Heatstroke in the super-sized athlete

Malignant Hyperthermia in PICU—From Diagnosis to Treatment in the Light of Up-to-Date Knowledge

Malignant Hyperthermia (MH) is a rare, hereditary, life-threatening disease triggered by volatile anesthetics and succinylcholine. Rarely, MH can occur after non-pharmacological triggers too. MH was detected more often in children and young adults, which makes this topic very important for every pediatric specialist, both anesthesiologists and intensivists. MH crisis is a life-threatening severe hypermetabolic whole-body reaction. Triggers of MH are used in pediatric intensive care unit (PICU) as well, volatile anesthetics in difficult sedation, status asthmaticus or epilepticus, and succinylcholine still sometimes in airway management. Recrudescence or delayed onset of MH crisis hours after anesthesia was previously described. MH can also be a cause of rhabdomyolysis and hyperpyrexia in the PICU. In addition, patients with neuromuscular diseases are often admitted to PICU and they might be at risk for MH. The most typical symptoms of MH are hypercapnia, tachycardia, hyperthermia, and muscle rigidity. Thinking of the MH as the possible cause of deterioration of a patient’s clinical condition is the key to early diagnosis and treatment. The sooner the correct treatment is commenced, the better patient´s outcome. This narrative review article aims to summarize current knowledge and guidelines about recognition, treatment, and further management of MH in PICU.

Clinical Spectrum of Pediatric Heat Illness and Heatstroke in a North American Desert Climate

ABSTRACT

The spectrum of historical features and clinical presentations of heat illness and heatstroke in the pediatric population has received limited focus in the emergency medicine literature. The majority of published cases involve children trapped in closed spaces and adolescent athletes undergoing high-intensity training regimens in geographical regions with moderately high ambient temperatures and high humidity. There has been less research on the potential impact of extreme temperatures and radiant heat that are the hallmarks of the US southwest region. We performed a retrospective review of pediatric heat illness at our facility located in a North American desert climate.

Health Risks and Interventions in Exertional Heat Stress

BACKGROUND

With climate change, heat waves are expected to become more frequent in the near future. Already, on average more than 25 000 "heat deaths" are estimated to occur in Europe every year. However, heat stress and heat illnesses arise not just when ambient temperatures are high. Physical exertion increases heat production within the organism many times over; if not enough heat is lost, there is a risk of exertional heat stress. This review article discusses contributing factors, at-risk groups, and the diagnosis and treatment of heat illnesses.

METHODS

A selective literature search was carried out on PubMed. Current guidelines and expert recommendations were also included.

RESULTS

Apart from muscular heat production (>70% of converted energy), there are other factors that singly or in combination can give rise to heat stress: clothing, climate/acclimatization, and individual factors. Through its insulating properties, clothing reduces the evaporation of sweat (the most effective physiological cooling mechanism). A sudden heat wave, or changing the climate zone (as with air travel), increases the risk of a heat-related health event. Overweight, low fitness level, acute infections, illness, dehydration, and other factors also reduce heat tolerance. In addition to children, older people are particularly at risk because of their reduced physiological adaptability, (multi-)morbidity, and intake of prescription drugs. A heat illness can progress suddenly to life-threatening heat stroke. Successful treatment depends on rapid diagnosis and cooling the body down as quickly as possible. The aim is to reduce core body temperature to <40 °C within 30 minutes.

CONCLUSION

Immediately effective cooling interventions are the only causal treatment for heat stroke. Time once lost cannot be made up. Prevention (acclimatization, reduced exposure, etc.) and terminating the heat stress in good time (e.g., stopping work) are better than any cure.

[Efficacy of dermal scaffold for promoting repair of acute full-thickness skin defects in pigs]

OBJECTIVE

To investigate the efficacy of Lando^® dermal scaffold for promoting repair of acute full-thickness skin defects in pigs and explore the possible mechanism.

METHODS

Three 5 cm×5 cm full-thickness skin defects were created on the left dorsal skin (control group) and another 3 on the right dorsal skin (treatment group) of each of 6 Tibetan pigs. The wounds in the treatment group were covered with a bilayer artificial skin (Lando) and the control wounds with vaseline gauze. In both groups, autogenous split-thickness skin were grafted to the wounds 2 weeks later (with the silicone rubber membrane removed before grafting in the treatment group). At 3 days and 2 and 10 weeks after the injury, the wounds were assessed for general condition and contraction, and tissue samples were collected from the wounds to examine the expressions of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) using immunohistochemistry and the expressions of MMP-1 and TIMP-1 mRNA using RT-PCR.

RESULTS

At 3 days after the injury, the wounds in the 2 groups showed no significant differences in the results of any examinations. At 2 weeks after the injury, the wounds in the treatment group showed rich and more smooth granulation tissues with more regular wound edges compared with the control wounds. At 2 and 10 weeks after the injury, the wound contraction rates in the treatment group were (30.5∓3.4)% and (39.2∓2.8)%, respectively, significantly lower than the rates of (51.8∓2.6)% (t=-29.840, P=0.000) and (60.7∓2.2)% (t=-50.213, P=0.000) in the control group. At 2 weeks, the wound tissues in the treatment group expressed significantly higher levels of α-SMA (t=15.921, P=0.000) and TGF-β1 (t=29.995, P=0.000) than the control wounds, but at 10 weeks, the expressions of α-SMA (t=-41.823, P=0.000) and TGF-β1 (t=-99.777, P=0.000) in the treatment group were significantly lower than those in the control group. Compared with those in the control group, the expression of MMP-1 mRNA in the treatment group was significantly lower at 2 weeks (t=-45.412, P=0.000) but significantly higher at 10 weeks (t=78.769, P=0.000), and the expression of TIMP-1 mRNA in the treatment group was significantly lower both at 2 weeks (t=-27.064, P=0.000) and at 10 weeks (t=-40.535, P=0.000).

CONCLUSIONS

Lando^® dermal scaffold can promote granulation tissue growth possibly in relation with increased TGF-β1 and decreased MMP-1 expression in the wounds. This scaffold material also reduces wound contraction and lessens scar hyperplasia and contracture after wound healing, probably as a result of decreased α-SMA, TGF-β1, and TIMP-1 and increased MMP-1 expressions.

Exertional heat stroke in navy and marine personnel: a hot topic

Although exertional heat stroke is considered a preventable condition, this life-threatening emergency affects hundreds of military personnel annually. Because heat stroke is preventable, it is important that Navy critical care nurses rapidly recognize and treat heat stroke casualties. Combined intrinsic and extrinsic risk factors can quickly lead to heat stroke if not recognized by deployed critical care nurses and other first responders. In addition to initial critical care nursing interventions, such as establishing intravenous access, determining body core temperature, and assessing hemodynamic status, aggressive cooling measures should be initiated immediately. The most important determinant in heat stroke outcome is the amount of time that patients sustain hyperthermia. Heat stroke survival approaches 100% when evidence-based cooling guidelines are followed, but mortality from heat stroke is a significant risk when care is delayed. Navy critical care and other military nurses should be aware of targeted assessments and cooling interventions when heat stroke is suspected during military operations.

Heat stroke with bimodal rhabdomyolysis: a case report and review of the literature

BACKGROUND

Severe heat stroke tends to be complicated with rhabdomyolysis, especially in patients with exertional heat stroke. Rhabdomyolysis usually occurs in the acute phase of heat stroke. We herein report a case of heat stroke in a patient who experienced bimodal rhabdomyolysis in the acute and recovery phases.

CASE PRESENTATION

A 34-year-old male patient was found lying unconscious on the road after participating in a half marathon in the spring. It was a sunny day with a maximum temperature of 24.2 °C. His medical and family history was unremarkable. Upon arrival, his Glasgow Coma Scale score was 10. However, the patient's marked restlessness and confusion returned. A sedative was administered and tracheal intubation was performed. On the second day of hospitalization, a blood analysis was compatible with a diagnosis of acute hepatic failure; thus, he received fresh frozen plasma and a platelet transfusion was performed, following plasma exchange and continuous hemodiafiltration. The patient's creatinine phosphokinesis (CPK) level increased to 8832 IU/L on the fifth day of hospitalization and then showed a tendency to transiently decrease. The patient was extubated on the eighth day of hospitalization after the improvement of his laboratory data. From the ninth day of hospitalization, gradual rehabilitation was initiated. However, he felt pain in both legs and his CPK level increased again. Despite the cessation of all drugs and rehabilitation, his CPK level increased to 105,945 IU/L on the 15th day of hospitalization. Fortunately, his CPK level decreased with a fluid infusion. The patient's rehabilitation was restarted after his CPK level fell to <10,000 IU/L. On the 31st day of hospitalization, his CK level decreased to 623 IU/L and he was discharged on foot. Later, a genetic analysis revealed that he had a thermolabile genetic phenotype of carnitine palmitoyltransferase II (CPT II).

CONCLUSIONS

Physicians should pay special attention to the stress of rehabilitation exercises, which may cause collapsed muscles that are injured by severe heat stroke to repeatedly flare up.

Out of the frying pan, into the fire: a case of heat shock and its fatal complications

Exertional heat stroke incidence is on the rise and has become the third leading cause of death in high school athletes. It is entirely preventable, yet this is a case of a 15-year-old, 97-kg male football player who presented unresponsive and hyperthermic after an August football practice. His blood pressure was 80/30, and his pulse was 180. He had a rectal temperature of 107.3°F, and upon entering the emergency department, he was rapidly cooled in 40 minutes. As he progressed, he developed metabolic acidosis, elevated liver enzymes, a prolapsed mitral valve with elevated troponin levels, and worsening hypotension even with extracorporeal membrane oxygenation support. After 3 days in the hospital, this young man was pronounced dead as a result of complications from exertional heat stroke. We address not only the complications of his hospital course relative to his positive blood cultures but also the complications that can result from attention-deficit/hyperactivity disorder medication our patient was taking. As the population of young adults becomes more obese and more highly medicated for attention-deficit/hyperactivity disorder, we sought out these growing trends in correlation with the increase in incidence of heat-related illness. We also address the predisposing factors that make young high school athletes more likely to experience heat illness and propose further steps to educate this susceptible population.

Therapeutic plasmapheresis and red blood cell exchange in a sickle cell trait patient with rhabdomyolysis

We report a case of a 16-year-old African-American male with sickle cell trait and a past medical history significant for asthma that was transferred to our hospital for management of respiratory failure. On the fourth day of hospitalization, the patient was found to have increased creatine kinase (CK) levels and urine myoglobin levels consistent with rhabdomyolysis. No clear etiology was identified. Aggressive standard hydration and urine alkalization were applied without response. On the sixth day of hospitalization, the patient underwent a 1-1.5 plasma volume therapeutic plasma exchange (TPE) resulting in a transient reduction of serum CK and myoglobin by 50%, which became elevated once again within 4 h. Since his clinical presentation resembles exertional rhabdomyolysis documented in patients with sickle cell trait, RBC exchange was performed. The patient tolerated the procedure without complications. In addition to his improved overall condition, the patient's post-exchange CK and serum myoglobin levels dropped dramatically without rebound. To our knowledge, this case represents the first reported case of TPE followed by RBC exchange in a SCT patient with rhabdomyolysis.

Prevention and Management of Physical and Social Environment Risk Factors for Sports-Related Injuries

An understanding of the environmental factors that contribute to injury risk will allow for the optimization of athletic performance and minimize morbidity. The purpose of this review is to discuss the physical and social environments of sport that affect injury risk, and to review the strategies that sports medicine professionals (eg, clinicians, certified athletic trainers) can implement to prevent injury. Searches using the PubMed, Cochrane, and Google Scholar databases were used to identify injury risk factors pertaining to the physical and social environment of athletics. Physical environmental risk factors identified include weather, air quality, playing surface, and the presence of sports medicine professionals. Social environmental factors include parents, teammates, coaches, media, policy/legislation, and sports medicine professionals. Sports medicine professionals seeking effective prevention and care strategies will benefit from (1) education about the physical and social environmental risk factors that place athletes at risk for injury and (2) a holistic approach that recognizes that physical and social factors are as important as individual risk factors in determining injury risk.

[Liver and sport]

The liver is a vital organ and plays a central role in energy exchange, protein synthesis as well as the elimination of waste products from the body. Acute and chronic injury may disturb a variety of liver functions to different degrees. Over the last three decades, the effects of physical activity and competitive sport on the liver have been described by various investigators. These include viral hepatitis and drug-induced liver disorders. Herein, we review acute and chronic liver diseases potentially caused by sport. Team physicians, trainers and others, responsible for the health of athletes, should be familiar with the risk factors, clinical features, and consequences of liver diseases that occur in sports.

Rhabdomyolysis: a review of clinical presentation, etiology, diagnosis, and management

Rhabdomyolysis is a condition that results from many underlying etiologies and can present in a myriad of ways to the emergency physician. However, some clinical and laboratory features are almost always present and, if noted, can help in making the diagnosis. This review article will focus on the presenting symptoms, the various etiologies, the underlying mechanisms, and the current management of pediatric rhabdomyolysis.