Wilderness cold-exposure injuries: An African perspective

Cold injuries may be systemic (hypothermia) or local (frostbite or non-freezing cold injury). Hypothermia (core temperature of <35°C) is very common in South Africa, particularly in trauma patients, and conditions suitable for the development of local cold injuries frequently occur. Despite this, cold injuries are underdiagnosed, and many practitioners lack insight into the modern management of frostbite. Risk factors include low ambient temperatures, increased duration of exposure, trauma, immobility, intoxication or mental illness, lack of protective clothing or equipment, immersion, level of fitness, extremes of age, and ethnicity. Core temperature measurement should be obtained using an oesophageal probe in intubated patients, or a rectal thermometer in those who are conscious. Field management involves prevention of further heat loss by insulation and vapour barriers, and moving the patient to shelter. Rewarming strategies depend on the severity of hypothermia, and include core rewarming with heat packs, warm blankets and warm fluids (orally or intravenously). Unconscious victims of severe hypothermia require careful handling, advanced airway management and invasive rewarming, which may include extracorporeal means. Local cold injuries should be protected and rewarmed in a warm-water bath as soon as they are no longer at a risk of refreezing. Warming should be completed before grading and prognostication. Surgery should be deferred in almost all cases. Intra-arterial thrombolysis and prostacyclin-analogue infusions are novel therapies which may prevent tissue loss

Heat-related illness in the African wilderness

Wilderness heat-related illnesses span a variety of conditions caused by excessive or prolonged heat exposure, and/or the inability to compensate adequately for increased endogenous production during strenuous outdoor activities. Despite management of well-known risk factors, such as lack of fitness or acclimatisation, dehydration, underlying illness and certain medications, even highly trained individuals may exceed their physiological capability to dissipate increased core temperature. Heat illnesses range from benign cramps to the more concerning heat syncope and exercise-associated collapse (with or without hyperthermia), and culminate in life-threatening heat stroke. The differential diagnosis in the wilderness is broad and should include exercise-associated hyponatraemia with or without encephalopathy. Clinical guidelines for wilderness and hospital management of these conditions are available. Field management and evacuation are based on severity, and include cooling, rehydration and assessment of core temperature and serum sodium, if possible. Hyponatraemia should be corrected with the use of oral or intravenous hypertonic saline, depending on whether the patient can safely take oral fluids. Hospital management may include aggressive and potentially invasive cooling, careful assessment for organ dysfunction, and intensive multi-organ support, if required. Paracetamol, non-steroidal anti inflammatory drugs and dantrolene should not be used

Acute high-altitude illness

A substantial proportion of South Africa (SA)’s population lives at high altitude (>1 500 m), and many travel to very high altitudes (>3 500 m) for tourism, business, recreation or religious pilgrimages every year. Despite this, knowledge of acute altitude illnesses is poor among SA doctors. At altitude, the decreasing ambient pressure proportionally decreases available oxygen (hypobaric hypoxia). This triggers both immediate respiratory compensation and gradual acclimatisation that occurs over days to weeks. Rapid ascents to altitudes above 2 500 m can precipitate acute altitude illness, including acute mountain sickness (AMS) and high-altitude pulmonary and cerebral oedema (HAPE and HACE). The best preventive measure is gradual ascent (no more than 300 - 500 m increase in sleeping altitude per day, with additional rest days for acclimatisation for every 1 000 m altitude gain), although chemoprophylaxis may speed acclimatisation. In the field, AMS, HAPE and HACE are diagnosed clinically. The Lake Louise Score questionnaire is used to elicit symptoms of AMS, and can be supplemented by assessing clinical signs such as tachycardia, tachypnoea, crepitations or ronchi, and ataxia. The mainstay of treatment for all but mild AMS is rapid descent to lower altitudes, which can be facilitated by administration of oxygen and drugs, including acetazolamide, dexamethasone and nifedipine, or use of a portable hyperbaric chamber

Expedition medicine: A southern African perspective

A growing number of people are undertaking expeditions and adventure travel to previously inaccessible areas. The risks posed by increasing accessibility of remote regions and interest in extreme sports have not been fully obviated by modern equipment and communications. Therefore, there remains a requirement for medical care during wilderness expeditions, for which expectations and formal standards continue to increase. Expedition medicine should take cognisance of the predicted problems, plan for contingencies, and be practised pragmatically in austere settings. Southern African medics have a broad skill set, which makes them ideally suited to the field, but they should seek to understand the epidemiology of expeditions in different environments, undergo specialised training, and become involved in all phases of planning and execution of an expedition. Routine general practice complaints and accidental trauma are ubiquitous; travel medical issues such as blisters, diarrhoea, insomnia, sunburn and dehydration occur commonly; area/activity-specific issues such as  infectious disease risks and altitude illnesses must be addressed; and women’s health and dental problems are frequently overlooked. The expedition medic plays a wide range of roles, and should have knowledge and skills to match the requirements of the expedition. Fortunately, many resources exist to assist medics in becoming competent in the field

Editorial: The United Kingdom National Audit Project Program - an opportunity for South Africa?

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Inter-pregnancy interval and risk of recurrent pre-eclampsia: systematic review and meta-analysis

Background: Women with a history of pre-eclampsia have a higher risk of developing pre-eclampsia in subsequentpregnancies. However, the role of the inter-pregnancy interval on this association is unclear.Objective: To explore the effect of inter-pregnancy interval on the risk of recurrent pre-eclampsia or eclampia.Search strategy: MEDLINE, EMBASE and LILACS were searched (inception to July 2015).Selection criteria: Cohort studies assessing the risk of recurrent pre-eclampsia in the immediate subsequentpregnancy according to different birth intervals.Data collection and analysis: Two reviewers independently performed screening, data extraction, methodologicaland quality assessment.Meta-analysis of adjusted odds ratios (aOR) with 95 % confidence intervals (CI) was used to measure the associationbetween various interval lengths and recurrent pre-eclampsia or eclampsia.Main results: We identified 1769 articles and finally included four studies with a total of 77,561 women. The meta-analysisof two studies showed that compared to inter-pregnancy intervals of 2?4 years, the aOR for recurrent pre-eclampsia was 1.01 [95 % CI 0.95 to 1.07, I2 0 %] with intervals of less than 2 years and 1.10 [95 % CI 1.02 to 1.19, I2 0 %] with intervals longerthan 4 years.Conclusion: Compared to inter-pregnancy intervals of 2 to 4 years, shorter intervals are not associated with an increasedrisk of recurrent pre-eclampsia but longer intervals appear to increase the risk. The results of this review should beinterpreted with caution as included studies are observational and thus subject to possible confounding factors.Keywords: Recurrence, Pre-eclampsia, Eclampsia, Inter-pregnancy interval, Birth interval, Meta-analysis, Systematic review,Birth spacing, Hypertensive disorders of pregnancyFil: Cormick, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: Betran, Ana Pilar. World Health Organization; SuizaFil: Ciapponi, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: Hall, David R.. Stellenbosch University; Sudáfrica. Tygerberg Hospital; SudáfricaFil: Hofmyer, G. Justus. University of the Witwatersrand; Sudáfrica. University of Fort Hare; Sudáfrica. Walter Sisulu University; Sudáfric

Update on drowning

Drowning is defined as the process of experiencing respiratory impairment from either submersion or immersion in liquid. Drowning morbidity and mortality are an under-recognised public health burden in southern Africa. Continuous concerted efforts are underway to improve awareness among recreational water users, but the prevention and management of drowning remain difficult to achieve owing to poor reporting and limited resources. Priorities for both prehospital and emergency department management of drowning victims include ensuring airway patency, adequate ventilation, supplemental oxygenation and rewarming for a pulsatile patient, and cardiopulmonary resuscitation with rewarming for a pulseless patient

Foreign body ingestion in children presenting to a tertiary paediatric centre in South Africa: A retrospective analysis focusing on battery ingestion

Background. Ingestion of foreign bodies remains a frequent reason for presentation to paediatric emergency departments worldwide. Among the variety of objects ingested, button batteries are particularly harmful owing to their electrochemical properties, which can cause extensive injuries if not diagnosed and treated rapidly. International trends show an increasing incidence of button battery ingestion, leading to concern that this pattern may be occurring in South Africa. Limited local data on paediatric foreign body ingestion have been published.Objectives. To assess battery ingestion rates in a tertiary paediatric hospital. We hypothesised that the incidence has increased, in keeping with international trends. Secondary objectives included describing admission rates, requirements for anaesthesia and surgery, and promoting awareness of the problems associated with battery ingestion.Methods. We performed a retrospective, descriptive analysis of the Red Cross War Memorial Children’s Hospital trauma database, including all children under 13 years of age seen between 1 January 2010 and 31 December 2015 with suspected ingestion of a foreign body. The ward admissions database was then examined to find additional cases in which children were admitted directly. After exclusion of duplicate records, cases were classified by type of foreign body, management, requirement for admission, anaesthesia and surgery. Descriptive statistics were used to analyse the data in comparison with previous studies published from this database.Results. Patient age and gender patterns matched the literature, with a peak incidence in children under 2 years of age. Over the 6-year period, 180 patients presented with food foreign bodies, whereas 497 objects were classified as non-food. After exclusion of misdiagnosed cases, the remaining 462 objects were dominated by coins (44.2%). Batteries were the causative agent in 4.8% (22/462). Although the subtypes of batteries were not reliably recorded, button batteries accounted for at least 64% (14/22). Most children who ingested batteries presented early, but more required admission, anaesthesia and surgery than children who ingested other forms of foreign body.Conclusions. The study demonstrated that the local incidence of button battery ingestion may be increasing, although data are still limited.Admission, anaesthesia and surgery rates for batteries were higher in this cohort than for all other foreign bodies. As button batteries can mimic coins, with much more dire consequences on ingestion, our ability to expedite diagnosis and management hinges on a high index of suspicion. It is imperative to increase awareness among healthcare workers and parents

Guest Editorial: Growing wilderness and expedition medicine education in southern Africa

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Perioperative comparison of the agreement between a portable fingertip pulse oximeter v a conventional bedside pulse oximeter in adult patients COMFORT trial

Background. Low-cost, portable fingertip pulse oximeters are widely available to health professionals and the public. They are often not tested to International Organization for Standardization standards, or only undergo accuracy studies in healthy volunteers under ideal laboratory conditions.Objectives. To pragmatically evaluate the agreement between one such device and a conventional bedside pulse oximeter in a clinical setting, in patients with varied comorbidities and skin pigmentations.Methods. A single-centre equipment comparison study was conducted. Simultaneous measurements were obtained in 220 patients with both a Contec CMS50D Fingertip Pulse Oximeter and a Nihon Kohden Life Scope MU-631 RK conventional bedside monitor. Peripheral oxygen saturations (SpO2) and pulse rates were documented, and patients’ skin tone was recorded using the Fitzpatrick scale. Data were assessed using a Bland-Altman analysis with bias, precision and limits of agreement (LOA) calculated with 95% confidence intervals (CIs). A priori acceptability for LOA was determined to be 3%, in keeping with international standards.Results. The mean difference (therefore bias) between the conventional and fingertip oximeters for all data was –0.55% (95% CI –0.73 - –0.36). Upper and lower limits of agreement were 2.16% (95% CI 1.84 - 2.47) and –3.25% (95% CI –3.56 - –2.94). Regression analysis demonstrated worsening agreement with decreasing SpO2. When samples were separated into ‘normal’ (SpO2≥93%) and ‘hypoxaemic’ (SpO2 <93%) groups, the normal range displayed acceptable agreement between the two oximeters (bias –0.20% with LOA 2.20 - –2.27), while the hypoxaemic group fell outside the study’s a priori limits. Heart rate measurements had a mean difference of –0.43 bpm (LOA –5.61 - 4.76). The study was not powered to detect differences among the skin tones, but demonstrated no trend for this parameter to alter the SpO2measurements.Conclusions. During normoxia, portable fingertip pulse oximeters are reliable indicators of SpO2and pulse rates in patients with various comorbidities in a pragmatic clinical context. However, they display worsening agreement with conventional pulse oximeters during hypoxaemia. Skin tones do not appear to affect measurements adversely