PAIS 2 (Paracetamol [Acetaminophen] in Stroke 2): Results of a Randomized, Double-Blind Placebo-Controlled Clinical Trial

Temperature Control in Acute Brain Injury: An Update

Temperature control in severe acute brain injury (SABI) is a key component of acute management. This manuscript delves into the complex role of temperature management in SABI, encompassing conditions like traumatic brain injury (TBI), acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), aneurysmal subarachnoid hemorrhage (aSAH), and hypoxemic/ischemic brain injury following cardiac arrest. Fever is a common complication in SABI and is linked to worse neurological outcomes due to increased inflammatory responses and intracranial pressure (ICP). Temperature management, particularly hypothermic temperature control (HTC), appears to mitigate these adverse effects primarily by reducing cerebral metabolic demand and dampening inflammatory pathways. However, the effectiveness of HTC varies across different SABI conditions. In the context of post-cardiac arrest, the impact of HTC on neurological outcomes has shown inconsistent results. In cases of TBI, HTC seems promising for reducing ICP, but its influence on long-term outcomes remains uncertain. For AIS, clinical trials have yet to conclusively demonstrate the benefits of HTC, despite encouraging preclinical evidence. This variability in efficacy is also observed in ICH, aSAH, bacterial meningitis, and status epilepticus. In pediatric and neonatal populations, while HTC shows significant benefits in hypoxic-ischemic encephalopathy, its effectiveness in other brain injuries is mixed. Although the theoretical basis for employing temperature control, especially HTC, is strong, the clinical outcomes differ among various SABI subtypes. The current consensus indicates that fever prevention is beneficial across the board, but the application and effectiveness of HTC are more nuanced, underscoring the need for further research to establish optimal temperature management strategies. Here we provide an overview of the clinical evidence surrounding the use of temperature control in various types of SABI.

Systematic Literature Review of the Association of Fever and Elevated Temperature with Outcomes in Critically Ill Adult Patients

Although most commonly associated with infection, elevated temperature and fever also occur in a variety of critically ill populations. Prior studies have suggested that fever and elevated temperature may be detrimental to critically ill patients and can lead to poor outcomes, but the evidence surrounding the association of fever with outcomes is rapidly evolving. To broadly assess potential associations of elevated temperature and fever with outcomes in critically ill adult patients, we performed a systematic literature review focusing on traumatic brain injury, stroke (ischemic and hemorrhagic), cardiac arrest, sepsis, and general intensive care unit (ICU) patients. Searches were conducted in Embase® and PubMed® from 2016 to 2021, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, including dual-screening of abstracts, full texts, and extracted data. In total, 60 studies assessing traumatic brain injury and stroke (24), cardiac arrest (8), sepsis (22), and general ICU (6) patients were included. Mortality, functional, or neurological status and length of stay were the most frequently reported outcomes. Elevated temperature and fever were associated with poor clinical outcomes in patients with traumatic brain injury, stroke, and cardiac arrest but not in patients with sepsis. Although a causal relationship between elevated temperature and poor outcomes cannot be definitively established, the association observed in this systematic literature review supports the concept that management of elevated temperature may factor in avoidance of detrimental outcomes in multiple critically ill populations. The analysis also highlights gaps in our understanding of fever and elevated temperature in critically ill adult patients.

Intravenous Versus Oral Acetaminophen Use in Febrile Neurocritical Care Patients

The use of intravenous (IV) acetaminophen (APAP) for fever has not been thoroughly studied in neurocritical care (NCC) patients, in whom a temperature of ≥38°C is associated with poor outcomes and treatment to normothermia is common practice. This retrospective study evaluated NCC patients admitted between May 1, 2012, and April 30, 2013, and received at least one dose of IV or oral (PO) APAP for a body temperature of ≥38°C. The primary aim of this study was to compare the reduction in body temperature (RIT) between IV and PO APAP, calculated as the change in temperature before and 0.5, 1, 2, 3, and 6 hours after administration. Descriptive statistics were used to assess use characteristics, and Kruskal-Wallis and Mann-Whitney U tests were used for between-group differences. There were 142 NCC patients who received a total of 405 IV APAP and 253 PO APAP doses. Seventy percent of all APAP doses resulted in a temperature of <38°C within 6 hours. The median oral body temperature before APAP was 38.8°C and 38.6°C for IV and PO APAP, respectively (p < 0.01). The median RIT at 0.5 (IV 0.25°C vs. PO 0.2°C), 1 (IV 0.4°C vs. PO 0.2°C), 2 (IV 0.7°C vs. PO 0.5°C), 3 (IV 0.9°C vs. PO 0.6°C), and 6 (IV 1°C vs. PO 0.8°C) hours was significantly greater for IV APAP than for PO APAP at all time points (p < 0.05). Patients with an acute ischemic stroke and patients with an intracerebral hemorrhage had a statistically significantly greater RIT with IV APAP therapy. IV APAP administered to febrile NCC patients was associated with a significantly greater RIT than PO, but 70% of all APAP doses resulted in a body temperature of <38°C within 6 hours. Further prospective studies are needed to determine if IV APAP improves clinical outcomes.

Sex Disparities in Enrollment in Recent Randomized Clinical Trials of Acute Stroke: A Meta-analysis

Importance

The underenrollment of women in randomized clinical trials represents a threat to the validity of the evidence supporting clinical guidelines and potential disparities in access to novel treatments.

Objective

To determine whether women were underenrolled in contemporary randomized clinical trials of acute stroke therapies published in 9 major journals after accounting for their representation in underlying stroke populations.

Data Sources

MEDLINE was searched for acute stroke therapeutic trials published between January 1, 2010, and June 11, 2020.

Study Selection

Eligible articles reported the results of a phase 2 or 3 randomized clinical trial that enrolled patients with stroke and/or transient ischemic attack and examined a therapeutic intervention initiated within 1 month of onset.

Data Extraction

Data extraction was performed by 2 independent authors in duplicate. Individual trials were matched to estimates of the proportion of women in underlying stroke populations using the Global Burden of Disease database.

Main Outcomes and Measures

The primary outcome was the enrollment disparity difference (EDD), the absolute difference between the proportion of trial participants who were women and the proportion of strokes in the underlying disease populations that occurred in women. Random-effects meta-analyses of the EDD were performed, and multivariable metaregression was used to explore the associations of trial eligibility criteria with disparity estimates.

Results

The search returned 1529 results, and 115 trials (7.5%) met inclusion criteria. Of 121 105 randomized patients for whom sex was reported, 52 522 (43.4%) were women. The random-effects summary EDD was -0.053 (95% CI, -0.065 to -0.040), indicating that women were underenrolled by 5.3 percentage points. This disparity persisted across virtually all geographic regions, intervention types, and stroke types, apart from subarachnoid hemorrhage (0.117 [95% CI, 0.084 to 0.150]). When subarachnoid hemorrhage trials were excluded, the summary EDD was -0.067 (95% CI, -0.078 to -0.057). In the multivariable metaregression analysis, an upper age limit of 80 years as an eligibility criterion was associated with a 6-percentage point decrease in the enrollment of women.

Conclusions and Relevance

Further research is needed to understand the causes of the underenrollment of women in acute stroke trials. However, to maximize representation, investigators should avoid imposing age limits on enrollment.

Severe Dysphagia Predicts Poststroke Fever

[Figure: see text].

Effects of a 4-Step Standard Operating Procedure for the Treatment of Fever in Patients With Acute Stroke

Background and Purpose: Fever in the acute phase of stroke leads to an unfavorable clinical outcome and increased mortality. However, no specific form of effective fever treatment has been established, so far. We analyzed the effectiveness of our in-house standard operating procedure (SOP) of fever treatment. Methods: This SOP was analyzed for a period of 33 weeks. Patients with cerebral ischemia (ischemic stroke, transient ischemic attack) or cerebral hemorrhage (intracerebral, subarachnoid) and body temperature elevation of ≥ 37.5°C within the first 6 days after admission were eligible for inclusion in the analysis. The results of SOP group, who's data have been collected prospectively were then compared with a historical control group that had been treated conventionally 1 year earlier in the same period. The data of control group have been collected in retrospect. The primary endpoint was the total duration of the fever for the first 6 days after admission to the stroke unit. Results: A total of 130 patients (mean age of 78 ± 12) received 370 antipyretic interventions. Sequential application of paracetamol (n = 245), metamizole (n = 53) and calf compress (n = 15) led to significant reduction in body temperature. In patients who did not respond to these applications, normothermia could be achieved after infusion of the cooled saline solution. Normothermia could be achieved within 120 min in more than 90% of the cases treated by the SOP. The SOP reduced the fever duration in the 6 days significantly, from 12.2 ± 2.7 h [95% confidence interval (CI) for mean] in the control group to 3.9 ± 1.0 h (95% CI) in the SOP group (p < 0.001). The SOP was rated to be reasonable and effective. Conclusion: Our in-house SOP is cost-efficient and effective for fever treatment in stroke patients, that can be implemented by local health care professionals.

Pharmacological management of cerebral ischemia in the elderly

Introduction: For elderly adults in the United States, stroke is the fifth leading cause of death of which ischemic strokes comprise a vast majority. Optimal pharmacological management of elderly ischemic stroke patients involves both reperfusion and supportive care. Recent research into pharmacological management has focused on vascular, immunomodulatory, cytoprotective, and alternative agents, some of which have shown limited success in clinical trials. However, no treatments have been established as a reliable mode for management of cerebral ischemia for elderly adults beyond acute thrombolysis.Areas covered: The authors conducted a literature search for ischemic stroke management in the elderly and a search for human drug studies for managing ischemic stroke on clinicaltrials.gov. Here, they describe recent progress in the pharmacological management of cerebral ischemia in the elderly.Expert opinion: Many drug classes (antihypertensive, cytoprotective and immunomodulatory, and alternative agents) have been explored with limited success in managing ischemic stroke, though some have shown preventative benefits. We generally observed a broad gap in evidence on elderly patients from studies across all drug classes, necessitating further studies to gain an understanding of effective management of ischemic stroke in this large demographic of patients.

[Atypical intracerebral hemorrhage-etiology and acute management]

Acute management as well as establishing the etiology of an intracerebral hemorrhage is still a challenge for clinicians. The location of the intracerebral hemorrhage alone should not be used to determine the cause because atypically located hemorrhages can be caused by long-standing arterial hypertension and typically located hemorrhages can occur due to non-hypertensive causes. Besides discussing the classification of intracerebral hemorrhages, this article focuses on a diagnostic algorithm as well as the presentation of potential (rarer) causes of non-traumatic intracerebral hemorrhages. Furthermore, the acute treatment of intracerebral hemorrhage with respect to recent data on blood pressure management as well as the management of bleeding under oral anticoagulant treatment are described.

Association of survival and hyperthermia after rt-PA for ischemic stroke

BACKGROUND

Hyperthermia in patients with acute ischemic stroke is associated with poor outcome. Although previous studies have shown a negative effect on functional outcome, even in patients treated with intravenous recombinant tissue plasminogen activator (rt-PA), the effect on survival remains unclear.

AIMS OF THE STUDY

The aim of this study was to evaluate the association between the functional and survival prognosis and hyperthermia in patients with acute ischemic stroke treated with rt-PA.

METHODS

We studied 120 patients treated with rt-PA from 2306 consecutive Japanese patients with acute cerebral infarction at Aomori Prefectural Central Hospital between December 2009 and March 2017. We defined hyperthermia as ≥38°C within 72 hours after rt-PA administration. Propensity score matching was used to compare 34 non-hyperthermia and hyperthermia patient pairs.

RESULTS

Final modified Rankin Scale scores were higher in the hyperthermia group than in the non-hyperthermia group. In addition, the Kaplan-Meier model showed that the non-hyperthermia group had significantly better survival rates than the hyperthermia group (hazard ratio, 5.3; 95% confidence intervals, 1.2-24.8).

CONCLUSIONS

Hyperthermia within 3 days after rt-PA is associated with poor functional prognosis and survival outcome in patients with acute cerebral infarction.

Temperature Management With Paracetamol in Acute Stroke Patients: Evidence From Randomized Controlled Trials

Whether or not paracetamol can improve functional outcomes in patients with acute stroke has been examined in several clinical trials. The inconsistent results of these trials have caused great controversy regarding the need for further studies. In the present meta-analysis, we have aimed to address this controversy. The main databases (Medline, Embase, and Cochrane Library) were searched for randomized controlled trials involving the use of paracetamol in acute stroke patients. Pooled relative risks (RRs) or mean differences (MDs) and 95% confidence intervals (CIs) were calculated using a random-effects model. A total of 1,836 patients were pooled from four phase II and two phase III trials. The use of paracetamol resulted in a significant reduction in body temperature after 24 h (MD, −0.21; 95% CI, −0.28 to −0.13; P < 0.001) and mortality rate after 7–14 days (RR, 0.62; 95% CI, 0.41–0.93; P = 0.02) when compared with the placebo group; however, no effect of paracetamol was observed in the modified Rankin Scale score (RR, 1.07; 95% CI, 0.91–1.27; P = 0.40) or Barthel Index score (RR, 0.98; 95% CI, 0.91–1.06; P = 0.63) at 30 or 90 days. No significant differences were observed with respect to serious adverse events between the paracetamol and the placebo groups (P > 0.05). Subgroup analyses were performed to detect the source of the heterogeneity, which showed that ischemic stroke, serious condition at baseline, and late time-to-treatment had adverse impacts on the effect of paracetamol post stroke. In conclusion, temperature management with paracetamol in acute stroke patients is safe. Although paracetamol reduced the mortality rate in the early stage of stroke, it did not appear to affect long-term mortality and functional recovery. It should be noted that this conclusion is based on the results from studies of poor quality. A large clinical trial with a focus on early treatment of patients with acute stroke is warranted.

Targeted temperature management in patients with intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke: consensus recommendations

BACKGROUND

A modified Delphi approach was used to identify a consensus on practical recommendations for the use of non-pharmacological targeted temperature management in patients with intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke with non-infectious fever (assumed neurogenic fever).

METHODS

Nine experts in the management of neurogenic fever participated in the process, involving the completion of online questionnaires, face-to-face discussions, and summary reviews, to consolidate a consensus on targeted temperature management.

RESULTS

The panel's recommendations are based on a balance of existing evidence and practical considerations. With this in mind, they highlight the importance of managing neurogenic fever using a single protocol for targeted temperature management. Targeted temperature management should be initiated if the patient temperature increases above 37.5°C, once an appropriate workup for infection has been undertaken. This helps prevent prophylactic targeted temperature management use and ensures infection is addressed appropriately. When neurogenic fever is detected, targeted temperature management should be initiated rapidly if antipyretic agents fail to control the temperature within 1 h, and should then be maintained for as long as there is potential for secondary brain damage. The recommended target temperature for targeted temperature management is 36.5-37.5°C. The use of advanced targeted temperature management methods that enable continuous, or near continuous, temperature measurement and precise temperature control is recommended.

CONCLUSIONS

Given the limited heterogeneous evidence currently available on targeted temperature management use in patients with neurogenic fever and intracerebral haemorrhage, subarachnoid haemorrhage, or acute ischaemic stroke, a Delphi approach was appropriate to gather an expert consensus. To aid in the development of future investigations, the panel provides recommendations for data gathering.

Fever worsens outcomes in animal models of ischaemic stroke: A systematic review and meta-analysis

Background

Subfebrile temperatures and fever in the first days after stroke are associated with a greater risk of a poor outcome. If this relation is causal, prevention of hyperthermia may improve outcome. Causality can be tested in animal models. We therefore assessed the effects of hyperthermia on outcomes in animal models of ischaemic stroke and explored under which conditions prevention of hyperthermia could be most effective.

Methods

We performed a systematic review and meta-analysis of data from animal experiments testing the effect of spontaneous or induced hyperthermia on outcome after focal cerebral ischaemia. Our primary outcome measure was infarct size. Normalised mean differences were combined using the random effects model and stratified meta-analysis was used to explore the impact of study characteristics.

Results

We included 19 publications, reporting on 49 comparisons involving 603 animals. Overall, hyperthermia increased infarct size by 43.4% (95% confidence interval, 29.8-56.9%) and worsened neurobehavioral outcomes by 48.5% (17.2-79.8%). The increase in infarct size was larger with higher temperatures. Hyperthermia was most harmful if present for more than 2 h and when started at the time of artery occlusion rather than later.

Conclusion

Hyperthermia substantially increased infarct size in animal models of ischaemic stroke, suggesting that the relation between fever and poor outcome observed in patients is at least in part causal. These data provide support to trials testing the effect of the prevention of fever with antipyretic drugs in patients with acute stroke.