Predictor role of heart rate variability in subarachnoid hemorrhage: A systematic review.

Background- Subarachnoid hemorrhage (SAH) is one of the most devastating diseases with a high rate of morbidity and mortality. The heart rate variability (HRV) is a non-invasive method of monitoring various components of the autonomic nervous system activity that can be utilized to delineate autonomic dysfunctions associated with various physiological and pathological conditions. The reliability of HRV as a predictor of clinical outcome in aneurysmal subarachnoid hemorrhage (aSAH) is not yet well investigated in literature. Methods- A systematic review and in depth analysis of 10 articles on early HRV changes in SAH patients was performed. Results- This systematic review demonstrates a correlation between early changes in HRV indices (time and frequency domain) and the development of neuro-cardiogenic complications and poor neurologic outcome in patients with SAH. Conclusions- A correlation between absolute values or changes of the LF/HF ratio and neurologic and cardiovascular complications was found in multiple studies. Because of significant limitations of included studies, a large prospective study with proper handling of confounders is needed to generate high-quality recommendations regarding HRV as a predictor of post SAH complications and poor neurologic outcome.

Variability of Resting Carbon Dioxide Tension in Patients with Intracranial Steno-occlusive Disease.

Introduction Controlling the partial pressure of carbon dioxide (PaCO 2 ) is an important consideration in patients with intracranial steno-occlusive disease to avoid reductions in critical perfusion from vasoconstriction due to hypocapnia, or reductions in blood flow due to steal physiology during hypercapnia. However, the normal range for resting PCO 2 in this patient population is not known. Therefore, we investigated the variability in resting end-tidal PCO 2 (P ET CO 2 ) in patients with intracranial steno-occlusive disease and the impact of revascularization on resting P ET CO 2 in these patients. Setting and Design Tertiary care center, retrospective chart review Materials and Methods We collected resting P ET CO 2 values in adult patients with intracranial steno-occlusive disease who presented to our institution between January 2010 and June 2021. We also explored postrevascularization changes in resting P ET CO 2 in a subset of patients. Results Two hundred and twenty-seven patients were included [moyamoya vasculopathy ( n = 98) and intracranial atherosclerotic disease ( n = 129)]. In the whole cohort, mean ± standard deviation resting P ET CO 2 was 37.8 ± 3.9 mm Hg (range: 26-47). In patients with moyamoya vasculopathy and intracranial atherosclerotic disease, resting P ET CO 2 was 38.4 ± 3.6 mm Hg (range: 28-47) and 37.4 ± 4.1 mm Hg (range: 26-46), respectively. A trend was identified suggesting increasing resting P ET CO 2 after revascularization in patients with low preoperative resting P ET CO 2 (<38 mm Hg) and decreasing resting P ET CO 2 after revascularization in patients with high preoperative resting P ET CO 2 (>38 mm Hg). Conclusion This study demonstrates that resting P ET CO 2 in patients with intracranial steno-occlusive disease is highly variable. In some patients, there was a change in resting P ET CO 2 after a revascularization procedure.

Sense understanding of text conversation using temporal convolution neural network.

This paper proposes a model which uses Spatio Temporal features for real-time sense understanding of a text conversation. The proposed model uses CNN along with the concept of LSTM to create a new Spatio temporal cell. Furthermore, the proposed model is used to classify the sentences into eight senses. The model achieved an F-Score around 0.984 on sense classification. Additionally, the efficiency and capabilities of the model are also tested on a standard IMDB sentiment classification dataset. On the IMDB dataset, the model gave an accuracy of 89.27. The experimental results show that the proposed model works better than a CNN model, a Bi-LSTM model, and a combination of CNN & LSTM model in terms of a number of parameters and execution time.

Goal-directed Fluid Therapy Versus Conventional Fluid Therapy During Craniotomy and Clipping of Cerebral Aneurysm: A Prospective Randomized Controlled Trial.

BACKGROUND: Fluid imbalance is common after aneurysmal subarachnoid hemorrhage and negatively impacts clinical outcomes. We compared intraoperative goal-directed fluid therapy (GDFT) using left ventricular outflow tract velocity time integral (LVOT-VTI) measured by transesophageal echocardiography with central venous pressure (CVP)-guided fluid therapy during aneurysm clipping in aneurysmal subarachnoid hemorrhage patients. METHODS: Fifty adults scheduled for urgent craniotomy for aneurysm clipping were randomly allocated to 2 groups: group G (n=25) received GDFT guided by LVOT-VTI and group C (n=25) received CVP-guided fluid management. The primary outcome was intraoperative mean arterial pressure (MAP). Secondary outcomes included volume of fluid administered and several other intraoperative and postoperative variables, including neurological outcome at hospital discharge and at 30 and 90 days. RESULTS: There was no difference in MAP between the 2 groups despite patients in group G receiving lower volumes of fluid compared with patients in group C (2503.6±534.3 vs. 3732.8±676.5 mL, respectively; P <0.0001). Heart rate and diastolic blood pressure were also comparable between groups, whereas systolic blood pressure was higher in group G than in group C at several intraoperative time points. Other intraoperative variables, including blood loss, urine output, and lactate levels were not different between the 2 groups. Postoperative variables, including creatinine, duration of postoperative mechanical ventilation, length of intensive care unit and hospital stay, and incidence of acute kidney injury, pneumonitis, and vasospasm were also comparable between groups. There was no difference in neurological outcome at hospital discharge (modified Rankin scale) and at 30 and 90 days (Extended Glasgow Outcome Scale) between the 2 groups. CONCLUSION: Compared with CVP-guided fluid therapy, transesophageal echocardiography-guided GDFT maintains MAP with lower volumes of intravenous fluid in patients undergoing clipping of intracranial aneurysms with no adverse impact on postoperative complications.

Fiberoptic bronchoscopy versus video laryngoscopy guided intubation in patients with craniovertebral junction instability: A cinefluroscopic comparison.

BACKGROUND: Manipulation during endotracheal intubation in patients with craniovertebral junction (CVJ) anomalies may cause neurological deterioration due to underlying instability. Fiberoptic-bronchoscopy (FOB) is better than video laryngoscope (VL) for minimizing cervical spine movement during intubation. However, evidence suggesting superiority of FOB in patients with CVJ instability is lacking. We prospectively compared dynamic movements of the upper cervical spine during intubation using FOB with VL in patients with CVJ anomalies. METHODS: A prospective, randomized, and clinical trial was conducted in 62 patients of American Society of Anaesthesiologist Grade I-II aged between 12 and 65 years with CVJ anomalies. Patients were randomized for intubation under general anesthesia with either VL or FOB. The intubation process was done with application of skeletal traction and recorded cinefluroscopically. The dynamic interrelationship of bony landmarks (horizontal, vertical, and diagonal distances between fixed points on posterior C1 and C2) was analyzed to indirectly calculate alteration of the upper cervical spinal canal diameter (at CVJ). Atlanto-dental interval (ADI) was calculated wherever possible. RESULTS: The alteration in canal diameter (using bony landmarks) at CVJ during intubation was not significant with the use of either VL or FOB (P > 0.05). In 41 patients, where ADI could be measured, ADI was reduced (increased spinal canal diameter) in a greater number of patients in VL group when compared to FOB group (P < 0.05). CONCLUSION: Using rigid skull traction, intubation under general anesthesia with VL offers similar advantage as FOB in terms of the spinal kinematics in patients with CVJ anomalies/instability. Nevertheless, greater number of patients intubated with VL may have an advantage of increased cervical spinal canal diameter when compared to FOB.

Comparison of End-Tidal Anesthetic Gas Concentration versus Bispectral Index-Guided Protocol as Directing Tool on Time to Tracheal Extubation for Sevoflurane-Based General Anesthesia.

BACKGROUND: Modalities for titrating anesthetic drug-like bispectral index (BIS) and end-tidal anesthetic gas (ETAG) concentration in predicting early extubation had been studied with old anesthetic agents such as isoflurane. AIM: The aim of this study is to compare the effect of ETAG concentration versus BIS-guided protocol as directing tool on time to tracheal extubation for sevoflurane-based general anesthesia. MATERIALS AND METHODS: This prospective, randomized, double-blind trial studied sixty patients with American Society of Anesthesiologists physical status classes I and II who received sevoflurane-based general anesthesia and were allocated to either BIS-guided anesthesia group (n = 30) or ETAG-guided anesthesia group (n = 30). Time to tracheal extubation was measured. BIS value was kept between 40 and 60 in BIS group, whereas minimum alveolar concentration value was kept between 0.7 and 1.3 in ETAG group. The two groups were compared using Student's t-test, and P < 0.05 was considered statistically significant. The statistical analysis was performed using the open source "R" programming language. RESULTS: Mean time to tracheal extubation was significantly shorter in BIS group (308.77 ± 20.48 s) as compared to ETAG group (377.90 ± 25.06 s) (P < 0.001). The sevoflurane concentration used was also significantly less in group BIS than group ETAG at multiple time intervals (P = 0.001). CONCLUSION: Prediction of extubation was significantly early with BIS monitoring as compared to ETAG monitoring in sevoflurane-based general anesthesia.