCLUSION

Application of amelogenin as an alternative sutureless repair technique did not improve wound healing in this animal model of duodenal perforation.

The effects of pneumothorax on the respiratory mechanics during laparoscopic surgery

Pneumothorax is rare but can be a severe complication of laparoscopic surgery. Diagnosis of pneumothorax in laparoscopy includes the sudden increase in end-tidal carbon dioxide (EtCO(2)) with a decrease in compliance and an abnormal increase in airway pressure. By these case reports, we recommend the simultaneous monitoring of airway pressures, dynamic compliance, and particularly, EtCO(2) for an immediate diagnosis and prompt treatment of pneumothorax.

Effect of pneumoperitoneum on the level of plasma potassium

The purpose of this study was to find out the impact of acute respiratory acidosis on serum potassium level during laparoscopy. The study was performed on ninety patients who underwent laparoscopic surgery. Ventilation parameters were kept constant throughout the study. Samples for assessment of blood gases were collected in the following sequence: before pneumoperitoneum, a the 20th minute of pneumoperitoneum, at the 60th minute of pneumoperitoneum, and after extubation. The systolic, diastolic pressures and heart rate were recorded simultaneously. Before pneumoperitoneum, heart rate, systolic and diastolic pressures were reduced according to baseline values. With the induction of pneumoperitoneum, both systolic and diastolic pressures returned to the baseline levels except the heart rate. There was a statistically significant increase in potassium level (Control: 3.49 mEq.L(-1), determined high level: 3.75 mEq.L(-1)). Electrolytes, especially potassium, should be monitored during laparoscopy utilizing CO2 pneumoperitoneum and when necessary, ventilatory parameters should be adjusted.

Effect of Intra-abdominal Pressure Level on Gastric Intramucosal pH During Pneumoperitoneum

The present study was designed to examine the effect of intra-abdominal pressure level on gastric intramucosal pH using gastric tonometry during pneumoperitoneum. One hundred patients were prospectively randomized into 5 equal groups (N = 20 each). Intra-abdominal pressure levels were 8, 10, 12, 14, and 16 mm Hg in groups I, II, III, IV, and V, respectively. Intramucosal pH measurement was done 2 times: 30 minutes following insufflation and 1 hour after the ending of the surgery. In the first and second measurements, intramucosal pH values were found as 7.39 +/- 0.02 and 7.36 +/- 0.03 in group I; 7.41 +/- 0.03 and 7.38 +/- 0.03 in group II; 7.37 +/- 0.03 and 7.37 +/- 0.03 in group III; 7.36 +/- 0.03 and 7.37 +/- 0.03 in group IV; and 7.39 +/- 0.03, 7.36 +/- 0.03 in group V, respectively. Statistical significance was not found in the comparison of these values within the groups and between the groups (P > 0.005, for each). In conclusion, intra-abdominal pressure between 8 and 16 mm Hg did not cause significant difference in gastric intramucosal pH.

Effects of Intraperitoneal and Extraperitoneal Carbon Dioxide Insufflation on Blood Gases During the Perioperative Period

The aim of this study was to evaluate the effects of intraperitoneal and extraperitoneal CO2 insufflation on blood gases during and after laparoscopic surgery. Forty patients were included in this study. Twenty patients underwent elective laparoscopic cholecystectomy with intraperitoneal insufflation (intraperitoneal group) and 20 patients underwent laparoscopic inguinal hernia repair with extraperitoneal insufflation (extraperitoneal group). Arterial blood gases were analyzed at four points: 10 minutes after induction, 10 minutes after insufflation, 10 minutes after desufflation, and 30 minutes after the operation in the recovery room. PaCO2 values in the intraperitoneal group at the four points were 36.8 +/- 4, 39.6 +/- 5.9, 40.7 +/- 4.4, and 42.3 +/- 4.8 mm Hg; in the extraperitoneal group, 35.8 +/- 3.9, 37.4 +/- 4, 42.8 +/- 6.6, and 46.2 +/- 5.9 mm Hg. In the extraperitoneal group, there was a significant increase in postoperative PaCO2 compared to the desufflation PaCO2. In our study, extraperitoneal CO2 insufflation caused increases in PaCO2 values that started perioperatively and continued in the postoperative period.

Effects of sevoflurane, propofol and position changes on respiratory mechanics

This study was designed to investigate the effects of propofol, sevoflurane and position changes on respiratory mechanics. Forty patients scheduled for thyroid surgery were divided randomly into two groups; those receiving sevoflurane (group S) (n=20), and those receiving TIVA propofol (group P) (n=22). Dynamic compliance (Cdyn), peak inspiratory pressure (PIP), and respiratory resistance (Rr) values were recorded with a VenTrak respiratory monitor (Novometrix Inc. USA) at three time instances. The first measurement was done immediately after the beginning of ventilation and before the inhalation agent was initiated (Induction). Second measurement was done after 5 minutes of thyroid position (Thyroid) (ventilation with 1 MAC sevoflurane concentration or propofol infusion at the rate of 6 mg/kg/h). The third measurement was performed 5 minutes after end of surgery in the supine position (Supine) Blood gases were measured at the three time instances. Respiratory mechanics did not change in the P group (51 +/- 13, 46 +/- 11, 48 +/- 10 mL/cmH2O) at Induction, Thyroid and Supine positions). In the S group, dynamic compliance measurements showed changes statistically significant in the supine position (52 +/- 6 mL/cmH2O)) when compared to Induction (47 +/- 9 mL/cmH2O) and Thyroid position (47 +/- 6 mL/cmH2O) measurements (p<0.05). When the groups were compared with each other, there was no significant difference whatsoever at all periods (p>0.05). His concluded that sevoflurane, propofol and position changes exhibit similar effects on respiratory mechanics and blood gases at described dose and concentration.

Respiratory mechanics in morbid obese patients with chronic obstructive pulmonary disease and hypertension during pneumoperitoneum

BACKGROUND AND OBJECTIVE

To evaluate the effects of pneumoperitoneum and the reverse Trendelenburg position on respiratory mechanics and blood-gases in morbid obese patients with chronic obstructive pulmonary disease and hypertension.

METHODS

Sixteen morbid obese patients with chronic obstructive pulmonary disease and hypertension were studied. Mean arterial pressure, heart rate, respiratory resistance, dynamic respiratory compliance and peak inspiratory pressures were measured at four time points: 5 min after induction of anaesthesia (T1), 5 min after insufflation of the peritoneum (T2), 5 min after adoption of a 20 degrees reverse Trendelenburg position (T3), and 5 min after deflation of the peritoneum (T4). Arterial blood-gas status was measured at the same measuring points.

RESULTS

Respiratory compliance was 40 +/- 12, 28 +/- 8, 32 +/- 8 and 37 +/- 11 mL cm H2O(-1) in T1, T2, T3 and T4, respectively. The changes were significant at T2, T3 and T4. Airway resistance and peak inspiratory pressures showed comparable changes throughout the study with that of respiratory compliance. Haemodynamic measurements showed no clinically significant changes in this study.

CONCLUSIONS

In morbid obese patients with chronic obstructive pulmonary disease and hypertension, a 20 degrees reverse Trendelenburg position improved respiratory mechanics and oxygenation without any apparent adverse effects on haemodynamics during laparoscopic gastric banding surgery.

Pulmonary mechanics during isoflurane, sevoflurane and desflurane anaesthesia

This study was designed to investigate the effects of desflurane on bronchial smooth muscle tone, following intubation and to compare these effects with isoflurane and sevoflurane. Patients were randomly divided into three groups to receive, isoflurane (n = 22), sevoflurane (n = 23), or desflurane (n = 22). Peak inspiratory pressure (PIP), respiratory resistance (Rr) and dynamic compliance (Cdyn) measurements were recorded at three time points; After the beginning of ventilation and before inhalation agent was started, following 5 min of ventilation with 1 MAC (minimum alveolar concentration) inhalation agent and following 5 min of 2 MAC inhalation agent. We found that all inhalation agents caused a significant decrease in Peak Inspiratory Pressure (PIP) and respiratory resistance (Rr), and an increase in dynamic compliance (Cdyn) at 1 MAC concentrations. When the agent concentration was increased to 2 MAC, desflurane caused a significant increase in Rr and PIP and a decrease in Cdyn. We concluded that desflurane, like isoflurane and sevoflurane, exhibits a bronchodilator effect at 1 MAC concentration. However, increasing the concentration to 2 MAC caused an increase in airway resistance with desflurane, whilst sevoflurane and isoflurane continued to have a bronchodilator effect.

The effects of pneumoperitoneum on respiratory mechanics during bariatric surgery

BACKGROUND

The aim of this study was to investigate the influence of laparoscopic and conventional open surgery on respiratory mechanics, and blood gases, and to determine convenient techniques from the point of view of intraoperative respiratory mechanics, for bariatric surgery.

METHOD

40 morbidly obese patients were divided into 2 groups, patients undergoing laparoscopy Group 1, and patients undergoing conventional open surgery Group 2. Resistance of airway, dynamic compliance, and peak inspiratory pressure were measured. Measurement was performed in 4 periods: a) after anesthesia induction, b) after pneumoperitoneum in the Group 1 and after incision in the Group 2, c) after gastric band placement, d) and 5 min before extubation. Blood gases were recorded concomitantly.

RESULTS

There was no significant difference between the 2 groups in values of blood gases and respiratory mechanics.

CONCLUSION

In the morbidly obese, laparoscopic and open surgery did not cause a significant difference for respiratory mechanics when compared with each other.

Influence of the patient positioning on respiratory mechanics during pneumoperitoneum

The aim of this study was to evaluate the effect of patient positioning during laparoscopic cholecystectomy on respiratory mechanics and arterial blood gases. Thirty patients of ASA I were included. Ventilation was controlled mechanically. Tidal volume and ventilator frequency were kept unchanged throughout the operation. Intra-abdominal pressure was kept constant at 12 mmHg. Ventrak respiratory system was used for measuring respiratory mechanics. The airway resistance (Raw), the dynamic compliance (Cdyn), and the peak inspiratory pressure (PIP) were monitored. Measurements were made in five intervals: "a" after induction of general anesthesia, "b" after insufflation, "c" in the Trendelenburg position of 40 degree, "d" in the Fowler position of 40 degree, and "e" after desufflation. Samples of arterial blood gases were collected while the respiratory mechanics were being recorded. The mean arterial pressure (MAP) and heart rate (HR) were also monitored. In our study, during intervals "c" and "d", PCO2, was increased and pH decreased. With the initiation of insufflation, Cdyn, PIP, and Rawx, were altered (P < 0.05). The patient positioning had a significant effect on respiratory mechanics. After desufflation only Cdyn changed (P < 0.05). Although HR remained in normal limits, MAP increased during pneumoperitoneum (P < 0.05). We conclude that blood gas changes and respiratory mechanics were affected by the duration of pneumoperitoneum and patient positioning. The Fowler position had the least influence on respiratory mechanics.

Systemic inflammatory response after laparoscopic and open application of adjustable banding for morbidly obese patients

BACKGROUND

Surgical injury induces a systemic inflammatory metabolic-endocrine response that is proportional to the severity of the surgical stress. Compared with the conventional open method, laparoscopic surgery is mini-invasive and has decreased postoperative pain and length of hospitalization. The aim of this study was to investigate the systemic inflammatory response, after laparoscopic and open stoma-adjustable silicone band application, which is thought to be mediated by cytokines.

METHOD

30 morbidly obese patients underwent Swedish adjustable gastric banding (SAGB). 15 patients underwent laparoscopic (group 1) and 15 open SAGB (group 2). Mean operative time for the laparoscopic group was 70-110 min and for the laparotomy group 80-120 min. Gallbladders were not removed, and there were no systemic diseases in the patients. The intensity of surgical trauma was evaluated by measurement of metabolic and hormonal responses to the surgery. Plasma levels of C-reactive (CRP), haptoglobin, ceruloplasmin, albumin, transferrin, IL-6, malonic dialdehyde (MDA) and creatinine were measured before and after the operation.

RESULTS

CRP and IL-6 levels increased during and after laparoscopic and open SAGB. However, postoperative responses were significantly greater after open SAGB (group 2) (p < 0.05). MDA level, an indicator of an oxidative trauma, was elevated in group 1 at the 6th postoperative hour but was significantly higher in group 2 at the 6th and 12th postoperative hours. The results were more significant in group 2 (p < 0.05). There was no statistical difference between groups 1 and 2 in terms of albumin, creatinine, and transferrin levels before and after surgery.

CONCLUSION

The systemic inflammatory responses after laparoscopic SAGB were significantly reduced compared with those after open SAGB.

Comparison of effects of remifentanil, alfentanil and fentanyl on cardiovascular responses to tracheal intubation in morbidly obese patients

BACKGROUND AND OBJECTIVE

The effects of remifentanil, alfentanil and fentanyl were compared on cardiovascular responses to laryngoscopy and endotracheal intubation in morbidly obese patients.

METHODS

Eighty morbidly obese ASA I-II patients were included in the study. Patients were randomly divided into four groups to receive either 1 microgkg(-1) fentanyl (Group F), 10 microgkg(-1) alfentanil (A), 1 microgkg(-1) followed by an infusion of 0.5 pg kg min(-1) remifentanil (R) or saline (P). The patients corrected weight was used to calculate the drug doses. Body mass indices (range) were: 54.3 +/- 7.37 (49-78.4), 55.67 +/- 7.44 (48.5-78.4), 53.17 +/- 5.36 (48.1-63.2), and 56.3 +/- 6.09 (46.6-67.7) kg m(-2), in Groups F, R, A and P respectively. Systolic, diastolic and mean arterial pressures and heart rate were measured non-invasively at three time points, which were 2 min before induction, 2 min after induction and 2 min after endotracheal intubation.

RESULTS

After induction of anaesthesia, arterial pressures decreased significantly in all groups, but the decrease was more pronounced in Groups A and R. After induction, heart rate decreased significantly in all groups except in Group P. After intubation, haemodynamic responses were similar in the remifentanil, fentanyl and alfentanil groups and were within normal limits. In Group P, arterial pressures and heart rates were significantly higher.

CONCLUSIONS

Alfentanil, fentanyl and remifentanil in the doses described had similar effects in controlling the haemodynamic response to tracheal intubation in ASA I-II morbidly obese patients.

Total intravenous anesthesia versus single breath technique and anesthesia maintenance with sevoflurane for bariatric operations

BACKGROUND

The choice of anesthetic technique for general anesthesia in morbidly obese patients remains controversial. We aimed to compare blood gases, recovery and hemodynamic parameters using TIVA and sevoflurane anesthesia in bariatric surgery.

METHODS

The study was performed with permission of the ethics committee. We studied 40 morbidly obese patients allocated to 2 groups. The total i.v. anesthesia (TIVA) group was named Group T, and the sevoflurane group was named Group S. In Group T, anesthesia induction was achieved with propofol. In Group S, anesthesia induction was achieved by sevoflurane with single breath technique, with maintenance provided with 1-2% volume sevoflurane. Student t, Chi square and ANOVA tests were used for data analysis; p-value < 0.05 was considered statistically significant.

RESULTS

There was no significant difference between the 2 groups in demographic data, blood gas values and recovery characteristic. Hemodynamic values were significantly lower in Group T than Group S, during and after the operative period.

CONCLUSION

While sevoflurane induction and maintenance is a suitable anesthetic modality for obese patients, TIVA can be applied easily in those patients possessing no extra risk factors other than morbid obesity.