Vasopressor Dose Research Articles

A Reinforcement Learning Application for Optimal Fluid and Vasopressor Interventions in Septic ICU Patients.

Sepsis is one of the leading causes of death in ICU and its timely recognition and management are of primary importance. Resuscitation from hypotension in patients with sepsis is one of the first challenges that require fluid and/or vasopressor administrations. Unfortunately, clinical guidelines provide only indications of the strategy that should be adopted in this critical population but personalized strategies are still missing. In this study, we propose a comparative analysis of reinforcement learning applications on ICU data collected in the electronic health records and publicly available within the MIMIC-III database. The ultimate goal of the study is to estimate the optimal fluid and vasopressor administrations. Results show that, after the use of principal component analysis for reducing feature space dimensionality, model performances increased, thus suggesting that additional preprocessing strategies might be used for both reducing the computational cost and refining model performances. Clinical relevance In a context where clinical guidelines are not able to provide the best treatment strategies at a patient level, reinforcement learning applications trained on retrospectively collected data may be used for developing models able to suggest to clinicians the optimal dosage of fluids and/or vasopressors in order to improve 90-day patients' survival.

Methylene blue for vasodilatory shock in the intensive care unit: a retrospective, observational study

BackgroundRefractory vasodilatory shock is a state of uncontrolled vasodilation associated with underlying inflammation and endothelial dysregulation. Rescue therapy for vasoplegia refractory to catecholamines includes methylene blue (MB) which restores vascular tone. We hypothesized that (1) at least 40% of critically ill patients would respond positively to MB administration and (2) that those who responded to MB would have a survival benefit.MethodsThis study was a retrospective review that included all adult patients admitted to an intensive care unit treated with MB for the indication of refractory vasodilatory shock. Responders to MB were identified as those with a ≥ 10% increase in mean arterial pressure (MAP) within the first 1-2 hours after administration. We examined the association of mortality to the groups of responders versus non-responders to MB. A subgroup analysis in patients undergoing continuous renal replacement therapy (CRRT) was also performed.Statistical calculations were performed in Microsoft Excel® (Redmond, WA, USA). Where appropriate, the comparison of averages and standard deviations of demographics, dosing, MAP, and reductions in vasopressor dosing were performed via Chi squared, Fisher's exact test, or two-tailed t-test with a p-value < 0.05 being considered as statistically significant. After using the F-test to assess for differences in variance, the proper two tailed t-test was used to compare SOFA scores among responders versus non-responders.ResultsA total of 223 patients were included in the responder analysis; 88 (39.5%) had a ≥ 10% increase in MAP post-MB administration that was not associated with a significant change in norepinephrine requirements between responders versus non-responders (p=0.41). There was a non-statistically significant trend (21.6% vs 14.8%, p=0.19) toward improved survival to hospital discharge in the MB responder group compared to the non-responder group. In 70 patients undergoing CRRT, there were 33 responders who were more likely to survive than those who were not (p = 0.0111).ConclusionsIn patients with refractory shock receiving MB, there is a non-statistically significant trend toward improved outcomes in responders based on a MAP increase >10%. Patients supported with CRRT who were identified as responders had decreased ICU mortality compared to non-responders.

Development of Machine Learning Models Predicting Estimated Blood Loss during Liver Transplant Surgery.

The incidence of major hemorrhage and transfusion during liver transplantation has decreased significantly over the past decade, but major bleeding remains a common expectation. Massive intraoperative hemorrhage during liver transplantation can lead to mortality or reoperation. This study aimed to develop machine learning models for the prediction of massive hemorrhage and a scoring system which is applicable to new patients. Data were retrospectively collected from patients aged >18 years who had undergone liver transplantation. These data included emergency information, donor information, demographic data, preoperative laboratory data, the etiology of hepatic failure, the Model for End-stage Liver Disease (MELD) score, surgical history, antiplatelet therapy, continuous renal replacement therapy (CRRT), the preoperative dose of vasopressor, and the estimated blood loss (EBL) during surgery. The logistic regression model was one of the best-performing machine learning models. The most important factors for the prediction of massive hemorrhage were the disease etiology, activated partial thromboplastin time (aPTT), operation duration, body temperature, MELD score, mean arterial pressure, serum creatinine, and pulse pressure. The risk-scoring system was developed using the odds ratios of these factors from the logistic model. The risk-scoring system showed good prediction performance and calibration (AUROC: 0.775, AUPR: 0.753).

Effect of fixed-dose hydrocortisone on vasopressor dose and mean arterial pressure in obese and nonobese patients with septic shock.

Several studies have shown hydrocortisone to be beneficial in the treatment of vasopressor-refractory septic shock, but there are minimal data evaluating the efficacy of this fixed dosing regimen in overweight and obese patients. The purpose of this study was to compare the effects of fixed-dose hydrocortisone on vasopressor dose and mean arterial pressure in obese and nonobese patients with septic shock refractory to adequate fluid resuscitation and vasopressor administration. In this multicenter, retrospective study, we included adult patients with a confirmed or suspected diagnosis of septic shock who received hydrocortisone (200 mg/day). Patients were divided into 4 study groups based on admission body mass index (BMI; defined as BMI of <25 kg/m2, 25-29.9 kg/m2, 30-34.9 kg/m2, and ≥35 kg/m2). The primary outcomes analyzed were change in norepinephrine equivalent dose requirements and mean arterial pressure (MAP) at 6, 12, and 24 hours after initiating hydrocortisone. Between October 1, 2017, and September 30, 2020, 431 patients were screened of whom 219 met inclusion criteria. Baseline characteristics were comparable among the groups. Mean vasopressor requirements (in μg/min) at 6, 12, and 24 hours were as follows: BMI of <25 kg/m2: 28.8, 24.8, and 20; BMI of 25-29.9 kg/m2: 34.1, 33.5, and 24.8; BMI of 30-34.9 kg/m2: 29.5, 33.5, and 24.8; and BMI of ≥35 kg/m2: 32, 25.7 and, 21.2 (P = 0.75, 0.41, and 0.61, respectively). Mean MAP (in mm Hg) at 6, 12, and 24 hours was as follows: BMI of <25 kg/m2: 73.5, 73.6, and 74; BMI of 25-29.9 kg/m2: 71.6, 73.8, and 71.9; BMI of 30-34.9 kg/m2: 72.2, 70, and 72.7; and BMI of ≥35 kg/m2: 70.7, 73.5, and 71.4 (P = 0.56, 0.15, and 0.62, respectively). BMI does not appear to impact the effects of fixed-dose hydrocortisone on vasopressor dose or blood pressure in patients with septic shock. Fixed-dose hydrocortisone should continue to be used for vasopressor-refractory septic shock in obese patients.

Evaluation of the Addition of Angiotensin II in Patients With Shock After Cardiac Surgery at a Veterans Affairs Medical Center.

Vasoplegic shock occurs in up to 37% of cardiac surgery patients. We investigated the use of angiotensin II for treating vasoplegic shock in these patients. We assessed clinical outcomes and mortality in patients undergoing cardiac surgery at our center between March 1, 2018 and October 31, 2020 who developed vasoplegic shock, comparing those who received angiotensin II with those who did not. This was a retrospective chart review. Response to angiotensin II was defined as increase in or maintenance of mean arterial pressure (MAP) and decrease in background vasopressor dosage. Angiotensin II was administered to 7 patients (postoperatively in 4 patients [57.1%]) with vasoplegic shock and baseline norepinephrine equivalent (NEE) of 0.49 ± 0.08 μg/kg/min; 12 patients with vasoplegic shock did not receive angiotensin II. Within 3 hours of angiotensin II administration, NEE decreased by 38.0 ± 33.1%. Angiotensin patients were more likely to newly require renal replacement therapy (66.7% vs 9.1%, P = 0.03) and had a longer, although not statistically significant, postoperative stay (23.1 vs 14.0 days, P = 0.16). Despite higher NEE requirements at baseline (0.49 vs 0.30, P = 0.03) and over the next 48 hours in the angiotensin group, no between-group differences in 7-day mortality (14.3% vs 0.0%, P = 0.37) or 30-day mortality (28.6% vs 8.3%, P = 0.52) were noted. In patients who developed vasoplegic shock after cardiac surgery, angiotensin II administration allowed immediate dosage reductions of other vasopressors while maintaining MAP. Despite its small sample size, this study adds to the paucity of data in these patients and highlights future research needs.

Hemodynamic effects of COVID-19 vaccination in hospitalized patients awaiting heart transplantation

BackgroundThe hemodynamic effects of pre-transplant vaccination against COVID-19 among heart transplant candidates hospitalized for advanced heart failure remains unknown. MethodsA retrospective chart review was conducted at a high-volume transplant center from January through December 2021. 22 COVID-19 vaccination events occurred among patients hospitalized for decompensated heart failure while awaiting transplantation. Primary outcomes included inotrope and vasopressor dosages. Secondary outcomes included vital signs, pulmonary artery catheter measurements, diuretic dosages, and renal function. Data were extracted 24 h before through 72 h after vaccination. ResultsOne of 22 vaccination events was associated with hemodynamic changes requiring increased inotropic and vasopressor support post-vaccination. In all other cases, transient hemodynamic changes occurred without need for escalated therapy. ConclusionsCOVID-19 vaccination can be administered safely to most critically ill patients with advanced heart failure including those awaiting transplantation. All patients should be monitored closely as some may be susceptible to significant hemodynamic changes.

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P50: Save leg: using contralateral femoral inflow for distal perfusion catheter placed for Impella CP

Background: Leg ischemia is a possible complication of percutaneous left ventricular device (Impella CP TM) placement. To avoid leg ischemia in atrisk patients, a distal perfusion catheter (DPC) should be placed. The DPC can be connected to the wire-reaccess port of the Impella CP as an inflow to the DPC to perfuse the leg. However, the wire-reaccess port of the Impella was not designed to bypass arterial blood to the distal limb, but rather for wire passage. We introduced a passive distal perfusion system from the contralateral femoral artery to optimize blood flow to the distal limb. Methods: A 65 year-old female with dilated cardiomyopathy developed refractory ventricular tachycardia. She was taken to the catherization laboratory because of hemodynamic instability requiring high doses of vasopressors. By left heart catheterization, we noted normal coronary arteries with elevated left ventricular end-diastolic pressure (38 mm Hg) and a poor cardiac index. Thus, Impella CP was placed from the right groin to stabilize her hemodynamics. A DCP was placed on right distal femoral artery and connected to the wire-reaccess port of the Impella CP. The leg appeared perfused by DPC via reaccess port in the catherization laboratory; however, despite this as well as appropriate anticoagulation, the leg became ischemic (cold leg, low leg regional saturation) shortly after admission to the ICU, where a lack of flow in the DPC was confirmed. Results: An additional contralateral femoral arterial line was placed. The contralateral femoral arterial line was then connected to the DPC (figure), and the reaccess port of the Impella was capped. Shortly after placement of the new DPC system, the pulse was returned and leg saturation improved. Additionally, leg ischemia during Impella support did not reoccur. Conclusion: A DPC using the Impella CP reaccess port provided inadequate distal flow. When a DPC is indicated during femoral Impella CP use, the contralateral femoral artery should be chosen for inflow cannulation. Figure 1. Impella CP and distal perfusion catheter (DPC) in the right femoral artery. The arterial line in the left femoral artery is feeding DPC in the right femroal artery.

SINGLE-CENTER EXPERIENCE WITH THE USE OF THE SERAPH-100 MICROBIND AFFINITY BLOOD FILTER IN-PARALLEL WITH EXTRACORPOREAL MEMBRANE OXYGENATION CIRCUIT IN SEPTIC PATIENTS

TYPE: Late Breaking Case Report TOPIC: Critical Care INTRODUCTION: Patients who require extracorporeal membrane oxygenation (ECMO) have a high mortality if they develop septic shock. With the emergence of novel and resistant pathogens, new therapies are needed to treat septic patients. The Seraph–100 Microbind Affinity Blood Filter was granted Emergency Use Authorization by the FDA to treat severe COVID-19. The Seraph-100 filter contains microbeads that can bind bacteria, fungi, viruses and cytokines. Recommended configurations for the Seraph–100 utilize hemodialysis or continuous renal replacement therapy (CRRT) machines in a stand-alone fashion or in-combination with a hemodialysis filter. In this series, we explore a new configuration for the Seraph-100 for patients requiring ECMO. CASE PRESENTATION: Five septic patients underwent treatment with the Seraph-100 in-parallel with ECMO. This configuration allowed for pressures generated by the ECMO circuit to drive blood flow through the Seraph-100. All five patients were on multiple high dose vasopressors prior to therapy with the Seraph-100. Within 12-24 hours of treatment, vasopressor support significantly decreased and repeat blood cultures showed clearance of pathogens. DISCUSSION: All our patients treated with Seraph–100 in-parallel with ECMO had significant reduction in vasopressor support. Benefits of this configuration include limiting need for additional vascular access and need for dialysis circuits, along with the associated risks of renal replacement therapy. CONCLUSIONS: The Seraph-100 represents an innovative solution for the treatment of septic patients. This case series demonstrated the effectiveness and safety of a new configuration for the Seraph-100 in patients requiring ECMO. Further studies are needed to elucidate the optimal use of the Seraph-100 blood filter. DISCLOSURE: Nothing to declare. KEYWORD: Seraph-100 Blood Filter

Off-label Rescue Agents for Vasoplegic Syndrome after Cardiopulmonary Bypass

Abstract Introduction: Cardiovascular disease is the number one cause of death in the United States today1. Cardiopulmonary bypass (CPB) is a common technique used in the surgical management of cardiovascular disease. A relatively common complication of CPB is vasoplegia, which has an approximate incidence of anywhere from 5-25%1-8. Methylene blue is used to treat vasoplegic syndrome (VS) when higher dose vasopressors are ineffective. Vasoplegic syndrome (VS) is defined as a syndrome of low systemic vascular resistance (SVR) in the presence of normal or high cardiac output1-4. Generally, VS is characterized as a high cardiac output state (CI &lt; 2.2 L/min/m2) with difficulty maintaining a mean arterial pressure (MAP) greater than 60 mmHg despite increasing vasopressor requirements1-3,7. The focus of this case report is to examine methylene blue’s effectiveness in treating vasoplegia after weaning from CPB. This case report will also compare and contrast methylene blue and another rescue agent, hydroxocobalamin, and how they combat vasoplegia. Case presentation: The case involved a 65-year-old male presenting for an aortic root and aortic valve replacement and removal of an abscess in his heart. The patient was under general anesthesia, put on cardiopulmonary bypass and then underwent a deep hypothermic circulatory arrest for the placement of the aortic root graft and aortic valve. Weaning from bypass was difficult as a result of vasoplegia, for which methylene blue was given when vasopressor requirements were increasing. Discussion: Methylene blue is a guanylyl cyclase inhibitor that has been found to increase SVR and decrease vasopressor requirements in vasoplegic syndrome by inhibiting nitric oxide synthase (NOS), thus limiting the production of nitric oxide (NO) as well as inhibiting the enzyme guanylyl cyclase and preventing vasodilation5. The timing of administration of methylene blue is debatable, being that it is commonly given postoperatively, but the literature favors earlier administration in high-risk patients that will be placed on CPB2-5. Typical dosing for methylene blue is 2 mg/kg intravenously (IV) but increasing the dose to 3 mg/kg can be used to account for the larger volume of distribution (Vd) that is present in patients on CPB2. The only true contraindications for methylene blue are a hypersensitivity to the drug and a deficiency in the glucose-6-phosphate dehydrogenase, which is the enzyme that is responsible for turning methylene blue into its metabolites1-8. Treating VS with methylene blue after CPB has shown significantly quicker recovery and normal hemodynamics, shorter duration of vasopressor infusions, less incidence of renal complications, shorter length of stay (LOS) and less 30-day mortality6.

Effects of Remimazolam vs. Sevoflurane Anesthesia on Intraoperative Hemodynamics in Patients with Gastric Cancer Undergoing Robotic Gastrectomy: A Propensity Score-Matched Analysis.

Remimazolam has been suggested to improve the maintenance of hemodynamic stability when compared with other agents used for general anesthesia. This study aimed to compare the effects of remimazolam and sevoflurane anesthesia on hemodynamic stability in patients undergoing robotic gastrectomy. We retrospectively reviewed the electronic medical records of 199 patients who underwent robotic gastrectomy with sevoflurane (n = 135) or remimazolam (n = 64) anesthesia from January to November 2021. Propensity scores were used for 1:1 matching between the groups. The primary outcome was the difference in use of intraoperative vasopressors between groups. Secondary outcomes included differences in incidence and dose of vasopressors, as well as intraoperative hemodynamic variables, between groups. Remimazolam anesthesia was associated with a significantly less frequent use of ephedrine (odds ratio (OR): 0.13; 95% confidence interval (CI): 0.05–0.38, p < 0.001), phenylephrine (OR: 0.12; 95% CI: 0.04–0.40, p < 0.001), and any vasopressor (OR: 0.06; 95% CI: 0.02–0.25, p < 0.001) compared with sevoflurane anesthesia. Remimazolam anesthesia enables better maintenance of hemodynamic stability than sevoflurane anesthesia. Thus, remimazolam anesthesia may be beneficial for patients who are expected to experience hypotension due to the combined effects of CO2 pneumoperitoneum and the head-up position utilized during robotic gastrectomy.

EPIDURAL ROPIVACAINE: EFFECTS OF HIGH-VOLUME/ LOW-CONCENTRATION VERSUS LOW-VOLUME/ HIGH-CONCENTRATION IN RENAL TRANSPLANT PATIENTS

Background: Choice of an appropriate analgesic regimen is especially important in ESRD patients. Regional analgesia technique such as epidural with local anaesthetic drugs has been found suitable in such patients. This study was designed to compare a high-volume/low-concentration with low-volume/high concentration ropivacaine regimen in ESRD transplant patients. Materials And Methods: This prospective, open level randomized control study was conducted on 40 end stage renal disease (ESRD) patients, aged between 20- 60 years of either sex who underwent live-related renal transplant surgery.GROUP A Low volume/High concentration group received 6 ml of 0.75% ropivacaine and GROUP B High volume/Low concentration group received 12 ml of 0.375% ropivacaine.Total dose of ropivacaine needed for postoperative pain control and for achieving T6 to S5 sensory block, Level of motor blockade and Dose of vasopressors needed for haemodynamic stability was compared. Results: Total dose of ropivacaine required to achieve T6 to S5 sensory block and total dose of vasopressor used was higher in low volume high concentration group at initiation of block. Postoperative quality of analgesia as assessed by VAS score and top up requirements (total dose of postoperative ropivacaine used) was comparable in both the groups. Conclusion: We conclude no added advantage of using low volume high concentration ropivacaine drug regimen in renal transplant recipients in terms of quality of analgesia and haemodynamic stability.

Establishment of a predictive model of septic myocardiopathy based on left ventricular global longitudinal strain

Objectives: To explore the risk factors associated with septic cardiomyopathy and establish a predictive model of the disease based on left ventricular global longitudinal strain (LV GLS). Methods: Data from sepsis patients without a history of cardiac dysfunction who were treated in the Critical Care Department of the Northern Jiangsu People's Hospital from September, 2019 to January, 2021 were included in the analysis. The LV GLS was measured by echocardiography within 72 hours and the patients were divided into a septic myocardiopathy group (LV GLS>-17%) and a normal cardiac function group (LV GLS≤-17%). Clinical data from two groups of patients were collected for univariate analysis. The receiver operating characteristic (ROC) curves of the factors that were statistically different were drawn for exploring the diagnostic and cut-off values. The continuous variable was converted to a dichotomous variable according to the cut-off value. Multivariate logistic regression analysis of sepsis cardiomyopathy was performed to screen the risk factors and create a predictive model. The predictive model was evaluated by ROC curve analysis and the Bootstrap method and shown as a nomograph. Results: Patients in the sepsis cardiomyopathy group had higher levels of high sensitive troponin I (Hs-TnI), procalcitonin (PCT), lactate (Lac), N-terminal pro-brain atriuretic peptide (NT-proBNP), vasopressor dosing intensity (VDI) and sequential organ failure assessment (SOFA) when compared to those in the normal cardiac function group (all P<0.05). The multivariate logistic regression analysis showed that Hs-TnI≥0.131 μg/L (OR=6.71, 95%CI:2.67-16.88, P<0.001), PCT≥40 μg/L (OR=3.08, 95%CI:1.10-8.59, P=0.032), Lac≥4.2 mmol/L (OR=2.80, 95%CI:1.02-7.69, P=0.045), NT-proBNP≥3 270 ng/L (OR=2.67, 95%CI:1.06-6.74, P=0.038) were independent risk factors for septic myocardiopathy. The area under the ROC curve of the predictive model based on the four indexes up-mentioned was 0.838 (95%CI:0.766-0.910), and the C-index was 0.822 (95%CI:0.750-0.894) which indicated the utility of the nomogram. The model had a good predictive ability, accuracy and discrimination. Conclusions: Hs-TnI≥0.131 μg/L, PCT≥40 μg/L, Lac≥4.2 mmol/L and NT-proBNP≥3 270 ng/L are independent risk factors for septic myocardiopathy, and the septic cardiomyopathy predictive model constructed based on these factors has a good diagnostic performance.

Intraoperative vasopressor use and early postoperative acute kidney injury in elderly patients undergoing elective noncardiac surgery

Background Intraoperative hypotension is a risk factor for postoperative acute kidney injury (AKI). Elderly patients are susceptible due to reduced responses to acute hemodynamic changes. Aims Determine the association between hypotension identified from anesthetic charts and postoperative AKI in elderly patients. Methods Retrospective cohort study of elective noncardiac surgery patients ≥65 years, at an Australian tertiary hospital (December 2019–March 2021), with the primary outcome of AKI ≤48 h of surgery. Factors of interest were intraoperative hypotension determined from anesthetic charts (mean arterial pressure <60 mmHg, systolic blood pressure <90 mmHg, recorded 5-min) and intraoperative vasopressor use. Results In 830 patients (mean age 75 years), systolic hypotension was more frequent than mean arterial hypotension (25.7% vs. 11.9%). Most hypotensive episodes were brief (7.2% of systolic and 4.2% of mean arterial hypotension lasted >10 min) but vasopressors were used in 84.7% of cases. The incidence of postoperative AKI was 13.9%. Systolic hypotension >20 min was associated with AKI (OR, 3.88; 95% CI: 1.38–10.9), which was not significant after adjusting for vasopressors, creatinine, American Society of Anesthesiologists class, and hemoglobin drop. The cumulative dose of any specific vasopressor >20 mg (or >10 mg epinephrine) was independently associated with AKI (adjusted OR, 2.47; 95% CI: 1.34–4.58). Every 5 mg increase in the total dose of all intraoperative vasopressors used during surgery was associated with 11% increased odds of AKI (95% CI: 3–19%). Conclusions High vasopressor use was associated with postoperative AKI in elderly patients undergoing noncardiac surgery, independent of hypotension identified from anesthetic charts.

Analgesic Outcomes in Opioid Use Disorder Patients Receiving Spinal Anesthesia with or without Intrathecal Clonidine for Cesarean Delivery: A Retrospective Investigation.

BackgroundIntrathecal (IT) clonidine has been observed to reduce 24-hour opioid requirements and time to first analgesic request after cesarean delivery, but has not been specifically studied in patients with opioid use disorder (OUD).MethodsPatients with OUD undergoing cesarean delivery under spinal or combined spinal-epidural (CSE) anesthesia at our institution from 2011 to 2020 were identified, and only patients with OUD were included in this study. Subjects that received IT clonidine were compared to a control group that did not receive IT clonidine to observe potential differences in analgesic outcomes (24-hour opioid requirements, pain scores and time to first post-operative pain medication) or side-effects (hypotension, vasopressor dosing and bradycardia).ResultsA total of 160 patients were included (clonidine n = 22, controls n = 138). For the clonidine group, the median IT clonidine dose was 30µg. Clonidine group patients were observed to have greater dose of IT bupivacaine (12 vs 12.75mg; p = 0.01) and IT morphine (100 vs 200µg; p < 0.001). The clonidine group was also observed to have greater incidence of intraoperative hypotension (20% vs 45%; p = 0.01) and maximum phenylephrine dose (50 vs 57.5 µg/min; p < 0.001). The time to first analgesic request (minutes) after surgery was significantly longer for the clonidine group (153.5 vs 207 min; p < 0.001). The average oral oxycodone equivalents taken per 24 hours of hospital admission were significantly less in the clonidine group (82.36 vs 41.67mg; p < 0.001), and the clonidine group also had significantly less oxycodone equivalents taken for each post-operative day.ConclusionIT clonidine was observed to result in reduced 24-hour opioid consumption in patients with OUD and may be useful as part of a multimodal analgesic regimen. The incidence of hypotension and vasopressor doses were greater in patients receiving IT clonidine, and this should be anticipated if IT clonidine is being administered.

Successful Management of a Septic Shock Caused by Acinetobacter baumanii XDR in a Young Heart Transplant Patient

<h3>Introduction</h3> In recent years, <i>Acinetobacter baumannii</i> (Acb) has emerged as a particularly challenging drug-resistant pathogen, but it has rarely been studied in solid organ transplanted patients. <h3>Case Report</h3> We present the case of a 21-year-old female patient who was admitted to our centre for severe cardiac failure due to post-cardiotomy shock. V-A ECMO and Impella were implanted. On admission, the patient presented a SOFA score of 11, an APACHE II score of 24 and a MODS score of 10, with predicted mortality of 50%. Pre-operative blood cultures resulted positive for Acb XDR, with meropenem MIC of 8 mg/l (R) and colistin MIC of 0.25(S). Specific antibiotic therapy with Colistin (4,5 MU x 2/die) and Meropenem (6g i.c. 12.5 ml/h) was started. As general conditions deteriorated, the patient underwent salvage heart transplant (HT).Before HT, in order to reduce the systemic inflammatory response and prevent the multi-organ dysfunction, a CytoSorb cartridge was mounted in the ECMO circuit for 24 h to remove cytokines from the blood. The following day, PCT, CRP and myoglobin started to decrease whereas WCC remained stable. Seven days after HT, the patient developed septic shock with severe hypotension nonresponsive to vasopressors: endotoxin blood level was high (0.72 at EAA). This time, 2 cycles of Toraymyxin hemo-filtration were applied for 48 h. Clinical conditions started to steadily improve, with the reduction of PCR, PCT, WCC levels and body temperature; vasopressor and inotrope dosages were decreased (Tab.1). After 23 days, the patient was transferred to the ward. On the 45th day, the first negative blood culture was obtained, and 20 days later, antibiotic therapy was interrupted. The patient was discharged 6 months after HT. She is reported fine at 27 months of follow-up. <h3>Summary</h3> In this case report, the combined use of Cytosorb, Toraymixyn, targeted antibiotic therapy based on the antibiogram, and modulation of immunosuppressant therapy proved effective in managing such a complex clinical situation.

Effect of Hydroxocobalamin Compared to Methylene Blue for Management of Vasoplegia

<h3>Purpose</h3> Vasoplegic syndrome is a common complication following cardiac surgery, characterized by profound systemic hypotension from poor systemic vascular resistance (SVR) requiring high doses of vasopressors. Hydroxocobalamin and methylene blue are two medications used to decrease vasoplegia and vasopressors requirements, thereby decreasing morbidity and mortality. The purpose of this study is to evaluate whether hydroxocobalamin or methylene blue is more effective in relieving vasoplegia as defined by reducing vasopressor requirements. <h3>Methods</h3> This was a retrospective chart review performed at an academic medical center between March 2020 through August 2021. Patients ages 18-89 who received a dose of hydroxocobalamin or methylene blue while in a cardiac intensive care unit for vasoplegia were included for analysis. The primary outcome was the time to reduction of 50% of original vasopressor requirements, defined in norepinephrine equivalents. Secondary outcomes include change in mean arterial pressure (MAP), cardiac index, SVR, ICU length of stay (LOS), mortality, and the need for renal replacement therapy. The primary outcome will be expressed as means with standard deviations as well as a time to event analysis with a Kaplan-Meier Curve and log rank test. <h3>Results</h3> Patients were treated with a one-time 5mg dose of hydroxocobalamin (n=8) or dose(s) of methylene blue (n=15). The time to reduction of 50% of vasopressor requirements was 5.75 hours with hydroxocobalamin and 13.08 hours with methylene blue (p=0.0248). Change in MAP at 4 hours post dose was 7.75 mmHg with hydroxocobalamin and -0.93 mmHg in methylene blue (p=0.150). There was no difference in change in cardiac index (p=0.11), ICU LOS (p=0.11), or mortality (p=1). Change in SVR increased by 428.4 dynes/sec/cm5 with hydroxocobalamin and 95.6 dynes/sec/cm5 with methylene blue (p=0.0238). Need for renal replacement therapy was 62.5% with hydroxocobalamin and 13% with methylene blue (p=0.0257). <h3>Conclusion</h3> Use of hydroxocobalamin for vasoplegia is associated with a significantly faster time to a 50% reduction of vasopressor requirements and an increase in SVR post administration compared to methylene blue. Hydroxocobalamin was also significantly associated with an increase in need for renal replacement therapy. The clinical significance of these effects must be determined in larger, randomized controlled trials.

Impact of Double-Machine Replacement Protocol at Start of Continuous Renal Replacement Therapy in Vasopressor-Dependent Patients: A Retrospective Cohort Study

Introduction: When starting continuous renal replacement therapy (CRRT), vasopressor-dependent patients are at risk of hemodynamic instability. Thus far, only a few studies have analyzed the impact of CRRT circuit replacement for vasopressor-dependent patients. Hence, we compared the effect of double-machine replacement protocol (DMRP) with single-machine replacement protocol (SMRP) for CRRT circuit replacement in vasopressor-dependent patients. Methods: The medical records of 96 vasopressor-dependent patients treated with CRRT in the general intensive care unit of the Shunde Hospital, Southern Medical University, between January 2017 and April 2018 were retrospectively analyzed. The major measures of the SMRP included returning the blood to the patient and sealing access catheter with heparin and starting a new CRRT machine with a slow blood pump, while DMRP involved simultaneous drawing and return of blood with two machines using a slow blood pump for circuit replacement. The primary outcome measures were changes in vasopressor dose and hemodynamic parameters, and the secondary outcome measure was the pause time difference between the two groups during the period. Results: A total of 53 patients were treated with SMRP and 43 patients with DMRP. Heart rate was higher in the SMRP group as compared to the DMRP group (p < 0.05). There were no significant changes in central venous pressure, mean arterial pressure, and vasopressor dose in either group (p > 0.05). The patients in the DMRP group had a significant reduction in CRRT pause time (5.62 ± 0.69 min in DMRP group vs. 37.01 ± 8.72 min in SMRP group, p < 0.01). The DMRP group needed a lower volume of circuit purging and priming fluid related to CRRT circuit replacement (0 mL in DMRP group vs. 463 mL in SMRP group). Conclusions: Implementation of the DMRP for CRRT circuit replacement had a slight hemodynamic effect on vasopressor-dependent patients. It also reduced the pause time and volume of circuit purging and priming fluid related to CRRT circuit replacement compared with SMRP.

Effects of vasopressor agents on the development of pressure ulcers in critically ill patients: a systematic review.

The primary objective of this systematic review was to determine the effect of vasopressor agents on the development of pressure ulcers (PUs) among critically ill patients in intensive care units (ICUs). The secondary outcome of interest was length of stay in the ICU. A systematic review was undertaken using the databases searched: Medline, Embase, CINAHL and The Cochrane Library. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used to formulate the review. Data were extracted using a predesigned data extraction table and analysed as appropriate using RevMan. Quality appraisal was undertaken using the EBL Critical Appraisal Tool. The inclusion criteria were met by 13 studies. Two studies provided sufficient data to compare the number of patients who developed a PU with and without the use of vasopressors. Consistently, within these two studies, being treated with a vasopressor increased the likelihood of PU development. RevMan analysis identified that shorter duration of administration of vasopressors was associated with less PU development (mean difference (MD) 65.97 hours, 95% confidence interval (CI): 43.47-88.47; p=0.0001). Further, a lower dose of vasopressors was also associated with less PU development (MD: 8.76μg/min, 95% CI: 6.06-11.46; p<0.00001). Mean length of stay increased by 11.46 days for those with a PU compared to those without a PU (MD: 11.46 days; 95% CI: 7.10-15.82; p<0.00001). The overall validities of the studies varied between 45-90%, meaning that there is potential for bias within all the included studies. Vasopressor agents can contribute to the development of PUs in critically ill patients in ICUs. Prolonged ICU stay was also associated with pressure ulcers in this specific patient group. Given the risk of bias within the included studies, further studies are needed to validate the findings of this review paper.

A pilot study of the pharmacokinetics of continuous magnesium infusion in critically ill patients

Objective: The pharmacokinetics and haemodynamic effect of continuous magnesium infusion in non-cardiac intensive care unit (ICU) patients are poorly understood. We aimed to measure serum and urine magnesium levels during bolus and continuous infusion in critically ill adults, compare serum levels with those of a control population, and assess its haemodynamic effect. Design: Pharmacokinetic study Setting: A single tertiary adult ICU. Participants: Mechanically ventilated adults requiring vasopressor support. Intervention: A 10 mmol bolus of magnesium sulfate followed by 1.5-3 mmol/h infusion for 24 hours. Main outcome measures: The primary outcome was the change in total serum magnesium concentration. The main secondary outcome was mean arterial pressure (MAP)- adjusted vasopressor dose. Results: We matched 31 treated patients with 93 controls. Serum total magnesium concentration increased from a median 0.94 mmol/L (interquartile range [IQR], 0.83-1.10 mmol/L) to 1.38 mmol/L (IQR, 1.25-1.69 mmol/L; P < 0.001) and stabilised between a median 1.64 mmol/L (IQR, 1.38-1.88 mmol/L) at 7 hours and 1.77 mmol/L (IQR, 1.53-1.85 mmol/L) at 25 hours. This was significantly greater than in the control group (P < 0.001). The MAP-adjusted vasopressor dose decreased during magnesium infusion (P < 0.001). Conclusion: In critically ill patients, a magnesium sulfate bolus followed by continuous infusion achieved moderately elevated levels of total serum magnesium with a decrease in MAP-adjusted vasopressor dose. Trial registration number: ACTRN12619000925145.