ABSTRACT
Introduction Optic nerve sheath diameter (ONSD) measured using ultrasonography has been widely used as a surrogate marker of elevated intracranial pressure. However, literature is sparse on the correlation between ONSD and ventriculoperitoneal (VP) shunt function, especially in adults with hydrocephalus. Our study was designed to assess the correlation between ONSD measured using ultrasonography before and 12 hours after VP shunt placement and the success of VP shunt placement assessed using computed tomography (CT) of the brain. Materials and Methods Fifty-one patients between 16 and 60 years of age, with obstructive hydrocephalus scheduled for VP shunt surgery were included in this prospective, observational study. ONSD measurements were obtained from both eyes prior to induction of anesthesia, immediately after the surgery, and at 6, 12, and 24 hours after the surgery. An average of three readings was obtained from each eye. Cerebrospinal fluid (CSF) opening pressure was noted after entry into the lateral ventricle. Noncontrast CT (NCCT) brain was obtained 12 hours after the surgery and was interpreted by the same neurosurgeon for signs of successful VP shunt placement. Results There was a significant reduction in ONSD in the postoperative period compared to ONSD measured preoperatively. The average ONSD (mean ± standard deviation) measured prior to induction of anesthesia, immediately after the surgery, and at 6, 12, and 24 hours after the surgery was 5.71 ± 0.95, 5.20 ± 0.84, 5.06 ± 0.79, 4.90 ± 0.79, and 4.76 ± 0.75 mm, respectively. The mean CSF opening pressure was 19.6 ± 6.9 mm Hg. Postoperative NCCT brain revealed misplacement of the shunt tip in only one patient. Conclusion ONSD measured using ultrasonography may be used as a reliable indicator of VP shunt function in adults with obstructive hydrocephalus.
ABSTRACT
Objectives The study was designed to elucidate the effects of dexmedetomidine as an anesthetic adjunct to propofol in total intravenous anesthesia (TIVA) on anesthetic dose reduction, the quality of intraoperative neurophysiological monitoring (IONM) recordings, analgesic requirements, and recovery parameters in patients undergoing neurosurgical procedures with neurophysiological monitoring. Methods A total of 54 patients for elective neurosurgical procedures with IONM were randomized to group D (dexmedetomidine) and group F (fentanyl). A loading dose of the study drug of 1µg/kg followed by 0.5 µg/kg/h infusion was used in two groups. Propofol-based TIVA with a Schneider target-controlled infusion model was used for induction and maintenance with effect site concentration of 4-5 and 2.5-4 µg/mL, respectively, titrated to a Patient State Index (PSI) of 25-40. Baseline IONM recordings were obtained after induction. The mean propofol consumption, number of patient movements, quality of IONM recordings, number of fentanyl boluses, hemodynamic characteristics, and recovery parameters were recorded. Results The mean propofol consumption was significantly lower in group D when compared to group F (101.4 ± 13.5 µg/kg/min vs 148.0 ± 29.8 µg/kg/min). Baseline IONM recordings were acquired in all patients without any difficulty. The two groups were comparable with respect to the number of additional boluses of fentanyl, patient movements, and recovery characteristics. Conclusion Dexmedetomidine as an adjuvant to propofol in TIVA reduces the requirement of the latter, without affecting the IONM recordings. The addition of dexmedetomidine also ensures stable hemodynamics and decreases the requirement of opioids with similar recovery characteristics.
ABSTRACT
INTRODUCTION: Ambu AuraGain and ProSeal laryngeal mask airway are second-generation supraglottic airway devices (SADs) with added advantage of gastric drain and better oropharyngeal sealing pressure. The primary objective was to study the difference in the gastric insufflation volume between Ambu AuraGain and ProSeal LMA in patients undergoing general anesthesia. METHODS: This randomized controlled trial involving 120 adult patients scheduled under general anesthesia were randomized into either Ambu AuraGain or LMA ProSeal group. Gastric cross-sectional area was measured using ultrasonography at baseline, after mask ventilation, and at the end of surgery. Gastric volume was calculated from the measured cross-sectional area. Oropharyngeal sealing pressure, peak airway pressure, and postoperative complications were noted. Statistical analysis was done using SPSS version 22 (Armonk, NY: IBM Corp.) and p < 0.05 was considered statistically significant. RESULTS: Demographic profile of the study groups was comparable. There was a significant difference in gastric volume between the groups at the end of surgery with 5.91 ml (±9.68 ml) in Ambu AuraGain group and 12.28 ml (±13.05 ml) in the LMA ProSeal group (p = 0.001). Similarly, there was a difference in volume between baseline and at the end of the surgery within the groups also (Ambu AuraGain group, p=0.0012; LMA ProSeal group, p=0.0015, respectively). Though the oropharyngeal sealing pressure and peak airway pressures were comparable, increased incidence of postoperative complications was observed with LMA ProSeal. CONCLUSION: Thus, Ambu AuraGain resulted in a lower gastric insufflation volume than LMA ProSeal with lesser incidence of postoperative complications.
