Changes in cerebral blood flow and oxygen metabolism during moderate hypothermia in patients with severe middle cerebral artery infarction

Beneficial Effects of Receiving Johrei on General Health or Hypothermia Tendency

OBJECTIVES

Johrei is a type of biofield therapy that is said to bring physical and mental well-being to the recipient. This study sought to measure changes in body temperature and circulation resulting from Johrei treatment, for generally healthy subjects and for individuals with a tendency toward hypothermia.

PARTICIPANTS

A total of 199 qualified Johrei practitioners and 144 non-qualified operators provided Johrei and placebo treatments, respectively. Volunteer subjects -186 in general health and 39 with a hypothermia tendency - participated in this study to receive either or both of these treatments.

METHODS

Each subject was given a 10 min treatment daily by either a qualified practitioner or a non-qualified operator. The effects on subjects of receiving each treatment were compared by observing quantitative changes in blood flow and surface body temperature after a course of treatment.

RESULTS

A total of 107 healthy subjects were randomly assigned to the qualified-practitioner group or the non-qualified operator group. Treatment by qualified practitioners significantly enhanced blood flow and surface body temperature in the subjects' designated neck area compared to that in treatment by non-qualified operators. This finding was further corroborated by a comparative experiment in which each healthy subject was treated by both a qualified practitioner and a non-qualified operator. These results indicate that only the qualified-practitioner treatment increased the subject's-blood flow and surface body temperature. Similarly, in a comparative study of qualified-practitioner treatment against non-qualified-operator treatment, subjects tending toward hypothermia showed increased blood flow and elevated body temperature with only the authentic Johrei treatment.

Temperature Difference between Brain and Axilla according to Body Temperature in the Patient with Brain Injury

Objective

Commonly, brain temperature is estimated from measurements of body temperature. However, temperature difference between brain and body is still controversy. The objective of this study is to know temperature gradient between the brain and axilla according to body temperature in the patient with brain injury.

Methods

A total of 135 patients who had undergone cranial operation and had the thermal diffusion flow meter (TDF) insert were included in this analysis. The brain and axilla temperatures were measured simultaneously every 2 hours with TDF (2 kinds of devices: SABER 2000 and Hemedex) and a mercury thermometer. Saved data were divided into 3 groups according to axillary temperature. Three groups are hypothermia group (less than 36.4°C), normothermia group (between 36.5°C and 37.5°C), and hyperthermia group (more than 37.6°C).

Results

The temperature difference between brain temperature and axillary temperature was 0.93±0.50°C in all data pairs, whereas it was 1.28±0.56°C in hypothermia, 0.87±0.43°C in normothermia, and 0.71±0.41°C in hyperthermia. The temperature difference was statistically significant between the hypothermia and normothermia groups (p=0.000), but not between the normothermia and hyperthermia group (p=0.201).

Conclusion

This study show that brain temperature is significantly higher than the axillary temperature and hypothermia therapy is associated with large brain-axilla temperature gradients. If you do not have a special brain temperature measuring device, the results of this study will help predict brain temperature by measuring axillary temperature.

Inducing Brain Cooling Without Core Temperature Reduction in Pigs Using a Novel Nasopharyngeal Method: An Effectiveness and Safety Study

BACKGROUND

Acute brain lesions constitute an alarming public health concern. Neuroprotective therapies have been implemented to stabilize, prevent, or reduce brain lesions, thus improving neurological outcomes and survival rates. Hypothermia is the most effective approach, mainly attributed to the reduction in cellular metabolic activity. Whole-body cooling is currently implemented by healthcare professionals; however, adverse events are frequent, limiting the potential benefits of therapeutic hypothermia. Therefore, selective methods have been developed to reduce adverse events while delivering neuroprotection. Nasopharyngeal approaches are the safest and most effective methods currently considered. Our primary objective was to determine the effects of a novel nasopharyngeal catheter on the brain temperature of pigs.

METHODS

In this prospective, non-randomized, interventional experimental trial, 10 crossbred pigs underwent nasopharyngeal cooling for 60 min followed by 15 min of rewarming. Nasopharyngeal catheters were inserted into the left nostril and properly positioned at the nasopharyngeal cavity.

RESULTS

Nasopharyngeal cooling was associated with a decrease in brain temperature, which was more significant in the left cerebral hemisphere (p = 0.01). There was a reduction of 1.47 ± 0.86 °C in the first 5 min (p < 0.001), 2.45 ± 1.03 °C within 10 min (p < 0.001), and 4.45 ± 1.36 °C after 1 h (p < 0.001). The brain-core gradient was 4.57 ± 0.87 °C (p < 0.001). Rectal, esophageal, and pulmonary artery temperatures and brain and systemic hemodynamic parameters, remained stable during the procedure. Following brain cooling, values of oxygen partial pressure in brain tissue significantly decreased. No mucosal lesions were detected during nasal, pharyngeal, or oral inspection after nasopharyngeal catheter removal.

CONCLUSIONS

In this study, a novel nasopharyngeal cooling catheter effectively induced and maintained exclusive brain cooling when combined with effective counter-warming methods. Exclusive brain cooling was safe with no device-related local or systemic complications and may be desired in selected patient populations.

Evidence-based guidelines for the management of large hemispheric infarction : a statement for health care professionals from the Neurocritical Care Society and the German Society for Neuro-intensive Care and Emergency Medicine

Large hemispheric infarction (LHI), also known as malignant middle cerebral infarction, is a devastating disease associated with significant disability and mortality. Clinicians and family members are often faced with a paucity of high quality clinical data as they attempt to determine the most appropriate course of treatment for patients with LHI, and current stroke guidelines do not provide a detailed approach regarding the day-to-day management of these complicated patients. To address this need, the Neurocritical Care Society organized an international multidisciplinary consensus conference on the critical care management of LHI. Experts from neurocritical care, neurosurgery, neurology, interventional neuroradiology, and neuroanesthesiology from Europe and North America were recruited based on their publications and expertise. The panel devised a series of clinical questions related to LHI, and assessed the quality of data related to these questions using the Grading of Recommendation Assessment, Development and Evaluation guideline system. They then developed recommendations (denoted as strong or weak) based on the quality of the evidence, as well as the balance of benefits and harms of the studied interventions, the values and preferences of patients, and resource considerations.

Endovascular Cooling Catheter for Selective Brain Hypothermia: An Animal Feasibility Study of Cooling Performance

BACKGROUND AND PURPOSE

Therapeutic hypothermia represents a promising neuroprotective treatment in acute ischemic stroke. Selective cerebral hypothermia applied early, prior to and during endovascular mechanical recanalization therapy, may be beneficial in the critical phase of reperfusion. We aimed to assess the feasibility of a new intracarotid cooling catheter in an animal model.

MATERIALS AND METHODS

Nine adult sheep were included. Temperature probes were introduced into the frontal and temporal brain cortices bilaterally. The cooling catheter system was introduced into a common carotid artery. Selective blood cooling was applied for 180 minutes. Systemic and local brain temperatures were measured during cooling and rewarming. Common carotid artery diameters and flow were measured angiographically and by Doppler sonography.

RESULTS

The common carotid artery diameter was between 6.7 and 7.3 mm. Common carotid artery blood flow velocities increased moderately during cooling and after catheter removal. Maximum cerebral cooling in the ipsilateral temporal cortex was -4.7°C (95% CI, -5.1 to -4.0°C). Ipsilateral brain temperatures dropped significantly faster and became lower compared with the contralateral cortex with maximum temperature difference of -1.3°C (95% CI, -1.5 to -1.0°C; P < .0001) and compared with systemic temperature (-1.4°C; 95% CI, -1.7 to -1.0°C; P < .0001).

CONCLUSIONS

Sheep proved a feasible animal model for the intracarotid cooling catheter. Fast induction of selective mild hypothermia was achieved within the cooled cerebral hemisphere, with stable temperature gradients in the contralateral brain and systemic blood. Further studies are required to demonstrate any therapeutic benefit of selective cerebral cooling in a stroke model.

Therapeutic Hypothermia Reduces Intracranial Pressure and Partial Brain Oxygen Tension in Patients with Severe Traumatic Brain Injury: Preliminary Data from the Eurotherm3235 Trial

Traumatic brain injury (TBI) is a significant cause of disability and death and a huge economic burden throughout the world. Much of the morbidity associated with TBI is attributed to secondary brain injuries resulting in hypoxia and ischemia after the initial trauma. Intracranial hypertension and decreased partial brain oxygen tension (PbtO2) are targeted as potentially avoidable causes of morbidity. Therapeutic hypothermia (TH) may be an effective intervention to reduce intracranial pressure (ICP), but could also affect cerebral blood flow (CBF). This is a retrospective analysis of prospectively collected data from 17 patients admitted to the Western General Hospital, Edinburgh. Patients with an ICP >20 mmHg refractory to initial therapy were randomized to standard care or standard care and TH (intervention group) titrated between 32°C and 35°C to reduce ICP. ICP and PbtO2 were measured using the Licox system and core temperature was recorded through rectal thermometer. Data were analyzed at the hour before cooling, the first hour at target temperature, 2 consecutive hours at target temperature, and after 6 hours of hypothermia. There was a mean decrease in ICP of 4.3±1.6 mmHg (p<0.04) from 15.7 to 11.4 mmHg, from precooling to the first epoch of hypothermia in the intervention group (n=9) that was not seen in the control group (n=8). A decrease in ICP was maintained throughout all time periods. There was a mean decrease in PbtO2 of 7.8±3.1 mmHg (p<0.05) from 30.2 to 22.4 mmHg, from precooling to stable hypothermia, which was not seen in the control group. This research supports others in demonstrating a decrease in ICP with temperature, which could facilitate a reduction in the use of hyperosmolar agents or other stage II interventions. The decrease in PbtO2 is not below the suggested treatment threshold of 20 mmHg, but might indicate a decrease in CBF.

Therapeutic hypothermia reduces middle cerebral artery flow velocity in patients with severe aneurysmal subarachnoid hemorrhage

BACKGROUND

Transcranial Doppler (TCD) is widely used to detect and follow up cerebral vasospasm after subarachnoid hemorrhage (SAH). Therapeutic hypothermia might influence blood flow velocities assessed by TCD. The aim of the study was to evaluate the effect of hypothermia on Doppler blood flow velocity after SAH.

METHODS

In 20 patients treated with hypothermia (33°) due to refractory intracranial hypertension or delayed cerebral ischemia (DCI), mean flow velocity of the middle cerebral artery (MFV(MCA)) was assessed by TCD. Thirteen patients were treated with combined hypothermia and barbiturate coma and seven with hypothermia alone. MFV(MCA) was obtained within 24 h before and after induction of hypothermia as well as before and after rewarming.

RESULTS

Hypothermia was induced on average 5 days after SAH (range 1-12) and maintained for 144 h (range 29-270). After hypothermia induction, MFV(MCA) decreased from 113.7 ± 49.0 to 93.8 ± 44.7 cm/s (p = 0.001). The decrease was independent of SAH-related complications and barbiturate coma. MFV(MCA) further decreased by 28.2 cm/s between early and late hypothermia (p < 0.001). This second decrease was observed in patients with DCI (p < 0.001), but not in patients with intracranial hypertension (p = 0.715). Compared to late hypothermia, MFV(MCA) remained unchanged after rewarming (65.6 ± 32.1 vs 70.3 ± 36.8 cm/s; p = 0.219). However, patients treated with hypothermia alone showed an increase in MFV(MCA) after rewarming (p = 0.016).

CONCLUSION

Therapeutic hypothermia after SAH decreases Doppler blood flow velocity in both intracranial hypertension and DCI cases. The results can be the effect of hypothermia-related mechanisms or resolving cerebral vasospasm during prolonged hypothermia.

Brain temperature: physiology and pathophysiology after brain injury

The regulation of brain temperature is largely dependent on the metabolic activity of brain tissue and remains complex. In intensive care clinical practice, the continuous monitoring of core temperature in patients with brain injury is currently highly recommended. After major brain injury, brain temperature is often higher than and can vary independently of systemic temperature. It has been shown that in cases of brain injury, the brain is extremely sensitive and vulnerable to small variations in temperature. The prevention of fever has been proposed as a therapeutic tool to limit neuronal injury. However, temperature control after traumatic brain injury, subarachnoid hemorrhage, or stroke can be challenging. Furthermore, fever may also have beneficial effects, especially in cases involving infections. While therapeutic hypothermia has shown beneficial effects in animal models, its use is still debated in clinical practice. This paper aims to describe the physiology and pathophysiology of changes in brain temperature after brain injury and to study the effects of controlling brain temperature after such injury.

Monitoring of cerebral hemodynamics and oxygenation to detect delayed ischemic neurological deficit after aneurysmal subarachnoid hemorrhage

One of the major goals in the treatment of patients with aneurysmal subarachnoid hemorrhage (aSAH) is early detection and treatment of delayed ischemic neurologic deficits (DINDs) to prevent cerebral infarction and thus poor outcome or even death. The complex changes of cerebral metabolism, hemodynamics, and oxygenation after SAH are underestimated if they are considered exclusively based on angiographic cerebral vasospasm (CVS). The discrepancies on one hand may arise from the heterogeneous and complex pathophysiology of DINDs. On the other hand, the occurrence of DINDs may depend on the relationship between local cerebral oxygen delivery and demand, which can only be determined if cerebral blood flow (CBF) and the cerebral metabolic rate of oxygen (CMRO(2)) can be measured. We briefly review the most relevant methods for monitoring cerebral hemodynamics and oxygenation and discuss the limitations associated with early diagnosis of DINDs in patients with severe aSAH not amenable for clinical neurological examination.

Use of hypothermia in the intensive care unit

Used for over 3600 years, hypothermia, or targeted temperature management (TTM), remains an ill defined medical therapy. Currently, the strongest evidence for TTM in adults are for out-of-hospital ventricular tachycardia/ventricular fibrillation cardiac arrest, intracerebral pressure control, and normothermia in the neurocritical care population. Even in these disease processes, a number of questions exist. Data on disease specific therapeutic markers, therapeutic depth and duration, and prognostication are limited. Despite ample experimental data, clinical evidence for stroke, refractory status epilepticus, hepatic encephalopathy, and intensive care unit is only at the safety and proof-of-concept stage. This review explores the deleterious nature of fever, the theoretical role of TTM in the critically ill, and summarizes the clinical evidence for TTM in adults.

Application of mild therapeutic hypothermia on stroke: a systematic review and meta-analysis

Background. Stroke occurs due to an interruption in cerebral blood supply affecting neuronal function. Body temperature on hospital admission is an important predictor of clinical outcome. Therapeutic hypothermia is promising in clinical settings for stroke neuroprotection. Methods. MEDLINE/PubMed, CENTRAL, Stroke Center, and ClinicalTrials.gov were systematically searched for hypothermia intervention induced by external or endovascular cooling for acute stroke. NIH Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were the main stroke scales used, and mortality was also reported. A meta-analysis was carried out on stroke severity and mortality. Results. Seven parallel-controlled clinical trials were included in the meta-analysis. Sample sizes ranged from 18 to 62 patients, yielding a total of 288. Target temperature (∼33°C) was reached within 3-4 hours. Stroke severity (Cohen's d = −0.17, 95% CI: −0.42 to 0.08, P = 0.32; I² = 73%; Chi² = 21.89, P = 0.0001) and mortality (RR = 1.60, 95% CI: 0.93 to 2.78, P = 0.11; I² = 0%; Chi² = 2.88, P = 0.72) were not significantly affected by hypothermia. Discussion. Hypothermia does not significantly improve stroke severity; however, this finding should be taken with caution due to the high heterogeneity and limited number of included studies. No impact on mortality was observed.

Physiologic and pharmacologic considerations for hypothermia therapy in neonates

With mounting evidence that hypothermia is neuroprotective in newborns with hypoxic-ischemic encephalopathy (HIE), an increasing number of centers are offering this therapy. Hypothermia is associated with a wide range of physiologic changes affecting every organ system, and awareness of these effects is essential for optimum patient management. Lowering the core temperature also alters pharmacokinetic and pharmacodynamic properties of medications commonly used in asphyxiated neonates, necessitating close attention to drug efficacy and side effects. Rewarming introduces additional risks and challenges as the hypothermia-associated physiologic and pharmacologic changes are reversed. In this review we provide an organ system-based assessment of physiologic changes associated with hypothermia. We also summarize evidence from randomized controlled trials showing lack of serious adverse effects of moderate hypothermia therapy in term and near-term newborns with moderate-to-severe HIE. Finally, we review the effects of hypothermia on drug metabolism and clearance based on studies in animal models and human adults, and limited data from neonates.

Emergency craniotomy for intraparenchymal massive hematoma after embolization of supratentorial arteriovenous malformations

OBJECTIVE

We sought to evaluate the efficacy of emergency craniotomy for patients with massive hematoma secondary to endovascular embolization of supratentorial arteriovenous malformations (AVMs) and to investigate relevant factors affecting outcome.

METHODS

Within the past 15 years, 605 patients with intracranial AVMs have undergone 1066 endovascular embolizations at our institution. Of these, 24 patients experienced intracranial hemorrhage during or after the procedure. Fourteen patients were demonstrated to have massive intraparenchymal hematomas and deteriorated to a comatose state (Glasgow Come Scale score < or =6). Twelve patients underwent craniotomy within 170 minutes of being diagnosed with intraparenchymal hemorrhage. The surgical procedures performed were hematoma evacuation with total (6 patients) or partial (2 patients) resection of the AVM or hematoma evacuation only (4 patients). The clinical records of these 12 patients were analyzed retrospectively.

RESULTS

Nine patients recovered to a favorable condition (good recovery, four patients; moderately disabled, five patients), one patient remained in a persistent vegetative state, and two patients died. The interval between hemorrhage and emergency craniotomy was significantly shorter in patients with favorable outcomes than in those with poor clinical outcomes. Advanced age and a larger volume of intraoperative blood loss were the factors relevant to poor outcome. Temporal lobe location of the AVM and incomplete embolization tended to correlate to poor clinical outcome, but this correlation was not statistically significant. The sizes of the AVM and the hematoma did not correlate to patient outcome. There was no difference in outcomes with regard to the surgical procedure performed.

CONCLUSION

In patients with massive postembolization hematomas, emergency craniotomy should be performed as soon as possible to achieve a favorable outcome. Cooperation among interventional neuroradiologists, intensive care physicians, and neurosurgeons is essential to manage AVM patients with critical postembolization hemorrhage. There is no need to persist in performing simultaneous total resection of the AVM at the emergency craniotomy.