Pharmacokinetics of intramuscular tranexamic acid in bleeding trauma patients: a clinical trial.

BACKGROUND: Intravenous tranexamic acid (TXA) reduces bleeding deaths after injury and childbirth. It is most effective when given early. In many countries, pre-hospital care is provided by people who cannot give i.v. injections. We examined the pharmacokinetics of intramuscular TXA in bleeding trauma patients. METHODS: We conducted an open-label pharmacokinetic study in two UK hospitals. Thirty bleeding trauma patients received a loading dose of TXA 1 g i.v., as per guidelines. The second TXA dose was given as two 5 ml (0·5 g each) i.m. injections. We collected blood at intervals and monitored injection sites. We measured TXA concentrations using liquid chromatography coupled to mass spectrometry. We assessed the concentration time course using non-linear mixed-effect models with age, sex, ethnicity, body weight, type of injury, signs of shock, and glomerular filtration rate as possible covariates. RESULTS: Intramuscular TXA was well tolerated with only mild injection site reactions. A two-compartment open model with first-order absorption and elimination best described the data. For a 70-kg patient, aged 44 yr without signs of shock, the population estimates were 1.94 h-1 for i.m. absorption constant, 0.77 for i.m. bioavailability, 7.1 L h-1 for elimination clearance, 11.7 L h-1 for inter-compartmental clearance, 16.1 L volume of central compartment, and 9.4 L volume of the peripheral compartment. The time to reach therapeutic concentrations (5 or 10 mg L-1) after a single intramuscular TXA 1 g injection are 4 or 11 min, with the time above these concentrations being 10 or 5.6 h, respectively. CONCLUSIONS: In bleeding trauma patients, intramuscular TXA is well tolerated and rapidly absorbed. CLINICAL TRIAL REGISTRATION: 2019-000898-23 (EudraCT); NCT03875937 (ClinicalTrials.gov).

Pulmonary embolism, frostbite and high-altitude retinopathy - a combination of life- and sight-threatening vascular complications at high altitude.

The effects of high altitude on the human vascular system are well described. This case demonstrates an interesting combination of vascular complications at high altitude which were both life- and sight-threatening. In May 2017, during an attempt on Mount Everest, a 58-year-old man was forced to descend from 8000 m because of adverse weather. He suffered significant frostbite of his right hand, later requiring termination of the distal phalanx of one of the affected digits. He also experienced increasing breathlessness and went on to develop pleuritic chest pain. A CT pulmonary angiogram performed upon return to sea level revealed multiple small sub-segmental pulmonary emboli. He was anticoagulated for three months and made a full recovery. The patient also reported visual loss in the left eye and on ophthalmic examination was found to have multiple retinal haemorrhages including a left macular haemorrhage, consistent with high altitude retinopathy. The retinal haemorrhages settled with conservative management. The vascular complications suffered by this patient demonstrate the potentially fatal changes that can occur at altitude. They also serve to act as a reminder for physicians, even at sea level of the potential complications in patients returning from high altitude.

Improvised first aid techniques for terrorist attacks.

Terrorist acts occur every day around the world. Healthcare professionals are often present as bystander survivors in these situations, with none of the equipment or infrastructure they rely on in their day-to-day practice. Within several countries there has been a move to disseminate the actions to take in the event of such attacks: in the UK, Run, Hide, Tell, and in the USA, Fight Back This paper outlines how a very basic medical knowledge combined with everyday high-street items can render highly effective first aid and save lives. We discuss and summarise modern improvised techniques. These include the ABCDE approach of treating catastrophic haemorrhage before airway management, bringing together improvised techniques from the military and wilderness medicine. We explain how improvised tourniquets, wound dressings, splinting and traction devices can be fabricated using items from the high street: nappies, tampons, cling film, duct tape and tablecloths. Cervical spine immobilisation is a labour-intensive protocol that is often practised defensively. With little evidence to support the routine use of triple immobilisation, this should be replaced with a common sense dynamic approach such as the Montana neck brace. Acid or alkali attacks are also examined with simple pragmatic advice. Analgesia is discussed in the context of a prehospital setting. Pharmacy-obtained oral morphine and diclofenac suppositories can be used to treat moderate pain without relying on equipment for intravenous/intraosseous infusion in prolonged hold situations. The differentiation between concealment and cover is summarised: scene safety remains paramount.

Faculty of Prehospital Care, Royal College of Surgeons Edinburgh guidance for medical provision for wilderness medicine.

To support leaders and those involved in providing medical care on expeditions in wilderness environments, the Faculty of Pre-Hospital Care (FPHC) of The Royal College of Surgeons of Edinburgh convened an expert panel of leading healthcare professionals and expedition providers. The aims of this panel were to: (1) provide guidance to ensure the best possible medical care for patients within the geographical, logistical and human factor constraints of an expedition environment. (2) Give aspiring and established expedition medics a 'benchmark' of skills they should meet. (3) Facilitate expedition organisers in selecting the most appropriate medical cover and provider for their planned activity. A system of medical planning is suggested to enable expedition leaders to identify the potential medical risks and their mitigation. It was recognised that the scope of practice for wilderness medicine covers elements of primary healthcare, pre-hospital emergency medicine and preventative medicine. Some unique competencies were also identified. Further to this, the panel recommends the use of a matrix and advisory expedition medic competencies relating to the remoteness and medical threat of the expedition. This advice is aimed at all levels of expedition medic, leader and organiser who may be responsible for delivering or managing the delivery of remote medical care for participants. The expedition medic should be someone equipped with the appropriate medical competencies, scope of practice and capabilities in the expedition environment and need not necessarily be a qualified doctor. In addition to providing guidance regarding the clinical competencies required of the expedition medic, the document provides generic guidance and signposting to the more pertinent aspects of the role of expedition medic.