Body Fluids ; physiology ; Dehydration ; metabolism ; prevention & control ; Fluid Therapy ; methods ; standards ; Humans ; Practice Guidelines as Topic

This review discusses human thermoregulation during exercise and the measurement of body temperature in clinical and exercise settings. The thermoregulatory mechanisms play important roles in maintaining physiological homeostasis during rest and physical exercise. Physical exertion poses a challenge to thermoregulation by causing a substantial increase in metabolic heat production. However, within a non-thermolytic range, the thermoregulatory mechanisms are capable of adapting to sustain physiological functions under these conditions. The central nervous system may also rely on hyperthermia to protect the body from "overheating." Hyperthermia may serve as a self-limiting signal that triggers central inhibition of exercise performance when a temperature threshold is achieved. Exposure to sub-lethal heat stress may also confer tolerance against higher doses of heat stress by inducing the production of heat shock proteins, which protect cells against the thermolytic effects of heat. Advances in body temperature measurement also contribute to research in thermoregulation. Current evidence supports the use of oral temperature measurement in the clinical setting, although it may not be as convenient as tympanic temperature measurement using the infrared temperature scanner. Rectal and oesophagus temperatures are widely accepted surrogate measurements of core temperature (Tc), but they cause discomfort and are less likely to be accepted by users. Gastrointestinal temperature measurement using the ingestible temperature sensor provides an acceptable level of accuracy as a surrogate measure of Tc without causing discomfort to the user. This form of Tc measurement also allows Tc to be measured continuously in the field and has gained wider acceptance in the last decade.
Body Temperature ; physiology ; Body Temperature Regulation ; physiology ; Exercise ; physiology ; Humans ; Monitoring, Physiologic ; methods

INTRODUCTIONThis study investigated the responses of plasma endotoxin and pro- and antiinflammatory cytokines during a 21-km road race in warm and humid conditions. The influence of carbohydrate-electrolyte (CE)-water (WA) drink mix ingested on leukocyte subset responses and the association between plasma lipopolysaccharide (LPS) concentration and fluid balance, exercise intensity, and body core temperature (Tc) were also studied.

MATERIALS AND METHODSThirty runners provided blood samples before and after the half-marathon for leukocyte, LPS and cytokine analyses. Tc was measured by the ingestible telemetric temperature sensor and fluid intake and split-times were recorded at 3 km intervals. Exercise intensity was determined by matching running speed and heart rate during the race with the corresponding speed-oxygen uptake relationship and heart rate measured in the laboratory 2 to 6 weeks before the race.

RESULTSPlasma LPS concentration increased from 1.9 +/- 1.9 pg/mL before, to 2.5 +/- 1.9 pg/mL after running (P <0.05). Peak plasma LPS concentration was 7.5 pg/mL. Plasma IL-1beta and TNF-concentration did not change significantly, whereas significant increases in IL-10 (50%), IL-1ra (23.2%) and IL-6 (65.2%) were observed after the race. No significant correlation between plasma LPS concentration and exercise intensity, hydration and Tc was observed.

CONCLUSIONLeukocyte subset responses were not related to the ratio of CE and water drink mix ingested. Running a half-marathon can induce mild endotoxaemia, which is not related to exercise intensity, fluid balance, and Tc responses. Mixing CE drink with water did not mitigate postexercise leukocytosis and lymphopenia.

Adult ; Beverages ; Cytokines ; immunology ; Endotoxins ; blood ; immunology ; Fluid Therapy ; Hot Temperature ; Humans ; Humidity ; Leukocytes ; immunology ; Lipopolysaccharides ; immunology ; Male ; Physical Exertion ; physiology ; Running ; physiology

INTRODUCTIONSevere acute respiratory syndrome (SARS) affected 8096 individuals in 29 countries, with 774 deaths. In Singapore, there were 238 cases of SARS with 33 deaths. A retrospective analysis was performed to identify predictors of poor outcome in patients with SARS locally.

MATERIALS AND METHODSClinical, laboratory and outcome data of 234 patients admitted to Tan Tock Seng Hospital and Singapore General Hospital were collected and analysed. Only data collected at the time of admission were used in the analysis for predictors of poor outcome. Adverse events were defined as admission to the intensive care unit or death.

RESULTSClinical (temperature, FiO2) and laboratory [leukocyte, lymphocyte, neutrophil, platelet, lactate dehydrogenase (LDH), albumin] trends in groups with and without an adversarial event were presented. Fifty patients experienced an adverse event. On univariate analysis, male gender, advanced age, presence of comorbidities, neutrophilia, lymphopaenia, hyponatraemia, hypoalbuminaemia, transaminitis and elevated LDH or C-reactive protein were found to be significant predictors. On multivariate analysis, predictors of poor outcome were increased age [odds ratio (OR) 1.73 for every 10-year increase; 95% CI, 1.35 to 2.21], neutrophilia (OR 1.06 for every 1 x 10(9)/L increase; 95% CI, 1.02 to 1.11) and high LDH (OR 1.17 for every 100 U/L increase; 95% CI, 1.02 to 1.34). None of the 12 paediatric patients had an adverse event.

CONCLUSIONAdvanced age, neutrophilia and high LDH predict poor outcomes in patients with SARS.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antibodies, Viral ; analysis ; Child ; Child, Preschool ; DNA, Viral ; analysis ; Female ; Fluorescent Antibody Technique ; Humans ; Incidence ; Infant ; Male ; Middle Aged ; Retrospective Studies ; Reverse Transcriptase Polymerase Chain Reaction ; SARS Virus ; genetics ; immunology ; Severe Acute Respiratory Syndrome ; epidemiology ; virology ; Severity of Illness Index ; Singapore ; epidemiology ; Survival Rate

INTRODUCTION: Haze is a recurrent problem in Southeast Asia. Exposure to haze is linked to ophthalmic, respiratory and cardiovascular diseases, and mortality. In this study, we investigated the role of demographic factors, knowledge and perceived risk in influencing protective behaviours during the 2013 haze in Singapore. METHODS: We evaluated 696 adults in a cross-sectional study. Participants were sampled via a 2-stage simple random sampling without replacement from a large residential district in Singapore in 2015. The questionnaire measured the participant's knowledge, perceived risk and behaviours during the Southeast Asian haze crisis in 2013. Reliability and validity of the questionnaire were assessed using comparative fit index (≥0.96) and root mean square error of approximation (≤0.05). We performed structural equation modelling to examine the relationship between the hypothesised factors and protective behaviours. RESULTS: More than 95% of the individuals engaged in at least 1 form of protective behaviour. Knowledge was strongly associated with protective behaviours via direct effect (β=0.45, 95% CI 0.19-0.69, CONCLUSION Knowledge was associated with protective behaviours, suggesting the importance of public education. Efforts should target those of lower education level and smokers. The wearing of N95 masks correlates with uptake of other protective behaviours.
Adult ; Asia, Southeastern ; Cross-Sectional Studies ; Ethnic Groups ; Humans ; Minority Groups ; Reproducibility of Results ; Singapore/epidemiology*

INTRODUCTION: The cross Kirschner wire (K-wire) configuration in closed reduction and percutaneous pinning of paediatric supracondylar humeral fracture affords superior stability. However, medial pin placement presents a risk of iatrogenic ulnar nerve injury. This study describes, in step-by-step detail, another safe method of percutaneous medial pin insertion. METHODS: The technique involved placing the patient's arm in external rotation, with elbow flexed no more than 45° after closed reduction. The surgeon held the K-wire close to its sharp end to pass it percutaneously onto the medial epicondyle, then adjusted his grip toward the blunt end. After fluoroscopy check, the wire driver was engaged and an anteriorly directed force was applied to the distal humerus fragment using the thumb of the surgeon's free hand. The K-wire was inserted at a 45° angle to the longitudinal axis of the humerus shaft. Clinical notes and radiographs of patients who underwent surgery with this technique from 2006 to 2008 were reviewed. RESULTS: A total of 125 patients (84 boys, 41 girls) were included, with a mean age of 7.1 (range 2-14) years. Most injuries were left-sided (72.8%, n = 91, vs. right: 27.2%, n = 34). 72 (57.6%) patients had two-pin cross K-wire configuration, while 53 (42.4%) patients had an additional lateral pin inserted. No patient had postoperative ulnar neuropathy. There were no complications of non-union, malunion or infection. CONCLUSION This safe method of medial pin placement for surgical stabilisation of paediatric supracondylar humeral fractures is easily learnt and reproducible, and produces excellent results.
Adolescent ; Bone Nails ; Child ; Child, Preschool ; Female ; Fluoroscopy ; Fracture Fixation, Intramedullary ; methods ; Humans ; Humeral Fractures ; surgery ; Humerus ; injuries ; Iatrogenic Disease ; Male ; Pediatrics ; Radiography ; Retrospective Studies ; Ulnar Nerve

The Ministry of Health (MOH) has updated the clinical practice guidelines on hypertension to provide doctors and patients in Singapore with evidence-based treatment for hypertension. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on hypertension, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http://www.moh.gov.sg/content/moh_web/healthprofessionalsportal/doctors/guidelines/cpg_medical.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.
Antihypertensive Agents ; therapeutic use ; Blood Pressure ; Evidence-Based Medicine ; Health Promotion ; Humans ; Hypertension ; diagnosis ; therapy ; Life Style ; Risk Factors ; Singapore