Maintain Mean Arterial Pressure Research Articles

Early laboratory markers may reflect the severity of pyogenic liver abscess infection: Retrospective cohort study

Background: Liver abscess carries significant morbidity and mortality rate due to its complications. We aimed to identify laboratory markers associated with septic shock related to pyogenic liver abscess. Methods: The study was conducted at Hamad General Hospital, a tertiary hospital in Qatar. Data were collected retrospectively. All patients diagnosed with pyogenic liver abscess between 2013 and 2017 were included. Liver abscess was diagnosed based on clinical presentation and radiological finding with or without microbiological evidence. Septic shock defined as the need of vasopressors to maintain mean arterial pressure > 60 mmHg. Data has been collected on admission time. Descriptive data were presented in mean ± SD and percentages. Normally distributed data were analyzed by T-test otherwise Mann–Whitney was used.Fisher Exact test was used for categorical data. The level of significance was set at P<0.05. Results: Pyogenic liver abscess has been identified in 78 patients. 89.9% were males. 48.7% of the patients were diabetic. Nine patients (11.5%) developed septic shock. Patients who developed septic shock had higher procalcitonin level (Hazard ratio [HR] 1.025, 95% CI 1.006-1.044, p0.009) but lower level of hemoglobin (HR 0.744, 95% CI 0.581-0.952, P. 0.019), protein(HR 0.867, 95% CI 0.779-0.966, p 0.009) and platelet (HR 0.994, 95% CI 0.988-1.000, p 0.035) Conclusion: Measurement of baseline procalcitonin, hemoglobin, protein, and platelet in pyogenic liver abscess may provide early information about the severity of the infection and the need for early aggressive management. However, a larger sample size is needed to achieve more statistical significance.

Abstract 272: Dose Optimization of Early High-Dose Valproic Acid for Neuroprotection After Cardiac Arrest

Introduction: High-dose valproic acid (VPA) has been shown to improve the survival and neurologic outcomes in preclinical brain injury models including asphyxial cardiac arrest (CA) in rats. However, its pharmacokinetics, pharmacodynamics, and safety profiles in large animal CA models are unknown. Hypothesis: High-dose VPA can be safely administered after return of spontaneous circulation (ROSC) and cross the blood-brain barrier dose-dependently in a swine CA model. Methods: After 8 minutes of untreated ventricular fibrillation CA, male Yorkshire swine [43.3 (3.0) kg] were resuscitated for up to 16 minutes until ROSC. They were randomized to receive placebo, 75 mg/kg, 150 mg/kg, or 300 mg/kg VPA as 90-minute intravenous infusion (n=5 per group) beginning 20 minutes after sustained ROSC. Animals were monitored for 2 additional hours after infusion ended and then euthanized. Experimental operators were blinded to the treatments. Results: The mean total cardiac arrest duration was 15.0 (1.6) minutes, with no significant differences between groups. At end of infusion, the serum free VPA concentration increased dose dependently, from 139.2 (10.1) mcg/mL [75 mg/kg VPA] to 287.2 (24.6) mcg/mL [150 mg/kg VPA] to 565.6 (36.5) mcg/mL [300 mg/kg VPA] (p<0.05). This corresponded to a dose-dependent decrease in the fraction of serum protein-bound VPA, from 41.8% (1.8) [75 mg/kg VPA] to 23.4% (3.8) [150 mg/kg VPA] to 14.4% (3.8) [300 mg/kg VPA] (p<0.05). Brain total VPA concentrations at end of experiment were 26.1 (3.1) mcg/g [75 mg/kg VPA], 72.5 (18.9) mcg/g [150 mg/kg VPA], and 212.3 (33.4) mcg/g [300 mg/kg VPA] (p<0.05). There was a strong linear correlation between serum free VPA and brain total VPA concentrations (R 2 =0.98). All animals survived until euthanasia, although the 300 mg/kg group required more epinephrine to maintain mean arterial pressure greater than or equal to 80 mmHg and had higher lactic acidosis. Conclusion: Brain VPA concentrations correlate strongly with serum free VPA when high-dose intravenous VPA is given after ROSC in a swine CA model. These results provide the foundation for dose-optimization studies of high-dose VPA as a neuroprotective therapy following resuscitation from CA.

Predictors and Clinical Outcomes of Vasoplegia in Patients Bridged to Heart Transplantation With Continuous-Flow Left Ventricular Assist Devices.

BackgroundThe presence of a durable left ventricular assist device (LVAD) is associated with increased risk of vasoplegia in the early postoperative period following heart transplantation (HT). However, preoperative predictors of vasoplegia and its impact on survival after HT are unknown. We sought to examine predictors and outcomes of patients who develop vasoplegia after HT following bridging therapy with an LVAD.Methods and ResultsWe identified 94 patients who underwent HT after bridging with continuous‐flow LVAD from 2008 to 2018 at a single institution. Vasoplegia was defined as persistent low vascular resistance requiring ≥2 intravenous vasopressors within 48 hours after HT for >24 hours to maintain mean arterial pressure >70 mm Hg. Overall, 44 patients (46.8%) developed vasoplegia after HT. Patients with and without vasoplegia had similar preoperative LVAD, echocardiographic, and hemodynamic parameters. Patients with vasoplegia were significantly older; had longer LVAD support, higher preoperative creatinine, longer cardiopulmonary bypass time, and higher Charlson comorbidity index; and more often underwent combined organ transplantation. In a multivariate logistic regression model, older age (odds ratio: 1.08 per year; P=0.010), longer LVAD support (odds ratio: 1.06 per month; P=0.007), higher creatinine (odds ratio: 3.9 per 1 mg/dL; P=0.039), and longer cardiopulmonary bypass time (odds ratio: 1.83 per hour; P=0.044) were independent predictors of vasoplegia. After mean follow‐up of 4.0 years after HT, vasoplegia was associated with increased risk of all‐cause mortality (hazard ratio: 5.20; 95% CI, 1.71–19.28; P=0.003).ConclusionsOlder age, longer LVAD support, impaired renal function, and prolonged intraoperative CPB time are independent predictors of vasoplegia in patients undergoing HT after LVAD bridging. Vasoplegia is associated with worse prognosis; therefore, detailed assessment of these predictors can be clinically important.

Incidence of intraoperative hypotension in acute traumatic spinal cord injury and associated factors.

The importance of maintaining mean arterial pressure (MAP) > 85 mm Hg for patients with acute spinal cord injury (SCI) is well documented, because systemic hypotension greatly increases the risk of secondary SCI. Current literature focuses on the ICU setting; however, there is a paucity of data describing the changes in MAP in the operating room (OR). In the present study, the authors investigated the incidence of intraoperative hypotension for patients with acute traumatic SCI as well as any associated factors that may have impacted these findings. This retrospective study was performed at a level 1 trauma center from 2015 to 2016. All patients with American Spinal Injury Association (ASIA) score A-D acute traumatic SCIs from C1 to L1 were identified. Those included underwent spinal instrumentation and/or laminectomy decompression. Associated factors investigated include the following: age, body mass index, trauma mechanism of injury, Injury Severity Score, level of SCI, ASIA score, hospital day of surgery, total OR time, need for laminectomy decompression, use of spinal fixation, surgical positioning, blood loss, use of blood products, length of hospital stay, length of ICU stay, and discharge disposition. Intraoperative minute-by-minute MAP recordings were used to determine time spent in various MAP ranges. Thirty-two patients underwent a total of 33 operations. Relative to the total OR time, patients spent an average of 51.9% of their cumulative time with an MAP < 85 mm Hg. Furthermore, 100% of the study population recorded at least one MAP measurement < 85 mm Hg. These hypotensive episodes lasted a mean of 103 cumulative minutes per operative case. Analysis of associated factors demonstrated that fall mechanisms of injury led to a statistically significant increase in intraoperative hypotension compared to motor vehicle collisions/motorcycle collisions (p = 0.033). There were no significant differences in MAP recordings when analyzed according to all other associated factors studied. This is the first study reporting the incidence of intraoperative hypotension for patients with acute traumatic SCIs, and the results demonstrated higher proportions of relative hypotension than previously reported in the ICU setting. Furthermore, the authors identified that every patient experienced at least one MAP below the target value, which was much greater than the initial hypothesis of 50%. Given the findings of this study, adherence to the MAP protocol intraoperatively needs to be improved to minimize the risk of secondary SCI and associated deleterious neurological outcomes.

Surgical Field Visibility during Functional Endoscopic Sinus Surgery: esmolol-induced hypotensive anesthesia versus hypotensive total intravenous anesthesia

Background: Functional endoscopic sinus surgery is widely practiced during daily otorhinolaryngology practice. It usually done under low blood pressure. However, the ideal hypotensive drug or technique is yet not well established.Aim of the work: To evaluate outcome of functional endoscopic sinus surgery under esmolol-induced hypotensive anesthesia [EHA] versus hypotensive total intravenous anesthesia [H-TIVA].Patients & Methods: 72 patients were randomly divided into two groups; Group A: H-TIVA and Group B [EHA]. After induction of anesthesia, remifentanil/ propofol and esmolol infusions were adjusted to maintain mean arterial pressure at 60-70 mmHg. After completion of surgical procedure, esmolol infusion was stopped, while remifentanil/propofol infusions were adjusted to allow restoration of blood pressure. Operative field bleeding and visibility were graded using Fromme scale. Primary outcome is the efficacy of EHA to minimize intraoperative bleeding to an extent that allows satisfactory completion of surgery.Results: Esmolol bolus significantly attenuated pressor reflexes to induction and intubation than induction by remifentanil. Intraoperative [IO] heart rate and MAP measures were significantly lower with EHA. At 10-minures after infusion stoppage, patients of group B still had significantly lower HR and MAP, while at 10-min later, the difference was non-significant. HA minimized IO blood loss down to no to slight bleeding in 16.7% and 55.5% of studied patients and improved field visibility to satisfactory-to-good levels in 51.4% and 43.1% of surgeries, respectively. Moreover, EHA provided better field visibility, so allowed significant reduction of operative time than with TIVA.Conclusion: Hypotensive anesthesia is safe and appropriate modality for FESS and improves surgical and clinical outcome. Both esmolol and remifentanil provided satisfactory results. Esmolol is superior to remifentanil.

The Impact of Hemodynamic Reflex Compensation Following Myocardial Infarction on Subsequent Ventricular Remodeling.

Patients who survive a myocardial infarction (MI) are at high risk for ventricular dilation and heart failure. While infarct size is an important determinant of post-MI remodeling, different patients with the same size infarct often display different levels of left ventricular (LV) dilation. The acute physiologic response to MI involves reflex compensation, whereby increases in heart rate (HR), arterial resistance, venoconstriction, and contractility of the surviving myocardium act to maintain mean arterial pressure (MAP). We hypothesized that variability in reflex compensation might underlie some of the reported variability in post-MI remodeling, a hypothesis that is difficult to test using experimental data alone because some reflex responses are difficult or impossible to measure directly. We, therefore, employed a computational model to estimate the balance of compensatory mechanisms from experimentally reported hemodynamic data. We found a strikingly wide range of compensatory reflex profiles in response to MI in dogs and verified that pharmacologic blockade of sympathetic and parasympathetic reflexes nearly abolished this variability. Then, using a previously published model of postinfarction remodeling, we showed that observed variability in compensation translated to variability in predicted LV dilation consistent with published data. Treatment with a vasodilator shifted the compensatory response away from arterial and venous vasoconstriction and toward increased HR and myocardial contractility. Importantly, this shift reduced predicted dilation, a prediction that matched prior experimental studies. Thus, postinfarction reflex compensation could represent both a source of individual variability in the extent of LV remodeling and a target for therapies aimed at reducing that remodeling.

Sensitivity to angiotensin II dose in patients with vasodilatory shock: a prespecified analysis of the ATHOS-3 trial

BackgroundEarly clinical data showed that some patients with vasodilatory shock are responsive to low doses of angiotensin II. The objective of this analysis was to compare clinical outcomes in patients requiring ≤ 5 ng kg−1 min−1 angiotensin II at 30 min (≤ 5 ng kg−1 min−1 subgroup) to maintain mean arterial pressure (MAP) ≥ 75 mmHg versus patients receiving > 5 ng kg−1 min−1 angiotensin II at 30 min (> 5 ng kg−1 min−1 subgroup). Data from angiotensin II-treated patients enrolled in the ATHOS-3 trial were used.ResultsThe subgroup of patients whose angiotensin II dose was down-titrated from 20 ng kg−1 min−1 at treatment initiation to ≤ 5 ng kg−1 min−1 at 30 min (79/163) had significantly lower endogenous serum angiotensin II levels and norepinephrine-equivalent doses and significantly higher MAP versus the > 5 ng kg−1 min−1 subgroup (84/163). Patients in the ≤ 5 ng kg−1 min−1 subgroup were more likely to have a MAP response at 3 h versus those in the > 5 ng kg−1 min−1 subgroup (90% vs. 51%, respectively; odds ratio, 8.46 [95% CI 3.63–19.7], P < 0.001). Day 28 survival was also higher in the ≤ 5 ng kg−1 min−1 subgroup versus the > 5 ng kg−1 min−1 subgroup (59% vs. 33%, respectively; hazard ratio, 0.48 [95% CI 0.28–0.72], P = 0.0007); multivariate analyses supported the survival benefit in patients with lower angiotensin II levels. The ≤ 5 ng kg−1 min−1 subgroup had a more favorable safety profile and lower treatment discontinuation rate than the > 5 ng kg−1 min−1 subgroup.ConclusionsThis prespecified analysis showed that down-titration to ≤ 5 ng kg−1 min−1 angiotensin II at 30 min is an early predictor of favorable clinical outcomes which may be related to relative angiotensin II insufficiency.

An outbreak of leptospirosis with predominant cardiac involvement: a case series

BackgroundSevere leptospirosis is known to cause multi organ dysfunction including cardiac involvement. In the clinical setting with limited resources, high degree of suspicion is needed to diagnose cardiac involvement including myocarditis. Although myocarditis is not reported as a common complication due to lack of diagnostic facilities, there are evidence to support myocarditis is more prevalent in post mortem studies of patients died due to leptospirosis. We present a case series of severe leptospirosis with cardiac involvement observed during a period of one month at Colombo-North Teaching Hospital, Sri Lanka.Case presentationWe report here five patients with severe leptospirosis complicated with cardiac involvement, admitted to a single medical ward, Colombo-North Teaching Hospital, Sri Lanka during a one-month period. Out of six suspected leptospirosis patients admitted during that period, five in a raw developed severe leptospirosis with cardiac involvement. In this case series, four patients were confirmed serologically or quantitative PCR and one patient had possible leptospirosis. All patients developed shock during their course of illness. Two patients developed rapid atrial fibrillation. One patient had dynamic T wave changes in ECG and the other two had sinus tachycardia. Two patients had evidence of myocarditis in 2D echocardiogram, whereas other two patients had nonspecific findings and one patient had normal 2D echocardiogram. All five patients had elevated cardiac troponin I titre and it was normalized with the recovery. All five patients developed acute kidney injury. Four patients needed inotropic/vasopressor support to maintain mean arterial pressure and one patient recovered from shock with fluid resuscitation. All patients were recovered from their illness and repeat 2D echocardiograms after recovery did not show residual complications. One patient had serologically proven dengue co-infection with leptospirosis.ConclusionsMyocarditis and cardiac involvement in leptospirosis may be overlooked due to non-specific clinical findings and co-existing multi-organ dysfunction. Atypical presentation of this case series may be due to micro-geographic variation and unusual outbreak of leptospirosis. Co-infection of dengue with leptospirosis should be considered in managing patients especially in endemic areas.

Elevated Pre-Transplant Neutrophil to Lymphocyte Ratio is Associated with Increased Vasoplegia Syndrome in Cardiac Transplantation

Purpose Neutrophil to lymphocyte ratio (NLR), calculated from a CBC, is a marker of systemic inflammation and long-term risk in chronic illness, including heart failure (HF). Vasoplegia syndrome is a severe vasodilatory shock state after cardiac surgery. Patients undergoing heart transplantation (HTx) may be at an increased risk of vasoplegia due to inflammatory cytokine release secondary to HF. The role of NLR as a predictive marker for vasoplegia in patients undergoing HTx has not been studied. Methods Retrospective review of consecutive patients who underwent HTx from 7/2016 to 7/2018. Patients with conditions or treatments known to affect WBC count were excluded. Pre-HTx NLR was calculated from day of HTx and stratified by tertile. Vasoplegia was defined as vasopressor administration for > 24 hours to maintain mean arterial pressure > 65 mmHg for hypotension not attributed to other etiologies within 48 hours of HTx. The primary outcome was rates of vasoplegia between tertiles. Results 78 patients underwent HTx of which 70 met inclusion criteria. 18 patients had vasoplegia. Vasoplegia occurred in 8.7% (n=2) in the 1st tertile, 25% (n=6) in the 2nd tertile and 43.4% (n= 10) in the 3rd tertile (comparison 1st vs 3rd tertile, p=0.04) (Figure). In a multivariate analysis, adjusted for prior LVAD, patients in the 3rd tertile had higher rates of vasoplegia (adjusted OR 2.47, 95% CI 1.87-4.55) compared to the 1st. Mean NLR in patients without vasoplegia was 3.68±0.48 compared to 6.72±1.7 in patients with vasoplegia (p=0.019). There was no demographic or medical comorbidity difference other than hypothyroidism (p=0.04) between groups. Conclusion Vasoplegia is associated with elevated pre-HTx NLR compared to patients without vasoplegia. Chronic inflammation due to HF may play a role in the development of post-HTx vasoplegia. NLR is an inexpensive tool which clinicians may use pre-HTx to stratify which patients are at an increased risk of development of vasoplegia post-HTx.

Automated Titration of Vasopressor Infusion Using a Closed-loop Controller: In Vivo Feasibility Study Using a Swine Model.

Intraoperative hypotension has been associated with adverse postoperative outcomes.A randomized controlled trial of individualized blood pressure management in patients undergoing major abdominal surgery found reduced postoperative adverse events in patients in the blood pressure management intervention group versus the standard of care group. In this study of pigs with normovolemic hypotension induced by administration of sodium nitroprusside, an automated closed-loop vasopressor administration device was able to maintain mean arterial pressure within 5 mmHg of 80 mmHg for 98% of the intraoperative period. This suggests that norepinephrine can be accurately titrated using an automated infusion device in order to maintain target blood pressure. Multiple studies have reported associations between intraoperative hypotension and adverse postoperative complications. One of the most common interventions in the management of hypotension is vasopressor administration. This approach requires careful and frequent vasopressor boluses and/or multiple adjustments of an infusion. The authors recently developed a closed-loop controller that titrates vasopressors to maintain mean arterial pressure (MAP) within set limits. Here, the authors assessed the feasibility and overall performance of this system in a swine model. The authors hypothesized that the closed-loop controller would be able to maintain MAP at a steady, predefined target level of 80 mmHg for greater than 85% of the time. The authors randomized 14 healthy anesthetized pigs either to a control group or a closed-loop group. Using infusions of sodium nitroprusside at doses between 65 and 130 µg/min, we induced four normovolemic hypotensive challenges of 30 min each. In the control group, nothing was done to correct hypotension. In the closed-loop group, the system automatically titrated norepinephrine doses to achieve a predetermined MAP of 80 mmHg. The primary objective was study time spent within ±5 mmHg of the MAP target. Secondary objectives were performance error, median performance error, median absolute performance error, wobble, and divergence. The controller maintained MAP within ±5 mmHg of the target for 98 ± 1% (mean ± SD) of the time. In the control group, the MAP was 80 ± 5 mmHg for 14.0 ± 2.8% of the time (P< 0.0001). The MAP in the closed-loop group was above the target range for 1.2 ± 1.2% and below it for 0.5 ± 0.9% of the time. Performance error, median performance error, median absolute performance error, wobble, and divergence were all optimal. In this experimental model of induced normovolemic hypotensive episodes in pigs, the automated controller titrated norepinephrine infusion to correct hypotension and keep MAP within ±5 mmHg of target for 98% of management time.

Effect of N-methyl-d-aspartate (NMDA) receptor antagonist combination as adjuvant to general anesthesia in functional endoscopic sinus surgery

BackgroundThis randomized, placebo-controlled, double-blind study was designed to assess controlled hypotension using N-methyl-d-aspartate (NMDA) receptor antagonists in patients undergoing functional endoscopic sinus surgery under general anesthesia.MethodsIn this randomized, double blind, prospective study, 40 patients undergoing functional endoscopic sinus surgery under general anesthesia were divided into two groups of 20 patients each. Group 1: Patients received after the induction of anesthesia an intravenous (IV) ketamine (racemic) bolus 0.2 mg/kg followed by continuous infusion 0.15 mg/kg/h in addition to IV bolus of magnesium sulfate 50 mg/kg in 15 min, followed by a continuous infusion 8 mg/kg/h until extubation. Group 2: Patients received after the induction of anesthesia a bolus and a continuous infusion of normal saline (placebo) until extubation.In both groups, nitroglycerin infusion was titrated to maintain mean arterial pressure (MAP) in the range of 50–60 mmHg. Intraoperative bleeding, the intraoperative nitroglycerin requirements, MAP, heart rate (HR), surgeon’s satisfaction, VAS for pain, Aldrete score, and the incidence of adverse events were recorded.ResultsGroup 1 patients had significantly lower (p value < 0.001) infusion rates of nitroglycerin than the placebo group 2 patients at all measured intervals. Intraoperative bleeding measured by bleeding scale was significantly less in group 1 than in group 2. The MAP was significantly lower in group 1 after starting infusion, after extubation, and at postanesthesia care unit (PACU) admission. The HR was significantly higher in group 2 during hypotensive period, after extubation, and at PACU admission. Surgeon satisfaction by using the Likert scale showed that group 1 was significantly higher than scores in group 2. As regards the use of postoperative rescue analgesic drug if VAS ˃ 3, the number of patients who needed pethidine as a postoperative rescue analgesic was significantly less in group 1 compared with group 2. There is no statistically significant difference between the two groups as regards the Aldrete score.ConclusionContinuous infusion of NMDA receptor antagonists magnesium and ketamine had led to optimal surgical field and reduction in MAP, heart rate, blood loss, and nitroglycerin consumption.

Hemodynamic response to administration of vasopressors among patients with septic shock

Background: Septic shock is characterized by refractory hypotension with a mortality of >50%. Early fluid resuscitation, if failed, vasopressors are recommended to maintain mean arterial pressure (MAP) of 65 mmHg to restore organ perfusion. Noradrenaline (NA) is the vasopressor of choice but can be associated with adrenergic hyposensitivity and adverse effects on prolonged high-dose treatment. Hence, the addition of arginine vasopressin (AVP) to reduce the dose of NA is recommended. In view of the paucity of data in our setup, the present observational study was undertaken. Aims and Objectives: The present study was conducted to analyze the hemodynamic response to vasopressors among patients in septic shock and to compare the same among patients receiving NA alone or NA + AVP. Materials and Methods: All consenting adult patients >18 years with septic shock receiving vasopressors were included in the study. Hemodynamic variables such as systolic and diastolic blood pressure and MAP were noted at baseline, 30 min, 1, 6, 24, and 48 h and the same was compared between patients receiving either NA alone or NA + AVP. Results: The median age was 45 years with male preponderance. At admission, median MAP was 63 mmHg. On administration of vasopressors, target MAP was achieved by 1-h and maintained in both the groups of patients receiving NA or NA + AVP. No significant differences were noted in terms of hemodynamic parameters among patients receiving NA alone or NA + AVP. Conclusion: As per the surviving sepsis guidelines 2018, vasopressor administration was initiated and the target MAP of >65 mmHg was achieved by 1 h, sustained over 48 h. No significant differences were noted among the patients receiving NA alone or NA + AVP in terms of hemodynamic variables.

Mesenteric lymph drainage alleviates hemorrhagic shock-induced spleen injury and inflammation.

Purpose:To investigate the effect of mesenteric lymph drainage on the spleen injury and the expressions of inflammatory cytokines in splenic tissue in mice following hemorrhagic shock.Methods:Male C57 mice were randomly divided into the sham shock, shock and shock+drainage groups. The mice in both shock and shock+drainage groups suffered femoral artery bleeding, maintained mean arterial pressure (MAP) of 40±2 mmHg for 90 min, and were resuscitated. And mesenteric lymph drainage was performed in the shock+drainage group at the time of resuscitation. After three hours of resuscitation, the splenic tissues were harvested for the histological observation and protein and mRNA expression analysis of cytokines.Results:The spleen in the shock group revealed a significantly structural damage and increased mRNA expressions of MyD88 and TRAF6 and protein expressions of TIPE2, MyD88, TRIF and TRAF3 compared to the sham group. By contrast, the splenic pathological injury in the shock+drainage group was alleviated significantly, and the mRNA and protein expressions of TIPE2, MyD88, TRIF, TRAF3 and TRAF6 were significantly lower than those in the shock group.Conclusion:These results indicate that post-hemorrhagic shock mesenteric lymph drainage alleviates hemorrhagic shock-induced spleen injury and the expressions of inflammatory cytokines.

Effect of octopus tissue stabilizer on cardiac output during off-pump coronary artery bypass graft surgery.

IntroductionSignificant hemodynamic derangements can occur during off-pump coronary artery bypass graft (OPCAB) surgery resulting from the displacement of the beating heart, which may necessitate conversion to on-pump surgery.AimWe proposed to evaluate the alterations in hemodynamic parameters in patients during the course of anastomosis in OPCAB surgery using the Octopus tissue stabilizer.Material and methodsIn 100 consecutive patients undergoing OPCAB surgery, hemodynamic variables including cardiac output (CO), heart rate (HR), mean arterial pressure (MAP) and central venous pressure (CVP) were recorded at baseline, during each coronary artery anastomosis at 2 min, 10 min and after release of the Octopus tissue stabilizer.ResultsCO decreased significantly after target stabilization and during all coronary anastomoses (5.42 ±1.1 l/min at baseline, 4.26 ±1.02 l/min at 2 min and 3.92 ±0.98 l/min at 10 min; p < 0.001), with the greatest decrease noted during obtuse marginal (OM) branch of left circumflex artery anastomosis (3.67 ±0.86 l/min at 2 min and 3.38 ±0.78 l/min at 10 min). Inotropic drugs were required to maintain mean arterial pressure (MAP) > 60 mm Hg in 43 patients, which was most frequently noted during OM anastomosis (p < 0.001). The incidence of bradycardia requiring inotropes was noted to be the highest during left anterior descending (LAD) artery anastomosis (p = 0.002).ConclusionsDuring OPCAB surgery using the Octopus for coronary target stabilization, CO decreased the most during OM anastomosis requiring inotropes, while bradycardia was most frequent during LAD anastomosis. Careful monitoring and management of hemodynamic variables are therefore of utmost importance to avoid conversion to on-pump surgery.

Esmolol Infusion Reduces Blood Loss and Opiate Consumption during Fertility Preserving Myomectomy.

Objectives:The objective of this study is to evaluate the effect of esmolol-induced hypotensive anesthesia (EIHA) on intra-operative (IO) bleeding during open myomectomy.Patients and Methods:Eighty-eight women were randomly divided into the study group received EIHA without uterine tourniquet and control group who received normotensive anesthesia with uterine tourniquet. EIHA was provided as priming dose of esmolol (0.5 mg.kg-1) before the induction of anesthesia and esmolol infusion (0.05-0.3 mg.kg-1.min-1) to maintain mean arterial pressure at 60–70 mmHg that was stopped on completion of myomectomy. Fentanyl was used as IO analgesia (loading dose: 1.0 μg.kg-1 then infusion of 0.2-0.4 μg.kg-1.h-1). All patients received 6% hydroxyethyl starch (HES; initially, 3 mL.kg-1 over 5-10 minutes and supplemental doses according to requirements) and Lactated Ringer's solution (LR; 5 mL.kg-1.h-1). Trigger for blood transfusion was hemoglobin concentration (HBC) <7 g.dL-1. Study outcomes included the extent of postoperative (PO) HBC deficit in relation to preoperative HBC, frequency of tourniquet application for the study patients, and total fentanyl consumption.Results:EIHA significantly reduced blood pressure measures since laryngoscopy and tracheal intubation till the end of surgery in the study group compared to control group. Eight study patients (18.9%) required tourniquet application for control of bleeding; however, amount of IO blood loss; total field visibility score and PO HBC deficit were non significantly lower in the study group. EIHA allowed significant reduction of the IO amount of LR and additional amounts of HES infusions. Study patients group consumed significantly lower IO fentanyl doses with significantly longer duration till the 1st PO request and the number of additional fentanyl, and lower numeric rating scale scores in study group compared to controls.Conclusion:Open myomectomy under EIHA is feasible and safe and allows fertility-sparing with minimal risk of blood transfusion. The applied procedure of EIHA allowed blunting of pressor reflexes secondary to LIT, surgical stresses and extubation, and allowed reduction of IO and PO opioid doses.

In-Depth Characterization of the Effects of Cigarette Smoke Exposure on the Acute Trauma Response and Hemorrhage in Mice.

Hemorrhagic shock accounts for a large amount of trauma-related mortality. The severity of trauma can be further aggravated by an additional blunt chest trauma (TxT), which independently contributes to mortality upon the development of an acute lung injury (ALI). Besides, cigarette smoke (CS) exposure before TxT enhanced posttraumatic inflammation, thereby aggravating ALI. We therefore aimed to characterize the impact of an acute and/or chronic lung injury on organ dysfunction in a murine model of traumatic hemorrhagic shock (HS). After 3 weeks of CS exposure, anesthetized mice underwent HS with/without TxT. Hemorrhagic shock was implemented for 1 h followed by retransfusion of shed blood and intensive care therapy for 4 h including lung-protective mechanical ventilation, fluid resuscitation, and noradrenaline titrated to maintain mean arterial pressure ≥50 mmHg. Lung mechanics and gas exchange were assessed together with systemic hemodynamics, metabolism, and acid-base status. Postmortem blood and tissue samples were analyzed for cytokine and chemokine levels, protein expression, mitochondrial respiration, and histological changes. CS exposure and HS alone coincided with increased inflammation, decreased whole blood sulfide concentrations, and decreased diaphragmatic mitochondrial respiration. CS-exposed mice, which were subjected to TxT and subsequent HS, showed hemodynamic instability, acute kidney injury, and high mortality. Chronic CS exposure per se had the strongest impact on inflammatory responses. The degree of inflammation was similar upon an additional TxT, however, mice presented with organ dysfunction and increased mortality rates. Hence, in mice the degree of inflammation may be dissociated from the severity of organ dysfunction or injury.

Methylene Blue Monotherapy Compared With Combination Therapy With Hydroxocobalamin for the Treatment of Refractory Vasoplegic Syndrome: ARetrospective Cohort Study

To compare the efficacy of methylene blue with combination therapy with hydroxocobalamin in patients experiencing vasoplegic syndrome after cardiac surgery. Retrospective cohort study. Tertiary medical center. Patients who received methylene blue with or without hydroxocobalamin for refractory vasoplegic syndrome rescue therapy. The primary outcome was 0.the ability to maintain mean arterial pressure (MAP) >60 mmHg beyond 1hour after study drug administration. Other pertinent outcomes included MAP at hours 6, 12, and 24 post-administration; both raw and proportional changes of vasopressor doses from baseline at hours 1, 6, 12, and 24 post-administration; and change in pulmonary artery catheter hemodynamics. Overall, 28 doses were administered in 14 patients in the monotherapy group and 17 doses (10 methylene blue, 7 hydroxocobalamin) were administered in 6 patients in the combination therapy group. There were no differences in ability to maintain MAP at 1hour, with 71% of the monotherapy and 82% of combination therapy patients meeting MAP goals (p = 0.49). Pairwise comparisons demonstrated vasopressor reductions at 6, 12, and 24hours in both groups, but only significant reductions at 1hour were observed in the combination therapy group (-0.06 µg/kg/min; p = 0.003) but not in the monotherapy group (-0.015 µg/kg/min; p = 0.14). This is the first study to compare methylene blue monotherapy with combination therapy, which suggests there may be an advantage to combination therapy. Further characterization of ideal dosing, timing, and agent selection should be investigated on a larger scale format.

Early therapeutic plasma exchange in septic shock: a prospective open-label nonrandomized pilot study focusing on safety, hemodynamics, vascular barrier function, and biologic markers

BackgroundGiven the pathophysiological key role of the host response to an infection rather than the infection per se, an ideal therapeutic strategy would also target this response. This study was designed to demonstrate safety and feasibility of early therapeutic plasma exchange (TPE) in severely ill individuals with septic shock.MethodsThis was a prospective single center, open-label, nonrandomized pilot study enrolling 20 patients with early septic shock (onset < 12 h) requiring high doses of norepinephrine (NE; > 0.4 μg/kg/min) out of 231 screened septic patients. Clinical and biochemical data were obtained before and after TPE. Plasma samples were taken for ex-vivo stimulation of human umbilical vein endothelial cells (HUVECs) to analyze barrier function (immunocytochemistry and transendothelial electrical resistance (TER)). Cytokines were measured by cytometric bead array (CBA) and enzyme-linked immunosorbent assays (ELISAs). An immediate response was defined as > 20% NE reduction from baseline to the end of TPE.ResultsTPE was well tolerated without the occurrence of any adverse events and was associated with a rapid reduction in NE (0.82 (0.61–1.17) vs. 0.56 (0.41–0.78) μg/kg/min, p = 0.002) to maintain mean arterial pressure (MAP) above 65 mmHg. The observed 28-day mortality was 65%. Key proinflammatory cytokines and permeability factors (e.g., interleukin (IL)-6, IL-1b, and angiopoietin-2) were significantly reduced after TPE, while the protective antipermeability factor angiopoietin-1 was not changed. Ex-vivo stimulation of HUVECs with plasma obtained before TPE induced substantial cellular hyperpermeability, which was completely abolished with plasma obtained after TPE.ConclusionsInclusion of early septic shock patients with high doses of vasopressors was feasible and TPE was safe. Rapid hemodynamic improvement and favorable changes in the cytokine profile in patients with septic shock were observed. It has yet to be determined whether early TPE also improves outcomes in this patient cohort. An appropriately powered multicenter randomized controlled trial is desirable.Trial registrationClinicaltrials.gov, NCT03065751. Retrospectively registered on 28 February 2017.

Efficacy of volume therapy guided by stroke volume variability in patients undergoing surgery for severe traumatic brain injury

Objective To evaluate the efficacy of volume therapy guided by stroke volume variability (SVV) in the patients undergoing surgery for severe traumatic brain injury. Methods Thirty patients of both sexes with severe traumatic brain injury, aged 18-64 yr, of American Society of Anesthesiologists physical status Ⅲ, who were admitted to the hospital within 24 h after injury, with Glasgow Coma Scale (GCS) score≤8, were divided into control group (C group, n=15) and SVV group (n=15) using a random number table method.In group C, conventional fluid administration was performed to maintain mean arterial pressure at 65-110 mmHg, central venous pressure at 5-12 cmH2O and urine volume>1 ml·kg-1·h-1.Fluid was given according to SVV, maintaining SVV≤13% and mean arterial pressure at 65-110 mmHg in group SVV.Immediately after skin incision (T0), immediately after opening cerebral dura mater (T1), at 1 h after opening cerebral dura mater (T2), immediately after suturing cerebral dura mater (T3) and at the end of operation (T4), blood samples were collected from the radial artery and internal jugular venous bulb for blood gas analysis, the jugular venous oxygen partial pressure, jugular venous bulb oxygen saturation, blood lactate, arterial oxygen partial pressure, arterial oxygen saturation and Hb were recorded, and the cerebral artery and arteriovenous blood O2 content difference and cerebral O2 extraction rate were calculated.Blood samples were collected from the internal jugular venous bulb at T0-2, T4 and 24 h after operation (T5) for determination of S100β protein concentrations by enzyme-linked immunosorbent assay.The intraoperative volume of fluid intake and output and consumption of vasoactive drugs were recorded.GCS scores were recorded immediately after admission to the operating room, and at 1, 3, 7 and 14 days after operation.The development of postoperative length of hospitalization and complications (pulmonary infection and brain edema) was recorded.Glasgow Outcome Scale Score was used to assess the early postoperative quality of life. Results Compared with group C, the urine volume was significantly increased, the consumption of vasoactive drugs was reduced, jugular venous bulb oxygen saturation was increased at T2, 3, the cerebral O2 extraction rate was decreased at T2-4, the serum S100β protein concentration was decreased at T2, and the GCS score was increased at day 3 after operation (P 0.05). Conclusion SVV-guided volume therapy can improve cerebral oxygen metabolism, ensure adequate tissue perfusion and reduce craniocerebral injury in the patients undergoing surgery for severe traumatic brain injury. Key words: Stroke volume; Fluid therapy; Craniocerebral trauma

Efficacy of fluid loading as a countermeasure to the hemodynamic and hormonal changes of 28-h head-down bed rest.

After exposure to microgravity, or head‐down bed rest (HDBR), fluid loading is often used with the intent of increasing plasma volume and maintaining mean arterial pressure during orthostatic stress. Nine men (aged 18–32 years) underwent three randomized trials with lower body negative pressure (LBNP) before and after: (1) 4‐h of sitting with fluid loading (1 g sodium chloride/125 mL of water starting 2.5‐h before LBNP), (2) 28‐h of 6‐degree HDBR without fluid loading, and (3) 28‐h of 6‐degree HDBR with fluid loading. LBNP was progressive from 0 to −40 mmHg. After 28‐h HDBR, fluid loading did not protect against the loss of plasma volume (−280 ± 64 mL without fluid loading, −207 ± 86 with fluid loading, P = 0.472) nor did it protect against a drop of mean arterial pressure (P = 0.017) during LBNP (Post‐28 h HDBR response from 0 to −40 mmHg LBNP: 88 ± 4 to 85 ± 4 mmHg without fluid loading and 93 ± 4 to 88 ± 5 mmHg with fluid loading, P = 0.557 between trials). However, fluid loading did protect against the loss of stroke volume index and central venous pressure observed after 28‐h HDBR. Fluid loading also attenuated the increase of angiotensin II seen after 28‐h HDBR and throughout the LBNP protocol (Post‐28 h HDBR response from 0 to −40 mmHg LBNP: 16.6 ± 3.4 to 23.7 ± 5.0 pg/mL without fluid loading and 6.1 ± 0.8 to 12.2 ± 2.3 pg/mL with fluid loading, P < 0.001 between trials). Our results indicate that fluid loading did not protect against plasma volume loss due to HDBR or change blood pressure responses to LBNP. However, changes in central venous pressure, stroke volume and fluid regulatory hormones could potentially influence longer duration studies and those with more severe orthostatic stress.