Norepinephrine Infusion Research Articles

Comparison of Phenylephrine infusion vs Nor-epinephrine Infusion on Maternal Hemodynamics and Neonatal Outcomes During Elective Lower Segment Caesarean Section under Sub-Arachnoid Block

Objective: To compare the efficacy of Phenylephrine and Nor-epinephrine IV infusions in maintaining maternal hemodynamics during EL-LSCS. Methodology: This randomized control trial study was conducted department of Anesthesia and Critical Care Medicine, Pakistan Institute of Medical Sciences (PIMS), Islamabad from March, 2023 to November, 2023. This study enrolled 62 patients fulfilling the inclusion criteria i.e., patient of age 18-45 years undergoing elective LSCS under SAB were enrolled in the study. While those having hypertension, pre-clampsia, eclampsia, pre-existing bradycardia, fetal distress and hypersensitivity to the medications used in the study were excluded. Enrolled patients were divided into two groups using computer generated random numbers with Group N patients received Nor-epinephrine infusion at rate of 2.5 Mcg/min while Group P patients received phenylephrine infusion at rate of 50 Mcg/min. Intraoperatively maternal hemodynamics were monitored and infusions were titrated to effect. Neonatal outcomes were assessed using APGAR score with umbilical cord ABGS carried out if clinically indicated. Results: Group P patients had statistically significant lower mean heart rate at 5,10,15 and 20 minutes as compared to group N. Similarly, pressures were significantly higher in group P than group N at 5,10,15,20 and 25 minutes. This required frequent changes in the rate of Phenylephrine infusion with the desired effect being achieved after 25 minutes of induction of Sub-Arachnoid block. Conclusion: Low dose Nor-Epinephrine infusion is safe and provides a better hemodynamic profile during Caesarean Section.

Safety of pre-hospital peripheral vasopressors: The SPOTLESS study (Safety of PrehOspiTaL pEripheral vaSopreSsors).

To assess the safety and effectiveness of peripheral vasoactive drugs initiated during pre-hospital care and retrieval missions, in Queensland, Australia. Three years of retrospective data was gathered from two sources. Medical notes were reviewed using a search for any patient having 'inotrope' recorded on an electronic medical record. Each case was reviewed to include only peripheral infusions of adrenaline or noradrenaline. Clinical Governance records were searched for adverse events related to vasoactive drugs, alerted for review to ensure complete capture. A total of 418 patients received peripheral infusions of adrenaline and noradrenaline over the 3-year period. No major complications were recorded either immediately or at Clinical Governance review. Minor complications were recorded in 4.7% of the cases, of which 3.5% occurred with peripheral vasoactives during the presence of the retrieval team. The frequency of use of peripheral vasoactives increased over the study period. In this retrospective data set there were no major complications of peripheral vasoactive drugs. Minor complications were similar to in-hospital use and related to vascular access and drug delivery.

Comparison of infusions of phenylephrine, norepinephrine, and mephentermine on maternal hemodynamics and neonatal outcomes in caesarean section under spinal anaesthesia

Although the subarachnoid block is the preferred anesthetic technique for the caesarean section, on the downside it is often associated with complications like maternal hypotension. We compared phenylephrine, norepinephrine, and mephentermine infusions to maintain blood pressure during the caesarian section under subarachnoid block. Our study included 240 parturients with singleton-term pregnancies undergoing a caesarian section under spinal anesthesia. Following spinal anesthesia till the delivery of the baby, parturients randomly assigned to three groups received phenylephrine, norepinephrine, and mephentermine infusions.Heart rate, blood pressure, intra-operative nausea and vomiting, neonatal Apgar score, and total rescue vasopressors required were analyzed. Except at 4 min (p=0.006), ANOVA revealed no statistically significant difference in systolic blood pressure between the groups across all time points. Systolic blood pressure showed a significant difference between the mephentermine group versus the phenylephrine group (p=0.013) and the norepinephrine group versus the phenylephrine group (p=0.022) at four minutes post hoc Bonferroni. Except at 15 and 60 minutes (p=0.02 and p=0.001, Refer This Article Amit Pradhan, Rasulata Swain, Priyadarsini Samanta, Laxman K Senapati, Ganesh C Satapathy, 2024. Comparison of infusions of phenylephrine, norepinephrine, and Mephentermine on maternal hemodynamics and neonatal outcomes in caesarean section under spinal anaesthesia. . Journal of medical pharmaceutical and allied sciences, V 13 - I 1, Pages- 6392 – 6400. Doi: https://doi.org/10.55522/jmpas.V13I1.5919.respectively), the mean heart rate was comparable among the three groups. The Chi-square test revealed no statistically significant difference in the requirement of rescue drugs among the groups (ϰ2=1.57, p=0.45) except at the time point of 4 minutes (p=0.01) when the highest requirement was observed in the phenylephrine group. The Apgar scores amongst the groups were comparable at 1 min (p=0.99) and 5 min (p=0.98). In the lower segment caesarian section under the subarachnoid block, infusions of phenylephrine, norepinephrine, and mephentermine were equally effective in managing maternal hypotension and achieving favorable neonatal outcomes.

Effects of vasodilators on beat-to-beat and every fifteen minutes blood pressure variability induced by noradrenaline infusion in rats

Increased blood pressure variability (BPV) was shown to be associated with cardiovascular morbidities and/or mortalities. There are various types of BPV depending on time intervals of BP measurements, ranging from beat-to-beat to visit-to-visit or year-to-year. We previously found that continuous infusion of noradrenaline (NA) for 14 days increased short-term BPV every 15 min in rats. The aims of this study were to examine (1) whether NA infusion increases very short-term beat-to-beat BPV, (2) the effects of azelnidipine and hydralazine on NA-induced BPV, and (3) whether baroreceptor reflex sensitivity (BRS) is affected by NA or NA plus those vasodilators. Nine-week-old Wistar rats infused subcutaneously with 30 μg/h NA were orally treated with or without 9.7 mg/day azelnidipine or 5.9 mg/day hydralazine over 14 days. BP levels were continuously monitored via abdominal aortic catheter with a telemetry system in an unrestrained condition. Standard deviations (SDs) were used to evaluate beat-to-beat BPV and BPV every 15 min which was obtained by averaging BP levels for 10-s segment at each time point. BRS was determined by a sequence analysis. Continuous NA infusion over 14 days increased average BP, beat-to-beat BPV, and BPV every 15 min, lowering BRS. Comparing the two vasodilators, hydralazine reduced BP elevation by NA; meanwhile, azelnidipine alleviated BPV augmentation, preserving BRS, despite a smaller BP reduction. Thus, NA infusion increased both very short- and short-term BPV concomitantly with impaired BRS, while azelnidipine had an inhibitory effect, possibly independent of BP-lowering, on those types of BPV and impairment of BRS.

Hemodynamic effects of noradrenaline in neonatal septic shock: a prospective cohort study.

The incidence of neonatal septic shock in low-income countries is 26.8% with a mortality rate of 35.4%. The evidence of the hemodynamic effects of noradrenaline in neonates remains sparse. This study was carried out to evaluate the effects of noradrenaline in neonates with septic shock. This was a single-center prospective cohort study in a tertiary care hospital's level III neonatal intensive care unit. Neonates with septic shock and those who received noradrenaline as a first-line vasoactive agent were included. Clinical and hemodynamic parameters were recorded before and after one hour of noradrenaline infusion. The primary outcomes were: response at the end of one hour after starting noradrenaline infusion and mortality rate. A total of 21 babies were analyzed. The cohort comprised 17 preterm neonates. The mean age of presentation with septic shock was 74.3 h. Resolution of shock at one hour after starting noradrenaline was achieved in 76.2% of cases. The median duration of hospital stay was 14 days. The mean blood pressure improved after the initiation of noradrenaline from 30.6 mm of Hg [standard deviation (SD) 6.1] to 37.8 mm of Hg (SD 8.22, p < 0.001). Fractional shortening improved after noradrenaline initiation from 29% (SD 13.5) to 45.1% (SD 21.1, p < 0.001). The mortality rate was 28.6% in our study. Noradrenaline is a potential drug for use in neonatal septic shock, with improvement in mean blood pressure and fractional shortening; however, further studies with larger sample sizes are needed to confirm our findings before it can be recommended as first-line therapy in neonatal septic shock.

Comparison of Mechanical Insufflation-Exsufflation and Hypertonic Saline and Hyaluronic Acid With Conventional Open Catheter Suctioning in Intubated Patients.

Open respiratory secretion suctioning with a catheter causes pain and tracheobronchial mucosal injury in intubated patients. The goal of mechanical insufflation-exsufflation (MI-E) is to move secretions proximally and noninvasively by generating a high peak expiratory air flow. Nebulized hypertonic saline with hyaluronic acid (HS-HA) may facilitate suctioning by hydration. We assessed the safety and tolerance of a single session of airway clearance with MI-E and HS-HA in critically ill intubated patients. Adults with a cuffed artificial airway were randomized to (1) open suctioning, (2) open suctioning after HS-HA, (3) MI-E, or (4) MI-E with HS-HA. Adverse events, pain and sedation/agitation scores, and respiratory and hemodynamic variables were collected before, during, and 5-min and 60-min post intervention. One-hundred twenty subjects were enrolled and completed the study. Median (interquartile range [IQR]) Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 22 (16-28); median (IQR) age was 69.0 (57.0-75.7) y, and 90 (75%) were male. Baseline respiratory and hemodynamic variables were comparable. Adverse events occurred in 30 subjects (25%), with no between-group differences. Behavioral pain equivalents and Richmond Agitation-Sedation Scale were higher during suctioning in groups 1 (P < .001) and 2 (P < .001). Independent predictive variables for higher pain and agitation/sedation scores were study groups 1 and 2 and simultaneous analgosedation, respectively. Noradrenaline infusion rates were lower at 60 min in groups 2 and 4. PaO2 /FIO2 had decreased at 5 min after open suctioning in group 1 and increased at 60 min in group 3. We observed no difference in adverse events. MI-E avoids pain and agitation.

Comparative dose-response study on the infusion of norepinephrine combined with intravenous ondansetron versus placebo for preventing hypotension during spinal anesthesia for cesarean section: a randomised controlled trial.

Ondansetron has been reported to attenuate the incidence of spinal anaesthesia-induced hypotension (SAIH) and norepinephrine requirement during caesarean section. However, no quantitative study has evaluated the extent of this effect. This study aimed to determine the dose-response of prophylactic infusion of norepinephrine to prevent SAIH in parturients who received intravenous ondansetron or placebo before spinal anaesthesia for caesarean section. The median effective dose (ED 50 ) and 90% effective dose (ED 90 ) were compared to evaluate the effect of ondansetron versus placebo on the norepinephrine requirement. One hundred fifty parturients undergoing caesarean section were randomized to receive either 0.1mg/kg ondansetron (group O) or saline control (group C) 10 min before spinal anaesthesia. The parturients were randomly assigned to one of five different norepinephrine infusion groups: 0.02, 0.04, 0.06, 0.08 or 0.10µg/kg/min. An effective infusion dose of norepinephrine was defined as non-occurrence of hypotension during the study period. The values for ED 50 and ED 90 of norepinephrine infusion were determined using probit regression. Differences between the two groups were evaluated by comparing the relative median potency with 95% CIs. The ED 50 values were 0.033 (95% CIs, 0.024-0.043) µg/kg/min in group C and 0.021 (95% CIs, 0.013-0.029) µg/kg/min in group O. The ED 90 values were 0.091 (95% CIs 0.068-0.147) µg/kg/min in group C and 0.059 (95% CIs 0.044-0.089) µg/kg/min in group O, respectively. The estimate of the relative median potency for norepinephrine in group C versus group O was 0.643 (95% CIs, 0.363-0.956). The incidence of side effects was comparable between groups. No significant difference in neonatal outcomes. Intravenous ondansetron 0.1mg/kg before spinal anaesthesia significantly reduced the dose requirement of prophylactic norepinephrine infusion in parturients undergoing elective caesarean section. This finding is potentially useful for clinical practice and further research.

Association Between Intraoperative Noradrenaline Infusion and Outcomes in Older Adult Patients Undergoing Major Non-Cardiac Surgeries: A Retrospective Propensity Score-Matched Cohort Study.

Noradrenaline (NA) is commonly used intraoperatively to prevent fluid overload and maintain hemodynamic stability. Clinical studies provided inconsistent results concerning the effect of NA on postoperative outcomes. As aging is accompanied with various diseases and has the high possibility of the risk for postoperative complications, we hypothesized that intraoperative NA infusion in older adult patients undergoing major non-cardiac surgeries might potentially exert adverse outcomes. In this retrospective propensity score-matched cohort study, older adult patients undergoing major non-cardiac surgeries were selected, 1837 receiving NA infusion during surgery, and 1072 not receiving NA. The propensity score matching was conducted with a 1:1 ratio and 1072 patients were included in each group. The primary outcomes were postoperative in-hospital mortality and complications. Intraoperative NA administration reduced postoperative urinary tract infection (OR:0.124, 95% CI:0.016-0.995), and had no effect on other postoperative complications and mortality, it reduced intraoperative crystalloid infusion (OR:0.999, 95% CI:0.999-0.999), blood loss (OR: 0.998, 95% CI: 0.998-0.999), transfusion (OR:0.327, 95% CI: 0.218-0.490), but increased intraoperative lactate production (OR:1.354, 95% CI:1.051-1.744), and hospital stay (OR:1.019, 95% CI:1.008-1.029). Intraoperative noradrenaline administration reduces postoperative urinary tract infection, and does not increase other postoperative complications and mortality, and can be safely used in older adult patients undergoing major non-cardiac surgeries.

Prevention of post-spinal anaesthesia hypotension in caesarean delivery using delayed supine positioning - A randomised controlled trial.

Maternal hypotension is a common and dangerous consequence after a subarachnoid block for a caesarean section. Combining pharmacological methods such as norepinephrine infusion, ondansetron and non-pharmacological methods in delayed supine positioning better impacts the maternal haemodynamic profile. The present study assessed the benefits and adverse effects of combining pharmacological and non-pharmacological methods in hypotension prophylaxis. This randomised controlled trial was conducted at Cairo University Hospital's obstetric theatre from January to October 2020. The study included 85 parturients who were randomised to two groups. Group Sitting was left seated for 2 min after injection, and Group Control was made to lie down in the supine position immediately after the subarachnoid block. Both groups received prophylactic intravenous norepinephrine infusion, in addition to an ondansetron bolus, before surgery. Patients' systolic blood pressure (SBP) from intrathecal injection until delivery of the foetus, was documented. The Sitting group's SBP (122 (14) mmHg) till delivery was statistically higher than the Control group's readings (114 (10) mmHg) (P = 0.004). The Sitting group's intraoperative SBP values were often greater than the Control group values. In addition, the Sitting group had a reduced hypotension incidence and a lower rate of ephedrine use than the other group, but bradycardia incidence was comparable between both groups. In elective caesarean delivery, combining pharmacological and non-pharmacological methods achieve better results regarding maternal hypotension, vasopressor consumption, nausea and vomiting, and foetal outcomes.

Prevention of arterial hypotension during cesarean section under spinal anesthesia: trial of a baby norepinephrine protocol at the Owendo University Hospital Center (Gabon)

Spinal anesthesia is a commonly used technique in cesarean section. This technique causes frequent maternal hypotension responsible for a reduction in placental perfusion rate causing fetal acidosis. Prophylactic vasopressor treatment is systematically recommended. Noradrenaline is today a molecule of choice. The objective of this work was to describe the benefit of using baby norepinephrine in the prevention of arterial hypotension in the context of cesarean section under spinal anesthesia. Methodology: Through a prospective observational study, parturients undergoing a planned or relative emergency cesarean section under spinal anesthesia during this period were included. Norepinephrine was administered by slow venous infusion at a rate of 0.028 to 0.057, or 4 to 10 drops/minute. Results: During the study period, 28 women were included. Their mean age was 30.1 ± 5.6. Scarred uterus (32%) and narrowed pelvis (25%) were the main indications. Parturients were classified according to the American Society of Anesthesia (ASA) as ASA1 in 82.1%. The systolic blood pressure recorded after the start of the baby norepinephrine infusion at the 1st minute, between the 5th and 15th minutes and between the 15th and 30th respectively between 100 and 140 mmHg in 71.4%, 85.7 % and 96.4% cases. Heart rate remained normal throughout norepinephrine administration. Conclusion: Low-dose norepinephrine ensures good hemodynamic stability perioperatively for cesarean section under spinal anesthesia.

Prophylactic infusion of norepinephrine does not affect the rostral spread of spinal anesthesia in pregnancy: a prospective, randomized, double-blinded study.

Background: The infusion of phenylephrine to prevent spinal-induced hypotension (SIH) in cesarean delivery may decrease the rostral spread of a spinal local anesthetic. We hypothesized that infusion of norepinephrine may decrease the rostral spread of spinal anesthesia, similar to that caused by phenylephrine. The aim of this study was to compare the block height of spinal anesthesia in the presence or absence of norepinephrine infusion administered to prevent SIH during cesarean delivery. Methods: Eighty patients were enrolled and allocated into groups receiving a norepinephrine infusion (group N) or saline infusion (group C). After intrathecal injection of hyperbaric bupivacaine 10mg, the block height for cold and pinprick sensation was checked 10 and 20min after the injection. The demographic characteristics, spinal anesthesia, side effects, and neonatal outcomes were also recorded. Results: The block height for cold and pinprick sensation was similar between the two groups, although the incidence of hypotension was significantly lower (p < 0.00) in group N than in group C. Systolic blood pressure was also more stable in group N than in group C, with the incidence of interventions being significantly lower in group N. There was no significant difference in patient satisfaction between the two groups. Conclusion: Evidence from this study suggested that prophylactic norepinephrine infusion does not reduce the rostral spread of spinal anesthesia in pregnancy. We suggest that it is not necessary to increase the dose of an intrathecal local anesthetic for cesarean delivery when prophylactic norepinephrine is administered. Clinical Trial Registration: https://www.chictr.org.cn/bin/project/edit?pid=152899, identifier [ChiCTR2200057439].

Establishment of a swine experimental model of non-occlusive mesenteric ischemia: Combining induced hemorrhagic shock and vasopressor administration.

Non-occlusive mesenteric ischemia (NOMI) is associated with high mortality rates, but definitive treatments have not yet been established. Although experimental animal models are worthwhile, reproducible models that reflect the pathophysiology of NOMI have not been developed. We combined risk factors for NOMI, comprising hemorrhagic shock, systemic vasopressor infusion, and local vasopressor infusion from the superior mesenteric artery (SMA) in swine under maintained anesthesia. Experiment 1 involved full-intensity (40%) phlebotomy and systemic vasopressor (norepinephrine and epinephrine). Experiment 2 involved full-intensity (40%) phlebotomy, systemic norepinephrine, and local vasopressor infusion into the SMA. Experiment 3 involved moderate (27%) phlebotomy, systemic norepinephrine infusion, and local epinephrine infusion. We evaluated serum lactate levels, intestinal serosa color, computed tomography (CT) angiography, and pathological findings. After inducing hemorrhage, systemic vasopressor alone and in combination with local vasopressin or norepinephrine infusion did not induce ischemic color changes in the intestine. The combination of systemic norepinephrine and local epinephrine (0.5 μg/kg/min) after moderate (27% blood loss) hemorrhage induced gross color change, pathological destruction, and elevation of serum lactate. Patent flow in the SMA was confirmed on CT angiography. We established a swine NOMI model with systemic norepinephrine infusion and local epinephrine with moderate hemorrhagic shock.

The effect of different norepinephrine administration methods on hypotension after spinal anesthesia in caesarean sections

We aimed to evaluate the effect of different routes of norepinephrine (NE) administration on maternal hypotension in pregnant females undergoing spinal anesthesia for caesarean section. 208 pregnant women were divided randomly into 4 groups (n=52). Bolus 4 µg/ml NE was administered intravenous (iv) immediately after spinal anesthesia in Group PB (Prophylactic Bolus). In Group PI (Prophylactic Infusion), 1 ml of saline solution was applied promptly after spinal anesthesia and then the NE infusion was started at 1 ml/min. In Group TB (Treatment Bolus), 1 ml Physiological Saline (PS) was administered after 1 ml/min infusion of PS immediately after spinal anesthesia and then 1 ml/min NE bolus when blood pressure decreased by 20% after the entry. In Group TBI (Treatment Bolus Infusion), 1 ml PS was administered after 1 ml/min infusion of PS immediately after spinal anesthesia, 1 ml NE and then 1 ml/min NE infusion was initiated when blood pressure decreased by 20% after the entry. At the 4th, 6th, and 8th minutes, the PI Group exhibited higher systolic and mean blood pressures than the other groups (p&lt;.001). Additionally, hypotension was statistically lower in the PI Group than in PB, TB, TBI groups (p&lt;.001), and episodes of hypotension, ephedrine required and extra NE boluses given were statistically lower in the PI Group than in the other groups (p&lt;.001). Umbilical vein (UV) pH values were lower in the TBI Group at compared to the other groups (p&lt;.001). It is suggested that a prophylactic infusion of 4 µg/min of NE in the prevention of hypotension following spinal anesthesia for cesarean section will reduce the possibility of maternal hypotension and better maintain fetal well-being than a prophylactic bolus, a treatment bolus or a post-treatment bolus infusion at the same dose.

Clinical profile of COVID-19 patients and factors impacting mortality in a rural tertiary care center of Solapur

Background: A retrospective and cohort study was conducted in our center to study the parameters among surviving and non-surviving patients that have a significant impact on in hospital mortality. Along with this, demographic and clinical profile was also studied. Aims and Objectives: The aim of this study was to evaluate clinical profile of COVID-19 patients and factors impacting mortality. Materials and Methods: The present study is a single-center, retrospective, and cohort study done on COVID-19 positive (by real-time polymerase chain reaction) patients admitted between May 2019 and June 2021 in the intensive care unit (ICU). Of the total 1694 patients, 422 required ICU treatment and the remaining 1272 patients were treated in wards and rooms and discharged home. The analysis was based on demographic, clinical, associated comorbidities, laboratory and radiological data, and treatment modalities used. Outcome data were analyzed by regression analysis and the Kaplan–Meir survival plot was used to calculate mortality trend. Results: Of the 422 patients, 158 (37.4%) died and 264 (62.6%) survived. Males predominated with 297/422 (70.4%). ICU admissions comprised 115/158 (72.8%) of the total deaths. Fever (88%), dyspnea (78.48), and cough (67.1%) were the most common symptoms in non-survival group. Hypertension (43.7%) and diabetes (37.3%) were the most common comorbidities. High oxygen (&gt;10 L/min) (P&lt;0.0001), invasive ventilation (P&lt;0.0001), noradrenaline infusion P&lt;0.0001), renal replacement therapy (P&lt;0.0001) and tocilizumab requirement (P&lt;0.0001), procalcitonin (P&lt;0.009) and interleukin-6 (P&lt;0.004) acute respiratory distress syndrome (ARDS) with septic shock, and multiorgan failure (P&lt;0.0001), all indicated higher risk of death. Conclusion: Mortality was 37.4% in our study. Elderly age (&gt;60 years), high serum ferritin (&gt;931.9), and severe disease with a high resolution computed tomography score (&gt;15), ARDS with septic complications requiring invasive ventilation and vasopressor support, are associated with increased mortality in these patients.

Determinants of 30-day mortality in elderly patients admitted to a cardiovascular surgery intensive care unit.

This study aims to identify the factors influencing 30-day morbidity and mortality in patients aged 65 and older undergoing cardiovascular surgery. Data from 360 patients who underwent cardiac surgery between January 2012 and August 2021 in the Cardiovascular Surgery Intensive Care Unit (CVS ICU) were analyzed. Patients were categorized into two groups: "mortality+" (33 patients) and "mortality-" (327 patients). Factors influencing mortality, including preoperative, intraoperative, and postoperative risk factors, complications, and outcomes, were assessed. Significant differences were observed between the two groups in factors affecting mortality, including extubation time, ICU stay duration, blood transfusion, surgical reexploration, aortic clamp duration, glomerular filtration rate (GFR), blood urea nitrogen (BUN), creatinine, hemoglobin A1c (HbA1c) levels, and the lowest systolic blood pressure during the first 24 hours in the ICU (p<0.05). The "mortality+" group had longer extubation times and ICU stays, required more blood transfusions, and had higher BUN-creatinine ratios, but lower systolic blood pressures, GFR, and HbA1c levels. Mortality was also higher in patients needing noradrenaline infusions and those who underwent reoperation for bleeding (p<0.05). By optimizing preoperative renal function, minimizing extubation time, shortening ICU stays, and carefully managing blood transfusions, surgical reexplorations, aortic clamp duration, and HbA1c levels, we believe that the mortality rate can be reduced in elderly patients. Key strategies include shortening aortic clamp times, reducing perioperative blood transfusions, and ensuring effective bleeding control.

Brain Regional Energy Metabolism in Patients with Traumatic Brain Injury: A Cerebral Microdialysis Guided Study.

In traumatic brain injuries (TBI), cerebral microdialysis (CMD)-derived parameters, especially the lactate to pyruvate ratio (LP ratio), have been utilized for cerebral perfusion optimization. The objectives were to identify cerebral ischemia as measured by CMD in TBI patients requiring decompressive craniectomy and to observe the correlation between cerebral perfusion pressure (CPP), intracranial pressure (ICP), and CMD variables in these patients. Our secondary aim was to observe the effect of CPP augmentation on ischemia biomarkers. After the Institute Ethics Committee approvals, seven adult patients requiring decompressive craniectomy following TBI were enrolled and CMD data were obtained prospectively for 72 h. CPP was augmented by 20% with noradrenaline infusion if LP ratio >40. Correlations were done with bootstrapping (n = 500) to obtain the confidence intervals (CI) due to the small sample size. One patient had cerebral ischemia (median LP ratio of 265.5 and median pyruvate of 38 μmol/L), while another patient had non-ischemic mitochondrial dysfunction (median LP ratio 40.7 and median pyruvate 278.5). The coefficients of correlation between the LP ratio with CPP and ICP were r = -0.05 (CI = -0.14-0.03) and r = 0.09 (CI = -0.03-0.24), respectively. The coefficient of correlation between cerebral and blood glucose was r = 0.38, (CI - 0.35-0.14). Only two patients needed CPP augmentation, however, postaugmentation cerebral biochemistry did not change appreciably. CMD can identify cerebral ischemia, however, no correlations were observed between the LP ratio and CPP or ICP. CPP augmentation did not improve cerebral biochemistry. More studies are required to understand and treat cerebral metabolism in TBI.

Determination of ED90s of Phenylephrine and Norepinephrine Infusion for Prevention of Spinal Anesthesia-Induced Hypotension in Patients with Preeclampsia During Cesarean Delivery.

Vasopressors remain an important strategy for managing spinal anesthesia-induced hypotension in women with preeclampsia. The aim of this study was to investigate the ED90s and efficacy ratio of phenylephrine and norepinephrine in managing spinal anesthesia-induced hypotension in women with preeclampsia during cesarean delivery. 60 women with preeclampsia, who underwent cesarean delivery, were randomly assigned to receive either a continuous intravenous infusion of phenylephrine or norepinephrine following spinal anesthesia. The initial dosage of phenylephrine or norepinephrine for the first women was 0.5 or 0.05 μg/kg/min, respectively, and subsequent infusion dosages were adjusted based on their efficacy in preventing spinal anesthesia-induced hypotension (defined as a systolic blood pressure less than 80% of the baseline level). The incremental or decremental doses of phenylephrine or norepinephrine were set at 0.1 or 0.01 μg/kg/min. The primary outcomes were the ED90s and efficacy ratio of phenylephrine and norepinephrine infusions for preventing spinal anesthesia-induced hypotension prior to delivery. The results obtained from isotonic regression analysis revealed that the ED90 values of the phenylephrine and norepinephrine group for preventing spinal anesthesia-induced hypotension were 0.597 (95% CI: 0.582-0.628) and 0.054 (95% CI: 0.053-0.056) μg/kg/min, respectively, with an efficacy ratio of 11.1:1. The results of Probit regression analysis revealed that the ED90 values were determined to be 0.665 (95% CI: 0.576-1.226) and 0.055 (95% CI: 0.047-0.109) μg/kg/min, respectively, with an efficacy ratio of 12.1:1. The administration of 0.6 μg/kg/min phenylephrine and 0.05 μg/kg/min norepinephrine has been found to effectively manage a 90% incidence of spinal anesthesia-induced hypotension in women with preeclampsia.

Prophylactic, Manually Titrable Variable Rate Norepinephrine Infusion for Prevention of Hypotension during Spinal Anesthesia for Cesarean Section: A Randomized, Double Blind, Controlled Study

Background and Aims: Norepinephrine is recently being investigated for mitigation of spinal-induced hypotension. Our study aimed at evaluating the role of manually titrated infusion of norepinephrine in preventing hypotension in patients undergoing lower segment cesarean section (LSCS) under subarachnoid block (SAB). Subjects and Methods: This prospective, randomized, double-blind, placebo-controlled trial was conducted in 140 parturients undergoing LSCS under SAB. Patients were randomly allocated to two groups: group A received an infusion of 5 µg/mL norepinephrine started at 30 mL/h (2.5 µg/min) immediately after SAB and manually adjusted within the range 0–60 mL/h (0–5 µg/min), according to the values of systolic blood pressure (SBP) until delivery; in group B, no prophylactic vasopressor was given, and bolus 1 mL norepinephrine (5 µg) was given whenever the SBP decreased to &lt;80% of the baseline value. Groups were compared with regard to the incidence of hypotension, hemodynamic parameters, and norepinephrine consumption. Categorical data were presented as number and compared using the Chi-square test. Continuous variables were presented as mean ± standard deviation (SD) and compared using t-test. P &lt;0.05 was considered statistically significant. Results: Cumulative episodes of hypotension were significantly lesser in group A (eight) than group B (29) (P &lt; 0.001). Mean time of onset of hypotension was significantly higher in group A (19.75 ± 8.24 min) compared to group B (4.36 ± 0.77 min) (P &lt; 0.001). Mean SBP, diastolic blood pressure (DBP), and mean arterial pressure (MAP) were significantly higher in group A compared to group B intraoperatively (P &lt; 0.001). Mean heart rate (HR) was significantly lower in group A compared to group B (P &lt; 0.05). Neonatal outcomes were comparable between both the groups. Conclusions: In patients undergoing SAB for LSCS, a manually titrated infusion of 5 µg/mL of norepinephrine was effective for maintaining BP and decreasing the incidence of hypotension, with no detectable detrimental effect on neonatal outcome.

Computer-controlled closed-loop norepinephrine infusion system for automated control of mean arterial pressure in dogs under isoflurane-induced hypotension: a feasibility study.

Intra-operative hypotension is a common complication of surgery under general anesthesia in dogs and humans. Computer-controlled closed-loop infusion systems of norepinephrine (NE) have been developed and clinically applied for automated optimization of arterial pressure (AP) and prevention of intra-operative hypotension in humans. This study aimed to develop a simple computer-controlled closed-loop infusion system of NE for the automated control of the mean arterial pressure (MAP) in dogs with isoflurane-induced hypotension and to validate the control of MAP by the developed system. NE was administered via the cephalic vein, whereas MAP was measured invasively by placing a catheter in the dorsal pedal artery. The proportional-integral-derivative (PID) controller in the negative feedback loop of the developed system titrated the infusion rate of NE to maintain the MAP at the target value of 60 mmHg. The titration was updated every 2 s. The performance of the developed system was evaluated in six laboratory Beagle dogs under general anesthesia with isoflurane. In the six dogs, when the concentration [median (interquartile range)] of inhaled isoflurane was increased from 1.5 (1.5-1.5)% to 4 (4-4)% without activating the system, the MAP was lowered from 95 (91-99) to 41 (37-42) mmHg. In contrast, when the concentration was increased from 1.5 (1.0-1.5)% to 4 (4-4.8)% for a 30-min period and the system was simultaneously activated, the MAP was temporarily lowered from 92 (89-95) to 47 (43-49) mmHg but recovered to 58 (57-58) mmHg owing to the system-controlled infusion of NE. If the acceptable target range for MAP was defined as target MAP ±5 mmHg (55 ≤ MAP ≤65 mmHg), the percentage of time wherein the MAP was maintained within the acceptable range was 96 (89-100)% in the six dogs during the second half of the 30-min period (from 15 to 30 min after system activation). The median performance error, median absolute performance error, wobble, and divergence were - 2.9 (-4.7 to 1.9)%, 2.9 (2.0-4.7)%, 1.3 (0.8-1.8)%, and - 0.24 (-0.34 to -0.11)%·min-1, respectively. No adverse events were observed during the study period, and all dogs were extubated uneventfully. This system was able to titrate the NE infusion rates in an accurate and stable manner to maintain the MAP within the predetermined target range in dogs with isoflurane-induced hypotension. This system can be a potential tool in daily clinical practice for the care of companion dogs.

Emergency Cesarean Section in a Parturient with Ruptured Sinus of Valsalva under Spinal Anesthesia: A Case Report.

Ruptured Sinus of Valsalva (RSOV) is a rarely encountered cardiac anomaly that can potentially lead to adverse clinical outcomes. RSOV increases the risk of morbidity during pregnancy due to the physiological changes associated with gestation, that can exacerbate the underlying cardiac pathology. We present the case of a 29-year-old female with an uncorrected RSOV who required an emergency cesarean section for abruptio placenta. The patient underwent the procedure under spinal anesthesia, with careful titration of norepinephrine infusion and close monitoring of hemodynamic parameters using an invasive intra-arterial line. Given the absence of established anesthetic protocols for parturients with RSOV undergoing cesarean delivery, a comprehensive understanding of the complex interaction between the hemodynamic effects of RSOV, pregnancy, and anesthesia is essential. This understanding enables the safe use of spinal anesthesia in urgent situations, leading to favorable patient outcomes.