Preoperative mannitol infusion improves perioperative cerebral oxygen saturation and enhances postoperative recovery after laparoscopic cholecystectomy

Effect of Mannitol on Ultrasonographically Measured Optic Nerve Sheath Diameter as a Surrogate for Intracranial Pressure During Robot-Assisted Laparoscopic Prostatectomy with Pneumoperitoneum and the Trendelenburg Position

INTRODUCTION

CO2 pneumoperitoneum and the steep Trendelenburg position during robot-assisted laparoscopic prostatectomy (RALP) can increase intracranial pressure (ICP). Mannitol is widely used to treat increased ICP. However, no studies to date have specifically evaluated the effect of mannitol on ICP in patients undergoing RALP. Ultrasonographic measurement of the optic nerve sheath diameter (ONSD) is considered a reliable technique to noninvasively evaluate the ICP. Therefore, this study compared ONSDs as a surrogate for ICP before and after mannitol administration in prostate cancer patients undergoing RALP.

METHODS

Mannitol (0.5 g/kg) was administered after pneumoperitoneum establishment and shifting to the Trendelenburg position. ONSDs were measured at six predetermined time points: 10 minutes after anesthesia induction (T0); 5 minutes after pneumoperitoneum and the Trendelenburg position before mannitol administration (T1); 30 minutes (T2), 60 minutes (T3), and 90 minutes (T4) after completion of mannitol administration during pneumoperitoneum and the Trendelenburg position; and at skin closure in the supine position (T5). Moreover, intraoperative hemodynamic and respiratory variables were evaluated simultaneously.

RESULTS

Thirty-six patients were analyzed. ONSDs were significantly lower at T2, T3, and T4 than at T1 (all p < 0.001), with the greatest decrease observed at T4 compared with T1 (4.46 ± 0.2 mm vs 4.81 ± 0.3 mm, p < 0.001). Regional cerebral oxygen saturation, cardiac output, corrected flow time, peak velocity, body temperature, arterial CO2 partial pressure, peak airway pressure, plateau airway pressure, dynamic compliance, and static compliance were not significantly different during pneumoperitoneum and the Trendelenburg position; however, mean arterial blood pressure and heart rate were significantly different.

CONCLUSIONS

Mannitol decreases the ONSD in patients undergoing RALP with CO2 pneumoperitoneum and the steep Trendelenburg position. This result provides useful information on the beneficial effects of mannitol administration on prostate cancer patients who may develop increased ICP during RALP.

Cerebral Oximetry for Detecting High-mortality Risk Patients with Cryptococcal Meningitis

Background

Cryptococcus is the commonest cause of adult meningitis in Africa, with 50%–70% experiencing increased intracranial pressure. Cerebral oximetry is a noninvasive near-infrared spectroscopy technology to monitor percent regional cerebral tissue oxygenation (rSO₂). We assessed if cerebral oximetry predicts meningitis mortality.

Methods

We performed cerebral oximetry within 14 days of cryptococcal meningitis diagnosis on 121 Ugandans from April 2016 to September 2017. We evaluated baseline rSO₂ association with mortality by multivariable logistic regression and correlation with other clinical factors. We compared groups formed by initial rSO₂ <30% vs ≥30% for longitudinal change with mixed effects models. We measured change in %rSO₂ before and after lumbar puncture (LP).

Results

The median initial rSO₂ (interquartile range) was 36% (29%–42%), and it was <30% in 29% (35/121). For 30-day mortality, the unadjusted odds ratio (per 5% increase in rSO₂) was 0.73 (95% confidence interval [CI], 0.58 to 0.91; P = .005). Those with initial rSO₂ <30% had 3.4 (95% CI, 1.5 to 8.0) higher odds of 30-day mortality than those with initial rSO₂ ≥30%. Hemoglobin correlated with initial rSO₂ (rho = .54; P < .001), but rSO₂ did not correlate with pulse oximetry, intracranial pressure, cerebral perfusion pressure, or quantitative cerebrospinal fluid culture, and rSO₂ was unchanged pre/post–lumbar punctures. The longitudinal rSO₂ measurements change was 15% (95% CI, 12% to 18%) lower in the group with initial rSO₂ <30%.

Conclusions

Individuals with cryptococcal meningitis and low cerebral oximetry (rSO₂ < 30%) have high mortality. Cerebral oximetry may be useful as a prognostic marker of mortality. Targeted interventions to improve rSO₂ should be tested in trials to try to decrease mortality in meningitis.

Effect of general anesthesia on serum β-amyloid protein and regional cerebral oxygen saturation of elderly patients after subtotal gastrectomy

The aim of the present study was to investigate the influence of general anesthesia on serum β-amyloid protein (Aβ) and regional cerebral oxygen saturation (rSO₂) of elderly patients after subtotal gastrectomy. From June, 2014 to December, 2015, among 168 patients undergoing subtotal gastrectomy, the Mini-Mental State Examination and Montreal Cognitive Assessment was administered the day prior to surgery and the second and ninth days after the operation. In addition, we administered the tests to 168 healthy adult volunteers (healthy controls) who were treated in our hospital medical center in the same period. Near-infrared spectroscopy technology was used for continuous monitoring of the intraoperative rSO₂, and the mean of intraoperative rSO₂ was then calculated. Of the 168 patients, 28 developed postoperative cognitive dysfunction (POCD) and the remaining 140 patients were normal (control). The ELISA method was used to test the expression levels of serum Aβ in the three groups and statistical analyses were conducted. Serum Aβ level in the POCD group was significantly higher than that in the control and healthy control groups, and the difference was statistically significant (P<0.05). The rSO₂ level in the patients with POCD was significantly lower than the control group (P<0.05). The correlation analysis with Aβ as an independent variable and other factors as dependent variables revealed that the serum Aβ level negatively correlated with rSO₂ (r=-1.6749, P<0.05). The combined Aβ and rSO₂ may be useful for the diagnosis and prevention of POCD after subtotal gastrectomy under general anesthesia.