An essential review of Singapore’s response to out-of-hospital cardiac arrests: improvements over a ten-year period

Care for patients who experience out-of-hospital cardiac arrest (OHCA) has rapidly evolved in the past decade. Increased sophistication of care in the community, emergency medical services (EMS) and hospital setting is associated with improved patient-centred outcomes. Notably, Utstein survival doubled from 11.6% to 23.1% between 2011 and 2016. These achievements involved collaboration between policymakers, clinicians and researchers, and were made possible by a strategic interplay of policy, research and implementation. We review the development and current state of OHCA in Singapore using primary population-based data from the Pan-Asian Resuscitation Outcomes Study and an unstructured search of research databases. We discuss the roles of important milestones in policy, community, dispatch, EMS and hospital interventions. Finally, we relate these interventions to relevant processes and outcomes, such as the relationship between the strategic implementation of bystander cardiopulmonary resuscitation and placement of automated external defibrillator with return of spontaneous circulation, survival to discharge and survival with favourable neurological outcomes.     

Early insulin sensitivity after restrictive bariatric surgery,inconsistency between HOMA-IR and steady-state plasma glucose levels

BackgroundThe low-grade inflammatory condition present in morbid obesity is thought to play a causative role in the pathophysiology of insulin resistance (IR). Bariatric surgery fails to improve this inflammatory condition during the first months after surgery. Considering the close relation between inflammation and IR, we conducted a study in which insulin sensitivity was measured during the first months after bariatric surgery. Different methods to measure IR shortly after bariatric surgery have given inconsistent data. For example, the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) levels have been reported to decrease rapidly after bariatric surgery, although clamp techniques have shown sustained insulin resistance. In the present study, we evaluated the use of steady-state plasma glucose (SSPG) levels to assess insulin sensitivity 2 months after bariatric surgery.MethodsInsulin sensitivity was measured using HOMA-IR and SSPG levels in 11 subjects before surgery and at 26% excess weight loss (approximately 2 months after restrictive bariatric surgery).ResultsThe SSPG levels after 26% excess weight loss did not differ from the SSPG levels before surgery (14.3 ± 5.4 versus 14.4 ± 2.7 mmol/L). In contrast, the HOMA-IR values had decreased significantly (3.59 ± 1.99 versus 2.09 ± 1.02).ConclusionDuring the first months after restrictive bariatric surgery, we observed a discrepancy between the HOMA-IR and SSPG levels. In contrast to the HOMA-IR values, the SSPG levels had not improved, which could be explained by the ongoing inflammatory state after bariatric surgery. These results suggest that during the first months after restrictive bariatric surgery, HOMA-IR might not be an adequate marker of insulin sensitivity.     

Trisomy 16 confined to the placenta.

Two cases with trisomy 16 confined to the placenta are presented. Prenatal diagnosis was indicated because of fetal growth retardation. In case 1, a phenotypically normal but small-for-date boy was born. In case 2, the fetus turned out to be triploid on cordocentesis. In both instances the trisomy 16 was recovered from the placenta. Recovery indicates that the abnormality was present in the placenta during the time of fetal growth retardation, which supports an aetiological relationship. Strict appliance of the current models cannot readily explain the observed discrepancies. In case 2, a chimeric placenta as a result of a vanishing twin is assumed. Cases of placental trisomy 16 published after 1988 are reviewed. It is concluded that confined placental trisomy 16 can cause intrauterine growth retardation if present in both the direct preparation and the villus culture. The chances of finding a chromosomally abnormal fetus (mosaic trisomy 16, triploidy) after diagnosis of trisomy 16 in chorionic villi are low but warrant further investigations.     

The first report of a patient with interrupted inferior vena cava,multiple post-renal veins and azygos-hemiazygos continuation

The first case of a patient with interrupted inferior vena cava, four post-renal veins and an azygoshemiazygos continuation is presented. The complicated anomalies were omphalocele and atrial septal defect. Cine-magnetic resonance imaging and cardiac catheterization showed an anomalous retroaortic left innominate vein, azygos-hemiazygos continuation in the prerenal portion, arch formed renal vein in the renal portion and four embryonic vessels in the post-renal portion. Combination of these anomalies in the major venous system suggested that the inferior vena cava had failed to form and that the bilateral embryonic venous system, postcardinal and supracardinal veins persisted to be the systemic venous channels.     

Apparent and internal validity of a Monte Carlo-Markov model for cardiovascular disease in a cohort follow-up study.

OBJECTIVE: To determine the apparent and internal validity of the Rotterdam Ischemic heart disease & Stroke Computer (RISC) model, a Monte Carlo-Markov model, designed to evaluate the impact of cardiovascular disease (CVD) risk factors and their modification on life expectancy (LE) and cardiovascular disease-free LE (DFLE) in a general population (hereinafter, these will be referred to together as (DF)LE). METHODS: The model is based on data from the Rotterdam Study, a cohort follow-up study of 6871 subjects aged 55 years and older who visited the research center for risk factor assessment at baseline (1990-1993) and completed a follow-up visit 7 years later (original cohort). The transition probabilities and risk factor trends used in the RISC model were based on data from 3501 subjects (the study cohort). To validate the RISC model, the number of simulated CVD events during 7 years' follow-up were compared with the observed number of events in the study cohort and the original cohort, respectively, and simulated (DF)LEs were compared with the (DF)LEs calculated from multistate life tables. RESULTS: Both in the study cohort and in the original cohort, the simulated distribution of CVD events was consistent with the observed number of events (CVD deaths: 7.1% v. 6.6% and 7.4% v. 7.6%, respectively; non-CVD deaths: 11.2% v. 11.5% and 12.9% v. 13.0%, respectively). The distribution of (DF)LEs estimated with the RISC model consistently encompassed the (DF)LEs calculated with multistate life tables. CONCLUSIONS: The simulated events and (DF)LE estimates from the RISC model are consistent with observed data from a cohort follow-up study.     

Mycobacterial infection in an inner city children's hospital

Childhood tuberculosis is perceived by many as a disease of the past. Experience in a children's hospital serving a deprived population suggested that tuberculosis and other mycobacterial infections were not declining in clinical practice. Fifty three tuberculous and 11 atypical mycobacterial infections were identified between 1978 and 1992. There was no decline in tuberculosis and nine of the 11 atypical infections occurred in the last five years. Altogether 40% of cases of tuberculosis were in non-Asian children; 32% had arrived in the UK or visited family overseas in the previous year; and 38% had a history of tuberculosis contact, usually a close adult relative. Nationally, the previous decline in tuberculosis in all ages has reversed. In the local health districts in London's east end, childhood tuberculosis has also stopped declining and seems to be increasing. It is regrettable that BCG vaccination has been abolished by some districts in the UK, against current recommendations. Childhood tuberculosis is still common in the practice described here, including among children who do not fall into conventionally recognised high risk groups. Inner city dwellers and junior doctors are both highly mobile populations, adding to the risk that paediatricians, particularly those in training, may encounter tuberculosis with little or no previous experience of the condition.     

Hypoxia, the subsequent systemic metabolic acidosis, and their relationship with cerebral metabolite concentrations: An in vivo study in fetal lambs with proton magnetic resonance spectroscopy

OBJECTIVE: The relationship among decreased fetal arterial oxygen saturation, the subsequent systemic metabolic acidosis, and changes in cerebral metabolite concentrations in the fetal lamb brain was investigated by means of quantitative proton magnetic resonance spectroscopy. STUDY DESIGN: Fetal hypoxia was induced in 6 fetal lambs by gradual reduction of the oxygen supply to the anesthetized pregnant ewe. In vivo proton magnetic resonance spectroscopy was performed on the fetal lamb brain simultaneously with repeated measurements of fetal arterial oxygen saturation and acid-base balance. RESULTS: Proton magnetic resonance spectra showed metabolites such as inositol, choline compounds, creatine, and N-acetylaspartate. A signal for cerebral lactate was below the detection level under normoxic conditions and increased during hypoxia to indicate concentrations varying from 2.8 to 11.1 mmol/kg wet weight brain tissue. N -Acetylaspartate signals decreased during hypoxia, whereas signals of inositol, choline compounds, and creatine remained constant. CONCLUSION: These results support the view that fetal cerebral anaerobic metabolism in fetal lambs does not start under hypoxic conditions if the arterial blood pH is >7.28 or the base excess is >-8 mmol/L.