Prognostic significance of early pyrexia in acute intracerebral haemorrhage: The INTERACT2 study

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.

Early fever in patients with primary intracerebral hemorrhage is associated with worse long-term functional outcomes: a prospective study

BACKGROUND

Primary intracerebral hemorrhage (ICH) accounts for 85% of ICH cases and is associated with high morbidity and mortality rates. Fever can cause secondary injury after ICH; however, relevant studies have reported inconsistent results regarding the effects of fever on functional outcomes after ICH. This study examined the effects of early fever on the prognosis of ICH, particularly on long-term functional outcomes.

METHODS

This prospective study recruited patients with primary ICH at a tertiary medical center between 2019 and 2021. Early fever was defined as a tympanic body temperature of ≥ 38 °C upon admission. Barthel Index (BI) and modified Rankin scale (mRS) were examined at 1 year after ICH. A BI of ≤ 60 or mRS of ≥ 4 was considered as indicating severe disability.

RESULTS

We included 100 patients, and early fever was significantly associated with less functional independence at 1 year post-ICH, as determined using the mRS (p = 0.048; odds ratio [OR] = 0.23), and with severe functional dependency at 1 year post-ICH, as determined using the BI (p = 0.043; OR = 3) and mRS (p = 0.045; OR = 3). In addition, patients with early fever had a longer length of hospital stay (p = 0.002; 95% confidence interval = 21.80-95.91).

CONCLUSIONS

Fever is common among patients with primary ICH. Our data indicate a significant association between early fever and worse functional outcomes in ICH survivors at 1 year after ICH. Additionally, patients with early fever had a significantly longer length of hospital stay after ICH.

INTEnsive care bundle with blood pressure reduction in acute cerebral hemorrhage trial (INTERACT3): study protocol for a pragmatic stepped-wedge cluster-randomized controlled trial

BACKGROUND

Early intensive blood pressure (BP) lowering remains the most promising treatment for acute intracerebral hemorrhage (ICH), despite discordant results between clinical trials and potential variation in the treatment effects by approach to control BP. As the third in a series of clinical trials on this topic, the INTEnsive care bundle with blood pressure Reduction in Acute Cerebral hemorrhage Trial (INTERACT3) aims to determine the effectiveness of a goal-directed care bundle protocol of early physiological control (intensive BP lowering, glycemic control, and pyrexia treatment) and reversal of anticoagulation, in acute ICH.

METHODS

INTERACT3 is a pragmatic, international, multicenter, stepped-wedge (4 phases/3 steps), cluster-randomized controlled trial to determine the effectiveness of a multifaceted care package in adult (age ≥ 18 years) patients (target 8360) with acute ICH (< 6 h of onset) recruited from 110 hospitals (average of 19 consecutive patients per phase) in low- and middle-income countries. After a control phase, each hospital implements the intervention (intensive BP lowering, target systolic < 140 mmHg; glucose control, target 6.1-7.8 mmol/L and 7.8-10.0 mmol/L in those without and with diabetes mellitus, respectively; anti-pyrexia treatment to target body temperature ≤ 37.5 °C; and reversal of anticoagulation, target international normalized ratio < 1.5 within 1 h). Information will be obtained on demographic and baseline clinical characteristics, in-hospital management, and 7-day outcomes. Central trained blinded assessors will conduct telephone interviews to assess physical function and health-related quality of life at 6 months. The primary outcome is the modified Rankin scale (mRS) at 6 months analyzed using ordinal logistic regression. The sample size of 8360 subjects provides 90% power (α = 0.05) to detect a 5.6% absolute improvement (shift) in the primary outcome of the intervention versus control standard care, with various assumptions.

DISCUSSION

As the largest clinical trial in acute ICH, INTERACT3 is on schedule to provide an assessment of the effectiveness of a widely applicable goal-directed care bundle for a serious condition in which a clearly proven treatment has yet to be established.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03209258. Registered on 1 July 2017. Chinese Trial Registry ChiCTR-IOC-17011787. Registered on 28 June 2017.

Prognostic Value of Circadian Brain Temperature Rhythm in Basal Ganglia Hemorrhage After Surgery

Introduction

Intracerebral hemorrhage (ICH) is associated with high mortality and morbidity rates. However, both the rhythmic variation and prognostic value of brain temperature after ICH remain unknown. In this study, we investigated brain temperature rhythm and its prognostic value for post-operative mortality and long-term functional outcomes in patients with ICH.

Methods

Post-operative diurnal brain temperature patterns at the basal ganglion are described. Following surgery for ICH, 78 patients were enrolled, and intracranial pressure and brain temperature were monitored using a fiber optic device. Brain temperature mesor, amplitude, and acrophase were estimated from the recorded temperature measurements, using cosinor analysis, and the association between these patterns and clinical parameters, mortality, and functional outcomes at the 12-month follow-up were examined.

Results

According to cosinor analysis, brain temperature in 55.1% of patients showed a circadian rhythm within 72 h post-surgery. The rhythm-adjusted mesor of brain temperature (± standard deviation) was 37.6 (± 0.7) °C, with a diminished mean amplitude. A temperature acrophase shift was also observed. Multivariate logistic regression analysis revealed that initial age and circadian rhythm of brain temperature appeared to be predictive and prognostic of functional outcomes. Further, patients with higher brain temperature mesor were more likely to survive than those with a lower mesor.

Conclusion

For patients with ICH, brain temperature rhythm analysis is an improved prognostic tool for mortality and functional outcome predictions.