A randomised trial to compare the increase in intracranial pressure as correlated with the optic nerve sheath diameter during propofol versus sevoflurane-maintained anesthesia in robot-assisted laparoscopic pelvic surgery

A Novel Method for Prediction of Raised Intracranial Pressure Through Automated ONSD and ETD Ratio Measurement From Ocular Ultrasound

The paper presents a novel framework for the prediction of the raised Intracranial Pressure (ICP) from ocular ultrasound images of traumatic patients through automated measurement of Optic Nerve Sheath Diameter (ONSD) and Eyeball Transverse Diameter (ETD). The measurement of ONSD using an ocular ultrasound scan is non-invasive and correlates with the raised ICP. However, the existing studies suggested that the ONSD value alone is insufficient to indicate the ICP condition. Since the ONSD and ETD values may vary among patients belonging to different ethnicity/origins, there is a need for developing an independent global biomarker for predicting raised ICP condition. The proposed work develops an automated framework for the prediction of raised ICP by developing algorithms for the automated measurement of ONSD and ETD values. It is established that the ONSD and ETD ratio (OER) is a potential biomarker for ICP prediction independent of ethnicity and origin. The OER threshold value is determined by performing statistical analysis on the data of 57 trauma patients obtained from the AIIMS, New Delhi. The automated OER is computed and compared with the conventionally measured ICP by determining suitable correlation coefficients. It is found that there is a significant correlation of OER with ICP (r = .81, p ≤ .01), whereas the correlation of ONSD alone with ICP is relatively less (r = .69, p = .004). These correlation values indicate that OER is a better parameter for the prediction of ICP. Further, the threshold value of OER is found to be 0.21 for predicting raised ICP conditions in this study. Scatter plot and Heat map analysis of OER and corresponding ICP reveal that patients with OER ≥ 0.21, have ICP in the range of 17 to 35 mm Hg. In the data available for this research work, OER ranges from 0.17 to 0.35.

Effect of sevoflurane, propofol and propofol with dexmedetomidine as maintenance agent on intracranial pressure in the Trendelenburg position during laparoscopic surgeries

Background and Aim

Pneumoperitoneum (PP) and the Trendelenburg position (TP) in laparoscopic surgeries are associated with rise in intracranial pressure (ICP). The optic nerve sheath diameter (ONSD) is a surrogate marker of ICP. The study aimed to evaluate the effect of sevoflurane, propofol and propofol with dexmedetomidine as maintenance agent on ICP in TP during laparoscopic surgeries.

Material and Methods

A total of 120 American Society of Anesthesiologists (ASA) physical status I/II patients, aged 18-65 years were randomly allocated into three groups: sevoflurane as group S, propofol as group P, and propofol with dexmedetomidine as group PD. The intra-abdominal pressure (IAP) was kept in the range of 12-14 mmHg and TP varied between 15°- 45° angle. The primary objective was comparison of ICP and secondary objectives were IOP, intraoperative hemodynamic and postoperative recovery characteristics among groups. The ONSD and IOP were measured in both eyes 10 min after endotracheal intubation (T0), 5 min after CO2 insufflation (T1), 5 min after TP (T2) and 5 min after deflation of gas (T3). The data were analyzed by using the Statistical Package for Social Sciences version 23.

Results

ONSD and IOP at T1 and T2 were significantly higher than T0 in all groups, but no significant difference was found among the intergroup groups. Significantly lower heart rate and mean blood pressure were observed in PD group at T1 and T2 compared to group S and group P.

Conclusion

The rise in ICP was comparable among sevoflurane, propofol, and propofol-dexmedetomidine combination as a maintenance agent during laparoscopic surgeries in TP.

Optic Nerve Changes Detected with Ocular Ultrasonography during Different Surgical Procedures: A Narrative Review

Ultrasonographic appraisal of the optic nerve sheath diameter has become popular in recent years as a useful diagnostic tool to detect intracranial pressure variations. Intracranial hypertension is a life-threatening disease with possible poor clinical outcomes and can be caused by a variety of neurological and non-neurological conditions. Considering the latter, increases in intracranial pressure have also been described during several surgical procedures. Ocular ultrasonography might be utilized to identify intracranial pressure increases by evaluating optic nerve sheath diameter variations. The aim of this review is to provide a wide overview on the use of the optic nerve ultrasound evaluation to detect intracranial pressure changes during surgical procedures, also discussing the pitfalls of the B-scan technique, the most widely used for such a purpose. PubMed medical database, Web of Science and Scopus were used to carry out this review. The present review showed that ocular ultrasonography could be considered a valuable diagnostic tool in the surgical setting to indirectly assess intracranial pressure. However, the use of the B-scan ultrasound should always be coupled with the standardized A-scan technique for a more accurate, precise and trustworthy ultrasound assessment.

Effects of sevoflurane versus propofol on cerebral autoregulation during anaesthesia for robot-assisted laparoscopic prostatectomy

Robot-assisted laparoscopic prostatectomy requires a pneumoperitoneum combined with steep Trendelenburg positioning, and these conditions can be associated with impairment of cerebral autoregulation. The objective of this study was to determine if choice of anaesthetic agent affects the preservation of cerebral autoregulation during robot-assisted laparoscopic prostatectomy. We randomly assigned 30 patients to maintenance of general anaesthesia with either propofol or sevoflurane. Cerebral autoregulation was tested by administration of intravenous phenylephrine to increase mean arterial pressure from approximately 80 mmHg to 100 mmHg while assessing cerebral blood flow using transcranial Doppler ultrasonography. Autoregulation was first tested in the supine position and then approximately once every hour after Trendelenburg positioning. The main outcome measure was the result of the final autoregulation test prior to completion of surgery. At that time, we found cerebral autoregulation to be significantly impaired in six of the 15 patients receiving sevoflurane and none of the 15 patients receiving propofol (P = 0.02). However, it should be noted that some patients in the propofol group had impaired autoregulation on earlier tests. In conclusion, we found that autoregulation during robot-assisted laparoscopic prostatectomy is less likely to be impaired with propofol compared to sevoflurane anaesthesia, particularly towards the end of the surgery.

Comparison of the Effects of Propofol and Sevoflurane Anesthesia on Optic Nerve Sheath Diameter in Robot-Assisted Laparoscopic Gynecology Surgery: A Randomized Controlled Trial

Optic nerve sheath diameter (ONSD) is used as a surrogate parameter for intracranial pressure. This study was conducted to evaluate the effect of the anesthetics (sevoflurane and propofol) on ONSD in women undergoing robotic surgery. The 42 patients who were scheduled for robot-assisted gynecology surgery were randomly allocated to the sevoflurane group or the propofol group. ONSD was recorded at 10 min after the induction of anesthesia (T0); 5 min, 20 min, and 40 min after carbon dioxide pneumoperitoneum was induced and the patients were put in a steep Trendelenburg position (T1, T2, and T3, respectively); and at skin closure after desufflation of the pneumoperitoneum (T4). Patients were observed for postoperative nausea and vomiting (PONV) during the immediate postoperative period. The propofol group had significantly lower ONSD than the sevoflurane group at T3. Mean ONSD values continuously increased from T0 to T3 in both groups. Two patients in the sevoflurane group experienced PONV. This study suggests that propofol anesthesia caused a lower increase in ONSD than sevoflurane anesthesia.

Influence of steep Trendelenburg position on postoperative complications: a systematic review and meta-analysis

Intraoperative physiologic changes related to the steep Trendelenburg position have been investigated with the widespread adoption of robot-assisted pelvic surgery (RAPS). However, the impact of the steep Trendelenburg position on postoperative complications remains unclear. We conducted a meta-analysis to compare RAPS to laparoscopic/open pelvic surgery with regards to the rates of venous thromboembolism (VTE), cardiac, and cerebrovascular complications. Meta-regression was performed to evaluate the influence of confounding risk factors. Ten randomized controlled trials (RCTs) and 47 non-randomized controlled studies (NRSs), with a total of 380,125 patients, were included. Although RAPS was associated with a decreased risk of VTE and cardiac complications compared to laparoscopic/open pelvic surgery in NRSs [risk ratio (RR), 0.59; 95% CI 0.51–0.72, p < 0.001 and RR 0.93; 95% CI 0.58–1.50, p = 0.78, respectively], these differences were not confirmed in RCTs (RR 0.92; 95% CI 0.52–1.62, p = 0.77 and RR 0.93; 95% CI 0.58–1.50, p = 0.78, respectively). In subgroup analyses of laparoscopic surgery, there was no significant difference in the risk of VTE and cardiac complications in both RCTs and NRSs. In the meta-regression, none of the risk factors were found to be associated with heterogeneity. Furthermore, no significant difference was observed in cerebrovascular complications between RAPS and laparoscopic/open pelvic surgery. Our meta-analysis suggests that the steep Trendelenburg position does not seem to affect postoperative complications and, therefore, can be considered safe with regard to the risk of VTE, cardiac, and cerebrovascular complications. However, proper individualized preventive measures should still be implemented during all surgeries including RAPS to warrant patient safety.

Study of the effect of anaesthesia on the canine ultrasonographic optic nerve sheath diameter

OBJECTIVES

To investigate the effects of anaesthetic duration and serial anaesthetic events on optic nerve sheath diameter in a population of dogs without intracranial disease using point-of-care ultrasonography.

MATERIALS AND METHODS

Client-owned dogs requiring advanced head imaging were prospectively enrolled. Exclusion criteria included signs of elevated intracranial pressure, glaucoma and optic nerve disease. Using a transpalpebral technique, two optic nerve sheath diameter measurements were recorded for each eye at three timepoints: following premedication, after induction within 7 minutes and before discontinuing isoflurane. Mixed model analysis was used to characterise optic nerve sheath diameter behaviour and investigate the effects of anaesthetic duration, bodyweight and anaesthetic protocol, age and sex.

RESULTS

Fourteen dogs of various ages, breeds and bodyweights were enrolled. A positive linear relationship was detected between body weight and optic nerve sheath diameter. In 12 of 14 dogs, the optic nerve sheath diameter increased from measurements taken after premedication when compared to measurements taken after induction within 7 minutes. In a subset of patients, measurements subsequently decreased when anaesthetic duration exceeded 120 minutes. Age, side, sex, final body temperature, blood pressure and anaesthetic protocol did not significantly affect optic nerve sheath diameter. No significant association was noted between optic nerve sheath diameter and end-tidal carbon dioxide after induction and before discontinuing isoflurane.

CLINICAL SIGNIFICANCE

When using point-of-care ultrasound, a transient increase in optic nerve sheath diameter occurs between premedication and within 7 minutes following induction, regardless of bodyweight. This should be taken into consideration when serial monitoring is performed.

Effects of prone positioning with neck extension on intracranial pressure according to optic nerve sheath diameter measured using ultrasound in children

PURPOSE

Optic nerve sheath diameter has been used for measure of intracranial pressure. The aim of this study was to evaluate the effect of prone positioning with neck extension on intracranial pressure in infants undergoing craniosynostosis surgery and to determine precautions using optic nerve sheath diameter measurement.

METHODS

We enrolled 30 infants who were scheduled for correction of craniosynostosis in which planning included the prone position with neck extension. Optic nerve sheath diameter (anterior/lateral transbulbar approach) was measured 5 times in each eyeball at the following time points: 15 min after intubation in supine position as the baseline value (supine 1); 10 min after final surgical position before skin incision (prone); and 10 min after returning to supine position at the conclusion of surgery (supine 2). Hemodynamic parameters, airway peak pressure, oxygen saturation, and E_TCO₂ were monitored. Data were analyzed using repeated-measures multivariate analysis of variance to evaluate the effect of different positions under anesthesia on changes in using optic nerve sheath diameter and P < 0.05 was considered to be statistically significant.

RESULTS

There was no difference in optic nerve sheath diameter after prone position with neck extension in all the measure. After surgery, optic nerve sheath diameter was decreased compared with the preoperative baseline values (Rt anterior/lateral 5.6/5.5: 5.4/5.2; Lt anterior/lateral 5.6/5.5: 5.4/5.3, P < 0.05, respectively).

CONCLUSIONS

In conclusion, prone positioning with head extension did not further increase intracranial pressure, although the surgical procedure could reduce intracranial pressure in the immediate postoperative period in infants undergoing craniosynostosis surgery.

Technical advancements in robotic prostatectomy: single-port extraperitoneal robotic-assisted radical prostatectomy and single-port transperineal robotic-assisted radical prostatectomy

Background

To describe our step-by-step techniques for single-port robotic-assisted extraperitoneal and perineal radical prostatectomy as recent technical advancements in this field.

Methods

An English-language literature review was done using search terms including extraperitoneal, transperineal, single-port, robotic surgery, prostate cancer, radical prostatectomy in various combinations. Unique features of the da Vinci SP^® platform are discussed. Details of surgical techniques with single-port robotic platform are also covered.

Results

The relatively recent introduction of the da Vinci SP platform has led to the development of novel techniques for radical prostatectomy. Unique features of this platform including intracorporeal triangulation and double-articulating instruments will likely lead to widespread applications of this novel system. The principles of radical prostatectomy are reproducible with both extraperitoneal and perineal approaches via a single incision.

Conclusions

A better cosmetic results as well as a quick recovery maybe potential advantages of single-port extraperitoneal/transperineal robotic prostatectomy. By avoiding the peritoneal cavity, a lower rate of bowel related complications and minimum systemic CO₂ absorption can be expected. Adverse effects of steep Trendelenburg positioning can be avoided with these techniques. Evaluation of the oncological and functional outcomes of these techniques will be necessary. Comparative trials with standard robotic surgery and cost-analysis studies remain hot topics for research after implementation of these new platforms at any institute.

Ultrasound optic nerve sheath diameter evaluation in patients undergoing robot-assisted laparoscopic pelvic surgery

Following the interesting reading of the article "A randomised trial to compare the increase in intracranial pressure as correlated with the optic nerve sheath diameter during propofol versus sevoflurane-maintained anesthesia in robot-assisted laparoscopic pelvic surgery", the authors comment some aspects about ocular ultrasonography to measure optic nerve sheath diameter as a tool to detect potential intracranial hypertension, pointing out the utility of Standardized A Scan technique for this purpose.