Induced hypothermia in comatose survivors of asphyxia: a case series of 14 consecutive cases

Wilderness Medical Society Clinical Practice Guidelines for the Treatment and Prevention of Drowning: 2024 Update

The Wilderness Medical Society convened a panel to review available evidence supporting practices for acute management of drowning in out-of-hospital and emergency care settings. Literature about definitions and terminology, epidemiology, rescue, resuscitation, acute clinical management, disposition, and drowning prevention was reviewed. The panel graded available evidence supporting practices according to the American College of Chest Physicians criteria and then made recommendations based on that evidence. Recommendations were based on the panel's collective clinical experience and judgment when published evidence was lacking. This is the second update to the original practice guidelines published in 2016 and updated in 2019.

Effects of Adjunctive Therapeutic Hypothermia Combined With Hyperbaric Oxygen Therapy in Acute Severe Carbon Monoxide Poisoning

OBJECTIVE

To determine the effects of adjunctive therapeutic hypothermia, by comparing hyperbaric oxygen therapy versus hyperbaric oxygen therapy combined with therapeutic hypothermia in acute severe carbon monoxide poisoning.

DESIGN

Retrospective analysis of data from our prospectively collected carbon monoxide poisoning registry.

SETTING

A single academic medical center in Wonju, Republic of Korea.

PATIENTS

Patients with acute severe carbon monoxide poisoning older than 18 years. Acute severe carbon monoxide poisoning was defined as mental status showing response to painful stimulus or unresponsive at the emergency department, and a continuation of this depressed mental status even after the first hyperbaric oxygen therapy. Patients were classified into the no-therapeutic hypothermia and therapeutic hypothermia groups. Hyperbaric oxygen therapy was performed up to twice within 24 hours after emergency department arrival, whereas therapeutic hypothermia was performed at a body temperature goal of 33°C for 24 hours using an endovascular cooling device after the first hyperbaric oxygen therapy.

INTERVENTIONS

Hyperbaric oxygen therapy versus hyperbaric oxygen therapy combined with therapeutic hypothermia.

MEASUREMENTS AND MAIN RESULTS

We investigated the difference in the Global Deterioration Scale score at 1 and 6 months after carbon monoxide exposure, between the no-therapeutic hypothermia and therapeutic hypothermia groups. Global Deterioration Scale scores were classified as follows: 1-3 points (favorable neurocognitive outcome) and 4-7 points (poor neurocognitive outcome). During the study period, 37 patients were treated for acute severe carbon monoxide poisoning, with 16 and 21 patients in the no-therapeutic hypothermia and therapeutic hypothermia groups, respectively. The therapeutic hypothermia group demonstrated significantly higher number of patients with favorable outcomes (p = 0.008) at 6 months after carbon monoxide exposure and better improvement of the 6-month Global Deterioration Scale score than the 1-month score (p = 0.006).

CONCLUSIONS

Our data suggest that in acute severe carbon monoxide poisoning, patients who were treated using therapeutic hypothermia combined with hyperbaric oxygen therapy had significantly more favorable neurocognitive outcomes at 6 months after carbon monoxide exposure than those treated with hyperbaric oxygen therapy alone.

Methane and Inflammation - A Review (Fight Fire with Fire)

Mammalian methanogenesis is regarded as an indicator of carbohydrate fermentation by anaerobic gastrointestinal flora. Once generated by microbes or released by a non-bacterial process, methane is generally considered to be biologically inactive. However, recent studies have provided evidence for methane bioactivity in various in vivo settings. The administration of methane either in gas form or solutions has been shown to have anti-inflammatory and neuroprotective effects in an array of experimental conditions, such as ischemia/reperfusion, endotoxemia and sepsis. It has also been demonstrated that exogenous methane influences the key regulatory mechanisms and cellular signalling pathways involved in oxidative and nitrosative stress responses. This review offers an insight into the latest findings on the multi-faceted organ protective activity of exogenous methane treatments with special emphasis on its versatile effects demonstrated in sepsis models.

Wilderness Medical Society Clinical Practice Guidelines for the Treatment and Prevention of Drowning: 2019 Update

The Wilderness Medical Society convened a panel to review available evidence supporting practices for acute management and treatment of drowning in out-of-hospital and emergency medical care settings. Literature about definitions and terminology, epidemiology, rescue, resuscitation, acute clinical management, disposition, and drowning prevention was reviewed. The panel graded available evidence supporting practices according to the American College of Chest Physicians criteria and then made recommendations based on that evidence. Recommendations were based on the panel's collective clinical experience and judgment when published evidence was lacking. This is the first update to the original practice guidelines published in 2016.

Pediatric Post–Cardiac Arrest Care: A Scientific Statement From the American Heart Association

Successful resuscitation from cardiac arrest results in a post–cardiac arrest syndrome, which can evolve in the days to weeks after return of sustained circulation. The components of post–cardiac arrest syndrome are brain injury, myocardial dysfunction, systemic ischemia/reperfusion response, and persistent precipitating pathophysiology. Pediatric post–cardiac arrest care focuses on anticipating, identifying, and treating this complex physiology to improve survival and neurological outcomes. This scientific statement on post–cardiac arrest care is the result of a consensus process that included pediatric and adult emergency medicine, critical care, cardiac critical care, cardiology, neurology, and nursing specialists who analyzed the past 20 years of pediatric cardiac arrest, adult cardiac arrest, and pediatric critical illness peer-reviewed published literature. The statement summarizes the epidemiology, pathophysiology, management, and prognostication after return of sustained circulation after cardiac arrest, and it provides consensus on the current evidence supporting elements of pediatric post–cardiac arrest care.

Predictors of Futility in Near-Hanging and Therapeutic Hypothermia

Favorable neurologic outcomes have been reported in near-hanging (NH) victims treated with therapeutic hypothermia (TH), but variable methods and small samples sizes limit interpretability. This study examines the relationship between clinical predictors, TH, and outcomes in NH patients. A risk profile was created by examining relationships between variables. Categorical predictors were assessed with chi-square tests and continuous variables were assessed with t-tests. Logistic regression was conducted to evaluate the unique effect of TH. Thirty-seven NH patients were treated, 22 with cardiac arrest (CA). Poor outcome was significantly associated with age, Glasgow Coma Scale-Motor (GCS-M), pupillary response, and out-of-hospital CA (OHCA) (p's < 0.02). Patients with poor neurologic outcomes were older (M = 40.2 vs. M = 27.6) and had lower GCS-M scores (M = 1.1 vs. M = 4.1). Poor outcome probability was 76% in patients with GCS-M <3, 100% with nonreactive pupils, and 72.1% with OHCA. TH was associated with a worse outcome overall that was not significant after adjusting for GCS-M. Our study demonstrates no impact of TH on NH outcome when controlling for variables associated with poor outcome and relative certainty of poor outcome with CA, GCS-M 1, and nonreactive pupils. Study findings could assist in decisions on the utilization of TH.

EAST Multicenter Trial on targeted temperature management for hanging-induced cardiac arrest

BACKGROUND

We sought to determine the outcome of suicidal hanging and the impact of targeted temperature management (TTM) on hanging-induced cardiac arrest (CA) through an Eastern Association for the Surgery of Trauma (EAST) multicenter retrospective study.

METHODS

We analyzed hanging patient data and TTM variables from January 1992 to December 2015. Cerebral performance category score of 1 or 2 was considered good neurologic outcome, while cerebral performance category score of 3 or 4 was considered poor outcome. Classification and Regression Trees recursive partitioning was used to develop multivariate predictive models for survival and neurologic outcome.

RESULTS

A total of 692 hanging patients from 17 centers were analyzed for this study. Their overall survival rate was 77%, and the CA survival rate was 28.6%. The CA patients had significantly higher severity of illness and worse outcome than the non-CA patients. Of the 175 CA patients who survived to hospital admission, 81 patients (46.3%) received post-CA TTM. The unadjusted survival of TTM CA patients (24.7% vs 39.4%, p < 0.05) and good neurologic outcome (19.8% vs 37.2%, p < 0.05) were worse than non-TTM CA patients. However, when subgroup analyses were performed between those with an admission Glasgow Coma Scale score of 3 to 8, the differences between TTM and non-TTM CA survival (23.8% vs 30.0%, p = 0.37) and good neurologic outcome (18.8% vs 28.7%, p = 0.14) were not significant. Targeted temperature management implementation and post-CA management varied between the participating centers. Classification and Regression Trees models identified variables predictive of favorable and poor outcome for hanging and TTM patients with excellent accuracy.

CONCLUSION

Cardiac arrest hanging patients had worse outcome than non-CA patients. Targeted temperature management CA patients had worse unadjusted survival and neurologic outcome than non-TTM patients. These findings may be explained by their higher severity of illness, variable TTM implementation, and differences in post-CA management. Future prospective studies are necessary to ascertain the effect of TTM on hanging outcome and to validate our Classification and Regression Trees models.

LEVEL OF EVIDENCE

Therapeutic study, level IV; prognostic study, level III.

Early diffusion-weighted imaging and outcome prediction of comatose survivors after suicidal hanging

PURPOSE

Early outcome prediction after suicidal hanging is challenging in comatose survivors. We analysed the early patterns of brain diffusion-weighted magnetic resonance imaging (DWI) abnormalities in comatose survivors after suicidal hanging.

METHODS

After suicidal hanging, 18 comatose survivors were prospectively evaluated from January 2013 to December 2016. DWI was performed within 3 h after hanging in comatose survivors. We evaluated Utstein style variables and analysed abnormal spatial profile of signal intensity on DWI, brain apparent diffusion coefficient (ADC) values, and qualitative DWI scores to predict neurological outcomes.

RESULTS

All hanging associated cardiac arrest (CA) patients demonstrated bad neurological outcomes; 80% of non-CA comatose patients experienced good neurological outcomes. In hanging survivors with CA, cortical grey matter structures and deep grey nuclei exhibited profound ADC reductions and high DWI scores within 3 h after hanging, which was associated with diffuse anoxic brain damage with poor cerebral performance categories scores. CA comatose survivors had significantly lower ADC values and higher DWI scores compared to non-CA comatose survivors in the cortex and deep grey nuclei.

CONCLUSION

Although the presence of CA is the most important clinical prognosticator in hanging-associated comatose survivors, HSI abnormalities and low ADC values in the cortex and deep grey nuclei on DWI performed within 3 h after hanging are well-correlated with unfavourable outcomes regardless of therapeutic hypothermia. Therefore, early DWI may increase the sensitivity of poor outcome prediction and may be an effective combinatorial screening method when available prognostic variables are not reliable or conclusive.

Hanging and asphyxia: Interventions, patient outcomes and resource utilisation in a UK tertiary intensive care unit

Introduction

Suicide is increasing in the UK, and hanging is now the commonest mechanism. United Kingdom intensive care unit outcomes (including organ donation) after hanging have not been reported.

Methods

Retrospective analysis of cases admitted to a UK tertiary intensive care unit with a primary or secondary diagnosis of hanging/asphyxia. Case analysis divided between those with and without a history of cardiopulmonary resuscitation, and outcomes described using the cerebral performance category score.

Results

A total of 33 cases were reviewed, 19 with a history of cardiopulmonary resuscitation (three survivors with cerebral performance category of 1-2), 14 without history of cardiopulmonary resuscitation (14 survivors, 11 cerebral performance category score of 1, 3 cerebral performance category score of 3). Three cases went on to have a good neurological outcome with a cerebral performance category score of one, and 16 died. The three survivors only had bystander cardiopulmonary resuscitation and cardiac arrest was not independently confirmed. All three had a good neurological recovery despite two having hypoxic-ischaemic encephalopathy on computed tomography head. Of the three survivors, one received no temperature management and two received targeted temperature management. Median intensive care unit length of stay after hanging with cardiopulmonary resuscitation was 3.0 days (2.4-6.7 days). Fifteen patients were discussed with the organ donation specialist nurse, with six consenting to donation and six declining consent, with 18 solid organs donated. All 14 of those without a history of cardiopulmonary resuscitation survived, 11 with a cerebral performance category score of 1 and three having a cerebral performance category score of 3. No patients received active temperature management. Median intensive care unit length of stay in this group was 2.9 days (1.2-3.8).

Conclusions

Outcomes after confirmed cardiac arrest following hanging are poor, in keeping with existing international data, even in those surviving to intensive care unit admission. Despite low rates of consent to organ donation, the overall organ donation is high due to high referral rates. Despite the poor prognosis in this population, early initiation of full resuscitation should be offered to optimise survival and facilitate the possibility of donation.

Clinical Experience of Therapeutic Hypothermia in Cases of Near-Hanging and Recovered from Cardiac Arrest Due to Hanging

Objective

There is no specific treatment for comatose patients after near-hanging or in those who recover from cardiac arrest (CA) caused by hanging. Since 2009, we have used therapeutic hypothermia (TH) to treat all comatose survivors of near-hanging and in patients who recovered from CA caused by hanging. The purpose of this study was to describe the outcomes in comatose patients after near-hanging.

Design

Case series.

Setting

Emergency departments of two regional hospitals.

Methods

We collected patient data from the Samsung Medical Center hypothermia database between November 2009 and November 2011. We included all patients presented with near-hanging or CA caused by hanging; who remained comatose and received TH after resuscitation for analysis. Clinical characteristics and outcome of patients were presented. Results During the study period, 26 patients were admitted to the emergency department after near-hanging or CA caused by hanging; 21 patients were enrolled in this study. Twelve patients with CA and 9 comatose patients without CA were treated with TH. Only 1 patient with CA had a good neurological outcome. By contrast, all near-hanging patients without CA had a good neurological outcome.

Conclusions

TH can be an effective therapeutic modality in cases of near-hanging without CA. However, the effectiveness of TH is questionable in patients who survive from CA caused by hanging. (Hong Kong j.emerg.med. 2014;21:316-321)

Therapeutic Hypothermia for Asphyxial Out-of-Hospital Cardiac Arrest Due to Drowning: A Systematic Review of Case Series and Case Reports

The objective of this review was to summarize published evidence of the effectiveness of therapeutic hypothermia in patients with drowning-associated asphyxial out-of-hospital cardiac arrest (OHCA) and to explore any preliminary favorable factors in the management of therapeutic hypothermia to improve survival and neurological outcome. Drowning may result in asphyxial OHCA or hypothermic OHCA, but the former does not provide any potential neuroprotective effect as the latter may do. Electronic literature searches of Ovid Medline, Embase, Cochrane Library, and Scopus were performed for all years from inception to July 2016. Primary studies in the form of case reports, letters to the editor, and others with higher quality are included, but guidelines, reviews, editorials, textbook chapters, conference abstracts, and nonhuman studies are excluded. Non-English articles are excluded. Relevant studies are then deemed eligible if the drowning OHCA patient's initial temperature was above 28°C, which implies asphyxial cardiac arrest, and intentional therapeutic hypothermia was instituted. Because of the narrow scope of interest and strict definition of the condition, limited studies addressed it, and no randomized controlled trials (RCT) could be selected. Thirteen studies covering 35 patients are included. No quantitative synthesis, assessment of study quality, or assessment of bias was performed. It is conjectured that extended therapeutic hypothermia of 48-72 hours might help prevent reperfusion injury during the intermediate phase of postcardiac arrest care to benefit patients of drowning-associated asphyxial OHCA, but this finding only serves as preliminary observation for future research. No conclusive recommendation could be made regarding the duration of and the time of onset of therapeutic hypothermia. Future research should put effort on RCT, particularly the effect of extended duration of 48-72 hours. Important parameters should be reported in detail. Asphyxial and hypothermic OHCA should be differentiated.

Comparison of Outcomes Between Patients Treated by Therapeutic Hypothermia for Cardiac Arrest Due to Cardiac or Respiratory Causes

Outcome for patients experiencing out-hospital cardiac arrest (OHCA) due to respiratory causes is poor, even with treatment by therapeutic hypothermia (TH). The purpose of this study is to clarify difference in outcome and respiratory state during resuscitation between cases due to respiratory causes versus those due to cardiac causes, to establish alternative strategies for the patient. This study was conducted as a retrospective analysis of patients with post CA syndrome who underwent TH. Patients were divided into two groups according to cause of CA: cardiac (C group) or respiratory (R group). Utstein Style data, outcome, and arterial blood gas (ABG) findings after emergency room admission of the two groups were compared. Of 74 patients treated with TH during the 2-year study period, 49 were placed in the C group and 19 in the R group. The rates of ventricular fibrillation/pulseless ventricular tachycardia at initial rhythm were significantly higher in the C group than in the R group. The rate of favorable neurological outcome was significantly higher in the C group (15/49: 30.6%) than in the R group (1/19: 5.3%) 30 days after resuscitation. In the ABG findings, PaCO2 was significantly higher in the R group than in the C group. For patients experiencing OHCA from respiratory causes, TH was less effective and PaCO2 accumulated immediately after admission. From this, interpretation of the significance of PaCO2 in these patients at the early stage after return of spontaneous circulation should be seriously considered.

Neurologic outcome of comatose survivors after hanging: a retrospective multicenter study

PURPOSE

The aim of this study is to identify the neurologic outcome of hanging patients and prognostic factors.

MATERIALS AND METHODS

We retrospectively investigated comatose hanging patients who arrived at the emergency departments (EDs) of twelve academic tertiary care centers during a period of seven years (2006-2012). Patients were analyzed separately according to whether out-of-hospital cardiac arrest (OHCA) occurred or not. The neurologic outcome was evaluated using the Cerebral Performance Category (CPC) at the time of hospital discharge.

RESULTS

A total of 1118 patients were admitted to the ED after hanging attempts. There were 159 comatose patients who did not experience OHCA. Twelve (7.5%) of 159 patients were discharged from the hospital with a poor neurologic outcome (CPC 3-5). These 12 patients received only conservative management without therapeutic hypothermia. On multivariate logistic regression analysis, mental state upon ED arrival and arterial pH were predicting factors for poor prognosis. One hundred twenty-one patients suffered OHCA and experienced restored spontaneous circulation after cardiopulmonary resuscitation. Among them, only five (4.1%) patients recovered consciousness to the level of CPC 1-2. The initial arterial pH and HCO3(-) were prognostic factors in hanging patients with OHCA.

CONCLUSIONS

Even though cardiac arrest did not occur after hanging injuries, 7.5% of patients could not recover consciousness. Therapeutic hypothermia should be considered for such patients. If OHCA occurred after the hanging injury, the proportion of patients with good neurologic outcome was very low at 4.1%.

Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Drowning

The Wilderness Medical Society convened a panel to review available evidence supporting practices for the prevention and acute management of drowning in out-of-hospital and emergency medical care settings. Literature about definition and terminology, epidemiology, rescue, resuscitation, acute clinical management, disposition, and drowning prevention was reviewed. The panel graded evidence supporting practices according to the American College of Chest Physicians criteria, then made recommendations based on that evidence. Recommendations were based on the panel's collective clinical experience and judgment when published evidence was lacking.

Therapeutic hypothermia after nonshockable cardiac arrest: the HYPERION multicenter, randomized, controlled, assessor-blinded, superiority trial

BACKGROUND

Meta-analyses of nonrandomized studies have provided conflicting data on therapeutic hypothermia, or targeted temperature management (TTM), at 33°C in patients successfully resuscitated after nonshockable cardiac arrest. Nevertheless, the latest recommendations issued by the International Liaison Committee on Resuscitation and by the European Resuscitation Council recommend therapeutic hypothermia. New data are available on the adverse effects of therapeutic hypothermia, notably infectious complications. The risk/benefit ratio of therapeutic hypothermia after nonshockable cardiac arrest is unclear.

METHODS

HYPERION is a multicenter (22 French ICUs) trial with blinded outcome assessment in which 584 patients with successfully resuscitated nonshockable cardiac arrest are allocated at random to either TTM between 32.5 and 33.5°C (therapeutic hypothermia) or TTM between 36.5 and 37.5°C (therapeutic normothermia) for 24 hours. Both groups are managed with therapeutic normothermia for the next 24 hours. TTM is achieved using locally available equipment. The primary outcome is day-90 neurological status assessed by the Cerebral Performance Categories (CPC) Scale with dichotomization of the results (1 + 2 versus 3 + 4 + 5). The primary outcome is assessed by a blinded psychologist during a semi-structured telephone interview of the patient or next of kin. Secondary outcomes are day-90 mortality, hospital mortality, severe adverse events, infections, and neurocognitive performance. The planned sample size of 584 patients will enable us to detect a 9% absolute difference in day-90 neurological status with 80% power, assuming a 14% event rate in the control group and a two-sided Type 1 error rate of 4.9%. Two interim analyses will be performed, after inclusion of 200 and 400 patients, respectively.

DISCUSSION

The HYPERION trial is a multicenter, randomized, controlled, assessor-blinded, superiority trial that may provide an answer to an issue of everyday relevance, namely, whether TTM is beneficial in comatose patients resuscitated after nonshockable cardiac arrest. Furthermore, it will provide new data on the tolerance and adverse events (especially infectious complications) of TTM at 32.5-33.5°C.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01994772 .

Outcome of avalanche victims with out-of-hospital cardiac arrest

STUDY BACKGROUND

Previous studies focused on the outcome of avalanche victims with out-of-hospital cardiac arrest (OHCA) after long duration of burial (>35min); the outcome of victims with short duration (≤35min) remains obscure.

AIM OF THE STUDY

To investigate outcome of avalanche victims with OHCA.

METHODS

Retrospective analysis of avalanche victims with OHCA between 2008 and 2013 in the Tyrolean Alps.

RESULTS

55 avalanche victims were identified, 32 of whom were declared dead after extrication without cardiopulmonary resuscitation (CPR), all with long duration of burial. In the remaining 23 CPR was initiated at scene; three were partially and 20 completely buried, nine of whom suffered short and 11 long duration of burial. All nine victims with short duration of burial underwent restoration of spontaneous circulation (ROSC) at scene, four of them after bystander CPR, five after advanced life support by the emergency physician. Two patients with ROSC after short duration of burial and bystander CPR survived to hospital discharge with cerebral performance category 1. None of the 11 victims with long duration of burial survived to hospital discharge, although six were transported to hospital with ongoing CPR and three were supported with extracorporeal circulation.

CONCLUSIONS

In this case series survival with favourable neurological outcome was observed in avalanche victims with short duration of burial only if bystander CPR was immediately performed and ROSC achieved. Strategies for reducing avalanche mortality should focus on prompt extrication from the snow and immediate bystander CPR by uninjured companions.

Outcomes of asphyxial cardiac arrest patients who were treated with therapeutic hypothermia: a multicentre retrospective cohort study

INTRODUCTION

While therapeutic hypothermia (TH) is in clinical use, its efficacy in certain patient groups is unclear. This study was designed to describe the characteristics and outcomes of patients with out-of-hospital cardiac-arrest (OHCA) caused by asphyxia, who were treated with TH.

PATIENTS AND METHODS

A multicentre, retrospective, registry-based study was performed using data from the period 2007-2012. Comatose patients who were treated with TH after asphyxial cardiac arrest were included, while those who with cardiac arrest attributed to hanging, drowning or gas intoxication were excluded.

RESULTS

Of a total of 932 OHCA patients in the registry, 111 were enrolled in this study. The mean age was 65.8±16.3 years with individuals who were ≥65 years of age accounted for 61.3% of the cohort. Foreign-body airway obstruction was the most common cause (70.3%) of the cardiac arrest. Eighty patients (72.1%) presented with an initial non-shockable rhythm. In all institutions target TH temperatures were 32-34°C, but TH maintenance times varied. A total of 52 patients (46.8%) survived, of whom six patients (5.4%) showed a good neurologic outcome (cerebral performance category scale 1-2). The pupil light reflex, corneal reflex and time to return of spontaneous circulation (p=0.012, 0.015 and 0.032, respectively) were associated with survival. Witnessed arrest, age, previous lung disease, bystander basic life support and time factors were not associated with survival.

CONCLUSION

About half of patients who underwent TH after asphyxial cardiac arrest survived, but a very small number showed a good neurologic outcome. The TH maintenance times were not uniform in these patients. Additional research regarding both the appropriate TH guidelines for patients with asphyxial cardiac arrest and improvement of their neurologic outcome is needed.

Outcomes of hanging-induced cardiac arrest patients who underwent therapeutic hypothermia: a multicenter retrospective cohort study

OBJECTIVES

The aim of this study was to analyze the outcomes of patients with hanging-induced cardiac arrest who underwent therapeutic hypothermia (TH).

METHOD

In this multicenter, retrospective registry-based study, discharged patients after out-of-hospital cardiac arrest and treatment with TH were enrolled between June 2007 and March 2013. Several prehospital and hospital variables were examined for an outcome analysis with multivariable logistic regression.

RESULTS

A total of 964 patients who had cardiac arrest were enrolled in this study. All patients underwent TH during post-cardiac arrest care after return of spontaneous circulation (ROSC). Of all patients, 105 were assigned to the hanging group and 859 to the non-hanging group. Six patients (6%) with good neurologic outcomes (Cerebral Performance Category 1 or 2) in the hanging group at the time of discharge were found. A shorter time interval between witnessed arrest and ROSC and a Glasgow Coma Scale over 4 after ROSC are statistically significant variables of good neurologic outcomes after hanging-induced cardiac arrest treated with TH.

CONCLUSION

A small number of patients who underwent TH after a hanging-induced cardiac arrest provided good neurologic outcomes, and some variables influenced these outcomes.

Injury after non-judicial hanging

Hanging is an important and increasingly common method of suicide in developed countries. Little is known about the true human pathophysiological changes and injury patterns associated with hanging and near hanging. Cervical spine injury is commonly reported; however, there is a paucity of large data sets concerning this injury. This review article focuses on the incidence of cervical spine and associated neck injuries and their role in morbidity and mortality following non-judicial hanging. A total of 26 heterogeneous studies were identified examining injury after hanging or near hanging. In total, there were 2795 patients; 1530 (54.7%) with true hanging and 1265 (45.3%) with near hanging. Cervical spine injury was reported in a total of 58 (2.08%) patients. Injuries to the airway and vessels of the neck seem rare. This is somewhat lower than the current accepted incidence for cervical spine injury after hanging or blunt force trauma. The overall incidence of cervical spine injury after hanging is low. Spinal immobilisation should probably be instituted depending on the mechanism of the hanging. However, a patient presenting with signs of life to an emergency department is unlikely to have a severe cervical spine injury.

Outcomes of patients admitted for hanging injuries with decreased consciousness but without cardiac arrest

OBJECTIVE

The objective of this study is to provide appropriate treatment of patients who showed decreased mentality but did not suffer cardiac arrest (CA) from hanging injury, from reviewing the characteristics and analyzing the outcomes in such patients.

METHODS

A retrospective review of victims with decreased mentality but without CA due to hanging presenting to 2 tertiary general hospitals between January 2005 and August 2011 was performed. Treatments and examinations were evaluated, and the outcomes were assessed by cerebral performance category at hospital discharge.

RESULTS

A total of 21 patients were included, and their initial Glasgow Coma Scale scores were between 3 and 11. No one received therapeutic hypothermia, but all regained consciousness spontaneously and were discharged with cerebral performance category 1. They received only conservative treatment such as respiratory care, fever control, and inotropic use. Computed tomography and magnetic resonance imaging studies revealed no definite abnormality if the patient did not show abnormal symptom and sign.

CONCLUSION

Unconscious patients without CA from hanging could recover consciousness through conservative treatment.

[Cardiac impairment after hanging attempt: a preliminary descriptive study]

PURPOSE OF THE STUDY

Cardiomyopathy has sometimes been reported after suicide attempts by hanging. The objective of this retrospective observational study was to describe cardiac dysfunction occurring after hanging and its consequences on prognosis.

PATIENTS AND METHODS

Fifteen patients admitted to the intensive care unit for hanging from 1997 to 2011 were included and divided into two groups according to presence or absence of cardiac arrest at initial presentation. Cardiac dysfunction was defined by the presence of clinical, biological, electrocardiographic or echocardiographic abnormalities.

RESULTS

Cardiac impairment was diagnosed in nine patients over 15 (60%). Of the six patients with initial cardiac arrest, only one survived without severe neurological sequellae. Among the nine patients without cardiac arrest, eight survived and five patients (56%) had cardiac impairment, including two cases of echocardiographic aspect of Takotsubo complicated by pulmonary edema. Mortality in intensive care was significantly related to the severity of the initial neurological state assessed by the Glasgow Coma Score (OR=1.7; P=0.02), and the occurrence of cardiac arrest (OR=40; P=0.016). The presence of cardiac involvement, reversible after the acute phase in all surviving patients was not associated with increased mortality.

CONCLUSION

In the aftermath of hanging, predictors of mortality are the presence of impaired consciousness or initial cardiac arrest, but not the occurrence of cardiac disease.

Brain resuscitation in the drowning victim

Drowning is a leading cause of accidental death. Survivors may sustain severe neurologic morbidity. There is negligible research specific to brain injury in drowning making current clinical management non-specific to this disorder. This review represents an evidence-based consensus effort to provide recommendations for management and investigation of the drowning victim. Epidemiology, brain-oriented prehospital and intensive care, therapeutic hypothermia, neuroimaging/monitoring, biomarkers, and neuroresuscitative pharmacology are addressed. When cardiac arrest is present, chest compressions with rescue breathing are recommended due to the asphyxial insult. In the comatose patient with restoration of spontaneous circulation, hypoxemia and hyperoxemia should be avoided, hyperthermia treated, and induced hypothermia (32-34 °C) considered. Arterial hypotension/hypertension should be recognized and treated. Prevent hypoglycemia and treat hyperglycemia. Treat clinical seizures and consider treating non-convulsive status epilepticus. Serial neurologic examinations should be provided. Brain imaging and serial biomarker measurement may aid prognostication. Continuous electroencephalography and N20 somatosensory evoked potential monitoring may be considered. Serial biomarker measurement (e.g., neuron specific enolase) may aid prognostication. There is insufficient evidence to recommend use of any specific brain-oriented neuroresuscitative pharmacologic therapy other than that required to restore and maintain normal physiology. Following initial stabilization, victims should be transferred to centers with expertise in age-specific post-resuscitation neurocritical care. Care should be documented, reviewed, and quality improvement assessment performed. Preclinical research should focus on models of asphyxial cardiac arrest. Clinical research should focus on improved cardiopulmonary resuscitation, re-oxygenation/reperfusion strategies, therapeutic hypothermia, neuroprotection, neurorehabilitation, and consideration of drowning in advances made in treatment of other central nervous system disorders.

Acute respiratory distress due to methane inhalation

Inhalation of toxic gases can lead to pneumonitis. It has been known that methane gas intoxication causes loss of consciousness or asphyxia. There is, however, a paucity of information about acute pulmonary toxicity from methane gas inhalation. A 21-year-old man was presented with respiratory distress after an accidental exposure to methane gas for one minute. He came in with a drowsy mentality and hypoxemia. Mechanical ventilation was applied immediately. The patient's symptoms and chest radiographic findings were consistent with acute pneumonitis. He recovered spontaneously and was discharged after 5 days without other specific treatment. His pulmonary function test, 4 days after methane gas exposure, revealed a restrictive ventilatory defect. In conclusion, acute pulmonary injury can occur with a restrictive ventilator defect after a short exposure to methane gas. The lung injury was spontaneously resolved without any significant sequela.

Continuous evaluation of neurological prognosis after cardiac arrest

Post-resuscitation care has changed in the last decade, and outcome after cardiac arrest has improved, thanks to several combined measures. Induced hypothermia has shown a treatment benefit in two randomized trials, but some doubts remain. General care has improved, including the use of emergency coronary intervention. Assessment of neurological function and prognosis in comatose cardiac arrest patient is challenging, especially when treated with hypothermia. In this review, we evaluate the recent literature and discuss the available evidence for prognostication after cardiac arrest in the era of temperature management. Relevant literature was identified searching PubMed and reading published papers in the field, but no standardized search strategy was used. The complexity of predicting outcome after cardiac arrest and induced hypothermia is recognized in the literature, and no single test can predict a poor prognosis with absolute certainty. A clinical neurological examination is still the gold standard, but the results need careful interpretation because many patients are affected by sedatives and by hypothermia. Common adjuncts include neurophysiology, brain imaging and biomarkers, and a multimodal strategy is generally recommended. Current guidelines for prediction of outcome after cardiac arrest and induced hypothermia are not sufficient. Based on our expert opinion, we suggest a multimodal approach with a continuous evaluation of prognosis based on repeated neurological examinations and electroencephalography. Somatosensory-evoked potential is an established method to help determine a poor outcome and is recommended, whereas biomarkers and magnetic resonance imaging are promising adjuncts. We recommend that a decisive evaluation of prognosis is performed at 72 h after normothermia or later in a patient free of sedative and analgetic drugs.

Therapeutic hypothermia in adult cardiac arrest because of drowning

BACKGROUND

Therapeutic hypothermia in adult victims who suffer cardiac arrest following drowning has been applied in only a small number of cases. In the last 4 years, we have employed therapeutic hypothermia to decrease hypoxia-induced brain injury in these patients. The purpose of the present study was to report the results of the treatment of these patients.

METHODS

This study investigated the utilisation of therapeutic hypothermia on consecutive patients with cardiac arrest because of drowning between 2005 and 2008. The study was conducted retrospectively, collecting data by reviewing medical records. Hypothermia, with a target temperature of 32-34°C, was induced for 24 h. Neurological outcomes were classified using the cerebral performance categories (CPCs). The primary outcome was neurological function at discharge.

RESULTS

Twenty patients were treated with therapeutic hypothermia. Four patients (20%) exhibited a favourable neurological outcome (CPC 1-2). Two patients (10%) remained in a vegetative state at discharge (CPC 4), and 14 patients (70%) died (CPC 5). The most common complications during therapeutic hypothermia were pancreatitis and rhabdomyolysis. A longer duration of advanced cardiac life support (P = 0.035), an absence of motor response to pain after 3 days (P = 0.003), an abnormal brain imaging (P = 0.005) and a lack of cortical response to somatosensory evoked potential (P = 0.008) were related to an unfavourable outcome (CPC 3-5).

CONCLUSION

The present study did not demonstrate an advantage of therapeutic hypothermia in adult cardiac arrest after drowning compared with previous studies treated with conventional therapy. Further prospective studies are needed to evaluate the effects of therapeutic hypothermia.