Predictors Of Hypotension Research Articles

Hypotension after Induction of Anesthesia as a Predictor of Hypotension after Opening the Dura Mater during Emergency Craniotomy.

Background: The subject of this study is intraoperative hypotension during the evacuation of acute subdural haematoma (ASH). We examined the association between the decrease in intraoperative blood pressure (BP) after the induction of anaesthesia and the decrease in BP after opening the dura mater. The second aim of this study was to assess the relationship between preoperative hypertension and the emergence of an intraoperative drop in BP. Methods: This was a retrospective cohort study on adult patients undergoing emergency craniotomy due to ASH. In total, 165 medical records from a 2-year period were analysed. The patients were divided into two groups: high blood pressure (HBP) (n = 89) and normal blood pressure (NBP) (n = 76). The HBP group included patients with hypertension in the preoperative period (systolic blood pressure (SBP) > 150 mmHg). The NBP group included patients with an SBP between 90 and 150 mmHg. Results: We observed a significant drop in blood pressure in two operational periods: after the induction of anaesthesia and after opening the dura mater. A highly relevant positive correlation was noted between the decrease in SBP after anaesthesia induction and the opening of the dura mater (p < 0.001). In the HBP group, after opening the dura mater, there was a 44% SBP decrease from the baseline value. Conclusions: The reduction in BP after the induction of anaesthesia is a predictor of a subsequent drop in BP after opening the dura mater during urgent surgery due to ASH. Patients with hypertension in the preoperative period of ASH tend to have a greater intraoperative drop in BP and worse outcomes.

Role of Pleth variability index and perfusion index for predicting hypotension following spinal anaesthesia in patients undergoing caesarean section

Pleth variability index and perfusion index are noninvasive continuous hemodynamic monitors that can assess peripheral vascular tone and intravascular volume status and thus can predict hypotension following spinal anaesthesia. Spinal anaesthesia is the choice of anaesthesia in caesarean sections. Approximately 70% of patients will develop hypotension after spinal anaesthesia, which can lead to maternal and fetal complications. Thus, the Pleth Variability Index (PVI) and perfusion index (PI) allow the identification of patients with an increased susceptibility to hypotension following spinal anaesthesia.: This prospective observational study was conducted in a tertiary care centre with 102 obstetric patients undergoing spinal anaesthesia for caesarean section in the age group of 18-35 years who were full term with ASA≤ grade II, BMI 35kg/m. Pleth variability index and Perfusion index were measured before and after spinal anaesthesia. The data was analysed using ROC and multiple linear regression models using SPSS software. In the hypotension group PVI and PI at one minute is higher than without the hypotension group. PVI at one minute is an independent factor for predicting hypotension following spinal anaesthesia (P=0.039). ROC analysis of baseline and one-minute PVI showed only one-minute PVI can predict hypotension with an AUC-0.633(95% CI-0.492-0.774) and an optimal cut-off value of 19.5. ROC analysis of baseline and one-minute PI revealed both baseline and one-minute PI could predict hypotension with AUC-0.507 (95% CI 0.378-0.636) and 0.540 (95% CI 0.410-0.682) respectively. The optimal cut-off of baseline PI for predicting hypotension is 2.5 with a sensitivity of 51.4%, specificity of 61.5% and one-minute PI is 4.5 with a sensitivity of 60.8% and specificity of 53.8%. Baseline PVI is not a predictor of hypotension and one-minute PVI ≥19.5 can predict hypotension following spinal anaesthesia. One minute PI ≥ 4.5 is more sensitive in predicting hypotension than Baseline PI ≥2.5.: The Pleth Variability Index and Perfusion Index are noninvasive monitors which can predict hypotension following spinal anaesthesia in cesarean sections.

Sacubitril/Valsartan-Related Hypotension in Patients With Heart Failure and Preserved or Mildly Reduced Ejection Fraction

BackgroundHypotension is a potential adverse effect of sacubitril/valsartan, but there are limited data regarding the predictors and implications of treatment-related hypotension in heart failure (HF) with mildly reduced and preserved ejection fraction. ObjectivesWe investigated predictors of treatment-associated hypotension, clinical outcomes after hypotension, and the relationship between left ventricular ejection fraction (LVEF) and incidence of hypotension in the PARAGON-HF (Prospective Comparison of ARNI with ARB Global Outcomes in HF with Preserved Ejection Fraction) trial. MethodsPARAGON-HF randomized patients with chronic HF (≥45%) to sacubitril/valsartan or valsartan. Following randomization, hypotension was defined as investigator-reported hypotension with a systolic blood pressure <100 mm Hg. Predictors of hypotension were assessed using multivariable Cox models. Associations between hypotension and clinical outcomes were evaluated in time-updated Cox models. The relationship among treatment, LVEF, and incident rates of hypotension and clinical outcomes was estimated using Poisson regression models. ResultsOf 4,796 patients in PARAGON-HF, 637 (13%) experienced hypotension, more frequently in the sacubitril/valsartan arm (P < 0.001). Following documented hypotension, patients had higher risk of cardiovascular death and total HF hospitalizations (adjusted RR: 1.63; 95% CI: 1.27-2.09; P < 0.001) and all-cause death (adjusted HR: 1.62; 95% CI: 1.28-2.05; P < 0.001). LVEF modified the association between sacubitril/valsartan and risk of hypotension (Pinteraction = 0.019) such that patients with LVEF ≥60% experienced substantially higher treatment-related risks of hypotension. ConclusionsIn PARAGON-HF, a higher LVEF was associated with an increased risk of hypotension in patients treated with sacubitril/valsartan compared with valsartan. Because these subjects are also less likely to derive clinical benefit from sacubitril/valsartan, our data reinforce that the benefit/risk ratio favors the use of sacubitril/valsartan in patients with LVEF below normal, but not at higher LVEF. (Efficacy and Safety of LCZ696 Compared to Valsartan, on Morbidity and Mortality in Heart Failure Patients With Preserved Ejection Fraction [PARAGON-HF]; NCT01920711)

Perfusion index as a predictor of hypotension following induction of general anaesthesia with propofol-An observational study

Background: Perfusion index (PI) is a somewhat novel parameter evaluating the pulsatility of blood in the extremities, calculated using the infrared spectrum as a component of plethysmography waveform processing. Aims and Objectives: To obtain a cutoff value of pre-anesthesia PI, which may be helpful for the prediction of hypotension following anesthetic induction with propofol. Materials and Methods: This descriptive observational research was carried out at the Sree Gokulam medical college and research foundation, Venjaramoodu, Trivandrum, Kerala, from June 2020 to June 2021. A total of 174 patients of age group 17–60 years, with ASA 1 or 2 scheduled for surgery under general anesthesia, were included. The parameters (systolic blood pressure [SBP], diastolic blood pressure, mean arterial pressure, PI, and SPO2) were recorded until 5 min of induction. Intravenous (IV) fentanyl 2 μg/kg was administered, propofol injected was given slowly at a rate of 10 mg per every 5 s, titrated to loss of verbal communication responseuronium 0.1 mg/kg IV was administered. The calculation for hypertension was done 5 min after anesthesia. The predictive validity of PI was calculated, keeping SBP as the standard gold test. For statistical analysis coGuide software. Results: The cutoff value for PI at 5 min was low (≤2.45) for 27 (90%) participants and high (&gt;2.45) for 3 (10%) participants. With a sensitivity of 90% in predicting hypotension and specificity of 87.50%, false-positive rate was 12.50%, false-negative rate was 10, positive predictive value was 60% (95 CI 44.43–74.30%), the negative predictive value (NPV) was 97.67%, and the total diagnostic accuracy was 87.93%. Conclusion: With the current study’s findings, we conclude that PI cutoff value 2.45 can be used to predict hypotension following anesthetic induction with propofol. It has a high NPV with fair diagnostic accuracy.

Construction of nomogram prediction model using heart rate and pulse perfusion variability index as predictors for hypotension in cervical cancer patients with spinal epidural anesthesia.

The prevention and treatment strategies for cervical cancer patients undergoing spinal epidural anesthesia have increasingly focused on early screening for high-risk factors associated with potential hypotension. We analyze the general conditions and preoperative examination results of 312 cervical cancer patients who received spinal epidural anesthesia, in order to identify independent risk factors for hypotension, assess their predictive efficacy, and construct a nomogram. 312 patients with cervical cancer received spinal epidural anesthesia were included in this study. Among them, 164 patients with hypotension after hysterectomy with spinal epidural anesthesia were in a hypotension group. Important risk predictors of hypotension after hysterectomy with spinal epidural anesthesia were identified using univariate and multivariate analyses, then a clinical nomogram was constructed. The predictive accuracy was assessed by unadjusted concordance index (C-index) and calibration plot. Univariate and multivariate regression analysis identified basal HR (≥95) (95% CI 0.831-0.900; P = 0.000) and basal PVI (95% CI 0.679-0.877; P = 0.000) were the independent risk factors for hypotension in cervical cancer patients with spinal epidural anesthesia. Those risk factors were used to construct a clinical predictive nomogram. The regression equation model based on the above factors was logit (P) = -6.820 + 0.216 * basal HR + basic PVI * 0.312. The calibration curves for hypotension risk revealed excellent accuracy of the predictive nomogram model. Decision curve analysis showed that the predictive model could be applied clinically when the threshold probability was 20 to 75%. We surmised that the basal HR values and PVI values are the independent risk factors for hypotension in cervical cancer patients with spinal epidural anesthesia. The construction of nomograms is beneficial in predicting the risk of hypotension in these patients.

INDEKS KOLAPSIBILITAS (CI) SEBAGAI PREDIKTOR HIPOTENSI PADA PASIEN DENGAN ANESTESI UMUM

Intraoperative hypotension (IOH) is important to identify early because it is associated with high morbidity and mortality in old age. Ultrasonographic measurement of the inferior vena cava collapsibility index (IVCCI) can detect volume responsiveness in circulatory shock. The purpose of this study was to examine the collapsibility index (CI) as a predictor of hypotension in patients under general anesthesia. This study was an observational cross-sectional design in adult patients who underwent elective surgery under general anesthesia at Sanglah General Hospital from December 2021 to January 2022 using a consecutive sampling technique. Immediate postinduction changes in systolic and mean blood pressure were compared. The performance of the IVC CI as a diagnostic tool for predicting hypotension (systolic pressure?&lt;?90?mmHg or a???30% drop from the baseline) was evaluated by ROC curve analysis. At the point of collapsibility index (CI) ? 47, there were 29 patients (96.7%) with hypotension. At the point of collapsibility index (CI) &lt; 47, there was 1 patient (3.3%) with hypotension and 24 patients (100%) without hypotension. The cut-off level of collapsibility index (CI) is obtained with the Receiver Operating Curve (ROC) curve, below 0.985. The cut-off CI level for hypotension was 47.0 with a sensitivity of 96.7% and specificity of 100%. There is a significant relationship between IVC CI with a decrease in MAP before and after induction at 4,8, and 10 minutes (p&lt;0,05). The collapsibility index (CI) 50 can be used as a predictor of the incidence of hypotension in patients under general anesthesia.&#x0D; Keywords : hypotension, collapsibility index, general anesthesia.

Perfusion index as a predictor of hypotension after induction of general anesthesia in elderly patients – a prospective observational study

ABSTRACT Introduction The elderly patients are at a greater risk for hypotension after induction of anesthesia. Perfusion index (PI) predicted patients vascular responses in many situations. This study hypothesized that baseline value of PI would predict hypotension in geriatric patients after anesthetic induction as population at risk for postinduction hypotension. Methods This observational, prospective study involved 30 patients aged >65 years who were scheduled for elective procedures under general anesthesia. From baseline to 15 min after propofol induction of anesthesia, the PI, heart rate, and blood pressure (BP) were recorded every minute. Hypotension was defined as a decrease greater than 30% in systolic BP from baseline. Results Early hypotension within 3 min after induction was experienced in 53.3%, while 36.7% had late hypotension within 15 min. Receiver operating characteristic (ROC) curves for PI as a predictive test of hypotension at 3 min showed good predictability of the baseline PI for early postinduction hypotension with area under receiver operating characteristic curve (AUC) 0.97, sensitivity 88%, specificity 93%, positive predictive value (PPV) 93%, negative predictive value (NPV) 87%, and a cutoff value of ≤1.3. After intubation, the predictive value decreased, with PI > 0.91 to predict late hypotension with sensitivity 91%, specificity 58%, PPV 56%, NPV 92%, and AUC 0.66. Conclusions PI could predict early hypotension following propofol induction in the geriatric population. So, it can be considered a valuable tool in monitoring this vulnerable population after induction of anesthesia.

Evaluation of urine specific gravity as a predictor of hypotension during anaesthesia in healthy dogs premedicated with dexmedetomidine

ObjectiveTo investigate the relationship between urine specific gravity (USG) and the risk of arterial hypotension during general anaesthesia (GA) in healthy dogs premedicated with dexmedetomidine and methadone. Study designProspective clinical cohort study. AnimalsA total of 75 healthy client-owned dogs undergoing GA for elective tibial plateau levelling osteotomy. MethodsAfter placing an intravenous catheter, dogs were premedicated with dexmedetomidine (5 μg kg–1) and methadone (0.3 mg kg–1) intravenously. After induction of GA with alfaxalone to effect, the bladder was expressed and USG measured. An arterial catheter was placed, and residual blood was used to measure packed cell volume (PCV) and total protein (TP). GA was maintained with isoflurane vaporised in oxygen and a femoral and sciatic nerve block were performed. Arterial blood pressure < 60 mmHg was defined as hypotension and recorded by the anaesthetist. Treatment for hypotension was performed in a stepwise manner following a flow chart. Frequency of hypotension, treatment and response to treatment were recorded. Logistic regression modelling was used to assess the association between USG, TP and PCV and incidence of perioperative hypotension; p < 0.05. ResultsData from 14 dogs were excluded. Of the 61 dogs, 16 (26%) were hypotensive during GA, 15 dogs needed treatment of which 12 were responsive to a decrease in inhalant vaporiser setting. The logistic regression model was not statistically significant (p = 0.8). There was no significant association between USG (p = 0.6), TP (p = 0.4), PCV (p = 0.8) and arterial hypotension during GA. Conclusions and clinical relevanceIn healthy dogs premedicated with dexmedetomidine and methadone and maintained under GA with isoflurane and a femoral and sciatic nerve block, there was no relationship between the specific gravity of urine collected after premedication and intraoperative arterial hypotension.

Non - Invasive hemodynamic parameters as predictors for hypotension following spinal anesthesia in parturients undergoing lower segment cesarean section: A prospective observational study

Non - Invasive hemodynamic parameters as predictors for hypotension following spinal anesthesia in parturients undergoing lower segment cesarean section: A prospective observational study

Perfusion index as a predictor of hypotension during spinal anesthesia for lower segment cesarean section: A prospective, observational study

Abstract Background and Aims: Hypotension following subarachnoid block (SAB) for lower segment cesarean section (LSCS) has adverse fetal and maternal implications. Perfusion index (PI) has been used for assessing peripheral perfusion dynamics. This study aimed to determine whether a baseline PI can predict hypotension after spinal anesthesia for LSCS. Materials and Methods: In this prospective, observational study, 152 term parturients were divided into two groups: Group I (PI of ≤ 3.5) and Group II (PI &gt;3.5). SAB was performed using bupivacaine 0.5% (hyperbaric) 10 mg with dexmedetomidine 5 μg. PI, vital parameters, and correlation between baseline PI and hypotension were observed. Receiver operating characteristic (ROC) curve was plotted for PI and the occurrence of hypotension. Statistical analysis was performed using Chi-square test, independent sample t-test, Mann–Whitney U-test, and regression analysis with Spearman’s rank correlation coefficient test. Results: The incidence of hypotension was higher in Group II (57.89%) compared to Group I (18.42%) (P &lt; 0.0001). The correlation between baseline PI &gt;3.5, the number of episodes of hypotension, and the total dose of mephentermine required were also significant. The sensitivity and specificity of baseline PI of 3.5 to predict hypotension were 72.37% and 81.58%, respectively. The area under the ROC curve for PI to predict hypotension was 0.830. Conclusion: Parturients with baseline PI &gt;3.5 are at higher risk of developing hypotension following SAB compared to those with baseline PI ≤3.5; hence, PI is a safe and reliable device for predicting hypotension following SAB.

Predictors of hypotension during anesthesia induction in patients with hypertension on medication: a retrospective observational study

BackgroundHypotension during anesthesia induction is a common event, and occurs more frequently in patients with hypertension than in healthy individuals. Intraoperative hypotension in non-cardiac surgery is reportedly associated with various postoperative complications. However, the predictors of hypotension during anesthesia induction in patients with hypertension have not yet been ascertained. Therefore, we aimed to determine the predictors of hypotension during anesthesia induction in patients with hypertension on medication focusing on the half-life of the medication used.MethodsIn this retrospective observational study, we enrolled patients with hypertension on medication who underwent general anesthesia for oral and maxillofacial surgery between January 1, 2013, and December 31, 2019. Multivariable logistic regression analysis was conducted to test for associations between clinical factors and hypotension during anesthesia induction in patients with hypertension on medication.ResultsA total of 395 patients were included in this study. The risk factors for hypotension during anesthesia induction in patients with hypertension on medication were pre-induction mean arterial blood pressure (adjusted unit odds ratio, 0.96 [95% confidence interval, 0.94 to 0.98]), female sex (adjusted odds ratio [aOR], 1.63 [1.03 to 2.57]), regular use of angiotensin receptor blockers (ARBs)/angiotensin-converting enzyme inhibitors (ACE-Is) with a long half-life (vs. no regular use of ARBs/ACE-Is aOR, 4.02 [1.77 to 9.12]; vs. regular use of ARBs/ACE-Is with a short-to-middle half-life aOR, 3.17 [1.46 to 6.85]), and regular use of beta blockers (aOR, 2.45 [1.19 to 5.04]). Regular use of calcium channel blockers (aOR, 0.44 [0.25 to 0.77]) was a suppressive factor for hypotension during anesthesia induction in patients with hypertension.ConclusionsIn patients with hypertension on medication, regular use of ARBs/ACE-Is with a long half-life, regular use of beta blockers, low pre-induction mean arterial blood pressure, and female sex were risk factors for hypotension during anesthesia induction. Notably, regular use of ARBs/ACE-Is with a long half-life was a high-risk factor for hypotension during anesthesia induction in patients with hypertension on medication even after a 24-h preoperative withdrawal period.

The Perfusion Index of the Ear as a Predictor of Hypotension Following the Induction of Anesthesia in Patients with Hypertension: A Prospective Observational Study.

Patients with hypertension develop hemodynamic instability more frequently during anesthesia-particularly post-induction. Therefore, different monitoring methods may be required in patients with hypertension. Perfusion index-the ratio of the pulsatile blood flow to the non-pulsatile static blood flow in a patient's peripheral tissues, such as the fingers or ears-can show the hemodynamic status of the patient in a non-invasive way. Among the sites used for measuring the perfusion index, it is assumed that the ear is more reliable than the finger for hemodynamic monitoring, because proximity to the brain ensures appropriate perfusion. We hypothesized that the low value of preoperative ear PI could be a predictor of post-induction hypotension in patients with hypertension. Thirty patients with hypertension were enrolled. The perfusion index and pleth variability index were measured using the ear, finger, and blood pressure, and heart rate was recorded to monitor hypotension. After insertion of the supraglottic airway, 20 patients developed post-induction hypotension. Those who developed hypotension showed a significantly lower preoperative perfusion index of the ear. The preoperative perfusion index of the ear could predict post-induction hypotension in patients with hypertension.

Tricuspid annular plane systolic excursion to predict arterial hypotension caused by general anesthesia induction.

Hypotension, which may develop after anesthesia induction, may cause ischemic stroke, myocardial damage, acute kidney injury, and postoperative mortality. Various assessments can be used to predict hypotension. We aimed to test the relationship of tricuspid annular plane systolic movement (TAPSE) with hypotension. A total of 47 patients aged 18-65 years, who were scheduled for general anesthesia for elective surgery, had ASA I-II, and had no known cardiovascular disease, were included in the study. TAPSE was calculated in an apical four-chamber view by placing an M-mode cursor along the tricuspid annulus, and measuring the longitudinal movement amount in the peak systole. TAPSE was measured 30 minutes before the surgery. The primary objective of the present study was to test the relationship between TAPSE and hypotension because of general anesthesia induction. We accepted hypotension as a decrease of 30% or more from baseline in systolic blood pressure (SBP) in the first 10 minutes following induction or a decrease in mean arterial pressure (MAP) below 60 mmHg. Statistically significant differences were detected in TAPSE values compared to the hypotension status after general anesthesia induction (P<0.001). The value of TAPSE had an optimal cut-off value of ≤2.48cm for the diagnostic yield of the development of hypotension after the general anesthesia induction. This cut-off value had a sensitivity and specificity of 90.00% and 95.83%. TAPSE predicted the development of hypotension after general anesthesia induction. Further studies are required to prove the diagnostic accuracy of TAPSE as a predictor of hypotension after general anesthesia induction.

Perfusion index as a predictor of hypotension following subarachnoid block in parturients with non-severe pre-eclampsia undergoing lower segment cesarean section

Background and Aims: Perfusion index, which assesses perfusion dynamics is used as a non‑invasive method in spinal anesthesia cases to detect the occurrence of hypotension. A Perfusion Index value after which hypotension is common can be assessed. Methods: In this prospective double-blind observational study, 100 parturients were included. Baseline Perfusion Index was recorded and spinal anesthesia was carried out with Injection bupivacaine 0.5% (hyperbaric), 10 mg at L3 - L4 / L2 - L3 intervertebral space. Fall in Systolic Blood Pressure &lt; 20 % of baseline was defined as hypotension. Chi-Square test and independent sample t-test was used for the statistical analysis. Spearman’s rank correlation coefficient was applied to assess the correlation between baseline PI and hypotension. The receiver operating characteristic (ROC) curve was mapped for PI and the occurrence of hypotension. Results: The occurrence of hypotension in parturients with PI &lt; 4.25 was 40.9% compared to 94.6% in parturients with PI &gt; 4.25. There was a remarkable association between baseline PI &gt; 4.25, the number of episodes of hypotension 53/100 (p-value &lt; 0.0001) and the total dose of phenylephrine used 53/100 (p-value 0.02). T

A study to evaluate perfusion index as a predictor of hypotension following spinal anesthesia for caesarean section.

Background and Aims:The perfusion index (PI) has been used as a marker of peripheral perfusion. A lower PI indicates greater peripheral vascular tone and increased risk of hypotension following spinal anesthesia. The present study was conducted to evaluate and correlate perfusion index (PI) with incidence of hypotension following spinal anesthesia for caesarean section.Material and Methods:The present prospective, double blind, observational study included sixty full term parturients in the age group 18-35 years belonging to American Society of Anesthesiologists (ASA) physical status I and II, having singleton pregnancy undergoing caesarean section under spinal anesthesia. On the basis of baseline PI, patients were allocated into one of the two groups: Group I (n = 30) Patients with baseline PI ≤.3.5 and Group II (n = 30) Patients with PI >3.5.Results:The incidence of hypotension in group I was 40% as compared to 73.3% in group II (p = 0.009). Thus, the incidence of hypotension in group II with baseline PI >.3.5 was more as compared to group I. Patients in group II with baseline PI >.3.5 had significantly more episodes of hypotension as compared to those in group I with baseline PI ≤3.5.Conclusion:PI can be used as a useful tool for predicting hypotension in parturients undergoing elective caesarean section under spinal anesthesia in everyday practice.

Predictability of Preoperative Carotid Artery-corrected Flow Time for Hypotension After Spinal Anaesthesia in Patients Undergoing Caesarean Section: A Prospective Observational Study

(Eur J Anaesthesiol. 2021;38:394–401) Hypotension affects more than 50% of cesarean delivery (CD) patients receiving spinal anesthesia (SA). Fluid administration (preload and co-load), as well as prophylactic use of phenylephrine, noradrenaline, and ondansetron are all used to prevent hypotension. There are a number of reasons for hypotension following SA, and predicting the pathway leading to hypotension by monitoring hemodynamics may help inform the best prevention and treatment. Corrected blood flow time (FTc) in the carotid artery is affected by left ventricular preload and associated with myocardial afterload. This study aimed to evaluate preanesthetic FTc as a predictor of hypotension in CD patients receiving spinal anesthesia.

Performance of non-invasive stroke volume variation during passive leg raising as a predictor of hypotension following induction of spinal anesthesia for elective cesarean delivery: a single cohort study

BackgroundSpinal anesthesia for cesarean delivery is accompanied by hypotension in up to 70% of cases. To date, there is no gold standard for predicting hypotension after spinal anesthesia for cesarean delivery. The Clearsight™ device is a non-invasive system that uses a digital cuff to calculate stroke volume. We hypothesized that stroke volume variation induced with passive leg raising before spinal anesthesia for elective cesarean delivery could predict the occurrence of hypotension. MethodsWe conducted a prospective observational study, including third trimester parturients undergoing elective cesarean delivery with spinal anesthesia. We analyzed the stroke volume variation performance for predicting hypotension. Stroke volume was collected in the semi-recumbent position (baseline) and during passive leg raising before spinal anesthesia. Systolic arterial blood pressure measurement was followed for 15 min after spinal anesthesia. Hypotension was defined as a ≥20% decrease from the baseline measurement. All parturients received appropriate hypotension prophylaxis. ResultsData from 42 parturients were analyzed. Hypotension occurred in 45%. The area-under-the curve for predicting hypotension using the stroke volume variation was 0.83 (95% CI 0.68 to 0.98; P=0.001). The best cut-off value for predicting hypotension was 7%, having a sensitivity of 87% (95% CI 0.70 to 0.99) and a specificity of 83% (95% CI 0.69 to 0.97). ConclusionIn our study of third trimester parturients undergoing cesarean delivery and receiving appropriate hypotension prophylaxis, a digital non-invasive monitoring device of stroke volume variation analysis was useful for predicting the occurrence of hypotension after spinal anesthesia.

Perfusion Index as a Predictor of Hypotension Following Spinal Anesthesia in Lower Abdominal Surgery

Perfusion Index as a Predictor of Hypotension Following Spinal Anesthesia in Lower Abdominal Surgery

To Study the Role of Perfusion Index as a Predictor of Hypotension during Spinal Anesthesia in Lower Segment Cesarean Section - A Prospective Observational Study.

Background and Aims:Spinal anesthesia has become the choice of neuraxial anesthesia for cesarean delivery. Hypotension, the most common side effect of spinal anesthesia is more in parturients. Perfusion index (PI) is one of the newest methods, used noninvasively for the prediction of hypotension postspinal anesthesia, evaluation of regional block success, and a tool for pain assessment. In our study, we have used PI for predicting the occurrence of hypotension postsubarachnoid block in elective lower segment cesarean section (LSCS).Methods:In this prospective observational study, parturients posted for elective LSCS under spinal anesthesia were included. Spinal anesthesia was performed at L3-L4 interspace using 25G (gauge) Quincke needle, with 1.8 mL of 0.5% hyperbaric bupivacaine plus 20 μg fentanyl. Hypotension was defined as a decrease in systolic blood pressure >25% from the baseline.Statistical Analysis Used:Statistical analysis was performed using the paired sample t-test, Chi-square test, and independent t-test.Results:From our study, we had found that a positive correlation exists between the baseline PI of the patient and the occurrence of hypotension intraoperatively. A cutoff value of 1.75 (with P < 0.001) was found to be significant; above which the occurrence of hypotension was definite. The sensitivity of this cutoff value was 75% and specificity was 71% for this value.Conclusion:Baseline perfusion of >1.75 can predict hypotension postspinal anesthesia in LSCS. The incidence of hypotension was about 93% in parturients whose baseline was above the cutoff value.

The application of a neural network to predict hypotension and vasopressor requirements non-invasively in obstetric patients having spinal anesthesia for elective cesarean section (C/S)

BackgroundNeural networks are increasingly used to assess physiological processes or pathologies, as well as to predict the increased likelihood of an impending medical crisis, such as hypotension.MethodWe compared the capabilities of a single hidden layer neural network of 12 nodes to those of a discrete-feature discrimination approach with the goal being to predict the likelihood of a given patient developing significant hypotension under spinal anesthesia when undergoing a Cesarean section (C/S). Physiological input information was derived from a non-invasive blood pressure device (Caretaker [CT]) that utilizes a finger cuff to measure blood pressure and other hemodynamic parameters via pulse contour analysis. Receiver-operator-curve/area-under-curve analyses were used to compare performance.ResultsThe results presented here suggest that a neural network approach (Area Under Curve [AUC] = 0.89 [p < 0.001]), at least at the implementation level of a clinically relevant prediction algorithm, may be superior to a discrete feature quantification approach (AUC = 0.87 [p < 0.001]), providing implicit access to a plurality of features and combinations thereof. In addition, the expansion of the approach to include the submission of other physiological data signals, such as heart rate variability, to the network can be readily envisioned.ConclusionThis pilot study has demonstrated that increased coherence in Arterial Stiffness (AS) variability obtained from the pulse wave analysis of a continuous non-invasive blood pressure device appears to be an effective predictor of hypotension after spinal anesthesia in the obstetrics population undergoing C/S.This allowed us to predict specific dosing thresholds of phenylephrine required to maintain systolic blood pressure above 90 mmHg.