Farshad Tahmasebi1, Mohamed M Hosni4, Maher Alazizi1, Sebnem Selek2, Hari Krovvidi3, Mohamad Ismail1,4, Khaled Afifi4, Hassan Morsi1,4*
The Dudley Group NHS Foundation Trust , UK
Princess Alexandra Hospital NHS Trust, UK
University Hospitals Birmingham NHS Foundation Trust , UK
Obstetrics & Gynaecology Department, Faculty of Medicine, Ain Shams University, Egypt
Received: 18 November 2024; Accepted: 22 Novembert 2024; Published: 03 December 2024.
Citation: Mohamed H, Farshad T, Maher A, and Sebnem S. “Changes in Intraoperative Anaesthetic Parameters During Laparoscopy with Low Pressure Vs Standard Insufflation: A Retrospective Cohort Study.” J Gynecol Matern Health (2024): 115. DOI: 10.59462/3068-3696.2.2.115
Copyright: © Mohamed H. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Objective: To evaluate the changes in intraoperative anaesthetic parameters during Low-Pressure laparoscopy with Air Seal® versus standard insufflation laparoscopy in gynaecological surgeries. Materials and methods: 77 patients who had laparoscopic hysterectomy for gynaecological causes were retrospectively identified. Patient demographics, procedure details, the data on intraoperative anaesthetic parameters and duration of recovery from GA after the procedure were collected from patients’ electronic and paper notes. No ethical approval was required for this project and the study was registered as a quality improvement project.
Results: 41 patients were operated with 7mmHg Air Seal® system and 36 with 15mmHg standard insufflation. Duration of recovery time from GA was significantly lower in the Air Seal® group. Statistically significant differences were also found in the midprocedure end tidal CO2 levels and peak airway pressure at the end of the procedure.
Conclusion: In conclusion, our results show that there is no statistically significant difference in anaesthetic parameters between the low-pressure group and standard insufflation group except EtCO2 levels midprocedure, and that the recovery time after general anaesthesia is significantly lower in the low-pressure group.
Laparoscopy, Pneumoperitoneum, Gynaecology, Low pressure
With the recent advances in methods and training in operative gynaecological treatments, laparoscopy has replaced open surgeries in treatment of various gynaecological diseases from endometriosis to endometrial cancer [1, 2].
One of the crucial steps of the laparoscopic surgeries is to create a pneumoperitoneum via CO2 insufflation to achieve direct view of the organs [1, 3]. Despite it being accepted as the most optimal and feasible method to date, several complications have been found to be associated with CO2 insufflation such as shoulder tip pain, subcutaneous emphysema, hypercapnia, and several cardiopulmonary changes [4-6].
Optimising the intra-abdominal pressure to maximise the surgeons’ view whilst minimising the haemodynamic and ventilatory complications and the duration of the post-op hospital admission has remained a challenge. Until recently, an intraabdominal pressure in the range of 12-15mmHg was the preferred pressure to achieve adequate working space, however, with the introduction of platforms operating through a valveless insufflation trocar such as AirSeal®, it has become possible to perform a laparoscopy with a pneumoperitoneum of 7mmHg [7, 8]. Recent studies have shown that, when lower intraabdominal pressure was applied during laparoscopic procedures, there was a reduction in the frequency and intensity of postoperative shoulder pain [8, 9, 10, 11], and decrease of End Tidal CO2 (ETCO2) and systolic blood pressure [8]. Furthermore, it was also reported that there was significantly less variability in pressure readings with AirSeal® as compared to the conventional insufflation methods using one-way valve trocar [12].
Although there has been an increased attention on the feasibility of the low-pressure laparoscopy in the academic world recently, there still is a paucity of data on its application in gynaecological procedures. Therefore, our aim is to evaluate and compare the anaesthetic outcomes of gynaecological laparoscopies with low pressure (7mmHg) vs standard insufflation (15mmHg).
This two-arm, retrospective, monocentre study has been registered as quality improvement project with the Dudley Group NHS Foundation Trust audit office. No ethical approvals were needed as all the patients were consented pre-operatively. 77 patients who were referred for laparoscopic procedure for treatment of various gynaecological illnesses of benign and low-grade malignant nature were identified retrospectively. Patients were operated on by two surgeons at the Dudley Group NHS Foundation Trust, UK over two years. The patients were grouped based on the pressure used during laparoscopy. First group was the ‘standard pressure’ group with conventional insufflation system at 15mmHg pneumoperitoneum, and the second group was the ‘low pressure’ group with AirSeal® system at 7mmHg pneumoperitoneum. Patient demographics, operation details and Peak Airway Pressure (cmH2O), Systolic Blood Pressure (mmHg) and End Tidal CO2 (kPa) values which were recorded at the beginning, in the middle and at the end of each procedure were collected from patients’ electronic and paper records retrospectively. Data on the duration of recovery for each case was also collected for comparison.
Surgical Procedure: Prior to induction of General Anaesthesia, the patient was attached to full monitoring including ECG, non-invasive blood pressure and pulse oximeter. General anaesthesia was induced in all cases with an intravenous bolus of Propofol 0.5-1 mg/kg and Fentanyl 1-2 microgram/ kg. Following this, muscle relaxation was achieved with intravenous Rocuronium 0.5-0.6mg/kg, and endotracheal intubation was performed. General anaesthesia was maintained with the help of inhalational agent Sevoflurane 2-4 % with Oxygen. Analgesia was maintained with intermittent boluses of intravenous Fentanyl. Incidence of postoperative nausea and vomiting was reduced using intravenous Dexamethasone (3.3-6.6mg) and Ondansetron (4-8mg). Trans-umbilical incision was performed, and laparoscopy was proceeded with conventional insufflation in standard pressure group, whereas AirSeal® was used after the insertion of all ports to achieve a lower intra-abdominal pressure in low pressure group. Each procedure was performed with designated pressure. Although the diagnoses were different, the procedures were similar in terms of surgical complexity, procedure time and recovery time.
Statistical analysis: Statistical analysis was performed using GraphPad Prism software (Version 9.0.0). Two-sided alpha level of 0.05 was considered statistically significant. Continuous variables were summarized as the mean ± standard deviation for normally distributed variables, and as median and interquartile range (IQR) if non-normally distributed; and were compared by student’s t-test, or by Mann- Whitney U-test, as appropriate. Categorical variables are summarized as number and percentage, and their distributions among the study groups were compared by Chi-square or Fisher’s exact tests, as appropriate.
Repeated measure data in the two groups were analyzed using a mixed-effects model with Geisser- Greenhouse correction and adjusting for multiple comparisons using Sidak’s multiple comparisons test. Effect size of using the low-pressure AirSeal®® was estimated for continuous outcomes by mean difference, or median of differences (calculated using Hodges-Lehmann method) between LP–AirSeal®
– Standard insufflation groups, and their 95% confidence interval.
Results: Apart from the higher age range for the AirSeal® group, patient demographics and clinical characteristics were not significantly different (Table 1).
| LP − AirSeal®® Group [n = 41] |
Standard Insufflation Group [n = 36] |
P | |
|---|---|---|---|
| Age (yrs) | 52.6 ± 16.8 | 34.9 ± 8.1 | <0.001 |
| BMI (Kg/m2) | 28.3 ± 7.2 | 28.7 ± 6.2 | 0.80 |
| ASA score | 2 (2 – 2) | 2 (1 – 2) | 0.05 |
| Medical comorbidities | |||
| Cardiovascular | 12 (29.3%) | 3 (8.3%) | 0.04 |
| Pulmonary | 8 (19.5%) | 7 (19.4%) | 0.78 |
| Indication for surgery | |||
| Endometriosis / DIE | 19 (46.3%) | 36 (100.0%) | <0.001 |
| Abnormal uterine bleeding | 4 (9.8%) | 0 (0%) | |
| Endometrial hyperplasia | 2 (4.9%) | 0 (0%) | |
| Endometrial cancer | 10 (24.4%) | 0 (0%) | |
| CIN II | 1 (2.4%) | 0 (0%) | |
| Adnexal mass | 4 (9.8%) | 0 (0%) | |
| Others | 1 (2.4%) | 0 (0%) |
Table 1: Baseline demographic and clinical character istics of the two study groups
As for the anaesthetic parameters monitored, the peak airway pressure tended to be lower in the the end of the operation by an average of 2.8 cmH2O middle of the operation and was significantly lower at (Graph 1). The same was also observed with the end tidal CO2 (Graph 2), which was significantly lower in the AirSeal® group in the middle of the operation by 0.34 kPa (Table 2). On the other hand, no significant differences were noted in the measured values for the systolic blood pressure in the two groups (Graph 3). The operating surgeons who performed low pressure laparoscopy did not report any intra-operative difficulties due to lower intraabdominal pressure. According to the Clavien- Dindo classification, there were no complications ≥ Grade II in either patient group. Finally, there was a statistically significant difference (p<0.05) between the two groups in duration of recovery from GA. Low pressure group recovered in a median duration of 42.5min, whereas it took standard insufflation group a median of 50min to recover.
Figure 1. Line graph comparing peak airway pressure at the beginning, middle and the end of the operation between the Air seal and the control groups.
Figure 2. Line graph comparing systolic blood pressure at the beginning, middle and the end of the operation between the Air seal and the control groups.
Figure 3. Line graph comparing end tidal CO2 at the beginning, middle and the end of the operation between the Airseal and the control groups.
| LP − AirSeal®® Group [n = 41] |
Standard Insuffla- tion Group [n = 36] |
P | Estimated effect of LP – AirSeal®® (95%CI) | |
|---|---|---|---|---|
| Peak airway pressure (cm H2O) | ||||
| BMI (Kg/m2) | 28.3 ± 7.2 | 28.7 ± 6.2 | 0.80 | |
| At the beginning of operation | 18.0 (16.0 – 23.0) | 16.0 (15.0 – 19.75) | 0.06 | + 2.5 (-0.1 – 5.1) |
| In the middle of the operation | 23.0 (21.0 – 25.8) | 24.5 (22.25 – 28.0) | 0.20 | – 1.6 (-3.8 – 0.56) |
| At the end of the operation | 18.0 (16.0 – 21.0) | 20.5 (18 – 24.75) | 0.02 | – 2.8 (-5.1 – -0.36) |
| Systolic blood pressure (mmHg) | ||||
| At the beginning of operation | 120.0 (100.0 – 130.0) | 120.0 (101.25 – 128.75) |
0.98 | + 1.7 (-11.0 – 14.0) |
| In the middle of the operation | 110.0 (100.0 – 124.0) | 105.0 (100.0 – 113.75) |
0.21 | + 6.3 (-2.2 – 15.0) |
| At the end of the operation | 110.0 (100.0 – 115.0) | 105.0 (100.0 – 110.0) |
0.59 | + 3.0 (-3.5 – 9.5) |
| End tidal CO2 (kPa) | ||||
| At the beginning of operation | 4.52 ± 0.45 | 4.58 ± 0.46 | 0.91 | – 0.06 (-0.32 – 0.19) |
| In the middle of the operation | 4.77 ± 0.37 | 5.10 ± 0.50 | 0.004 | – 0.34 (-0.59 – -0.09) |
| At the end of the operation | 4.84 ± 0.61 | 5.04 ± 0.63 | 0.45 | – 0.19 (-0.54 – 0.16) |
| Duration of recovery wfrom GA (min) | 42.5 (33.5 – 52.5) | 50.0 (40.0 – 70.0) | 0.02 | – 10.0 (-20.0 – 0.0) |
Table 2: Comparison of the anaesthetic parameters in the two study groups.
Low pressure laparoscopy is commonly performed when a high insufflation pressure might be considered harmful such as patients with multiple comorbidities [13] and in pregnancy [14], but there is not enough evidence to recommend using this low pressure routinely in minimally invasive surgery. One of the well-studied benefits of using low pressure in laparoscopic surgery is that it causes less post-op pain [15-17].
Results of the study of Topcu et.al. demonstrated that the post-operative pain was significantly lower when intraoperative pressure of 8mmHg was preferred [15].
Kyle EB et al. also reported a significant reduction in standardised pain measurement, which was the most significant 24 hours after the surgery [16]. In conjunction with these findings, Bogani et. al reported less shoulder tip pain with lower pressure on the first and third hours following the surgery, and less use of rescue analgesics in their study in 2014 [17].
Another understudied area when it comes to low pressure laparoscopy is whether it causes shortened hospital admission. Our study showed that the lowpressure group recovered from general anaesthesia about 7 minutes quicker than the standard insufflation group. In their study on cholecystectomy patients, Hua J et.al [18] also demonstrated that the duration of hospital stay was 0.2 days shorter with low pressure, supporting our findings and the theory that the duration of hospital stay could be shortened by lowering intraoperative pressure. It was mentioned at Kyle EB et al’s systematic review in 2016 that low pressure laparoscopy might result in poor visibility and that because of this, the surgical technique could be affected [16].
As difficult a parameter as this can be to evaluate, Hua et.al [18] and Gurusamy et.al [19] found in their study on cholecystectomy that the operative times in low pressure and standard pressure were comparable. They reported that there was no difference in the amount of blood loss between the two groups. Surprisingly, the need to increase the pressure during surgery and rate of conversion to laparotomy were also similar in low pressure and standard insufflation groups. Post-op complication rates were comparable in both groups in these studies. In our study, the only significant difference in patient demographics was the mean age which was higher in the low-pressure arm. We do not think that this has affected our main results.
Our study showed that the anaesthetic parameters were overall comparable with both standard and low intraabdominal pressure and the duration of recovery from GA was significantly shorter after low pressure laparoscopy. In the current healthcare climate where enhanced recovery and same day discharges are encouraged due to limited inpatient capacity, low pressure laparoscopy could be a good method to achieve faster patient turnover, and potentially reduce mortality and morbidity due to hospital admission, however, further studies on bigger populations are needed.
In summary, when the benefits of less post-operative pain with low pressure laparoscopy with similar surgical parameters such as estimated blood loss and operating time considered, low pressure laparoscopy could be a method to follow to improve patient flow. However, more data with higher level of evidence is needed before it could be recommended for complex gynaecological cases such as endometriosis excision surgery or low-grade gynaecological malignancies.
Strengths and limitations
One of the weaknesses of our study is our sample size. There is need for further studies on bigger samples. Another weakness of our study is that it is a retrospective study which makes it subject to confounding and some less crucial key statistics could not be measured.
In conclusion, our results show that there is no statistically significant difference in anaesthetic parameters between the low-pressure group and standard insufflation group except EtCO2 levels midprocedure, and that the recovery time after general anaesthesia is significantly lower in the low-pressure group.
Acknowledgements
The authors wish to express their appreciation to the theatre and secretarial teams for their support during this study.
Funding
The authors declare no funding has been received for this research article. This was performed as part of the employment of the authors by the Dudley Group NHS Foundation Trust.
Authorship Contribution
Farshad Tahmsebi: Conceptualization, Operating Gynaecologist. Mohamed M Hosni: Reviewing and Editing Maher Alazizi: Data curation. Sebnem Selek: Writing, Original draft preparation. Hari Krovvidi: Anaesthetist, Reviewing. Mohamad Ismail: Data curation. Khaled Afifi: Statistical Analysis. Hassan Morsi: Operating Gynaecologist, Reviewing and Editing.
Disclosure of interest
The authors have no conflict of interest to disclose.