Hyperthermia in brain hemorrhage

Clinical experience with bromocriptine for central hyperthermia after brain insult

INTRODUCTION

Bromocriptine is a dopamine receptor agonist used for central hyperthermia with limited data. We describe our single-center experience utilizing bromocriptine for central hyperthermia, including the population treated, most common dosing regimens, adverse events, and discontinuation reasons.

METHODS

A retrospective study was conducted screening patients who were admitted to intensive care units for acute neurological insults and administered bromocriptine for central hyperthermia between April 2016 and September 2022. Baseline characteristics, disease severity markers, and bromocriptine doses were collected. Body temperatures prior to the first dose of bromocriptine, at the time of dose, and after each dose were recorded. Co-administration of additional hyperthermia management therapies was noted.

RESULTS

Thirty patients were included. The most common diagnosis was traumatic brain injury (TBI) (N = 14). The most common reason for discontinuation was resolution of indication (N = 14). Discontinuation due to mild adverse effects occurred in four patients; hepatotoxicity was the most common. There was a paired mean difference of -0.37°C (p = 0.005) between temperatures before and after bromocriptine initiation.

CONCLUSION

Bromocriptine is a potential therapy for the management of central hyperthermia in patients with severe acute neurologic insults who have failed other therapies. Bromocriptine was well tolerated and associated with a low incidence of adverse events.

Presumed pituitary apoplexy in 26 dogs: Clinical findings, treatments, and outcomes

BACKGROUND

Pituitary apoplexy refers to hemorrhage or infarction within the pituitary gland resulting in acute neurological abnormalities. This condition is poorly described in dogs.

OBJECTIVES

To document presenting complaints, examination findings, endocrinopathies, magnetic resonance imaging (MRI), treatments, and outcomes of dogs with pituitary apoplexy.

ANIMALS

Twenty-six client-owned dogs with acute onset of neurological dysfunction.

METHODS

Retrospective case series. Dogs were diagnosed with pituitary apoplexy if MRI or histopathology documented an intrasellar or suprasellar mass with evidence of hemorrhage or infarction in conjunction with acute neurological dysfunction. Clinical information was obtained from medical records and imaging reports.

RESULTS

Common presenting complaints included altered mentation (16/26, 62%) and gastrointestinal dysfunction (14/26, 54%). Gait or posture changes (22/26, 85%), mentation changes (18/26, 69%), cranial neuropathies (17/26, 65%), cervical or head hyperpathia (12/26, 46%), and hyperthermia (8/26, 31%) were the most frequent exam findings. Ten dogs (38%) lacked evidence of an endocrinopathy before presentation. Common MRI findings included T1-weighted hypo- to isointensity of the hemorrhagic lesion (21/25, 84%), peripheral enhancement of the pituitary mass lesion (15/25, 60%), brain herniation (14/25, 56%), and obstructive hydrocephalus (13/25, 52%). Fifteen dogs (58%) survived to hospital discharge. Seven of these dogs received medical management alone (median survival 143 days; range, 7-641 days) and 8 received medications and radiation therapy (median survival 973 days; range, 41-1719 days).

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with pituitary apoplexy present with a variety of acute signs of neurological disease and inconsistent endocrine dysfunction. Dogs that survive to discharge can have a favorable outcome.

Predictive Relevance of Early Temperature Elevation on the Risk of Delayed Cerebral Ischemia Development Following Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Fever in aneurysmal subarachnoid hemorrhage (aSAH) has been associated with delayed cerebral ischemia (DCI), but its relevance in risk stratification has not been explored. This study investigated whether early temperature elevation following aSAH predicts impending clinical deterioration caused by DCI.

METHODS

Relevant cases were identified from a prospectively maintained database for consecutive patients with aSAH treated at our center between July 2015 and January 2020. Temperature readings obtained every 2 hours for individual patients from admission through day 14 were recorded and analyzed. Demographic, clinical, treatment, and angiographic data were extracted from the electronic medical record. The primary end point was the occurrence of DCI (clinical and radiographic vasospasm). Multivariate logistic regression analyses were performed to account for patient age, smoking status, and VASOGRADE classification.

RESULTS

The study included 175 patients (124 women) with aSAH. The median age at diagnosis was 55.4 years (range, 20.5-87.2 years). Clinical DCI occurred in 58 patients; 2 (1.1%) responded to hemodynamic augmentation, and 56 (32.0%) required intra-arterial therapy. Temperature graphs showed a marked divergence on day 4 between clinical DCI and non-DCI groups (1.12°C ± 0.15°C and 0.76°C ± 0.08°C, respectively, P = 0.007). Patients with temperature elevation ≥2.5°C on day 4 or 5 compared with their admission temperature were more likely to clinically deteriorate owing to DCI (odds ratio 4.55, 95% confidence interval 1.31-15.77, P = 0.017).

CONCLUSIONS

Temperature elevation of ≥2.5°C on day 4 or 5 compared with baseline suggests a greater risk of clinical deterioration owing to DCI.

Continuous infusion of low-dose unfractionated heparin after aneurysmal subarachnoid hemorrhage: a preliminary study of cognitive outcomes

OBJECTIVE

Cognitive dysfunction occurs in up to 70% of aneurysmal subarachnoid hemorrhage (aSAH) survivors. Low-dose intravenous heparin (LDIVH) infusion using the Maryland protocol was recently shown to reduce clinical vasospasm and vasospasm-related infarction. In this study, the Montreal Cognitive Assessment (MoCA) was used to evaluate cognitive changes in aSAH patients treated with the Maryland LDIVH protocol compared with controls.

METHODS

A retrospective analysis of all patients treated for aSAH between July 2009 and April 2014 was conducted. Beginning in 2012, aSAH patients were treated with LDIVH in the postprocedural period. The MoCA was administered to all aSAH survivors prospectively during routine follow-up visits, at least 3 months after aSAH, by trained staff blinded to treatment status. Mean MoCA scores were compared between groups, and regression analyses were performed for relevant factors.

RESULTS

No significant differences in baseline characteristics were observed between groups. The mean MoCA score for the LDIVH group (n = 25) was 26.4 compared with 22.7 in controls (n = 22) (p = 0.013). Serious cognitive impairment (MoCA ≤ 20) was observed in 32% of controls compared with 0% in the LDIVH group (p = 0.008). Linear regression analysis demonstrated that only LDIVH was associated with a positive influence on MoCA scores (β = 3.68, p =0.019), whereas anterior communicating artery aneurysms and fevers were negatively associated with MoCA scores. Multivariable linear regression analysis resulted in all 3 factors maintaining significance. There were no treatment complications.

CONCLUSIONS

This preliminary study suggests that the Maryland LDIVH protocol may improve cognitive outcomes in aSAH patients. A randomized controlled trial is needed to determine the safety and potential benefit of unfractionated heparin in aSAH patients.

Time from onset of SIRS to antibiotic administration and outcomes after subarachnoid hemorrhage

INTRODUCTION

The interval from presentation with systemic inflammatory response syndrome (SIRS) to the start of antibiotic administration affects mortality in patients with sepsis. However, patients with subarachnoid hemorrhage (SAH) often develop SIRS directly from their brain injury, making it a less useful indicator of infection. We therefore hypothesized that SIRS would not be a suitable trigger for antibiotics in this population.

METHODS

We examined the time from the development of SIRS until antibiotic initiation and its relationship to long-term neurological outcomes in patients with nontraumatic SAH. Patients' baseline characteristics, time of antibiotic administration, and hospital course were collected from retrospective chart review. The primary outcome, 6-month functional status, was prospectively determined using blinded, structured interviews incorporating the modified Rankin Scale (mRS).

RESULTS

Sixty-six of 70 patients with SAH during the study period had 6-month follow-up and were included in this analysis. SIRS developed in 57 patients (86%, 95% CI 78-95%). In ordinal logistic regression models controlling for age and illness severity, the time from SIRS onset until antibiotic initiation was not associated with 6-month mRS scores (OR per hour, 0.994; 95% CI 0.987-1.001).

CONCLUSIONS

In this cohort of patients with SAH, time from SIRS onset until antibiotic administration was not related to functional outcomes. Our results indicate that SIRS is nonspecific in patients with SAH, and support the safety of withholding antibiotics in those who lack additional evidence of infection or hemodynamic deterioration.

The epidemiology of spontaneous fever and hypothermia on admission of brain injury patients to intensive care units: a multicenter cohort study

OBJECTIVES

Fever and hypothermia (dysthermia) are associated with poor outcomes in patients with brain injuries. The authors sought to study the epidemiology of dysthermia on admission to the intensive care unit (ICU) and the effect on in-hospital case fatality in a mixed cohort of patients with brain injuries.

METHODS

The authors conducted a multicenter retrospective cohort study in 94 ICUs in the United States. Critically ill patients with neurological injuries, including acute ischemic stroke (AIS), aneurysmal subarachnoid hemorrhage (aSAH), intracerebral hemorrhage (ICH), and traumatic brain injury (TBI), who were older than 17 years and consecutively admitted to the ICU from 2003 to 2008 were selected for analysis.

RESULTS

In total, 13,587 patients were included in this study; AIS was diagnosed in 2973 patients (22%), ICH in 4192 (31%), aSAH in 2346 (17%), and TBI in 4076 (30%). On admission to the ICU, fever was more common among TBI and aSAH patients, and hypothermia was more common among ICH patients. In-hospital case fatality was more common among patients with hypothermia (OR 12.7, 95% CI 8.4-19.4) than among those with fever (OR 1.9, 95% CI 1.7-2.1). Compared with patients with ICH (OR 2.0, 95% CI 1.8-2.3), TBI (OR 1.5, 95% CI 1.3-1.8), and aSAH (OR 1.4, 95% CI 1.2-1.7), patients with AIS who developed fever had the highest risk of death (OR 3.1, 95% CI 2.5-3.7). Although all hypothermic patients had an increased mortality rate, this increase was not significantly different across subgroups. In a multivariable analysis, when adjusted for all other confounders, exposure to fever (adjusted OR 1.3, 95% CI 1.1-1.5) or hypothermia (adjusted OR 7.8, 95% CI 3.9-15.4) on admission to the ICU was found to be significantly associated with in-hospital case fatality.

CONCLUSIONS

Fever is frequently encountered in the acute phase of brain injury, and a small proportion of patients with brain injuries may also develop spontaneous hypothermia. The effect of fever on mortality rates differed by neurological diagnosis. Both early spontaneous fever and hypothermia conferred a higher risk of in-hospital death after brain injury.

Effectively managing intractable central hyperthermia in a stroke patient by bromocriptine: a case report

Central hyperthermia is characterized by a rapid onset, high temperature, marked temperature fluctuation, and poor response to antipyretics and antibiotics. Although poststroke central hyperthermia is common, prolonged instances are rare. We report a case of prolonged central fever after an intracranial hemorrhage. Before the accurate diagnosis and management of central fever, the patient underwent long-term antibiotic use that led to pseudomembranous colitis. Bromocriptine was used to treat the prolonged central hyperthermia, after which the fever did not exceed 39°C. A week later, the body temperature baseline was reduced to 37°C and a low-grade fever with minor temperature fluctuation occurred only a few times. No fever occurred in the month following the treatment. After the fever subsided, the patient could undergo an aggressive rehabilitation program.

PREDICTORS OF GLOBAL COGNITIVE IMPAIRMENT 1 YEAR AFTER SUBARACHNOID HEMORRHAGE

OBJECTIVE

We sought to determine the frequency, risk factors, and impact on functional outcome and quality of life (QOL) of global cognitive impairment 1 year after subarachnoid hemorrhage.

METHODS

We prospectively evaluated global cognitive status 3 and 12 months after hospitalization with the Telephone Interview for Cognitive Status in 232 subarachnoid hemorrhage survivors. Cognitive impairment was defined as a score of 30 or less (scaled 0 = worst, 51 = best). Logistic regression was performed to calculate adjusted odds ratios (AORs) for impairment at 1 year. Basic activities of daily living were evaluated with the Barthel Index, instrumental activities of daily living were assessed with the Lawton scale, and QOL was evaluated with the Sickness Impact Profile.

RESULTS

The frequency of cognitive impairment was 27% at 3 months and 21% at 12 months. After the effects of age, education, and race/ethnicity were controlled for, risk factors for cognitive impairment at 12 months included anemia treated with transfusion (AOR, 3.4; P = 0.006), any temperature level higher than 38.6°C (AOR, 2.7; P = 0.016), and delayed cerebral ischemia (AOR, 3.6; P = 0.01). Among cognitively impaired patients at 3 months, improvement at 1 year occurred in 34% and was associated with more than 12 years of education and the absence of fever higher than 38.6°C during hospitalization (P = 0.015). Patients with cognitive impairment at 1 year had worse concurrent QOL and less ability to perform instrumental and basic activities of daily living (all P < 0.001).

CONCLUSION

Global cognitive impairment affects more than 20% of subarachnoid hemorrhage survivors at 1 year, is predicted by fever, anemia treated with transfusion, and delayed cerebral ischemia, and adversely affects functional recovery and QOL.

Risk factors for fever in critically ill patients with acute new-onset stroke

OBJECTIVE

The purpose of this project was to identify risk factors for fever among critically ill patients with acute new-onset stroke, treated in a neurological intensive care unit (NICU). The frequency and risk factors for fever in the stroke patients during the first 7 days after admission were retrospectively studied.

METHODS

Fever was defined as a patient's axillary temperature >37.5 degrees C in two separate measurements or >37.8 degrees C in one single measurement. Multivariable logistic regressions were applied to analyse the risk factors for any fever, explained infectious fever and unexplained fever. One hundred and thirty-seven patients were included in the final analysis.

RESULTS

Febrile episodes occurred in 65% (89/137) of the patients; 48.9% of the fever were explained by infection (predominantly pneumonia or bronchitis), and 15.3% were unexplained despite a complete diagnostic evaluation. Significant risk factors for any fever included age 65 years or older, impaired consciousness, extremity paralysis (muscle force < or = grade 3), center venous catheterization and tracheal intubation. In addition to those risk factors, the length of the stay at NICU before the fever was also a significant risk factor for explained infectious fever. Brain midline shift and initial serum leucocyte count more than 12.0 x 10(9)/l were significant risk factors for unexplained fever.

CONCLUSION

These results suggest that critically ill and new-onset stroke patients treated in NICU often have fever. The risk factors for different types of fever vary considerably.

Temperature management in acute neurologic disorders

Temperature management in acute neurologic disorders has received considerable attention in the last 2 decades. Numerous trials of hypothermia have been performed in patients with head injury, stroke, and cardiac arrest. This article reviews the physiology of thermoregulation and mechanisms responsible for hyperpyrexia. Detrimental effects of fever and benefits of normalizing elevated temperature in experimental models are discussed. This article presents a detailed analysis of trials of induced hypothermia in patients with acute neurologic insults and describes methods of fever control.

Hyperthermia as an early sign of intracranial hemorrhage in full-term neonates

BACKGROUND

Intracranial hemorrhage (ICH) in full-term infants is uncommon and is a rare cause of neonatal fever. This study was conducted to estimate the incidences of ICH and fever in a hospital-based population, and to determine if the clinical features of neonatal ICH with and without hyperthermia differ.

METHODS

We selected 315 afebrile neonates who received cranial ultrasonography screening from 2003 to 2004 as the control group, and 153 neonates diagnosed with fever from 1998 to 2004 as the study group. During the same period, 28 full-term neonates with birth weights >2500g and ICH in the first week of life were enrolled retrospectively. They were divided into hyperthermia (n=11) and nonhyperthermia (n=17) groups.

RESULTS

Three babies in the control group and 11 in the study group had ICH; the incidence of ICH in the hyperthermia group was significantly higher (3/315 vs. 11/153; p < 0.001). Compared with the nonhyperthermia group, the hyperthermia group had Less cyanosis (2/11 vs. 10/17; p = 0.04), Less lymphocyte predominance (33.7 vs. 80%; p = 0.032), higher neutrophil/lymphocyte ratio (1.9 vs. 0.3; p = 0.006), higher erythrocyte/leukocyte ratio (425 vs. 79.5; p = 0.05) in cerebrospinal fluid and an increased incidence of subarachnoid hemorrhage accompanied by intracerebral parenchymal hemorrhage (4/11 vs. 0/17; p = 0.016).

CONCLUSION

The incidence of ICH was higher in febrile than in afebrile neonates. ICH presenting with hyperthermia might go unrecognized, because its other symptoms are subtle and a neutrophil predominance in the cerebrospinal fluid might result in a misdiagnosis of meningitis. ICH in the interior brain tended to manifest more commonly as hyperthermia than did ICH in the superficial brain. A cranial image examination should be considered in the evaluation of neonatal fever.

Non-infectious fever in the neurological intensive care unit: incidence, causes and predictors

BACKGROUND AND OBJECTIVE

Non-infectious causes of fever are often considered in critical neurological patients but their true significance has not been formally studied. The aim of this study was to evaluate the incidence, causes and predictors of fever in patients with acute neurological/neurosurgical disease and no documented infection.

METHODS

Prospective data collection of consecutive patients admitted to the neurological intensive care unit (NICU) of an academic medical centre for more than 48 h was carried out. Fever was defined as body temperature > or = 101 degrees F (38.3 degrees C) documented on at least one measurement for 2 consecutive days. Patients were enrolled only if a diagnostic workup, including cultures of > or = 2 body samples, was performed before antibiotic use. Febrile patients with no proven evidence of infection were considered to have non-infectious fever.

RESULTS

93 patients were included in the final analysis. Fever was non-infectious in 31 patients (33%). There were no differences between the infectious and non-infectious fever groups in terms of age, use and duration of invasive catheters, daily duration of fever and number of days with fever. Documented infections tended to be more common among febrile patients with traumatic brain injury (52% vs 36%; p = 0.06). Non-infectious fever was more frequent among patients with subarachnoid haemorrhage (48% vs 18%; p = 0.01) in whom it was associated with vasospasm (p = 0.03) and symptomatic vasospasm (p = 0.05). Non-infectious fever started earlier (mean 2.6 vs 4 days; p = 0.007) and onset of fever within the first 72 h of admission predicted negative evaluation for infection (p = 0.01). Subarachnoid haemorrhage and fever onset within the first 72 h were independent predictors of non-infectious fever on multivariable analysis.

CONCLUSIONS

Fever in the absence of documented infections occurs commonly in the NICU, especially among patients with subarachnoid haemorrhage and vasospasm. Early onset of fever predicts a non-infectious cause.

Fever after subarachnoid hemorrhage: risk factors and impact on outcome

OBJECTIVE

To identify risk factors for refractory fever after subarachnoid hemorrhage (SAH), and to determine the impact of temperature elevation on outcome.

METHODS

We studied a consecutive cohort of 353 patients with SAH with a maximum daily temperature (T(max)) recorded on at least 7 days between SAH days 0 and 10. Fever (>38.3 degrees C) was routinely treated with acetaminophen and conventional water-circulating cooling blankets. We calculated daily T(max) above 37.0 degrees C, and defined extreme T(max) as daily excess above 38.3 degrees C. Global outcome at 90 days was evaluated with the modified Rankin Scale (mRS), instrumental activities of daily living (IADLs) with the Lawton scale, and cognitive functioning with the Telephone Interview of Cognitive Status. Mixed-effects models were used to identify predictors of T(max), and logistic regression models to evaluate the impact of T(max) on outcome.

RESULTS

Average daily T(max) was 1.15 degrees C (range 0.04 to 2.74 degrees C). The strongest predictors of fever were poor Hunt-Hess grade and intraventricular hemorrhage (IVH) (both p < 0.001). After controlling for baseline outcome predictors, daily T(max) was associated with an increased risk of death or severe disability (mRS > or = 4, adjusted OR 3.0 per degrees C, 95% CI 1.6 to 5.8), loss of independence in IADLs (OR 2.6, 95% CI 1.2 to 5.6), and cognitive impairment (OR 2.5, 95% CI 1.2 to 5.1, all p < or = 0.02). These associations were even stronger when extreme T(max) was analyzed.

CONCLUSION

Treatment-refractory fever during the first 10 days after subarachnoid hemorrhage (SAH) is predicted by poor clinical grade and intraventricular hemorrhage, and is associated with increased mortality and more functional disability and cognitive impairment among survivors. Clinical trials are needed to evaluate the impact of prophylactic fever control on outcome after SAH.

Temperature Management in Acute Neurologic Disorders

Temperature management in acute neurologic disorders has received considerable attention in the last 2 decades. Numerous trials of hypothermia have been performed in patients with head injury, stroke, and cardiac arrest. This article reviews the physiology of thermoregulation and mechanisms responsible for hyperpyrexia. Detrimental effects of fever and benefits of normalizing elevated temperature in experimental models are discussed. This article presents a detailed analysis of trails of induced hypothermia in patients with acute neurologic insults and describes methods of fever control.

Role of inferior olive and thoracic IML neurons in nonshivering thermogenesis in rats

Removal of the midbrain tonic inhibitory mechanism on nonshivering thermogenesis (NST) results in increased temperatures of the interscapular brown adipose tissue (IBAT) and rectum (T(IBAT) and T(rec), respectively) via an enhanced central sympathetic output. Because it is unlikely that neurons (primary) of the midbrain inhibitory mechanism tonically inhibit the IBAT monosynaptically, there must be secondary or tertiary neurons posterior to the midbrain. Such neurons, therefore, may increase their activity during enhanced NST after removal of the midbrain tonic inhibition. The aim of the present experiments was to localize these secondary or tertiary neurons and establish descending neuronal pathway(s) that may project to the major NST effector IBAT. T(IBAT) and T(rec) increases induced by removal of the tonic inhibition by midbrain procaine microinjections were accompanied with appearance of c-Fos-positive neurons in the inferior olive (IO) and the intermediolateral (IML) cell column of the thoracic spinal cord. Electrical stimulation of and L-glutamate microinjections into the IO increased T(IBAT) and T(rec). Midbrain procaine-induced T(IBAT) and T(rec) increases were blocked by electrolytic IO lesions. These results suggest that central thermal signals produced from the lower midbrain are transmitted to IBAT through the IO and IML and that the IO has a role in the central sympathetic functions.