Ten tips to optimize vasopressors use in the critically ill patient with hypotension

Exploration of Norepinephrine Dose-Capping Practices: Report From an International, Interprofessional Survey of Critical Care Clinicians

Purpose: The Joint Commission standards for titrated infusions require specification of maximum rates of infusion. This practice has led to the development of protocolized maximum doses that can be overridden by provider order ("soft maximums") and to dose caps that cannot be superseded ("hard maximums"). The purpose of this study was to determine the prevalence of and attitudes towards dose capping of norepinephrine. Methods: A 20-item cross-sectional survey assessing norepinephrine dose capping practices, perceptions of norepinephrine protocols, and respondent and practice site demographics was distributed electronically to the mailing list of an international medical podcast. Responses were stratified according to use of weight-based dosing (WBD) or non-WBD of norepinephrine. The primary objective was to characterize norepinephrine dosing practices including protocolized maximum doses and/or dose capping. Categorical and continuous variables were compared using the Chi-square test and Mann-Whitney U test, respectively, with P < .05 indicating statistical significance. Results: The survey was completed by 586 physicians, nurses, pharmacists, and advanced practice providers. WBD was used by 51% and non-WBD by 47%. A standardized titration protocol was reported by 65% and dose capping was reported by 19%. The protocolized maximum dose ranged from 20-400 mcg/min for respondents using non-WBD (median [interquartile range] 30 [30-50]) and ranged from .2-10 mcg/kg/min for respondents using WBD (1 [.5-3]). The dose cap was 50 (40-123) mcg/min with non-WBD and 2 (1-3) mcg/kg/min with WBD. Conclusions: An international, multi-professional survey of critical care and emergency medicine clinicians revealed wide variability in norepinephrine dosing practices including maximum doses allowed.

Development and Validation of Multimodal Models to Predict the 30-Day Mortality of ICU Patients Based on Clinical Parameters and Chest X-Rays

We aimed to develop and validate multimodal ICU patient prognosis models that combine clinical parameters data and chest X-ray (CXR) images. A total of 3798 subjects with clinical parameters and CXR images were extracted from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database and an external hospital (the test set). The primary outcome was 30-day mortality after ICU admission. Automated machine learning (AutoML) and convolutional neural networks (CNNs) were used to construct single-modal models based on clinical parameters and CXR separately. An early fusion approach was used to integrate both modalities (clinical parameters and CXR) into a multimodal model named PrismICU. Compared to the single-modal models, i.e., the clinical parameter model (AUC = 0.80, F1-score = 0.43) and the CXR model (AUC = 0.76, F1-score = 0.45) and the scoring system APACHE II (AUC = 0.83, F1-score = 0.77), PrismICU (AUC = 0.95, F1 score = 0.95) showed improved performance in predicting the 30-day mortality in the validation set. In the test set, PrismICU (AUC = 0.82, F1-score = 0.61) was also better than the clinical parameters model (AUC = 0.72, F1-score = 0.50), CXR model (AUC = 0.71, F1-score = 0.36), and APACHE II (AUC = 0.62, F1-score = 0.50). PrismICU, which integrated clinical parameters data and CXR images, performed better than single-modal models and the existing scoring system. It supports the potential of multimodal models based on structured data and imaging in clinical management.

Development of a new miniaturized system for ultrafiltration

Acute decompensated heart failure and fluid overload are the most common causes of hospitalization in heart failure patients, and often, they contribute to disease progression. Initial treatment encompasses intravenous diuretics although there might be a percentual of patients refractory to this pharmacological approach. New technologies have been developed to perform extracorporeal ultrafiltration in fluid overloaded patients. Current equipment allows to perform ultrafiltration in most hospital and acute care settings. Extracorporeal ultrafiltration is then prescribed and conducted by specialized teams, and fluid removal is planned to restore a status of hydration close to normal. Recent clinical trials and European and North American practice guidelines suggest that ultrafiltration is indicated for patients with refractory congestion not responding to medical therapy. Close interaction between nephrologists and cardiologists may be the key to a collaborative therapeutic effort in heart failure patients. Further studies are today suggesting that wearable technologies might become available soon to treat patients in ambulatory and de-hospitalized settings. These new technologies may help to cope with the increasing demand for the care of chronic heart failure patients. Herein, we provide a state-of-the-art review on extracorporeal ultrafiltration and describe the steps in the development of a new miniaturized system for ultrafiltration, called AD1 (Artificial Diuresis).

Association between peripheral perfusion index and postoperative acute kidney injury in major noncardiac surgery patients receiving continuous vasopressors: a post hoc exploratory analysis of the VEGA-1 trial

BACKGROUND

The peripheral perfusion index is the ratio of pulsatile to nonpulsatile static blood flow obtained by photoplethysmography and reflects peripheral tissue perfusion. We investigated the association between intraoperative perfusion index and postoperative acute kidney injury in patients undergoing major noncardiac surgery and receiving continuous vasopressor infusions.

METHODS

In this exploratory post hoc analysis of a pragmatic, cluster-randomised, multicentre trial, we obtained areas and cumulative times under various thresholds of perfusion index and investigated their association with acute kidney injury in multivariable logistic regression analyses. In secondary analyses, we investigated the association of time-weighted average perfusion index with acute kidney injury. The 30-day mortality was a secondary outcome.

RESULTS

Of 2534 cases included, 8.9% developed postoperative acute kidney injury. Areas and cumulative times under a perfusion index of 3% and 2% were associated with an increased risk of acute kidney injury; the strongest association was observed for area under a perfusion index of 1% (adjusted odds ratio [aOR] 1.32, 95% confidence interval [CI] 1.00-1.74, P=0.050, per 100%∗min increase). Additionally, time-weighted average perfusion index was associated with acute kidney injury (aOR 0.82, 95% CI 0.74-0.91, P<0.001) and 30-day mortality (aOR 0.68, 95% CI 0.49-0.95, P=0.024).

CONCLUSIONS

Larger areas and longer cumulative times under thresholds of perfusion index and lower time-weighted average perfusion index were associated with postoperative acute kidney injury in patients undergoing major noncardiac surgery and receiving continuous vasopressor infusions.

CLINICAL TRIAL REGISTRATION

NCT04789330.

Should we initiate vasopressors earlier in patients with septic shock: A mini systemic review

Septic shock treatment remains a major challenge for intensive care units, despite the recent prominent advances in both management and outcomes. Vasopressors serve as a cornerstone of septic shock therapy, but there is still controversy over the timing of administration. Specifically, it remains unclear whether vasopressors should be used early in the course of treatment. Here, we provide a systematic review of the literature on the timing of vasopressor administration. Research was systematically identified through PubMed, Embase and Cochrane searching according to PRISMA guidelines. Fourteen studies met the eligibility criteria and were included in the review. The pathophysiological basis for early vasopressor use was classified, with the exploration on indications for the early administration of mono-vasopressors or their combination with vasopressin or angiotensinII. We found that mortality was 28.1%-47.7% in the early vasopressors group, and 33.6%-54.5% in the control group. We also investigated the issue of vasopressor responsiveness. Furthermore, we acknowledged the subsequent challenge of administration of high-dose norepinephrine via peripheral veins with early vasopressor use. Based on the literature review, we propose a possible protocol for the early initiation of vasopressors in septic shock resuscitation.

Blood Pressure Goals in Critically Ill Patients

Blood pressure goals in the intensive care unit (ICU) have been extensively investigated in large datasets and have been associated with various harm thresholds at or greater than a mean pressure of 65 mm Hg. While it is difficult to perform interventional randomized trials of blood pressure in the ICU, important evidence does not support defense of a higher pressure, except in retrospective database analyses. Perfusion pressure may be a more important target than mean pressure, even more so in the vulnerable patient population. In the cardiac ICU, blood pressure targets are tailored to specific cardiac pathophysiology and patient characteristics. Generally, the goal is to maintain adequate blood pressure within a certain range to support cardiac function and to ensure end organ perfusion. Individualized targets demand the use of both invasive and noninvasive monitoring modalities and frequent titration of medications and/or mechanical circulatory support where necessary. In this review, we aim to identify appropriate blood pressure targets in the ICU, recognizing special patient populations and outlining the risk factors and predictors of end organ failure.

Fluids and Early Vasopressors in the Management of Septic Shock: Do We Have the Right Answers Yet?

Septic shock is a common condition associated with hypotension and organ dysfunction. It is associated with high mortality rates of up to 60% despite the best recommended resuscitation strategies in international guidelines. Patients with septic shock generally have a Mean Arterial Pressure below 65 mmHg and hypotension is the most important determinant of mortality among this group of patients. The extent and duration of hypotension are important. The two initial options that we have are 1) administration of intravenous (IV) fluids and 2) vasopressors, The current recommendation of the Surviving Sepsis Campaign guidelines to administer 30 ml/kg fluid cannot be applied to all patients. Complications of fluid over-resuscitation further delay organ recovery, prolong ICU and hospital length of stay, and increase mortality. The only reason for administering intravenous fluids in a patient with circulatory shock is to increase the mean systemic filling pressure in a patient who is volume-responsive, such that cardiac output also increases. The use of vasopressors seems to be a more appropriate strategy, the very early administration of vasopressors, preferably during the first hour after diagnosis of septic shock, may have a multimodal action and potential advantages, leading to lower morbidity and mortality in the management of septic patients. Vasopressor therapy should be initiated as soon as possible in patients with septic shock.

Norepinephrine versus phenylephrine for treating hypotension during general anaesthesia in adult patients undergoing major noncardiac surgery: a multicentre, open-label, cluster-randomised, crossover, feasibility, and pilot trial

BACKGROUND

Intraoperative hypotension is associated with postoperative complications. The use of vasopressors is often required to correct hypotension but the best vasopressor is unknown.

METHODS

A multicentre, cluster-randomised, crossover, feasibility and pilot trial was conducted across five hospitals in California. Phenylephrine (PE) vs norepinephrine (NE) infusion as the first-line vasopressor in patients under general anaesthesia alternated monthly at each hospital for 6 months. The primary endpoint was first-line vasopressor administration compliance of 80% or higher. Secondary endpoints were acute kidney injury (AKI), 30-day mortality, myocardial injury after noncardiac surgery (MINS), hospital length of stay, and rehospitalisation within 30 days.

RESULTS

A total of 3626 patients were enrolled over 6 months; 1809 patients were randomised in the NE group, 1817 in the PE group. Overall, 88.2% received the assigned first-line vasopressor. No drug infiltrations requiring treatment were reported in either group. Patients were median 63 yr old, 50% female, and 58% white. Randomisation in the NE group vs PE group did not reduce readmission within 30 days (adjusted odds ratio=0.92; 95% confidence interval, 0.6-1.39), 30-day mortality (1.01; 0.48-2.09), AKI (1.1; 0.92-1.31), or MINS (1.63; 0.84-3.16).

CONCLUSIONS

A large and diverse population undergoing major surgery under general anaesthesia was successfully enrolled and randomised to receive NE or PE infusion. This pilot and feasibility trial was not powered for adverse postoperative outcomes and a follow-up multicentre effectiveness trial is planned.

CLINICAL TRIAL REGISTRATION

NCT04789330 (ClinicalTrials.gov).

Elevated pulsatility index of the superior mesenteric artery indicated prolonged mechanical ventilation in patients after cardiac valve surgery

Purpose

This study examined whether alterations in Doppler parameters of superior mesenteric artery (SMA) are associated with prolonged mechanical ventilation (PMV) in patients who underwent cardiac valve surgery.

Methods

Hemodynamic and SMA Doppler parameters were collected at intensive care unit(ICU) admission. The duration of mechanical ventilation was monitored. PMV was defined as mechanical ventilation ≥96 h.

Results

A total of 132 patients admitted to ICU after cardiac valve surgery were evaluated for enrollment, of whom 105 were included. Patients were assigned to the control (n = 63) and PMV (n = 42) groups according to the mechanical ventilation duration. The pulsatility index(SMA-PI) and resistive index of SMA (SMA-RI) were 3.97 ± 0.77 and 0.88 (0.84-0.90) in the PMV group after cardiac valve surgery, which was lower than the SMA-PI (2.95 ± 0.71, p < 0.0001) and SMA-RI of controls (0.8, 0.77-0.88, p < 0.0001). SMA-PI at admission had favorable prognostic significance for PMV (AUC = 0.837, p < 0.0001).

Conclusions

An elevated SMA-PI is common in patients after cardiac valve surgery with PMV. Increased SMA-PI could help predict PMV after cardiac valve surgery. Using point-of-care ultrasound to measure SMA-PI at ICU admission is an acceptable and reproducible method for identifying patients with PMV.

Critical Care Management Following Lung Transplantation

Postoperative critical care management for lung transplant recipients in the intensive care unit (ICU) has expanded in recent years due to its complexity and impact on clinical outcomes. The practical aspects of post-transplant critical care management, especially regarding ventilation and hemodynamic management during the early postoperative period in the ICU, are discussed in this brief review. Monitoring in the ICU provides information on the patient’s clinical status, diagnostic assessment of complications, and future management plans since lung transplantation involves unique pathophysiological conditions and risk factors for complications. After lung transplantation, the grafts should be appropriately ventilated with lung protective strategies to prevent ventilator-induced lung injury, as well as to promote graft function and maintain adequate gas exchange. Hypotension and varying degrees of pulmonary edema are common in the immediate postoperative lung transplantation setting. Ventricular dysfunction in lung transplant recipients should also be considered. Therefore, adequate volume and hemodynamic management with vasoactive agents based on their physiological effects and patient response are critical in the early postoperative lung transplantation period. Integrated management provided by a professional multidisciplinary team is essential for the critical care management of lung transplant recipients in the ICU.