Factors influencing the decision to convey or not to convey elderly people to the emergency department after emergency ambulance attendance:a systematic mixed studies review

BACKGROUND: The decision over whether to convey after emergency ambulance attendance plays a vital role in preventing avoidable admissions to a hospital's emergency department (ED). This is especially important with the elderly, for whom the likelihood and frequency of adverse events are greatest. OBJECTIVE: To provide a structured overview of factors influencing the conveyance decision of elderly people to the ED after emergency ambulance attendance, and the outcomes of these decisions. DATA SOURCES: A mixed studies review of empirical studies was performed based on systematic searches, without date restrictions, in PubMed, CINAHL and Embase (April 2018). Twenty-nine studies were included. STUDY ELIGIBILITY CRITERIA: Only studies with evidence gathered after an emergency medical service (EMS) response in a prehospital setting that focused on factors that influence the decision whether to convey an elderly patient were included. SETTING: Prehospital, EMS setting; participants to include EMS staff and/or elderly patients after emergency ambulance attendance. STUDY APPRAISAL AND SYNTHESIS METHODS: The Mixed Methods Appraisal Tool was used in appraising the included articles. Data were assessed using a 'best fit' framework synthesis approach. RESULTS: ED referral by EMS staff is determined by many factors, and not only the acuteness of the medical emergency. Factors that increase the likelihood of non-conveyance are: non-conveyance guidelines, use of feedback loop, the experience, confidence, educational background and composition (male-female) of the EMS staff attending and consulting a physician, EMS colleague or other healthcare provider. Factors that boost the likelihood of conveyance are: being held liable, a lack of organisational support, of confidence and/or of baseline health information, and situational circumstances. Findings are presented in an overarching framework that includes the impact of these factors on the decision's outcomes. CONCLUSION: Many non-medical factors influence the ED conveyance decision after emergency ambulance attendance, and this makes it a complex issue to manage

Prehospital risk stratification in patients with chest pain

OBJECTIVES: The History, ECG, Age, Risk Factors and Troponin (HEART) Score is a decision support tool applied by physicians in the emergency department developed to risk stratify low-risk patients presenting with chest pain. We assessed the potential value of this tool in prehospital setting, when applied by emergency medical services (EMS), and derived and validated a tool adapted to the prehospital setting in order to determine if it could assist with decisions regarding conveyance to a hospital. METHODS: In 2017, EMS personnel prospectively determined the HEART Score, including point-of-care (POC) troponin measurements, in patients presenting with chest pain, in the north of the Netherlands. The primary endpoint was a major adverse cardiac event (MACE), consisting of acute myocardial infarction or death, within 3 days. The components of the HEART Score were evaluated for their discriminatory value, cut-offs were calibrated for the prehospital setting and sex was substituted for cardiac risk factors to develop a prehospital HEART (preHEART) Score. This score was validated in an independent prospective cohort of 435 patients in 2018. RESULTS: Among 1208 patients prospectively recruited in the first cohort, 123 patients (10.2%) developed a MACE. The HEART Score had a negative predictive value (NPV) of 98.4% (96.4-99.3), a positive predictive value (PPV) of 35.5% (31.8-39.3) and an area under the receiver operating characteristic curve (AUC) of 0.81 (0.78-0.85). The preHEART Score had an NPV of 99.3% (98.1-99.8), a PPV of 49.4% (42.0-56.9) and an AUC of 0.85 (0.82-0.88), outperforming the HEART Score or POC troponin measurements on their own. Similar results were found in a validation cohort. CONCLUSIONS: The HEART Score can be used in the prehospital setting to assist with conveyance decisions and choice of hospitals; however, the preHEART Score outperforms both the HEART Score and single POC troponin measurements when applied by EMS personnel in the prehospital setting

Laboratory environment effects on the reproduction and mortality of adult screwworm (Diptera: Calliphoridae)

The New World screwworm, Cochliomyia hominivorax Coquerel, is mass reared for screwworm eradication initiatives that use the sterile insect technique. New methods for rearing have helped to reduce the cost of the eradication program. We examined the effect and interaction of three temperatures (24.5, 29.5 and 34.5ºC), two diets (2% spray-dried blood plus 0.05% vitamins and corn syrup carrageenan) and three population densities (300, 400, and 500 flies/cage) on egg production, egg hatch, number of observable fertilized eggs, mortality (male and female) and ovarian development. The three population densities did not affect any of the parameters monitored. Using the protein diet increased egg production at all temperatures. Diet did not affect egg hatch or female mortality. Male mortality was significantly greater when fed the protein diet and reared at 24.5ºC and 34.5ºC. Egg hatch was significantly less when the flies were reared at 34.5ºC. When exposed to high temperatures (37ºC and 40ºC) egg production, egg hatch, fertility and mortality were adversely affected. At the higher temperatures, yolk did not adequately form during oogenesis. When compared to the normal rearing photoperiod (12 L: 12 D), short photoperiod (1 L: 23 D) increased egg production, egg hatch and fertility but lowered mortality

Laboratory environment effects on the reproduction and mortality of adult screwworm (Diptera: Calliphoridae)

The New World screwworm, Cochliomyia hominivorax Coquerel, is mass reared for screwworm eradication initiatives that use the sterile insect technique. New methods for rearing have helped to reduce the cost of the eradication program. We examined the effect and interaction of three temperatures (24.5, 29.5 and 34.5ºC), two diets (2% spray-dried blood plus 0.05% vitamins and corn syrup carrageenan) and three population densities (300, 400, and 500 flies/cage) on egg production, egg hatch, number of observable fertilized eggs, mortality (male and female) and ovarian development. The three population densities did not affect any of the parameters monitored. Using the protein diet increased egg production at all temperatures. Diet did not affect egg hatch or female mortality. Male mortality was significantly greater when fed the protein diet and reared at 24.5ºC and 34.5ºC. Egg hatch was significantly less when the flies were reared at 34.5ºC. When exposed to high temperatures (37ºC and 40ºC) egg production, egg hatch, fertility and mortality were adversely affected. At the higher temperatures, yolk did not adequately form during oogenesis. When compared to the normal rearing photoperiod (12 L: 12 D), short photoperiod (1 L: 23 D) increased egg production, egg hatch and fertility but lowered mortality