Inhalational versus Intravenous General Anesthesia for mechanical thrombectomy for stroke: A single centre retrospective study.

BACKGROUND: When general anesthesia is used for endovascular thrombectomy (EVT) for acute ischemic stroke (AIS), the choice of anesthetic agents for maintenance remains inconclusive. The different effects of intravenous anesthetic and volatiles agents on cerebral hemodynamics are known and may explain differences in outcomes of patients with cerebral pathologies exposed to the different anesthetic modalities. In this single institutional retrospective study, we assessed the impact of total intravenous (TIVA) and inhalational anesthesia on outcomes after EVT. METHODS: We conducted a retrospective analysis of all patients ≥ 18 years who underwent EVT for AIS of the anterior or posterior circulation under general anesthesia. Baseline patient characteristics, anesthetic agents, intra operative hemodynamics, stroke characteristics, time intervals and clinical outcome data were collected and analyzed. RESULTS: The study cohort consisted of 191 patients. After excluding 76 patients who were lost to follow up at 90 days, 51 patients received inhalational anesthesia and 64 patients who received TIVA were analyzed. The clinical characteristics between the groups were comparable. Multivariate logistic regression analysis of outcome measures for TIVA versus inhalational anesthesia showed significantly increased odds of good functional outcome (mRS 0-2) at 90 days (adjusted odds ratio, 3.24; 95% CI, 1.25-8.36; p = 0.015) and a non-significant trend towards decreased mortality (adjusted odds ratio, 0.73; CI, 0.15-3.6; p = 0.70). CONCLUSION: Patients who had TIVA for mechanical thrombectomy had significantly increased odds of good functional outcome at 90 days and a non-significant trend towards decrease in mortality. These findings warrant further investigation with large randomized, prospective trials.

Capnography-sample line leak and incremental positive end expiratory pressure (PEEP); an interesting interplay.

The capnography is an important monitor to assess the patient's respiratory status. Importance of education for clinicians in interpretation of alarms and various capnography waveforms in different clinical scenarios and equipment malfunction is an understatement. Capnography waveforms due to sample line tube leak is described well in literature. This report describes an interesting effect of incremental positive end expiratory pressure (PEEP) on capnography waveforms linked to sample line leak.

An abrupt reduction in end tidal carbon di oxide concentration in a mechanically ventilated patient in neurocritical care ward: a capnogram artifact.

In patients with normal lung and reasonable cardiac function such as head injury patients, the PETCo2 can be used as a surrogate for partial pressure of Carbon dioxide (PaCO2) in mechanically ventilated patients. Thus early interpretation and accurate assessment of capnogram is crucial in neurocritical care patients. Here we present and discuss a scenario where in connection of a jet nebulizer to the ventilator lead to abrupt decrease in end tidal carbon dioxide leading to a diagnostic dilemma. Also this report highlights and discusses the importance of the proper placement of breathing circuit components to ensure accurate CO2 readings in particular the use of a jet nebulizer.

Low-Flow Anesthesia, Low Fresh Gas Flow, and Oxygen Flush: An Interesting Interplay.

Identification and analysis of critical respiratory alarms during use of an advanced anesthesia workstation is essential in the intraoperative period. We present and discuss a scenario in which there was activation of a fresh gas flow alarm during low-flow anesthesia intraoperatively and use of oxygen flush to counteract it led to a diluted concentration of the inspired anesthetic agent.

Acute kidney injury in survivors of surgery for severe traumatic brain injury: Incidence, risk factors, and outcome from a tertiary neuroscience center in India.

BACKGROUND: Non-neurological complications like acute kidney injury (AKI) can affect outcome of traumatic brain injury (TBI). This study aims to analyze the incidence, predictive factors, and impact of AKI in operated patients with severe TBI. METHODS: We retrospectively reviewed the data of 395 patients who underwent surgery for severe TBI and survived to be discharged from the hospital over a 1-year period. Of these, 95 patients were finally included in the analysis. Their demographic data, laboratory parameters, and clinical courses were reviewed. Diagnosis and staging of AKI was made using Acute Kidney Injury Network (AKIN) criteria. RESULTS: The incidence of AKI was 11.6% (11 patients). Out of the 11 patients who had AKI, 7 were in stage I (63.6%), 3 were in stage II (27.3%), and 1 in stage III (9.1%). Nine Patients (81.8%) developed AKI within 5 days of admission. Aminoglycoside therapy had an association with occurrence of AKI. There was no mortality and none of the patients required renal replacement therapy (RRT). Renal function of all these patients returned to baseline before hospital discharge. Hospital stay and intensive care unit (ICU) stay were longer and Glasgow coma scale (GCS) was lower in patients with AKI when compared with patients without AKI group at discharge. CONCLUSION: Reversible AKI without need for RRT occurred in nearly 12% of patients with severe TBI requiring surgical intervention. Aminoglycoside therapy was the only predictive factor for the occurrence of AKI. Patients with AKI have a longer period of mechanical ventilation, longer ICU and hospital stay, and poorer GCS at discharge.

An unusual cause of high peak airway pressure: Interpretation of displayed alarms.

Airway pressure monitoring is critical in modern day anesthesia ventilators to detect and warn high or low pressure conditions in the breathing system. We report a scenario leading to unexpectedly very high peak inspiratory pressure in the intraoperative period and describe the mechanism for high priority alarm activation. We also discuss the role of a blocked bacterial filter in causing sustained display of increased airway pressure. This scenario is a very good example for understanding the unique safety feature present in the Dräger ventilators and the attending anesthesiologist must have an adequate knowledge of the functioning and safety feature of the ventilators they are using to interpret the alarms in the perioperative to prevent unnecessary anxiety and intervention.

Malfunction of the Expiratory Valve During Spontaneous Ventilation.

The integrity of inspiratory and expiratory unidirectional valves is very important in the normal functioning of an anesthetic circle breathing system. We describe our experience of an emergency manipulation of a ceramic valve disk of a circle breathing system (Dräger Fabius GS, Dräger Medical Inc) that altered its characteristics and led to rebreathing only during spontaneous ventilation.

Fall in inspired oxygen and anaesthetic agent concentrations during change of soda lime absorber.

Following an episode of reduction in inspired oxygen concentration (FiO(2)) and inhalational agent concentration (Fi agent) during the changing of a soda lime absorber, We conducted an in vitro experiment to understand the impact of disconnection of the absorber on inspired gas dilution at different fresh gas flows. We found that both in Dräger Fabius GS and Primus anaesthesia work stations, disconnection of the absorber caused progressive reduction in FiO(2) and Fi agent as the FGF was decreased. The operating principle of fresh gas decoupling (FGD) valve is a potential source of this complication, which must be kept in mind while changing the soda lime during the course of surgery where an anaesthetic work stations utilizing FGD valves are used.

Anesthetic management of patients with Joubert syndrome: a retrospective analysis of a single-institutional case series.

OBJECTIVE: To analyze the anesthetic techniques used for sedation during magnetic resonance imaging (MRI) study of patients with Joubert syndrome (JS) and assess the safety and efficacy of these anesthetic regimens in these children. BACKGROUND: Joubert syndrome is a rare neurological disorder with significant anesthetic implications. This study describes the anesthetic management of children with JS undergoing MRI study with different anesthetic agents and implications of various anesthetic techniques in these patients. MATERIALS AND METHODS: The records of ten patients with JS undergoing MRI study with different anesthetic techniques were retrospectively reviewed over the last 5 years. RESULTS: The patients were aged between 6 months and 21 years. The most commonly used sedation technique involved use of alpha-2 agonists, and this technique had least complications such as apnea and patient movement during imaging. None of the patients had postanesthetic respiratory problems, although one patient receiving propofol had apnea and desaturation on induction requiring airway intervention. CONCLUSION: Alpha-2 agonist based anesthetic technique appears to be most suitable for sedation during MRI study in patients with JS with respect to adverse events and outcome.

An abrupt reduction in end-tidal carbon-dioxide during neurosurgery is not always due to venous air embolism: a capnograph artefact.

Venous air embolism (VAE) is a well recognized complication during neurosurgery. Pre-cordial doppler and trans-esophageal echocardiography are sensitive monitors for the detection of VAE. A sudden, abrupt reduction in the end-tidal carbondioxide (ETCO2) pressure with associated hypotension during neurosurgery might suggest VAE, when more sensitive monitors are not available. We describe an unusual cause for sudden reduction in ETCO2 during neurosurgery and discuss the mechanism for such presentation.

Dräger Fabius GS Ventilator Failure: An Unusual Cause.

Understanding the functioning of modern anesthesia workstations is very important because workstation failures in the intraoperative period may place the patient at risk of perioperative hypoxia and lead to unnecessary anxiety and confusion among anesthesia care providers. We present and simulate a critical event leading to Dräger Fabius GS ventilator failure.