Vasoactive pharmacologic therapy in cardiogenic shock: a critical review

Background

Cardiogenic shock (CS) is an acute complex condition leading to morbidity and mortality. Vasoactive medications, such as vasopressors and inotropes are considered the cornerstone of pharmacological treatment of CS to improve end-organ perfusion by increasing cardiac output (CO) and blood pressure (BP), thus preventing multiorgan failure.

Objective

A critical review was conducted to analyze the currently available randomized studies of vasoactive agents in CS to determine the indications of each agent and to critically appraise the methodological quality of the studies.

Methods

PubMed database search was conducted to identify randomized controlled trials (RCTs) on vasoactive therapy in CS. After study selection, the internal validity of the selected studies was critically appraised using the three-item Jadad scale.

Results

Nine studies randomized 2388 patients with a mean age ranged between 62 and 69 years, were identified. Seven of studies investigated CS in the setting of acute myocardial infarction (AMI). The studies evaluated the comparisons of norepinephrine (NE) vs. dopamine, epinephrine vs. NE, levosimendan vs. dobutamine, enoximone or placebo, and nitric oxide synthase inhibitors (NOSi) vs. placebo. The mean Jadad score of the nine studies was 3.33, with only three studies of a score of 5.

Conclusions

The evidence from the studies of vasoactive agents in CS carries uncertainties. The methodological quality between the studies is variable due to the inherent difficulties to conduct a study in CS. Vasopressors and inotropes continue to have a fundamental role given the lack of pharmacological alternatives.

Vasopressor-Sparing Strategies in Patients with Shock: A Scoping-Review and an Evidence-Based Strategy Proposition

Despite the abundant literature on vasopressor therapy, few studies have focused on vasopressor-sparing strategies in patients with shock. We performed a scoping-review of the published studies evaluating vasopressor-sparing strategies by analyzing the results from randomized controlled trials conducted in patients with shock, with a focus on vasopressor doses and/or duration reduction. We analyzed 143 studies, mainly performed in septic shock. Our analysis demonstrated that several pharmacological and non-pharmacological strategies are associated with a decrease in the duration of vasopressor therapy. These strategies are as follows: implementing a weaning strategy, vasopressin use, systemic glucocorticoid administration, beta-blockers, and normothermia. On the contrary, early goal directed therapies, including fluid therapy, oral vasopressors, vitamin C, and renal replacement therapy, are not associated with an increase in vasopressor-free days. Based on these results, we proposed an evidence-based vasopressor management strategy.

Associations of Vasopressor Requirements With Echocardiographic Parameters After Out-of-Hospital Cardiac Arrest

BACKGROUND

Post-arrest hypotension is common after out of hospital cardiac arrest (OHCA) and many patients resuscitated after OHCA will require vasopressors. We sought to determine the associations between echocardiographic parameters and vasopressor requirements in OHCA patients.

METHODS

We retrospectively analyzed adult patients with OHCA treated with targeted temperature management between December 2005 and September 2016 who underwent a transthoracic echocardiogram (TTE). Categorical variables were compared using 2-tailed Fisher's exact and Pearson's correlation coefficients and variance (r²) values were used to assess relationships between continuous variables.

RESULTS

Among 217 included patients, the mean age was 62 ± 12 years, including 74% males. The arrest was witnessed in 90%, the initial rhythm was shockable in 88%, and 58% received bystander CPR. At the time of TTE, 41% of patients were receiving vasopressors; this group of patients was older, had greater severity of illness, higher inpatient mortality and left ventricular ejection fraction (LVEF) was modestly lower (36.8 ± 17.1% vs. 41.4 ± 16.4%, P = 0.04). Stroke volume, cardiac power output and left ventricular stroke work index correlated with number of vasopressors (Pearson r -0.24 to -0.34, all P < 0.002), but the correlation with LVEF was weak (Pearson r -0.13, P = 0.06).

CONCLUSIONS

In patients after OHCA, left ventricular systolic dysfunction was associated with the need for vasopressors, and Doppler TTE hemodynamic parameters had higher correlation coefficients compared with vasopressor requirements than LVEF. This emphasizes the complex nature of shock after OHCA, including pathophysiologic processes not captured by TTE assessment alone.

[Risk Factors for Patients Using Intraoperative Vasopressor Infusions During Carotid Body Tumor Excision]

Objective To investigate the risk factors for patients using intraoperative vasopressor infusions during carotid body tumor(CBT)excision.Patients' mean arterial pressure(MAP)and heart rate(HR)fluctuations as well as their requirements for vasoactive agents during surgery were assessed. Methods The patients receiving CBT excision in Peking Union Medical College Hospital from May 1,2013 to July 31,2017 were included for a retrospective cohort study.The potential factors of intraoperative requirement for vasopressor infusions were investigated using univariate analysis and Logistic multivariate analysis.Furthermore,the relationships of Shamblin types of CBT with intraoperative MAP/HR fluctuations and requirements for vasoactive agents were analyzed. Results A total of 108 patients with 116 CBTs were included.Univariate analysis revealed that maximum tumor diameter >4 cm,intraoperative internal carotid artery injury,internal carotid artery reconstruction,malignant pathology,advanced Shamblin types(type Ⅱ and Ⅲ),estimated blood loss ≥400 ml,and operation duration >4 hours were associated with intraoperative requirements for vasopressor infusions.Logistic analysis showed that Shamblin type Ⅲ(OR=2.286,95% CI=1.324-14.926,P=0.016)and operation duration >4 hours(OR=3.874,95% CI=1.020-14.623,P=0.046)were risk factors for intraoperative requirements for vasopressor infusions during CBT surgery.In addition,Shamblin type Ⅲ was associated with intraoperative abnormal HR elevation and requirements for vasopressors.Conclusions Shamblin type Ⅲ and operation duration>4 hours are risk factors for intraoperative requirements of patients for using vasopressor infusions during CBT surgery.Shamblin type Ⅲ is associated with intraoperative abnormal HR elevation and requirements for vasopressors.

The Surviving Sepsis Campaign: Fluid Resuscitation and Vasopressor Therapy Research Priorities in Adult Patients

OBJECTIVE

Expand upon the priorities of fluid resuscitation and vasopressor therapy research priorities identified by a group of experts assigned by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine.

DATA SOURCES

Original article, literature search.

STUDY SELECTION

Several members of the original task force with expertise specific to the area of fluid resuscitation and vasopressor therapy.

DATA EXTRACTION

None.

DATA SYNTHESIS

None.

CONCLUSION

In the second of a series of manuscripts subsequent to the original article, members with expertise in the subjects expound upon the three identified priorities related to fluid resuscitation and vasopressor therapies. This analysis summarizes what is known and what were identified as ongoing and future research.

Overcoming challenges to enteral nutrition delivery in critical care

PURPOSE OF REVIEW

Existing data and all ICU nutrition guidelines emphasize enteral nutrition (EN) represents a primary therapy leading to both nutritional and non-nutritional benefits. Unfortunately, iatrogenic malnutrition and underfeeding is virtually ubiquitous in ICUs worldwide for prolonged periods post-ICU admission. Overcoming essential challenges to EN delivery requires addressing a range of real, and frequently propagated myths regarding EN delivery.

RECENT FINDINGS

Key recent data addresses perceived challenges to EN including: Adequately resuscitated patients on vasopressors can and likely should receive trophic early EN and this was recently associated with reduced mortality; Patients paralyzed with neuromuscular blocking agents can and should receive early EN as this was recently associated with reduced mortality/hospital length of stay; Proned patients can safely receive EN; All ICU nutrition delivery, including EN, should be objectively guided by indirect calorimetry (IC) measures. This is now possible with the new availability of a next-generation IC device.

SUMMARY

It is the essential implementation of this new evidence occurs to overcome real and perceived EN challenges. This data should lead to increased standardization/protocolization of ICU nutrition therapy to ensure personalized nutrition care delivering the right nutrition dose, in the right patient, at the right time to optimize clinical outcome.

Cerebrovascular and neurological perspectives on adrenoceptor and calcium channel modulating pharmacotherapies

Adrenoceptor and calcium channel modulating medications are widely used in clinical practice for acute neurological and systemic conditions. It is generally assumed that the cerebrovascular effects of these drugs mirror that of their systemic effects - and this is reflected in how these medications are currently used in clinical practice. However, recent research suggests that there are distinct cerebrovascular-specific effects of these medications that are related to the unique characteristics of the cerebrovascular anatomy including the regional heterogeneity in density and distribution of adrenoceptor subtypes and calcium channels along the cerebrovasculature. In this review, we critically evaluate existing basic science and clinical research to discuss known and putative interactions between adrenoceptor and calcium channel modulating pharmacotherapies, the neurovascular unit, and cerebrovascular anatomy. In doing so, we provide a rationale for selecting vasoactive medications based on lesion location and lay a foundation for future investigations that will define neuroprotective paradigms of adrenoceptor and calcium channel modulating therapies to improve neurological outcomes in acute neurological and systemic disorders.

Conservative oxygen supplementation versus usual oxygen supplementation among septic medical intensive care units patients: A before-after investigation

Patients admitted in the intensive care unit (ICU) are always managed with excessive high fraction of inspired oxygen and have hyperoxia for a significant period of time, which has potential harms. The guidelines for the management of patients in ICUs do not provide the target values for partial pressure of oxygen or arterial oxyhemoglobin saturations. The study was a before-after investigation comparing two time periods in which different oxygenation strategies were applied. Data of oxygen control, outcome measures, and mortality of a total of 273 patients (>18 years) admitted at least for 2 days in ICUs and received treatment for the sepsis were retrospectively collected and analyzed. Patients were received usual oxygen supplementation (targeted partial pressure of oxygen: 150 mmHg; a high fraction of inspired oxygen: 0.4; UOS cohort; n = 142) or conservative oxygen supplementation (targeted partial pressure of oxygen: 70-100 mmHg; a high fraction of inspired oxygen as low as possible; COS cohort; n = 131). Mechanical ventilation-free hours were significantly higher for patients of COS cohort than those of UOS cohort (77.99 ± 21.26 h/patient vs 70.01 ± 23.57 h/patient, p = 0.016). ICUs length of stays of patients of COS cohort was fewer than those of UOS cohort (7.05 ± 2.13 days/patient vs 7.69 ± 2.43 days/patients, p = 0.016). The probability of survival of patients was higher among patients of COS cohort than those of UOS cohort (p = 0.049). A higher number of patients from UOS cohort needed vasopressors than those from COS cohort (55 vs 35, p = 0.039). Conservative oxygen supplementation to maintain partial pressure of oxygen was improved outcome measures and decreases mortality as compared to that of usual oxygen supplementation.Level of Evidence: III.Technical Efficacy Stage: 4.

Recognition and management of neonatal hemodynamic compromise

Hemodynamic compromise of the neonate can occur in various clinical situations, including but not limited to maladaptation during the early transitional period, sepsis, congenital heart anomalies, hemodynamically significant patent ductus arteriosus, persistent pulmonary hypertension of the newborn, systemic inflammatory diseases such as necrotizing enterocolitis, and dehydration. Despite the handful of advances in neonatal care through ground-breaking clinical trials, the management of neonatal shock is often dependent on the bedside clinician's experience and training without the aid of high-level evidence. However, the recognition for the importance of comprehensive and serial hemodynamic assessment is growing. There is now a wealth of literature investigating the use of functional echocardiography, near-infrared spectroscopy, and noninvasive impedance-based cardiometry to complement common bedside hemodynamic measures such as blood pressure and heart rate measurement. In this review article, the pathophysiology of neonatal hemodynamic compromise is outlined, and concomitant best-evidence management for hemodynamic compromise in the neonate is proposed.

Recognition and management of neonatal hemodynamic compromise

Hemodynamic compromise of the neonate can occur in various clinical situations, including but not limited to maladaptation during the early transitional period, sepsis, congenital heart anomalies, hemodynamically significant patent ductus arteriosus, persistent pulmonary hypertension of the newborn, systemic inflammatory diseases such as necrotizing enterocolitis, and dehydration. Despite the handful of advances in neonatal care through ground-breaking clinical trials, the management of neonatal shock is often dependent on the bedside clinician's experience and training without the aid of high-level evidence. However, the recognition for the importance of comprehensive and serial hemodynamic assessment is growing. There is now a wealth of literature investigating the use of functional echocardiography, near-infrared spectroscopy, and noninvasive impedance-based cardiometry to complement common bedside hemodynamic measures such as blood pressure and heart rate measurement. In this review article, the pathophysiology of neonatal hemodynamic compromise is outlined, and concomitant best-evidence management for hemodynamic compromise in the neonate is proposed.

Automated closed-loop versus manually controlled norepinephrine infusion in patients undergoing intermediate- to high-risk abdominal surgery: a randomised controlled trial

BACKGROUND

Hypotension occurs frequently during surgery and may be associated with adverse complications. Vasopressor titration is frequently used to correct hypotension, but requires considerable time and attention, potentially reducing the time available for other clinical duties. To overcome this issue, we have developed a closed-loop vasopressor (CLV) controller to help correct hypotension more efficiently. The aim of this randomised controlled study was to evaluate whether the CLV controller was superior to traditional vasopressor management at minimising hypotension in patients undergoing abdominal surgery.

METHODS

Thirty patients scheduled for elective intermediate-to high-risk abdominal surgery were randomised into two groups. In the CLV group, hypotension was corrected automatically via the CLV controller system, which adjusted the rate of a norepinephrine infusion according to MAP values recorded using an advanced haemodynamic device. In the control group, management of hypotension consisted of standard, manual adjustment of the norepinephrine infusion. The primary outcome was the percentage of time that a patient was hypotensive, defined as MAP <90% of their baseline value, during surgery.

RESULTS

The percentage of time patients were hypotensive during surgery was 10 times less in the CVL group than in the control group (1.6 [0.9-2.3]% vs 15.4 [9.9-24.3]%; difference: 13 [95% confidence interval: 9-19]; P<0.0001). The CVL group also spent much less time with MAP <65 mm Hg (0.2 [0.0-0.4]% vs 4.5 [1.1-7.9]%; P<0.0001).

CONCLUSIONS

In patients undergoing intermediate- to high-risk surgery under general anaesthesia, computer-assisted adjustment of norepinephrine infusion significantly decreases the incidence of hypotension compared with manual control.

CLINICAL TRIAL REGISTRATION

NCT04089644.

Effect of Phenylephrine Push Before Continuous Infusion Norepinephrine in Patients With Septic Shock

BACKGROUND

IV pushes of phenylephrine may be used for patients with septic shock with the intent of rapidly achieving mean arterial pressure (MAP) goals. However, the clinical effectiveness and safety of this approach are unclear.

RESEARCH QUESTION

In patients with septic shock, is administration of a phenylephrine push before norepinephrine initiation associated with a higher incidence of hemodynamic stability?

METHODS

This retrospective, multicenter cohort study included adult patients with septic shock initiated on norepinephrine. Propensity scores for initial phenylephrine push receipt were generated, and patients receiving an initial phenylephrine push were propensity score-matched 1:2 to those not receiving an initial phenylephrine push. The primary outcome was achievement of hemodynamic stability (defined as maintaining MAP of ≥ 65 mm Hg for at least 6 h without an increase in continuous infusion vasoactive agent dosage) within 3 and 12 h of norepinephrine initiation.

RESULTS

Of 1,317 included patients, 181 received an initial phenylephrine push; 141 phenylephrine push patients were matched to 282 patients not receiving a phenylephrine push. More patients who received a phenylephrine push achieved hemodynamic stability at hour 3 than those who did not receive a phenylephrine push (28.4% vs 18.8%; risk difference, 10%; 95% CI, 0.9%-18%). Phenylephrine push receipt was associated independently with hemodynamic stability within 3 h (adjusted OR, 1.8; 95% CI, 1.09-2.97), but not at 12 h (adjusted OR, 1.42; 95% CI, 0.93-2.16). Phenylephrine push receipt was associated independently with higher ICU mortality (adjusted OR, 1.88; 95% CI, 1.1-3.21).

INTERPRETATION

Phenylephrine pushes were associated with a higher incidence of early, but not sustained, hemodynamic stability and were associated independently with higher ICU mortality. Caution is warranted when clinicians are considering the use of phenylephrine pushes in patients with septic shock.

Impact of Hyperoncotic Albumin on Duration of Vasopressor Support in Septic Shock: A Propensity Score-Matched Analysis

BACKGROUND

While albumin has not been shown to reduce mortality in sepsis and septic shock, a tertiary analysis of a large trial suggested that it may reduce the duration of vasopressor use in septic shock.

OBJECTIVE

We sought to test if 25% albumin administration was associated with reduced cumulative vasopressor use in septic shock in a real-world setting.

METHODS

This was a retrospective, propensity score-matched cohort study of septic shock in which patients receiving albumin were compared with a matched cohort of those not receiving albumin. The primary outcome was days alive and free of vasopressors.

RESULTS

The matched cohort included 335 patients who received albumin and 335 who did not. The days alive and free of vasopressors were similar between the albumin and no albumin groups: 17.4 (0-24.8) versus 19.4 (0-25.3); P = 0.160. Similarly, in-hospital mortality was no different between groups (46.9% vs 44.8%; P = 0.587). Receipt of albumin was associated with fewer ventilator-free and intensive care unit (ICU)-free days: 0 (0-19) versus 11 (0-23), P = 0.007, and 0 (0-18) versus 10.6 (0-22.1), P = 0.002, respectively.

CONCLUSION AND RELEVANCE

Albumin use in septic shock was not associated with additional days alive and free of vasopressors or in-hospital mortality. The finding of fewer ventilator- and ICU-free days may reflect selection of patients who were critically ill for longer periods of time before or after albumin administration. Additional study is needed to clarify the impact that timing may have on the effectiveness of albumin in septic shock.

Vasopressor-Refractory Shock From Clozapine Overdose Treated With Synthetic Angiotensin II Infusion

Background:

Clozapine is an atypical antipsychotic with potent alpha-adrenergic blocking properties when administered at high dosages, resulting in vasodilatory shock in overdose settings.

Case Summary:

A 39-year-old man presented with profound catecholamine- and vasopressin-refractory vasodilatory shock following massive clozapine ingestion. Angiotensin II was initiated when the patient was requiring 2.2 µg/kg/min norepinephrine equivalents of vasopressor support, resulting in a prompt increase in the perfusion pressure. All vasopressors were liberated within 18 hours of angiotensin II initiation, and the patient was discharged with no deficits.

Conclusions:

Synthetic angiotensin II may represent a therapeutic option for refractory hypotension resulting from high dosages of clozapine or other potent alpha-adrenergic blocking medications.

High-Dose Vasopressor Therapy for Pediatric Septic Shock: When Is Too Much?

It is unknown if the requirement for high dose of vasopressor (HDV) represents a poor outcome in pediatric septic shock. This is a retrospective observational analysis with data obtained from a single center. We evaluated the association between the use of HDV and survival in these patients. A total of 62 children (38 survivors and 24 nonsurvivors) were assessed. The dose of vasopressor (hazard ratio 2.06) and oliguria (hazard ratio 3.17) was independently associated with mortality. The peak of vasopressor was the best prognostic predictor. A cutoff of 1.3 μg/kg/min was associated with mortality with a sensitivity of 75% and specificity of 89%. Vasopressor administration higher than 1.3 μg/kg/min was associated with increased mortality in children with septic shock.

Treatment for Severe Coronavirus Disease 2019 With the Seraph-100 Microbind Affinity Blood Filter

To determine whether Seraph-100 (Exthera Medical Corporation, Martinez, CA) treatment provides clinical benefit for severe coronavirus disease 2019 cases that require mechanical ventilation and vasopressor support.

Data Sources

The first two patients in the United States treated with the novel Seraph-100 device. These cases were reviewed by the Food and Drug Administration prior to granting an emergency use authorization for treatment of coronavirus disease 2019.

Study Selection

Case series.

Data Extraction

Vasopressor dose, mean arterial pressure, temperature, interleukin-6, C-reactive protein, and other biomarker levels were documented both before and after Seraph-100 treatments.

Data Synthesis

Vasopressor dose, temperature, interleukin-6, and C-reactive protein levels declined after Seraph-100 treatments. Severe acute respiratory syndrome coronavirus 2 viremia was confirmed in the one patient tested and cleared by the completion of treatments.

Conclusions

Seraph-100 use may improve hemodynamic stability in coronavirus disease 2019 cases requiring mechanical ventilation and vasopressor support. These findings warrant future study of a larger cohort with the addition of mortality and total hospital day outcomes.

Minimising haemodynamic lability during changeover of syringes infusing norepinephrine in adult critical care patients: a multicentre randomised controlled trial

BACKGROUND

Arterial pressure lability is common during the process of replacing syringes used for norepinephrine infusions in critically ill patients. It is unclear if there is an optimal approach to minimise arterial pressure instability during this procedures. We investigated whether 'double pumping' changeover (DPC) or automated changeover (AC) reduced blood pressure lability in critically ill adults compared with quick syringe changeover (QC).

METHODS

Patients requiring a norepinephrine infusion syringe change were randomised in a non-blinded trial undertaken in six ICUs. Randomisation was minimised by norepinephrine flow rate at inclusion and centre. The primary outcome was the frequency of increased/decreased mean arterial pressure (defined by </>15 mm Hg from baseline measurements) within 15 min of switching the syringe compared with QC.

RESULTS

Patients (mean age: 64 (range:18-88)) yr were randomly assigned to QC (n=95), DPC (n=95), or AC (n=96). Increased MAP was the commonest consequence of syringe changeovers. MAP variability was most frequent after DPC (89/224 changeovers; 39.7%) compared with 57/223 (25.6%) changeovers after quick syringe switch and 46/181 (25.4%) in patients randomised to receive automated changeover (P=0.001). Fewer events occurred with QC compared with DPC (P=0.002). Sensitivity analysis based on mixed models showed that performing several changeovers on a single patient had no impact. Both type of changeover and norepinephrine dose before syringe changeover were independently associated with MAP variations >15 mm Hg.

CONCLUSIONS

Quick changeover of norepinephrine syringes was associated with less blood pressure lability compared with DPC. The prevalence of MAP variations was the same between AC and QC.

CLINICAL TRIAL REGISTRATION

NCT02304939.

Safety and Tolerance of Enteral Nutrition in the Medical and Surgical Intensive Care Unit Patient Receiving Vasopressors

BACKGROUND

Multiple societal guidelines recommend enteral nutrition (EN) be initiated within 24 to 48 hours of admission to the intensive care unit (ICU) once a patient is hemodynamically stable. Gastrointestinal intolerance and occurrence of bowel ischemia have been a concern for patients receiving vasopressors while concurrently receiving luminal nutrients. The study objective was to determine whether patients receiving vasopressors while concomitantly receiving enteral nutrients had more incidences of bowel ischemia and intolerance than those receiving EN without vasopressor agents.

METHODS

This retrospective study included 319 medical and surgical ICU patients from a level 1 trauma center. The patients were either receiving vasopressors simultaneously with EN (n = 178) or EN alone (n = 141). Data regarding gastric residual volume (GRV), new abdominal pain, emesis, and bowel ischemia were collected.

RESULTS

There were more patients who had elevated GRV in the group that received vasopressors than patients who did not (20% vs 7%; P-value < .01). There were no differences between rates of bowel ischemia, emesis, or new abdominal pain between the 2 groups.

CONCLUSION

Based on our findings, EN is generally well tolerated and safe for those patients simultaneously receiving vasopressors.

Vasopressors and Inotropes in Acute Myocardial Infarction Related Cardiogenic Shock: A Systematic Review and Meta-Analysis

Vasopressors and inotropes are routinely used in acute myocardial infarction (AMI) related cardiogenic shock (CS) to improve hemodynamics. We aimed to investigate the effect of routinely used vasopressor and inotropes on mortality in AMI related CS. A systematic search of MEDLINE, EMBASE and CENTRAL was performed up to 20 February 2019. Randomized and observational studies reporting mortality of AMI related CS patients were included. At least one group should have received the vasopressor/inotrope compared with a control group not exposed to the vasopressor/inotrope. Exclusion criteria were case reports, correspondence and studies including only post-cardiac surgery patients. In total, 19 studies (6 RCTs) were included, comprising 2478 CS patients. The overall quality of evidence was graded low. Treatment with adrenaline, noradrenaline, vasopressin, milrinone, levosimendan, dobutamine or dopamine was not associated with a difference in mortality between therapy and control group. We found a trend toward better outcome with levosimendan, compared with control (RR 0.69, 95% CI 0.47-1.00). In conclusion, we found insufficient evidence that routinely used vasopressors and inotropes are associated with reduced mortality in patients with AMI related CS. Considering the limited evidence, this study emphasizes the need for randomized trials with appropriate endpoints and methodology.

Haemodynamics and vasopressor support during prolonged targeted temperature management for 48 hours after out-of-hospital cardiac arrest: a post hoc substudy of a randomised clinical trial

BACKGROUND

Comatose patients admitted after out-of-hospital cardiac arrest frequently experience haemodynamic instability and anoxic brain injury. Targeted temperature management is used for neuroprotection; however, targeted temperature management also affects patients' haemodynamic status. This study assessed the haemodynamic status of out-of-hospital cardiac arrest survivors during prolonged (48 hours) targeted temperature management at 33°C.

METHODS

Analysis of haemodynamic and vasopressor data from 311 patients included in a randomised, clinical trial conducted in 10 European hospitals (the TTH48 trial). Patients were randomly allocated to targeted temperature management at 33°C for 24 (TTM24) or 48 (TTM48) hours. Vasopressor and haemodynamic data were reported hourly for 72 hours after admission. Vasopressor load was calculated as norepinephrine (µg/kg/min) plus dopamine(µg/kg/min/100) plus epinephrine (µg/kg/min).

RESULTS

After 24 hours, mean arterial pressure (mean±SD) was 74±9 versus 75±9 mmHg (P=0.19), heart rate was 57±16 and 55±14 beats/min (P=0.18), vasopressor load was 0.06 (0.03-0.15) versus 0.08 (0.03-0.15) µg/kg/min (P=0.22) for the TTM24 and TTM48 groups, respectively. From 24 to 48 hours, there was no difference in mean arterial pressure (Pgroup=0.32) or lactate (Pgroup=0.20), while heart rate was significantly lower (average difference 5 (95% confidence interval 2-8) beats/min, Pgroup<0.0001) and vasopressor load was significantly higher in the TTM48 group (Pgroup=0.005). In a univariate Cox regression model, high vasopressor load was associated with mortality in univariate analysis (hazard ratio 1.59 (1.05-2.42) P=0.03), but not in multivariate analysis (hazard ratio 0.77 (0.46-1.29) P=0.33).

CONCLUSIONS

In this study, prolonged targeted temperature management at 33°C for 48 hours was associated with higher vasopressor requirement but no sign of any detrimental haemodynamic effects.