Comparison of hands-free Trans-nasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) with conventional facemask ventilation technique for oxygenation in patients undergoing electroconvulsive therapy - A cross over study.

OBJECTIVES: Modified ECT is routinely conducted using face mask (FM) and bag ventilation technique. Trans-nasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) is a novel hands-free insufflation technique that provides oxygenation and prolongs apnoea time. There is limited literature comparing the two techniques. Primary objective of this study was to compare oxygen desaturation between THRIVE and FM techniques during ECT while secondary objective was to compare hemodynamics and complications. METHODS: Patients aged 18-50 years undergoing 3rd-5th ECT treatments were enrolled. First ECT was with FM technique followed by THRIVE (with LUBO collar) in the next ECT. Except for the oxygenation technique, the protocol for ECT administration was similar with both techniques. SpO2 values were recorded every minute for 10 min while hemodynamic parameters were measured at 2 min and 5 min following administration of electrical stimulus. Any drop in SpO2 below 92 % was considered as a desaturation event. RESULTS: A total of 201 patients underwent ECTs, one each with FM and THRIVE technique. Median age of patients was 28 years. There was no difference in SpO2 between the techniques (main effect P = 0.324, interaction P = 0.14). Only one patient had desaturation with THRIVE requiring intervention with FM. None of the patients had any airway complications in terms of nasal injury, hoarseness, or pneumothorax with THRIVE. CONCLUSION: THRIVE is a safe alternative option for hands-free oxygenation while administering ECT. However, considering patient safety, an anaesthesiologist competent in airway management must be readily available.

Does Propofol Effect Site (Brain) Concentration Predicted by Target-Controlled Infusion Correlate with Propofol Measured in the Brain? An Exploratory Study in Neurosurgical Patients.

BACKGROUND: Total intravenous anesthesia with propofol can be administered by target-controlled infusion pumps, which work on the principles of pharmacokinetic modeling. While designing this model, neurosurgical patients were excluded as the surgical site and drug action site remained the same (brain). Whether the predicted set propofol concentration and the actual brain site concentration correlate, especially in neurosurgical patients with impaired blood-brain barrier (BBB), is still unknown. In this study we compared the set propofol effect-site concentration in the target-controlled infusion pump with actual brain concentration measured by sampling the cerebrospinal fluid (CSF). METHODS: Consecutive adult neurosurgical patients requiring propofol infusion intraoperatively were recruited. Blood and CSF samples were collected simultaneously when patients received propofol infusion at 2 different target effect-site concentrations-2 and 4 ug/mL. To study BBB integrity, CSF-to-blood albumin ratio and imaging findings were compared. The propofol level in the CSF was compared with set concentration using the Wilcoxon signed-rank test. RESULTS: Fifty patients were recruited, and the data were analyzed from 43 patients. There was no correlation between propofol concentration set in TCI and propofol concentration measured in blood and CSF. Though imaging findings were suggestive of BBB disruption in 37/43 patients, the mean (±standard deviation) CSF-to-serum albumin ratio was 0.0028 ± 0.002, suggesting intact BBB integrity (ratio >0.3 was considered as disrupted BBB). CONCLUSIONS: CSF propofol level did not correlate with set concentration in spite of acceptable clinical anesthetic effect. Also, the CSF-to-blood albumin measurement did not provide information on the BBB integrity.

Clinical Scoring and Ultrasound-Based Diaphragm Assessment in Predicting Extubation Failure in Neurointensive Care Unit: A Single-Center Observational Study.

BACKGROUND: Patients in the neurointensive care unit (NICU) fail extubation despite successful weaning from mechanical ventilation. Parameters currently used in the general intensive care unit do not accurately predict extubation success in the NICU. In this study, peak cough expiratory flow rate, ultrasound-based diaphragm function assessment, and comprehensive clinical scoring systems were measured to determine whether these new variables, in isolation or combination, could predict extubation failure successfully in the NICU. METHODS: All adult patients extubated after 48 h of mechanical ventilation in the NICU of a single tertiary care center were recruited into the prospective cohort. The patient's cough peak expiratory flow rate (C-PEFR), diaphragm function, and clinical scores were measured before extubation. C-PEFR was measured using a hand-held spirometer, diaphragm function (excursion, thickness fraction, and diaphragm contraction velocity on coughing) was assessed using ultrasound, and the clinical scores included the visual pursuit, swallowing, age, Glasgow Coma Scale for extubation (VISAGE) and respiratory insufficiency scale-intubated (RIS-i) scores. The patients requiring reintubation within 48 h were considered as extubation failure. Univariate and multivariate logistic regression analyses were done to identify predictors of extubation failure. RESULTS: Of the 193 patients screened, 43 were recruited, and 15 had extubation failure (20.9%). Patients with extubation failure had higher RIS-i scores (p < 0.001) and lower VISAGE scores (p = 0.043). The C-PEFR and diaphragm function (excursions and contraction velocity on coughing) were lower in patients with extubation failure but not statistically significant. The variables with p < 0.2 in univariate analysis (RIS-i, VISAGE, and diaphragm cough velocity) were subjected to multivariate regression analysis. RIS-I score remained an independent predictor (odds ratio 3.691, 95% confidence interval 1.5-8.67, p = 0.004). In a receiver operating characteristic analysis, the area under the curve for RIS-i was 0.963. An RIS-i score of 2 or more had 94% specificity and 89% sensitivity for predicting extubation failure. CONCLUSIONS: The RIS-i score predicts extubation failure in NICU patients. The addition of ultrasound-based diaphragm measurements to the RIS-i score to improve prediction accuracy needs further study. Clinical trial registration Clinical Trials Registry of India identifier CTRI/2021/03/031923.

Superselective Anesthesia Functional Examination of the Diaphragm during Endovascular Embolization of Spinal Cord Arteriovenous Malformation.

Superselective anesthesia functional evaluation (SAFE) is an adjunct to the Wada test. It is performed to rule out unintentional positioning of the tip of the embolization catheter proximal to the origin of a normal artery supplying eloquent region of spinal cord. We report a case of a 36-year-old male with cervical intramedullary spinal cord arteriovenous malformation (SCAVM) at C3 level. In this patient, we monitored motor-evoked potentials (MEPs) of bilateral upper and lower limbs along with diaphragm. Electrodes for compound muscle action potential of diaphragm were placed under fluoroscopy guidance. Through this case, we want to emphasize that intraprocedural diaphragmatic MEPs enhance the safety margin during endovascular embolization of cervical intramedullary SCAVMs. Placement of electrodes under fluoroscopy guidance ensures proper positioning into the diaphragm muscle.

Feasibility of THRIVE oxygenation and intra-operative lung-protective ventilation in morbidly obese patients undergoing neurosurgical procedures.

The conduct of anesthesia in morbidly obese patients undergoing neurosurgical procedures can be challenging considering the multi-system organ involvement. Implementation of conventional lung-protective ventilation in morbidly obese patients can have a negative impact on the intra-cranial dynamics. We report a series of three patients with morbid obesity and a difficult airway for the neurosurgical procedure. The patients were oxygenated with high-flow oxygen devices to ensure an adequate oxygen reserve in the peri-operative period. A modified intra-operative lung-protective ventilation with normocarbia was implemented with no impact on the intra-cranial pressure in the prone position in two of the patients. Oxygenation with high-flow devices should be considered during the peri-operative period in morbidly obese patients to avert an adverse respiratory event, and a modified lung-protective ventilation technique is feasible with normal intra-cranial dynamics intra-operatively.

Fatal multiorgan dysfunction following repeated iodinated radiocontrast injection in a patient receiving low-dose oral methotrexate -a case report.

BACKGROUND: Methotrexate is an antimetabolite drug that blocks dihydrofolate reductase and impairs cellular DNA synthesis. Administration of intravenous iodinated radiocontrast agents can cause life-threatening toxicity in patients receiving methotrexate. CASE: A 60-year-old female patient with rheumatoid arthritis underwent a craniotomy and clipping of a distal anterior cerebral artery aneurysm. The patient had been on low-dose oral methotrexate for the previous 5 years, which was discontinued two days before surgery. The patient received the first intravenous contrast agent injection (iohexol) during diagnostic cerebral angiography one day prior to surgery (50 ml) and the second contrast dose on the first postoperative day (60 ml). The patient developed severe methotrexate toxicity, leading to fatal multiorgan failure and death following repeated contrast imaging with intravenous iohexol. CONCLUSIONS: Even though low-dose oral methotrexate has minor adverse effects, life-threatening toxicity can be precipitated in the presence of iodinated contrast agents.

Trans-nasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) ventilation during electroconvulsive therapy (ECT) for a pregnant patient- A novel technique.

Maintaining oxygenation and ventilation is imperative in a pregnant patient undergoing electroconvulsive therapy (ECT). Here, we present the successful utilization of Trans-nasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) in a six-month pregnant patient who received ECT under general anesthesia.

A prospective observational study of electrocardiographic and echocardiographic changes in traumatic brain injury - effect of surgical decompression.

BACKGROUND: Traumatic brain injury (TBI) causes significant changes in myocardial function, which is represented by ECG and echocardiographic changes. We intended to study the effect of surgical decompression on these changes. MATERIALS AND METHODS: We recruited adult TBI patients undergoing surgery within 48 h of injury. Preoperatively, the patient's demographic and clinical details were recorded. ECG and TTE were performed before surgery and 24 h later (first postoperative day [POD1]). ECG was analyzed for heart rate, PR, QRS, and QTc intervals, morphologic end-repolarization abnormalities (MERA), and ST-segment and T wave changes. TTE data included left ventricular ejection fraction (LVEF) and regional wall motion abnormalities (RWMA). Glasgow coma scale (GCS) at discharge was recorded. ECG and TTE changes before and after surgery were compared, and its association with discharge GCS was analyzed. Preoperative predictors of LV dysfunction were analyzed. RESULTS: Of the 110 patients recruited, common ECG changes were prolonged QTc interval (42%) and MERA (47%). TTE showed poor LVEF (<50%) in 10% and RWMA in 10.8% of patients. Following surgery, both ECG and TTE changes improved. Preoperative LVEF <50% and/or RWMA were associated with a lower GCS score at discharge. Preoperative poor GCS motor score and prolonged QTc interval were independent predictors of LV dysfunction. CONCLUSIONS: Poor LV function was associated with poor admission GCS and prolonged QTc interval. Patients with reduced LV function had lower GCS at discharge.

Postoperative Outcomes Following Elective Surgery in India.

INTRODUCTION: The incidence of complications and mortality in patients undergoing elective surgery in India are unknown. We contributed Indian data to ISOS. Since there were fewer than ten centers, Indian data were not included in the primary analysis. We report postoperative outcomes in the Indian data set of patients following elective surgery. MATERIALS AND METHODS: In this prospective 7-day observational study, after obtaining a waiver of informed consent, data were collected for 30 days from consecutive patients >18 years undergoing elective surgery. The primary outcome was in-hospital postoperative complications. The secondary outcomes were in-hospital all-cause mortality, the relationship between postoperative complications and admission to critical care, and the duration of hospital stay. Complications were graded as mild, moderate, and severe. Failure to rescue was defined as mortality in patients admitted to an intensive care unit (ICU) for the treatment of complications. RESULTS: Complications occurred in 57 (27.5%) patients, who were older (53 vs 47 years, p < 0.001) and had American Society of Anaesthesiologists grades III and IV physical status (p = 0.029). One hundred and thirty-eight (65.7%) patients underwent a major surgical procedure of which 132 (62.8%) procedures were done for malignancy. Postoperative complications were significantly higher (41.5% vs 22.7%) in patients electively admitted to ICU. The overall mortality rate was 2.4%, whereas the mortality rate was 8.8% in those who developed complications. CONCLUSION: We found that 28% of patients developed postoperative complications. The overall mortality was 2.4% but was higher (8.8%) in those who developed complications. Age and complex surgical procedures independently predicted complications, while lower preoperative hemoglobin appeared to be protective. STUDY REGISTRATION: ISRCTN51817007. HOW TO CITE THIS ARTICLE: Agarwal V, Muthuchellappan R, Shah BA,Rane PP, Kulkarni AP, et al. Postoperative Outcomes Following Elective Surgery in India. Indian J Crit Care Med 2021;25(5):528-534.

Diaphragm Function Assessment During Spontaneous Breathing Trial in Patients with Neuromuscular Diseases.

INTRODUCTION: The optimal time to discontinue patients from mechanical ventilation is critical as premature discontinuation as well as delayed weaning can result in complications. The literature on diaphragm function assessment during the weaning process in the intriguing subpopulation of critically ill neuromuscular disease patients is lacking. METHODS: Patients with neuromuscular diseases, on mechanical ventilation for more than 7 days, and who were ready for weaning were studied. During multiple T-piece trials over days, diaphragm function using ultrasound and diaphragm electrical activity (Edi peaks using NAVA catheter) was measured every 30 min till a successful 2 h weaning. RESULTS: A total of 18 patients were screened for eligibility over 5-month period and eight patients fulfilled the inclusion criteria. Sixty-three data points in these 8 subjects were available for analysis. A successful breathing trial was predicted by Edi reduction (1.22 µV for every 30 min increase in weaning duration; 0.69 µV for every day of weaning) and increase in diaphragm excursion (2.81 mm for every 30 min increase in weaning duration; 2.18 mm for every day of weaning). CONCLUSION: The Edi and diaphragm excursion changes can be used as additional objective tools in the decision-making of the weaning trials in neuromuscular disease.

Incidence of Deep Vein Thrombosis in Neurointensive Care Unit Patients-Does Prophylaxis Modality Make Any Difference?

BACKGROUND AND AIMS: To determine the incidence of upper and lower limb deep vein thrombosis (DVT) using ultrasonography (USG) in adult patients admitted to neuro-medical and neurosurgical intensive care unit (ICU). MATERIALS AND METHODS: In this prospective observational study, patients admitted to the medical and surgical neuro-ICU and remained in the ICU for more than 48 hours were recruited. All patients were clinically examined for DVT. Basilic and axillary veins in the upper limbs and popliteal and femoral veins in the lower limbs were screened for DVT using USG. USG examination was performed on the day of admission to ICU and thereafter every 3rd day till discharge from ICU or death. Intermittent pneumatic compression (IPC) stockings were applied to the lower limbs to all the patients in both ICUs. Unfractionated heparin (UFH) was given subcutaneously to neuromedical ICU patients, while in surgical ICU, it was left to the discretion of the neurosurgeons. RESULTS: A total of 130 adult patients were admitted to the ICU during the 8 month study period. Thirty patients were excluded and the remaining 98 patients' (38 in medical and 60 in surgical ICU) data were analyzed. None of the 38 medical ICU patients developed DVT, while in neurosurgical ICU, 4 out of 60 patients developed DVT. CONCLUSION: A combination of UFH and IPC stockings were effective in minimizing the DVT in neuromedical ICU patients. In surgical patients, through IPC stockings were effective, UFH can be considered for patients with intracranial malignancy. HOW TO CITE THIS ARTICLE: Behera SS, Krishnakumar M, Muthuchellappan R, Philip M. Incidence of Deep Vein Thrombosis in Neurointensive Care Unit Patients-Does Prophylaxis Modality Make Any Difference? Indian Journal of Critical Care Medicine, January 2019;23(1):43-46.

Correlation between time lag of arterial-plethysmographic waveforms and systemic vascular resistance: a prospective study.

Blood pressure (BP), a surrogate of cardiac output (CO), is also dependent on systemic vascular resistance (SVR). But SVR is not routinely monitored in daily clinical practice. We hypothesise that the time difference between the peripheral arterial waveform and the finger plethysmographic waveform (time lag index - TLi) could indicate the systemic vascular resistance. In this study, we correlated TLi with the systemic vascular resistance measured by minimally invasive CO monitor (pulse contour analysis). SVR changes in response to administration of mannitol were studied. American Society of Anesthesiologists (ASA) class I and II patients undergoing major intracranial surgeries were recruited. Arterial cannulation and pulse-oximetry recordings were done in the same limb. Arterial and plethysmographic waveforms were recorded before mannitol infusion (baseline) and at every 10 minutes for 60 minutes after the termination of mannitol infusion. Simultaneously, SVR was recorded from the Vigileo FLotrac CO monitor. Using custom-made programme, the time difference between both waveforms was calculated and corrected for heart rate (TLi). The correlation between time lag and the systemic vascular resistance was assessed using a mixed effect model, adjusting for the subject. Data of one hundred subjects were analysed. Following mannitol administration, there was a significant decrease in the SVR and the TLi (p < .001). The patient characteristics influenced both the baseline values of SVR (intercept) and the changes in SVR over time (slope). As both the baseline value and the change over time for SVR were different in each patient, we used mixed effect model analysis to assess the relationship between SVR and TLi for different time periods. The effect of TLi on SVR was significant (ß = 877.16, p = .008). The high beta coefficient suggests that when SVR increases, the TLi also increase and vice versa. A strong correlation between SVR and TLi was demonstrated for a given patient. Further studies are needed to explore the possibility of utilising this parameter to follow up changes in SVR in an individual patient at a particular point in time in different clinical scenarios.

Volatile anesthetic for the control of posthypoxic refractory myoclonic status.

Posthypoxic myoclonus (Lance-Adams syndrome) is characterized by myoclonus involving multiple muscle groups which is resistant to most conventional antiepileptic drugs. We present a case of hypoxic brain injury-induced myoclonic status epilepticus successfully controlled with isoflurane. The antimyoclonic effects of isoflurane are likely due to potentiation of inhibitory postsynaptic GABAA receptor-mediated currents and its effects on thalamocortical pathways. It is effective even when intravenous agents fail to control myoclonus. It may be a useful alternative to intravenous anesthetics as a third tier therapy in patients with refractory status myoclonus.

Cerebral vasospasm: current understanding.

PURPOSE OF REVIEW: With recent research trying to explore the pathophysiologic mechanisms behind vasospasm, newer pharmacological and nonpharmacological treatments are being targeted at various pathways involved. This review is aimed at understanding the mechanisms and current and future therapies available to treat vasospasm. RECENT FINDINGS: Computed tomography perfusion is a useful alternative tool to digital subtraction angiography to diagnose vasospasm. Various biomarkers have been tried to predict the onset of vasospasm but none seems to be helpful. Transcranial Doppler still remains a useful tool at the bedside to screen and follow up patients with vasospasm. Hypertension rather than hypervolemia and hemodilution in 'Triple-H' therapy has been found to be helpful in reversing the vasospasm. Hyperdynamic therapy in addition to hypertension has shown promising effects. Endovascular approaches with balloon angioplasty and intra-arterial nimodipine, nicardipine, and milrinone have shown consistent benefits. Endothelin receptor antagonists though relieved vasospasm, did not show any benefit on functional outcome. SUMMARY: Endovascular therapy has shown consistent benefit in relieving vasospasm. An aggressive combination therapy through various routes seems to be the most useful approach to reduce the complications of vasospasm.

Measurement of systolic pressure variation during graded volume loss using simple tools on Datex Ohmeda S/5 monitor.

Direct invasive arterial monitoring is performed routinely for all major neurosurgical procedures. Systolic pressure variation (SPV) used, independently or in combination with central venous pressure (CVP) allows optimal fluid management in hypovolemia and hemorrhage. This study aims to quantify SPV during graded hypovolemia using the simple technique described by Gouvea and Gouvea using Datex Ohmeda S/5, and to compare its reliability relative to other hemodynamic indicators of hypovolemia. Twenty anesthetized neurosurgical patients of ASA grade I and II patients were administered furosemide 0.5 mg/kg intravenously to obtain graded volume loss in the form of urine output. Invasive arterial pressure from radial artery and CVP were monitored using Datex OhmedaS/5 (Finland). Invasive arterial pressure label was changed to pulmonary artery label with the scale appropriate for arterial pressure. The trace was frozen in the wedge mode to reduce the sweep speed and the cursor was used to measure SPV and pulse pressure variation (PPV). Heart rate, systolic blood pressure, diastolic blood pressure, CVP at zero end-expiratory pressure, SPV and PPV are measured at baseline, and after a urine output of 200 and 500 mL. There was a significant correlation between volume loss and CVP, SPV, and PPV. The area under the curve of receiver operating characteristic analysis was >0.75 for CVP, SPV, and PPV. SPV of 7.5 mm Hg and a change of SPV by 4.5 mm Hg, a PPV of 4.5 and change in PPV by 2.5 mm Hg were the best cut-off values that corresponded to a volume change of 500 mL. This simple method enabled calculation of SPV without the computerized modules, and detected volume loss comparable to CVP.