Emergence Patterns from General Anesthesia after Epilepsy Surgery: An Observational Pilot Study.

Objective Emergence from anesthesia starts from the limbic structures and then spreads outwards to brainstem, reticular activating systems, and then to the cortex. Epilepsy surgery often involves resection of limbic structures and hence may disrupt the pattern of emergence. The aim of this study was to explore the pattern of emergence from anesthesia following epilepsy surgery and to determine associated variables affecting the emergence pattern. Setting and Design Tertiary care center, prospective observational study. Materials and Methods We conducted a prospective observation pilot study on adult patients undergoing anterior temporal lobectomy and amygdalohippocampectomy for epilepsy. Anesthesia management was standardized in all patients, and they were allowed to wake up with "no touch" technique. Primary outcome of the study was the pattern of emergence (normal emergence, agitated emergence, or slow emergence) from anesthesia. Secondary outcomes were to explore the differences in preoperative neuropsychological profile and limbic structure volumes between the different patterns of emergence. Quantitative variables were analyzed using Student's t -test. Qualitative variables were analyzed using chi-square test. Results Twenty-nine patients completed the study: 9 patients (31%) had agitated emergence, and 20 patients had normal emergence. Among the agitated emergence, 2 patients had Riker scale of 7 indicating violent emergence. Patient demographics, anesthetic used, neuropsychological profile, and limbic structure volumes were similar between normal emergence and agitated emergence groups. However, two patients who had severe agitation (Riker scale of 7) had the lowest intelligence quotient. Conclusion Our pilot study showed that emergence agitation is not uncommon in patients undergoing epilepsy surgery. However, due to smaller sample size, the role of preoperative neuropsychologic profile and hippocampal volumes in predicting the pattern of emergence is inconclusive.

Comparison of the novel membrane-based carbon dioxide filter memsorb™ with a chemical granulate absorbent using a high-fidelity lung simulator: a prospective randomized in vitro trial.

PURPOSE: Memsorb™ is a novel device for carbon dioxide (CO2) removal from anesthesia circuits via a semipermeable polymeric membrane. We evaluated the performance of the memsorb device for the removal of CO2 in an Aisys™ CS2 machine and compared it with a standard chemical granulate absorber (CGA) using a high-fidelity lung simulator. METHODS: We used an in vitro lung simulator (DUCt) to control CO2 release by imitating alveolar gas exchange. The ventilator settings were identical for all measurements. The fresh gas flow (FGF) was randomized to either 0.5 L·min-1 or 2 L·min-1, completing three trials for each FGF for either memsorb or CGA. The EtCO2 and FICO2 levels were recorded for 30 min in each setting. RESULTS: EtCO2 was comparable between the groups with 2 L·min-1 FGF over the observation period. FICO2 was significantly higher in the memsorb group during the trial (2 L·min-1; 3.9 mm Hg; 95% CI, 4.4 to 3.3; P < 0.001). EtCO2 with 0.5 L·min-1 FGF was higher with memsorb than with CGA over the observation period (3.7 mm Hg; 95% CI, 2.7 to 4.7; P = 0.004). With 0.5 L·min-1 FGF, FICO2 was significantly higher in the memsorb group compared with CGA over the whole observation period (6 mm Hg; 95% CI, 6.4 to 5.5; P < 0.001). DISCUSSION: CO2 was successfully removed from the anesthesia circuit. FICO2 was significantly higher with memsorb throughout the observation period. Nevertheless, the clinical impact of these observations remains unclear. Further clinical trials are required to determine the utility of the novel device.

RéSUMé: OBJECTIF: Le memsorb™ est un nouveau dispositif pour l'élimination du dioxyde de carbone (CO2) des circuits d'anesthésie par une membrane polymère semi-perméable. Nous avons évalué la performance du dispositif memsorb pour éliminer le CO2 dans une machine d'anesthésie Aisys™ CS2 et l'avons comparé à la chaux sodée standard en utilisant un simulateur pulmonaire haute fidélité. MéTHODE: Nous avons utilisé un simulateur pulmonaire (DUCt) in vitro pour contrôler la libération de CO2 en imitant l'échange gazeux alvéolaire. Les réglages du ventilateur étaient identiques pour toutes les mesures. Le débit de gaz frais (DGF) a été randomisé à 0,5 L·min−1 ou 2 L·min−1, complétant trois essais pour chaque DGF pour le memsorb ou la chaux sodée. Les taux d'EtCO2 et de FICO2 ont été enregistrés pendant 30 minutes dans chaque réglage. RéSULTATS: Les valeurs d'EtCO2 était comparables entre les groupes avec un DGF à 2 L·min−1 au cours de la période d'observation. La FICO2 était significativement plus élevée avec le MEMsorb pendant l'essai (2 L·min−1; 3,9 mm Hg; IC 95 %, 4,4 à 3,3; P < 0,001). À un DGF 0,5 L·min−1, l'EtCO2 était plus élevé avec le memsorb qu'avec la chaux sodée au cours de la période d'observation (3,7 mm Hg; IC 95 %, 2,7 à 4,7; P = 0,004). À un DGF de 0,5 L·min−1, la FICO2 était significativement plus élevée avec le MEMsorb par rapport à la chaux sodée sur l'ensemble de la période d'observation (6 mm Hg; IC 95 %, 6,4 à 5,5; P < 0,001). DISCUSSION: Le CO2 a bien été éliminé du circuit d'anesthésie. La FICO2 était significativement plus élevée avec le MEMsorb tout au long de la période d'observation. Néanmoins, l'impact clinique de ces observations reste incertain. D'autres études cliniques sont nécessaires pour déterminer l'utilité du nouveau dispositif.

Effect of dexmedetomidine on dynamic cerebral autoregulation and carbon dioxide reactivity during sevoflurane anesthesia in healthy patients.

BACKGROUND: There are conflicting opinions on the effect of dexmedetomidine on cerebral autoregulation. This study assessed its effect on dynamic cerebral autoregulation (dCA) using a transcranial Doppler (TCD). METHODS: Thirty American Society of Anesthesiologists physical status I and II patients between 18 and 60 years, who underwent lumbar spine surgery, received infusions of dexmedetomidine (Group D) or normal saline (Group C), followed by anesthesia with propofol and fentanyl, and maintenance with oxygen, nitrous oxide and sevoflurane. After five minutes of normocapnic ventilation and stable bispectral index value (BIS) of 40-50, the right middle cerebral artery flow velocity (MCAFV) was recorded with TCD. The transient hyperemic response (THR) test was performed by compressing the right common carotid artery for 5-7 seconds. The lungs were hyperventilated to test carbon dioxide (CO2) reactivity. Hemodynamic parameters, arterial CO2 tension, pulse oximetry (SpO2), MCAFV and BIS were measured before and after hyperventilation. Dexmedetomidine infusion was discontinued ten minutes before skin-closure. Time to recovery and extubation, modified Aldrete score, and emergence agitation were recorded. RESULTS: Demographic parameters, durations of surgery and anesthesia, THR ratio (Group D: 1.26 ± 0.11 vs. Group C: 1.23 ± 0.04; P = 0.357), relative CO2 reactivity (Group D: 1.19 ± 0.34 %/mmHg vs. Group C: 1.23 ± 0.25 %/mmHg; P = 0.547), blood pressure, SpO2, BIS, MCAFV, time to recovery, time to extubation and modified Aldrete scores were comparable. CONCLUSIONS: Dexmedetomidine administration does not impair dCA and CO2 reactivity in patients undergoing spine surgery under sevoflurane anesthesia.

Intracranial Pressure Monitoring in Children with Severe Traumatic Brain Injury: A Retrospective Study.

INTRODUCTION: There is a paucity of literature on intracranial pressure (ICP) monitoring in children. The aim of this study was to ascertain whether ICP monitoring is useful in children with severe traumatic brain injury (TBI). MATERIALS AND METHODS: Medical records of children between 1 and 12 years, admitted to neurocritical care unit with severe TBI in 2 years, were reviewed. The children were divided into two groups: study group (ICP monitored) and control group (ICP not monitored). Admission demographics, vital parameters, and computed tomographic scan findings were recorded. In the study group, date of ICP catheter insertion/removal with ICP values and treatment carried out for increased ICP were noted. Data on tracheostomy, duration of mechanical ventilation, hospital stay, and outcome at discharge were noted. RESULTS: Demographic variables were comparable between the two groups. When adjusted for death, no significant difference was observed between the study and the control groups in median duration of mechanical ventilation: 35 days (95% confidence interval [CI]: 12-73) versus 55 days (95% CI: 29-55) (P = 0.96), hospital stay: 36 days (95% CI: 12-73) versus 58 days (95% CI: 29-58) (P = 0.96), and time to tracheostomy: 6 days (95% CI: 5-8) versus 5 days (95% CI: 4-7) (P = 0.49). Mortality rates, incidence of cranial surgeries, and outcome at discharge were also comparable. CONCLUSION: ICP monitoring did not reduce the incidence of death, cranial surgeries, duration of mechanical ventilation, hospital stay, or improve the outcome at discharge in children with severe TBI.

Early Post-operative Hemodynamic Perturbation Associated with Topiramate-induced Metabolic Acidosis: A Case Report.

Topiramate is a potent antiepileptic drug with multiple modes of action including inhibition of carbonic anhydrase activity. Inhibition of this enzyme predisposes to non-anion gap metabolic acidosis which has been amply described in the literature. However, the severity is yet to be well defined. We encountered a case of topiramate-induced non-anion gap metabolic acidosis associated with hemodynamic perturbations in an 8-year-old child in the postoperative period.

Asystole during lumbar discectomy: a case report.

Hemodynamic derangements have been reported after surgery involving upper cervical spine. Similar observations, however, are rare during a lumbar spine surgery. We share our experience in a patient who had 2 episodes of bradycardia leading to transient asystole while undergoing lumbar discectomy for prolapsed intervertebral disc. The risk of life-threatening hemodynamic disturbances during seemingly uncomplicated surgery in prone position has been emphasized.

Increased airway pressure due to superior mediastinal hematoma during endovascular coiling by transcarotid approach.

An elderly woman with subarachanoid hemorrhage presented to our interventional neuroradiology suite for coil embolization of multiple intracranial aneurysms. The patient had difficult vascular access for the passage of microcatheter; hence, the embolization procedure was carried out with direct puncture of the left common carotid artery. During the procedure, the patient developed thromboembolism which was treated by administration of an antiplatelet agent, abciximab. At the end of procedure, she developed airway compromise due to extension of a local neck hematoma into the superior mediastinum. The management issues in such a scenario have been discussed.

Rheumatoid arthritis and ocular involvement.

To study the occurrence and incidence of different ocular manifestations in rheumatoid arthritis a random cross-sectional study was carried out among 54 patients with active rheumatoid arthritis. The patients were examined thoroughly to detect any ocular disease associated with rheumatoid arthritis. Complete ocular examination with special emphasis on anterior segment evaluation and tearfilm study was done. Two-thirds of the patients examined had some kind of visual problem at presentation. Three patients (5.55%) had marked dry eye with another 20 (37.03%) having borderline tear deficiency. Two cases ( 3.70% ) of episcleritis were also seen. No cases of scleritis or retinopathy were found. The most common ocular association with rheumatoid arthritis was secondary Sjogren's syndrome. Other conditions include episcleritis and marginal keratitis.