Electrocardiography ; Humans ; ST Elevation Myocardial Infarction/therapy*

INTRODUCTIONMaximal oxygen uptake, V&O2 peak, among athletes is an important foundation for all training programmes to enhance competition performance. In Singapore, the V& O2 peak of athletes is apparently not widely known. There is also controversy in the modelling or scaling of maximal oxygen uptake for differences in body size - the use of ratio-scaling remains common but allometric scaling is gaining acceptance as the method of choice.

MATERIALS AND METHODSOne hundred fifty-eight male (age, 21.7 +/- 4.9 years; body mass, 64.8 +/- 8.6 kg) and 28 female (age, 21.9 +/- 7.0 years; body mass, 53.0 +/- 7.0 kg) athletes completed a maximal treadmill run to volitional exhaustion, to determine VO2 peak.

RESULTSV& O2 peak in L/min of female athletes was 67.8% that of male athletes (2.53 +/- 0.29 vs. 3.73 +/- 0.53 L/min), and V& O2 peak in mL/kg BM1.0/min of female athletes was 83.4% of male athletes (48.4 +/- 7.2 vs. 58.0 +/- 6.9 mL/kg BM1.0/min). Ratio-scaling of V& O2 peak did not create a size-free variable and was unsuitable as a scaling method. Instead, V& O2 peak, that was independent of the effect of body mass in male and female athletes, was best described using 2 separate and allometrically-derived sex-specific regression equations; these were V& O2 peak = 2.23 BM0.67 for male athletes and V& O2 peak = 2.23 BM0.24 for female athletes.

Adolescent ; Adult ; Body Size ; Exercise Test ; Female ; Humans ; Male ; Models, Biological ; Monitoring, Physiologic ; methods ; Oxygen Consumption ; physiology ; Physical Fitness ; physiology ; Singapore ; Sports

INTRODUCTIONMany consider the Wingate Anaerobic Test (WAnT) as a reference standard assessment mode in the measurement of lower limb short-term power output. However the WAnT is criticised for having low ecological validity, in non-cycling tasks and is reliant on a predetermined applied force, which might not elicit the highest power output. A viable alternative to the WAnT is the Non-Motorised Treadmill (NMT) Test, which allows for power measurement in all-out intensity effort sprint-running. With the reliability of the NMT to elicit power in sedentary adults already established, the aim was to compare peak power (PP) and mean power (MP) derived from a 10-s sprint on the NMT to that derived from a 10-s WAnT, to establish concurrent validity.

MATERIALS AND METHODSTwelve male [age 26.6 +/- 2.4 years, body mass (BM) 63.0 +/- 7.2 kg] and 11 female (age 25.3 +/- 3.6 years, BM 51.0 +/- 4.0 kg) sedentary adults participated in the study. PP and MP in absolute, ratio-scaled and allometrically-scaled to BM were analysed. Ratio limits of agreement (LOA) was used to establish the agreement between PP and MP from the NMT and the WAnT.

RESULTSPP in absolute and ratio-scaled to BM from the NMT was between 1.04 and 1.12 times that of PP from the WAnT in 95% of the attempts (PP: NMT, 647.1 +/- 176.4W vs WAnT, 597.0 +/- 146.0W). MP in absolute and ratio-scaled to BM from the NMT test was between 0.88 and 0.97 times of that from the WAnT (MP: NMT, 508.9 +/- 130.7W vs WAnT, 548.7 +/- 131.3W). Power produced on the NMT and the WAnT by sedentary adults shared moderate and acceptable levels of agreement.

CONCLUSIONSThese results affirmed that the NMT could be considered as a viable alternative to the WAnT for the assessment of PP and MP in allout intensity sprint-running lasting 10 s in sedentary adults.

Adult ; Exercise ; physiology ; Exercise Test ; instrumentation ; standards ; Female ; Humans ; Life Style ; Male ; Motor Activity ; physiology ; Muscle Strength ; physiology ; Physical Fitness ; physiology

INTRODUCTIONPrompt recognition of cardiac arrest and initiation of cardiopulmonary resuscitation (CPR) and defibrillation is necessary for good outcomes from out-of-hospital cardiac arrest (OHCA). This study aims to describe the recognition and treatment of OHCA in patients conveyed by non-emergency ambulance services (EAS) in Singapore.

MATERIALS AND METHODSThis is a multi-centre, retrospective chart review, of cases presenting to public emergency departments (EDs), conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. The study was from October 2002 to August 2009. The following variables were examined: ability to recognise cardiac arrest, whether CPR was carried out by the ambulance crew and whether an automated external defibrillator (AED) was applied.

RESULTSEighty-six patients were conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. Mean age was 63 years (SD 21.8), 70.9% were males. A total of 53.5% of arrests occurred in the ambulance while 70.9% were found to be asystolic upon ED arrival. Seven patients had a known terminal illness. Survival to discharge was 3.5%. Cardiac arrest went unrecognised by the ambulance crew in 38 patients (44.2%). CPR was performed in 35 patients (40.7%) of the 86 patients and AED was applied in only 10 patients (11.6%).

CONCLUSIONWe found inadequate recognition and delayed initiation of treatment for OHCA. Possible reasons include a lack of training in patient monitoring and detection of cardiac arrest, lack of CPR training, lack of confidence in performing CPR, lack of AEDs on ambulances and lack of training in their use.

Aged ; Aged, 80 and over ; Ambulances ; Cardiopulmonary Resuscitation ; standards ; Electric Countershock ; standards ; Emergency Medical Services ; standards ; Female ; Humans ; Male ; Middle Aged ; Out-of-Hospital Cardiac Arrest ; diagnosis ; therapy ; Retrospective Studies ; Singapore ; Transportation of Patients ; standards

INTRODUCTION: Bystander cardiopulmonary resuscitation (B-CPR) is associated with improved out-of hospital cardiac arrest survival. Community-level interventions including dispatcher-assisted CPR (DA-CPR) and myResponder were implemented to increase B-CPR. We sought to assess whether these interventions increased B-CPR. METHODS: The Singapore out-of-hospital cardiac arrest registry captured cases that occurred between 2010 and 2017. Outcomes occurring in 3 time periods (Baseline, DA-CPR, and DA-CPR plus myResponder) were compared. Segmented regression of time-series data was conducted to investigate our intervention impact on the temporal changes in B-CPR. RESULTS: A total of 13,829 out-of-hospital cardiac arrest cases were included from April 2010 to December 2017. Higher B-CPR rates (24.8% versus 50.8% vs 64.4%) were observed across the 3 time periods. B-CPR rates showed an increasing but plateauing trend. DA-CPR implementation was significantly associated with an increased B-CPR (level odds ratio [OR] 2.26, 95% confidence interval [CI] 1.79-2.88; trend OR 1.03, 95% CI 1.01-1.04), while no positive change was detected with myResponder (level OR 0.95, 95% CI 0.82-1.11; trend OR 0.99, 95% CI 0.98-1.00). CONCLUSION B-CPR rates in Singapore have been increasing alongside the implementation of community-level interventions such as DA-CPR and myResponder. DA-CPR was associated with improved odds of receiving B-CPR over time while the impact of myResponder was less clear.

INTRODUCTION: Despite adhering to criteria for extubation, up to 20% of intensive care patients require re-intubation, even with use of post-extubation high-flow nasal cannula (HFNC). This study aims to identify independent predictors and outcomes of extubation failure in patients who failed post-extubation HFNC. METHODS: We conducted a multicentre observational study involving 9 adult intensive care units (ICUs) across 5 public hospitals in Singapore. We included patients extubated to HFNC following spontaneous breathing trials. We compared patients who were successfully weaned off HFNC with those who failed HFNC (defined as re-intubation ≤7 days following extubation). Generalised additive logistic regression analysis was used to identify independent risk factors for failed HFNC. RESULTS: Among 244 patients (mean age: 63.92±15.51 years, 65.2% male, median APACHE II score 23.55±7.35), 41 (16.8%) failed HFNC; hypoxia, hypercapnia and excessive secretions were primary reasons. Stroke was an independent predictor of HFNC failure (odds ratio 2.48, 95% confidence interval 1.83-3.37). Failed HFNC, as compared to successful HFNC, was associated with increased median ICU length of stay (14 versus 7 days, CONCLUSION Post-extubation HFNC failure, especially in patients with stroke as a comorbidity, remains a clinical challenge and predicts poorer clinical outcomes. Our observational study highlights the need for future prospective trials to better identify patients at high risk of post-extubation HFNC failure.
Adult ; Airway Extubation ; Cannula ; Critical Care ; Female ; Humans ; Intensive Care Units ; Male ; Middle Aged ; Respiratory Insufficiency/therapy* ; Singapore/epidemiology*

BACKGROUND AND OBJECTIVES: Recent studies showed that, in addition to parasympathetic nerves, cervical vagal nerves contained significant sympathetic nerves. We hypothesized that cervical vagal nerve stimulation (VNS) may capture the sympathetic nerves within the vagal nerve and activate the stellate ganglion. MATERIALS AND METHODS: We recorded left stellate ganglion nerve activity (SGNA), left thoracic vagal nerve activity (VNA), and subcutaneous electrocardiogram in seven dogs during left cervical VNS with 30 seconds on-time and 30 seconds off time. We then compared the SGNA between VNS on and off times. RESULTS: Cervical VNS at moderate (0.75 mA) output induced large SGNA, elevated heart rate (HR), and reduced HR variability, suggesting sympathetic activation. Further increase of the VNS output to >1.5 mA increased SGNA but did not significantly increase the HR, suggesting simultaneous sympathetic and parasympathetic activation. The differences of integrated SGNA and integrated VNA between VNS on and off times (DeltaSGNA) increased progressively from 5.2 mV-s {95% confidence interval (CI): 1.25-9.06, p=0.018, n=7} at 1.0 mA to 13.7 mV-s (CI: 5.97-21.43, p=0.005, n=7) at 1.5 mA. The difference in HR (DeltaHR, bpm) between on and off times was 5.8 bpm (CI: 0.28-11.29, p=0.042, n=7) at 1.0 mA and 5.3 bpm (CI 1.92 to 12.61, p=0.122, n=7) at 1.5 mA. CONCLUSION: Intermittent cervical VNS may selectively capture the sympathetic components of the vagal nerve and excite the stellate ganglion at moderate output. Increasing the output may result in simultaneously sympathetic and parasympathetic capture.
Animals ; Autonomic Nervous System ; Dogs* ; Electrocardiography ; Heart Rate ; Stellate Ganglion* ; Vagus Nerve Stimulation*

INTRODUCTIONDeveloping effective exercise programmes for the paediatric population is a strategy for decreasing obesity and is expected to help in eventually limiting obesity-associated long-term health and societal impact. In this study, the effects of a 12-week twice weekly additional exercise training, which comprised a combination of circuit-based resistance training and aerobic exercises, in additional to typical physical education sessions, on aerobic fitness, body composition and serum C-reactive protein (CRP) and lipids were analysed in 13- to 14-year-old obese boys contrasted with a control group.

MATERIALS AND METHODSBoth the exercise group (EG, n = 12) and control group (CG, n = 12) participated in the typical 2 sessions of 40-minute physical education (PE) per week in schools, but only EG participated in additional 2 sessions per week of 45 to 60 minutes per session of exercise training, which comprised a combination of circuit-based resistance training and aerobic exercises maintained at 65% to 85% maximum heart rate (HRmax = 220 - age). Body composition was measured using dual energy X-ray absorptiometry (DEXA). Fasting serum CRP and blood lipids were analysed pre- and postexercise programme. Aerobic fitness was measured by an objective laboratory submaximal exercise test, PWC170 (Predicted Work Capacity at HR 170 bpm).

RESULTSExercise training significantly improved lean muscle mass, body mass index, fitness, resting HR, systolic blood pressure and triglycerides in EG. Serum CRP concentrations were elevated at baseline in both groups, but training did not result in a change in CRP levels. In the CG, body weight increased significantly at the end of the 12-week period.

CONCLUSIONThis study supports the value of an additional exercise training programme, beyond the typical twice weekly physical education classes, to produce physiological benefits in the management of obesity in adolescents, including prevention of weight gain.

Adolescent ; C-Reactive Protein ; analysis ; metabolism ; Exercise Therapy ; Humans ; Lipids ; analysis ; blood ; Male ; Obesity ; physiopathology ; therapy ; Physical Fitness ; physiology

INTRODUCTION: Nursing home (NH) residents with out-of-hospital cardiac arrests (OHCA) have unique resuscitation priorities. This study aimed to describe OHCA characteristics in NH residents and identify independent predictors of survival. MATERIALS AND METHODS: OHCA cases between 2010-16 in the Pan-Asian Resuscitation Outcomes Study were retrospectively analysed. Patients aged <18 years old and non-emergency cases were excluded. Primary outcome was survival at discharge or 30 days. Good neurological outcome was defined as a cerebral performance score between 1-2. RESULTS: A total of 12,112 cases were included. Of these, 449 (3.7%) were NH residents who were older (median age 79 years, range 69-87 years) and more likely to have a history of stroke, heart and respiratory diseases. Fewer NH OHCA had presumed cardiac aetiology (62% vs 70%, <0.01) and initial shockable rhythm (8.9% vs 18%, <0.01), but had higher incidence of bystander cardiopulmonary resuscitation (74% vs 43%, <0.01) and defibrillator use (8.5% vs 2.8%, <0.01). Non-NH (2.8%) residents had better neurological outcomes than NH (0.9%) residents ( <0.05). Factors associated with survival for cardiac aetiology included age <65 years old, witnessed arrest, bystander defibrillator use and initial shockable rhythm; for non-cardiac aetiology, these included witnessed arrest (adjusted odds ratio [AOR] 3.8, <0.001) and initial shockable rhythm (AOR 5.7, <0.001). CONCLUSION Neurological outcomes were poorer in NH survivors of OHCA. These findings should inform health policies on termination of resuscitation, advance care directives and do-not-resuscitate orders in this population.

INTRODUCTION: Hospital-based resuscitation interventions, such as therapeutic temperature management (TTM), emergency percutaneous coronary intervention (PCI) and extracorporeal membrane oxygenation (ECMO) can improve outcomes in out-of-hospital cardiac arrest (OHCA). We investigated post-resuscitation interventions and hospital characteristics on OHCA outcomes across public hospitals in Singapore over a 9-year period. METHODS: This was a prospective cohort study of all OHCA cases that presented to 6 hospitals in Singapore from 2010 to 2018. Data were extracted from the Pan-Asian Resuscitation Outcomes Study Clinical Research Network (PAROS CRN) registry. We excluded patients younger than 18 years or were dead on arrival at the emergency department. The outcomes were 30-day survival post-arrest, survival to admission, and neurological outcome. RESULTS: The study analysed 17,735 cases. There was an increasing rate of provision of TTM, emergency PCI and ECMO (P<0.001) in hospitals, and a positive trend of survival outcomes (P<0.001). Relative to hospital F, hospitals B and C had lower provision rates of TTM (≤5.2%). ECMO rate was consistently <1% in all hospitals except hospital F. Hospitals A, B, C, E had <6.5% rates of provision of emergency PCI. Relative to hospital F, OHCA cases from hospitals A, B and C had lower odds of 30-day survival (adjusted odds ratio [aOR]<1; P<0.05 for hospitals A-C) and lower odds of good neurological outcomes (aOR<1; P<0.05 for hospitals A-C). OHCA cases from academic hospitals had higher odds ratio (OR) of 30-day survival (OR 1.3, 95% CI 1.1-1.5) than cases from hospitals without an academic status. CONCLUSION Post-resuscitation interventions for OHCA increased across all hospitals in Singapore from 2010 to 2018, correlating with survival rates. The academic status of hospitals was associated with improved survival.
Hospitals, Public ; Humans ; Out-of-Hospital Cardiac Arrest/therapy* ; Percutaneous Coronary Intervention ; Prospective Studies ; Singapore/epidemiology*