High positive end-expiratory pressure preserves cerebral oxygen saturation during laparoscopic cholecystectomy under propofol anesthesia

Effect of different positive end expiratory pressure levels on optic nerve sheath diameter in patients with or without midline shift who are undergoing supratentorial craniotomy

PURPOSE

In general, high levels of PEEP application is avoided in patients undergoing craniotomy to prevent a rise in ICP. But that approach would increase the risk of secondary brain injury especially in hypoxemic patients. Because the optic nerve sheath is distensible, a rise in ICP is associated with an increase in the optic nerve sheath diameter (ONSD). The cutoff value for elevated ICP assessed by ONSD is between 5.6 and 6.3 mm. We aimed to evaluate the effect of different PEEP levels on ONSD and compare the effect of different PEEP levels in patients with and without intracranial midline shift.

METHODS

This prospective observational study was performed in aged 18-70 years, ASA I-III, 80 patients who were undergoing supratentorial craniotomy. After the induction of general anesthesia, the ONSD's were measured by the linear transducer from 3 mm below the globe at PEEP values of 0-5-10 cmH2O. The ONSD were compered between patients with (n = 7) and without midline shift (n = 73) at different PEEP values.

RESULTS

The increases in ONSD due to increase in PEEP level were determined (p < 0.001). No difference was found in the comparison of ONSD between patients with and without midline shift in different PEEP values (p = 0.329, 0.535, 0.410 respectively). But application of 10 cmH2O PEEP in patients with a midline shift increased the mean ONSD value to 5.73 mm. This value is roughly 0.1 mm higher than the lower limit of the ONSD cutoff value.

CONCLUSIONS

The ONSD in adults undergoing supratentorial tumor craniotomy, PEEP values up to 5 cmH2O, appears not to be associated with an ICP increase; however, the ONSD exceeded the cutoff for increased ICP when a PEEP of 10 cmH2O was applied in patients with midline shift.

Positive End-Expiratory Pressure in Rhinoplasty Surgery; Risks and Benefits

Aims

The aim of this study is to evaluate the effect of Positive End Expiratory Pressure (PEEP) on surgical field bleeding and its respiratory and hemodynamic consequences in rhinoplasty surgeries.

Materials and methods

This single-blind clinical trial performed in Amir Al-Momenin university Hospital in 2018. Seventy cases of rhinoplasty surgery patients Enrolled and were randomized into two groups; intervention (PEEP = 5) and comparison group (PEEP = 0). Surgical field bleeding and arterial oxygen saturation pulmonary dynamics and hemodynamic parameters were evaluated during operation and in post anesthesia care unit. Data were analyzed by SPSS software using descriptive and analytical statistics.

Results

PEEP applying had no negative effect on surgical bleeding as well as surgeon satisfaction, heart rate and blood pressure were similar in two groups. Pulmonary dynamics and oxygenation were stable and within normal values in all cases. The mean peak airway pressure was 17.87 ± 2.24 in the PEEP group and 16.08 ± 3.37 in the ZEEP group (P = 0.029).

Conclusion

applying low level PEEP during anesthesia improved recovery oxygen saturation but had no negative effects on the patient`s hemodynamics, and did not aggravate bleeding and visual clarity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03854-7.

Impact of a positive end-expiratory pressure strategy on oxygenation, respiratory compliance, and hemodynamics during laparoscopic surgery in non-obese patients: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Higher positive end-expiratory pressure (PEEP) during laparoscopic surgery may increase oxygenation and respiratory compliance. This meta-analysis aimed to compare the impact of different intraoperative PEEP strategies on arterial oxygenation, compliance, and hemodynamics during laparoscopic surgery in non-obese patients.

METHODS

We searched RCTs in PubMed, Cochrane Library, Web of Science, and Google Scholar from January 2012 to April 2022 comparing the different intraoperative PEEP (Low PEEP (LPEEP): 0-4 mbar; Moderate PEEP (MPEEP): 5-8 mbar; high PEEP (HPEEP): >8 mbar; individualized PEEP - iPEEP) on arterial oxygenation, respiratory compliance (Cdyn), mean arterial pressure (MAP), and heart rate (HR). We calculated mean differences (MD) with 95% confidence intervals (CI), and predictive intervals (PI) using random-effects models. The Cochrane Bias Risk Assessment Tool was applied.

RESULTS

21 RCTs (n = 1554) met the inclusion criteria. HPEEP vs. LPEEP increased PaO2 (+ 29.38 [16.20; 42.56] mmHg, p < 0.0001) or PaO2/FiO2 (+ 36.7 [+ 2.23; +71.70] mmHg, p = 0.04). HPEEP vs. MPEEP increased PaO2 (+ 22.00 [+ 1.11; +42.88] mmHg, p = 0.04) or PaO2/FiO2 (+ 42.7 [+ 2.74; +82.67] mmHg, p = 0.04). iPEEP vs. MPEEP increased PaO2/FiO2 (+ 115.2 [+ 87.21; +143.20] mmHg, p < 0.001). MPEEP vs. LPEP, and HPEEP vs. MPEEP increased PaO2 or PaO2/FiO2 significantly with different heterogeneity. HPEEP vs. LPEEP increased Cdyn (+ 7.87 [+ 1.49; +14.25] ml/mbar, p = 0.02). MPEEP vs. LPEEP, and HPEEP vs. MPEEP did not impact Cdyn (p = 0.14 and 0.38, respectively). iPEEP vs. LPEEP decreased driving pressure (-4.13 [-2.63; -5.63] mbar, p < 0.001). No significant differences in MAP or HR were found between any subgroups.

CONCLUSION

HPEEP and iPEEP during PNP in non-obese patients could promote oxygenation and increase Cdyn without clinically significant changes in MAP and HR. MPEEP could be insufficient to increase respiratory compliance and improve oxygenation. LPEEP may lead to decreased respiratory compliance and worsened oxygenation.

PROSPERO REGISTRATION

CRD42022362379; registered October 09, 2022.

The effects of positive end-expiratory pressure (PEEP) application on optic nerve sheath diameter in patients undergoing laparoscopic cholecystectomy: a randomized trial

BACKGROUND

Positive end-expiratory pressure (PEEP) can overcome respiratory changes that occur during pneumoperitoneum application in laparoscopic procedures, but it can also increase intracranial pressure. We investigated PEEP vs. no PEEP application on ultrasound measurement of optic nerve sheath diameter (indirect measure of increased intracranial pressure) in laparoscopic cholecystectomy.

METHODS

Eighty ASA I-II patients aged between 18 and 60 years scheduled for elective laparoscopic cholecystectomy were included. The study was registered in the Australian New Zealand Clinical Trials (ACTRN12618000771257). Patients were randomly divided into either Group C (control, PEEP not applied), or Group P (PEEP applied at 10 cmH20). Optic nerve sheath diameter, hemodynamic, and respiratory parameters were recorded at six different time points. Ocular ultrasonography was used to measure optic nerve sheath diameter.

RESULTS

Peak pressure (PPeak) values were significantly higher in Group P after application of PEEP (p = 0.012). Mean respiratory rate was higher in Group C at all time points after application of pneumoperitoneum (p < 0.05). The mean values of optic nerve sheath diameters measured at all time points were similar between the groups (p > 0.05). The pulmonary dynamic compliance value was significantly higher in group P as long as PEEP was applied (p = 0.001).

CONCLUSIONS

During laparoscopic cholecystectomy, application of 10 cmH2O PEEP did not induce a significant change in optic nerve sheath diameter (indirect indicator of intracranial pressure) compared to no PEEP application. It would appear that PEEP can be used safely to correct respiratory mechanics in cases of laparoscopic cholecystectomy, with no significant effect on optic nerve sheath diameter.

Effects of individualized positive end-expiratory pressure combined with recruitment maneuver on intraoperative ventilation during abdominal surgery: a systematic review and network meta-analysis of randomized controlled trials

Low tidal volume ventilation strategy may lead to atelectasis without proper positive end-expiratory pressure (PEEP) and recruitment maneuver (RM) settings. RM followed by individualized PEEP was a new method to optimize the intraoperative pulmonary function. We conducted a systematic review and network meta-analysis of randomized clinical trials to compare the effects of individualized PEEP + RM on intraoperative pulmonary function and hemodynamic with other PEEP and RM settings. The primary outcomes were intraoperative oxygenation index and dynamic compliance, while the secondary outcomes were intraoperative heart rate and mean arterial pressure. In total, we identified 15 clinical trials containing 36 randomized groups with 3634 participants. Ventilation strategies were divided into eight groups by four PEEP (L: low, M: moderate, H: high, and I: individualized) and two RM (yes or no) settings. The main results showed that IPEEP + RM group was superior to all other groups regarding to both oxygenation index and dynamic compliance. LPEEP group was inferior to LPEEP + RM, MPEEP, MPEEP + RM, and IPEEP + RM in terms of oxygenation index and LPEEP + RM, MPEEP, MPEEP + RM, HPEEP + RM, IPEEP, and IPEEP + RM in terms of dynamic compliance. All comparisons were similar for secondary outcomes. Our analysis suggested that individualized PEEP and RM may be the optimal low tidal volume ventilation strategy at present, while low PEEP without RM is not suggested.

Effect of Different Levels of Positive End-Expiratory Pressure (PEEP) on Respiratory Status during Gynecologic Laparoscopy

Background

During gynecologic laparoscopy, pneumoperitoneum, and the position of the patient's head can lead to pathophysiologic changes in cardiovascular and respiratory systems, complicating the management of anesthesia in these patients. One of the strategies for improving the respiratory status of patients undergoing laparoscopy is the use of Positive End-Expiratory Pressure (PEEP).

Objectives

This study aimed to evaluate the effect of different levels of PEEP on the respiratory status of patients undergoing gynecologic laparoscopy.

Methods

In this clinical trial, 60 patients with ASA I were randomly assigned to three groups to control anesthesia: ZEEP (PEEP 0 cmH₂O; 20 cases), PEEP₅ (PEEP 5 cmH₂O; 20 cases), and PEEP₁₀ (PEEP 10 cmH₂O; 20 cases). Respiratory and hemodynamic variables of patients were compared before general anesthetic induction and immediately after CO₂ insufflation at intervals of 5, 10, 20, 30, and 60 min and the end of the operation in the three study groups.

Results

The PEEP application improved pH, PaCO₂, and PaO₂ levels at the end of pneumoperitoneum compared to baseline when compared with the non-use of PEEP (ZEEP group). Also, the frequency of dysrhythmia in the use of PEEP in controlled ventilation was significantly lower in patients with PEEP₁₀ (P < 0.05). The application of PEEP₅ resulted in similar effects to PEEP₁₀ in the levels of respiratory variables.

Conclusions

The PEEP application is associated with improved arterial blood gas in patients with gynecologic laparoscopy. The use of PEEP₁₀ has a greater effect on the improvement of respiratory parameters and complications of pneumoperitoneum.

Impact of Altered Airway Pressure on Intracranial Pressure, Perfusion, and Oxygenation: A Narrative Review

OBJECTIVES

A narrative review of the pathophysiology linking altered airway pressure and intracranial pressure and cerebral oxygenation.

DATA SOURCES

Online search of PubMed and manual review of articles (laboratory and patient studies) of the altered airway pressure on intracranial pressure, cerebral perfusion, or cerebral oxygenation.

STUDY SELECTION

Randomized trials, observational and physiologic studies.

DATA EXTRACTION

Our group determined by consensus which resources would best inform this review.

DATA SYNTHESIS

In the normal brain, positive-pressure ventilation does not significantly alter intracranial pressure, cerebral oxygenation, or perfusion. In injured brains, the impact of airway pressure on intracranial pressure is variable and determined by several factors; a cerebral venous Starling resistor explains much of the variability. Negative-pressure ventilation can improve cerebral perfusion and oxygenation and reduce intracranial pressure in experimental models, but data are limited, and mechanisms and clinical benefit remain uncertain.

CONCLUSIONS

The effects of airway pressure and ventilation on cerebral perfusion and oxygenation are increasingly understood, especially in the setting of brain injury. In the face of competing mechanisms and priorities, multimodal monitoring and individualized titration will increasingly be required to optimize care.

Effects of different levels of end-expiratory pressure on hemodynamic, respiratory mechanics and systemic stress response during laparoscopic cholecystectomy

OBJECTIVE

General anesthesia causes reduction of functional residual capacity. And this decrease can lead to atelectasis and intrapulmonary shunting in the lung. In this study we want to evaluate the effects of 5 and 10cmH₂O PEEP levels on gas exchange, hemodynamic, respiratory mechanics and systemic stress response in laparoscopic cholecystectomy.

METHODS

American Society of Anesthesiologist I-II physical status 43 patients scheduled for laparoscopic cholecystectomy were randomly selected to receive external PEEP of 5cmH₂O (PEEP 5 group) or 10cmH₂O PEEP (PEEP 10 group) during pneumoperitoneum. Basal hemodynamic parameters were recorded, and arterial blood gases (ABG) and blood sampling were done for cortisol, insulin and glucose level estimations to assess the systemic stress response before induction of anesthesia. Thirty minutes after the pneumoperitoneum, the respiratory and hemodynamic parameters were recorded again and ABG and sampling for cortisol, insulin, and glucose levels were repeated. Lastly hemodynamic parameters were recorded; ABG analysis and sampling for stress response levels were taken after 60minutes from extubation.

RESULTS

There were no statistical differences between the two groups about hemodynamic and respiratory parameters except mean airway pressure (P_mean). P_mean, compliance and PaO₂; pH values were higher in 'PEEP 10 group'. Also, PaCO₂ values were lower in 'PEEP 10 group'. No differences were observed between insulin and lactic acid levels in the two groups. But postoperative cortisol level was significantly lower in 'PEEP 10 group'.

CONCLUSION

Ventilation with 10cmH₂O PEEP increases compliance and oxygenation, does not cause hemodynamic and respiratory complications and reduces the postoperative stress response.

Comparison of palonosetron, granisetron, and ramosetron for the prevention of postoperative nausea and vomiting after laparoscopic gynecologic surgery: a prospective randomized trial

BACKGROUND

Selective 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists are reported to have potent antiemetic effects for postoperative nausea and vomiting (PONV). The purpose of this study was to prospectively evaluate the efficacy of palonosetron, granisetron, and ramosetron for the prevention of PONV in patients undergoing laparoscopic gynecologic surgery.

METHODS

In this prospective, randomized observational study, 105 healthy female patients who were undergoing laparocopic hystectomy under general anaesthesia were enrolled (clinical trial number: NCT01752374, www.clinicaltrials.gov ). Patients were divided into three groups: the palonostron (0.075 mg i.v.; n = 35), the granisetron group (3 mg i.v.; n = 35), and the ramosetron group (0.3 mg i.v.; n = 35). The treatments were given before the end of surgery. The incidence of PONV, severity of nausea/vomiting, and the use of rescue antiemetic requirements during the first 48 h after surgery were evaluated.

RESULTS

The overall incidence of PONV was 33.3 % for this series. The number of complete responders at 48 h after the surgery was 21 (60.0 %) for palonosetron, 24 (68.6 %) for granisetron, and 26 (71.4 %) for ramosetron, representing no statistical difference (P = 0.086).

CONCLUSIONS

There were no significant differences in the overall incidence of postoperative nausea and vomiting and complete responders for palonosetron, granisetron and ramosetron group.

TRIAL REGISTRATION

CLINICAL TRIAL NUMBER

NCT01752374 , www.clinicaltrials.gov .

Brain oxygenation during laparoscopic correction of hypertrophic pyloric stenosis

BACKGROUND

Concern remains about the safety of carbon dioxide (CO2) pneumoperitoneum (PP) in young infants having surgery for pyloric stenosis via laparoscopy. Interests here mainly focus on possible jeopardized organ perfusion and in particular brain oxygenation with possible adverse neurodevelopmental outcomes. The aim of this study was to investigate the intraoperative effects of CO2 gas PP on cerebral oxygenation during laparoscopic surgery for hypertrophic pyloric stenosis in young infants.

PATIENTS AND METHODS

In this single-center prospective observational study, we investigated brain oxygenation in 12 young infants receiving laparoscopic pyloromyotomy with CO2 PP, with a pressure of 8 mm Hg and a flow rate of 5 L/minute. Intraoperative hemodynamic parameters and transcranial near-infrared spectroscopy to assess regional cerebral oxygen saturation (rScO2) were monitored continuously during the whole procedure. Parameters were analyzed in four intervals: before insufflation (T0), during (start [T1] and end [T2]), and after cessation (T3) of the CO2 PP.

RESULTS

Blood pressure and end-tidal CO2 (etCO2) increased during the procedure: mean arterial pressure, 35±5 mm Hg at T0 to 43±9 mm Hg at T2; etCO2, 35±4 mm Hg at T0 to 40±3 mm Hg at T3. The rScO2 remained stable throughout the whole anesthetic period. In none of the patients did the rScO2 drop below the safety threshold of 55% (rScO2, 68±14% at T0 to 71±9% at T3).

CONCLUSIONS

Our results indicate that a laparoscopic procedure with a CO2 PP of 8 mm Hg can be performed under safe anesthetic conditions in the presence of gradually increasing blood pressure and etCO2 without altering regional brain oxygenation levels.