N-terminal prohormone of brain natriuretic peptide: a useful tool for the detection of acute pulmonary artery embolism in post-surgical patients.

BACKGROUND: Acute pulmonary embolism (APE) is an important clinical problem in patients after major surgery and often remains a difficult diagnosis because of unspecific clinical symptoms. Therefore, we investigated the role of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) for the detection of APE. METHODS: In 44 patients with suspected APE referred to the intensive care unit after major surgery, serum NT-proBNP, troponin-I, and D-dimers were measured according to the standard hospital protocol. To definitively confirm or exclude APE, all patients underwent an angiographic CT scan of the thorax. RESULTS: APE was confirmed in 28 and excluded in 16 patients by CT scan. NT-proBNP was significantly (P<0.01) higher in patients with APE [4425 (sd 8826; range 63-35 000) pg ml(-1)] compared with those without [283 (sd 327; range 13-1133) pg ml(-1)]. The sensitivity of the NT-proBNP screening was 93%, specificity 63%, positive predictive value 81%, and negative predictive value 83%. There were no significant (P = 0.96) differences in D-dimers between subjects with and without APE [confirmed APE: 511 (sd 207; range 83-750) µg litre(-1); excluded APE: 509 (sd 170; range 230-750) µg litre(-1)]. Troponin-I levels were not elevated in 32% of the patients with APE. CONCLUSIONS: D-dimer levels are frequently elevated in post-surgical patients and not applicable for confirmation or exclusion of APE. In contrast, NT-proBNP appears to be a useful biomarker for APE diagnosis in the postoperative setting. In the case of NT-proBNP levels below the upper reference limit, haemodynamically relevant APE is unlikely. Troponin-I in contrast is not considered to be helpful.

Effects of FLIRT on bubble growth in man.

Recompression during decompression has been suggested to possibly reduce the risk of decompression sickness (DCS). The main objective of the current study was to investigate the effects of FLIRT (First Line Intermittent Recompression Technique) on bubble detection in man. 29 divers underwent 2 simulated dives in a dry recompression chamber to a depth of 40 msw (500 kPa ambient pressure) in random order. A Buehlmann-based decompression profile served as control and was compared to an experimental profile with intermittent recompression during decompression (FLIRT). Circulating bubbles in the right ventricular outflow tract (RVOT) were monitored by Doppler ultrasound and quantified using the Spencer scoring algorithm. Heat shock protein 70 (HSP70), thrombocytes, D-Dimers and serum osmolarity were analyzed before and 120 min after the dive. Both dive profiles elicited bubbles in most subjects (range Spencer 0-4). However, no statistically significant difference was found in bubble scores between the control and the experimental dive procedure. There was no significant change in either HSP70, thrombocytes, and D-Dimers. None of the divers had clinical signs or symptoms suggestive of DCS. We conclude that FLIRT did not significantly alter the number of microbubbles and thus may not be considered superior to classical decompression in regards of preventing DCS.

Pulmonary function in children after open water SCUBA dives.

An increasing number of children and adolescents is diving with Self-Contained Underwater Breathing Apparatus (SCUBA). SCUBA diving is associated with health risks such as pulmonary barotrauma, especially in children and in individuals with airflow limitation. As no data has been published on the effects of open-water diving on pulmonary function in children, the objective of this study was to evaluate the effects of SCUBA dives on airflow in children. 16 healthy children aged 10-13 years underwent spirometry and a cycle-exercise challenge while breathing cold air. They subsequently performed dives to 1-m and 8-m depth in random order. Pulmonary function was measured before and after the exercise challenge and the dives. There were statistically significant decreases in FEV1, FVC, FEV1/FVC, MEF25 and MEF50 after the cold-air exercise challenge and the dives. Changes in lung function following the exercise challenge did not predict the responses to SCUBA diving. In 3 children the post-dive decrements in FEV1 exceeded 10%. These children had a lower body weight and BMI percentile. SCUBA diving in healthy children may be associated with relevant airflow limitation. A low body mass might contribute to diving-associated bronchoconstriction. In the majority of subjects, no clinically relevant airway obstruction could be observed.

[The ulm emergency algorithm for the acute treatment of drug-induced, bradykinin-mediated angioedema]. / Ulmer Notfallalgorithmus: die Akuttherapie von medikamenteninduzierten bradykininvermittelten Angioödemen.

BACKGROUND: Bradykinin-mediated, drug-induced edema like ACE-inhibitor-induced angioedema (ACEi AE) is almost exclusively located in the head and neck region and is potentially life threatening. To date, there are no guidelines or officially-approved treatments available for this pathology. OBJECTIVES: We sought to provide a structured therapeutic algorithm for the acute treatment of drug-induced bradykinin-mediated angioedema. MATERIALS AND METHODS: We analyzed data (especially the course of disease and therapy) of all patients with acute angioedema, who presented to the Department of Otorhinolaryngology, Head and Neck Surgery at the University of Ulm (2010-2015). We also conducted a literature review on PubMed with the terms "acute angioedema", "angioedema emergency", "ACE angioedema", "bradykinin angioedema" and "angioedema therapy". Other fundamental references were the recent German guidelines "hereditary angioedema", "anaphylaxis" and "airway management". RESULTS: An emergency algorithm was generated as a flowchart for the acute therapy of bradykinin-mediated drug-induced angioedema was generated. We focused on the decision criteria for intubation/airway management and pharmacological therapy: antihistamines and glucocorticoids versus anti-bradykinin treatment. Furthermore, recommendations for inpatient monitoring have been derived. CONCLUSION/DISCUSSION: To date, therapy of drug-induced bradykinin-mediated angioedema is performed according to an "off-label" use and without officially-approved guidelines. The presented emergency algorithm provides a first approach for a structured therapeutic concept for a potentially life-threatening pathology.

Lung hyperinflation: foe or friend?

Breath-hold divers employ glossopharyngeal insufflation (GI) in order to prevent the lungs from compressing at great depth and to increase intrapulmonary oxygen stores, thus increasing breath-hold time. The presented case study shows the physiological data and dynamic magnetic resonance imaging (dMRI) findings of acute hyperinflation, deliberately induced by GI, in a breath-hold diver and discusses the current state of knowledge regarding the associated hazards of this unique competitive sport. Static and dynamic lung volumes and expiratory flows were within the normal range, with vital capacity and peak expiratory flow being higher than the predicted values. Airway resistance and diffusing capacity of the lung for carbon monoxide were normal. Static compliance was normal and increased five-fold with hyperinflation. dMRI revealed a preserved shape of the thorax and diaphragm with hyperinflation. A herniation of the lung beneath the sternum and enlargement of the costodiaphragmatic angle were additional findings during the GI manoeuvre. After expiration, complete resolution to baseline was demonstrated. Hyperinflation can be physiological and even protective under abnormal physical conditions in the sense of acute adaptation to deep breath-hold diving. Dynamic magnetic resonance imaging is adequate for visualisation of the sequence of the glossopharyngeal insufflation manoeuvre and the complete reversibility of deliberate hyperinflation.

[Diving fitness of children and adolescents. Importance for ENT doctors]. / Tauchtauglichkeit von Kindern und Jugendlichen. Bedeutung für den HNO-Arzt.

About 10% of all sport scuba divers are children and adolescents. Little is known about the particular risks and consequences of this sport on a child's health. Due to the peculiarities of childhood anatomy and physiology, certain restrictions apply to the diving fitness of children and adolescents. Before starting scuba training, the presence of particular cognitive abilities must be demonstrated and eustachian tube dysfunction must be ruled out by a specialist. Medical contra-indications to scuba diving for adults apply to children too but must be adapted. Relative risks for adults may translate to absolute contra-indications in children and adolescents. When planning dives, there should be rigorous limitations as to depth and time. Experienced adult divers must always assist with dive planning and accompany children and adolescents when scuba diving.

[Diving fitness for scuba divers--what the primary care physician should know]. / Untersuchung auf Tauchtauglichkeit beim Hausarzt. Wer darf abtauchen?

The diving fitness medical examination serves to show and reveal medical conditions that are a contraindication for diving or to evaluate the risk of preexisting conditions. For this reason, it should never have the character of a certification given as a matter of courtesy. Fitness to dive is given if the candidate is healthy and when there are no pathological findings. Even with deviations from the norm, diving is still possible, but with restrictions. Important organ systems for the diving fitness examination are the cardiovascular system, the respiratory organs and the ears. In addition, adequate eyesight is important. The German Society of Diving and Hyperbaric Medicine (GTOUM) has drawn up recommendations on the examination of scuba divers to assist the physician (www.gtuem.org).

[Medical aspects of diving in the tropics]. / Tauchen in den Tropen. Salz im Ohr und Fische, die sich wehren.

Scuba diving vacations in tropical surroundings belong to the repertoire of most divers. In addition to carefully making travel plans and taking care of the necessary vaccinations and appropriate malaria prophylaxis, the following points also must be observed. The flight itself affects diving safety. In particular, a too short time interval between diving and the return flight can lead to decompression problems. Because most of the diving areas are reached by ship, many divers need a prophylaxis against motion sickness. Moreover, external otitis occurs more frequently while diving in the tropics. Finally, there is potential danger from the sea inhabitants, primarily from scorpion fishes, Portuguese Man-of-Wars, box jellyfishes as well as cone snails.

[Injuries caused by pressure differences while diving]. / Schäden durch Druckdifferenzen beim Tauchen. Barotraumen.

Barotraumas are caused by pressure differences. As described by Boyle's Law, barotraumas develop during the descent phase of diving (and much more rarely during the ascent). The most frequently affected are the ears and paranasal sinuses, in addition to the facial skin and eyes. The most important preventive measure is performing pressure compensation in the affected body cavities. Barotrauma is treated symptomatically.

[Decompression injuries]. / Dekompressionsschäden. "Wie eine Rakete nach oben ..."

A decompression accident occurs during uncontrolled dive ascent with diving equipment. Through the rapid decrease in the surrounding pressure, gas bubbles form in the blood and tissues. Depending upon the mechanism of onset, the decompression illness (DCI) is classified as decompression sickness (DCS) or arterial gas embolism (AGE). The therapy consists of administering, as quickly as possible, 100% oxygen as well as a volume substitution. The treatment is continued in a recompression chamber.

[Problems in the deep: the isopression phase]. / Tauchzwischenfälle durch erhöhte Partialdrucke oder falsche Atmung. Der Rausch der Tiefe.

Fundamentally, accident mechanisms during the isopression phase of diving are primarily dependent upon the partial pressures of the respiratory gases. An increased nitrogen partial pressure leads to compressed-air intoxication; an increased oxygen partial pressure while diving with oxygen-enriched gas mixtures can trigger an oxygen-induced convulsion. Elevated pCO2 can be provoked by inadequate breathing and/or physical exertion at greater diving depths. Through an adjusted diving behavior and observation of the limits, these problems could be easily avoided.

A case of breath holding and ascent-induced circulatory hypotension.

We report a case of transient circulatory depression due to inadvertent apnea of a subject during decompression from a stimulated dive. The dive consisted of exposure to air at 5 bar and subsequent decompression stops. Arterial blood pressure and a lead II ECG were recorded continuously. During decompression from 1.6 to 1.3 bar, the subject inadvertently held his breath. Arterial pressure fell rapidly from 120/80 to 60/53 mmHg within 20 s. Recognizing that the subject held his breath, one of the supervisors ordered him to resume breathing, and arterial blood pressure was restored rapidly. This circulatory depression was probably due to reduced stroke volume such as described for the syncope of ascent: with the subject retaining his breath, the expanding lung volume increased intrathoracic pressure resulting in impaired venous return.

Exercise effects on central venous nitrogen tensions after simulated non-decompression dives.

In five subjects we examined the effect of exercise on the pattern of central venous (right atrial) N2 tensions (PVN2) after ascent from simulated non-decompression dives. The dives consisted of exposure to air at 3 bar for 20 min with 10 min of exercise (workload 75 W) at depth to achieve near-complete N2 saturation of the muscles. After the dive the subjects rested or, on another day, exercised for 30 min (workload 100 W) starting 10 min after completing the ascent. Blood samples taken every 10 min until the 60th min and 90 min after the dive were analyzed for PVN2 using a manometric Van Slyke apparatus. The amount of N2 eliminated was estimated from the PVN2 by adapting the Fick principle. Immediately after the ascent, PVN2 were 950 +/- 39 and 942 +/- 27 mmHg, respectively, in the rest and experiment series. In the rest experiments PVN2 continuously decreased to 606 +/- 8 mmHg 90 min after the dive, remaining significantly higher (P < 0.05) than before the dive. Exercise caused the PVN2 to increase beyond the corresponding levels of the rest experiments (P < 0.05 at 20 and 30 min exercise). After the exercise PVN2 rapidly declined, reaching predive levels 60 min after the ascent. Exercise increased N2 elimination to 970 +/- 143 ml, whereas it had been 311 +/- 61 ml (P < 0.05) in the corresponding phase of the rest experiments. We conclude that if extensive supersaturation and bubble formation can be avoided, such as probably was the case in our shallow non-decompression dives, exercise after the ascent accelerates N2 elimination.

Nitrogen partial pressures in man after decompression from simulated scuba dives.

In five subjects arterial and central venous nitrogen partial pressures (PN2) were measured after decompression from a chamber dive following a decompression schedule for scuba diving. The simulated dives consisted of exposure at rest to air at 6 bar for 30 min. corresponding to a depth of 50 m. Afterwards the subjects were decompressed with decompression stops at 2.5, 2.2, 1.9, 1.6 and 1.3 bar with a total decompression time of 73 min. Immediately after decompression and every 40 min. until the 240th min. arterial and central venous blood samples were analyzed for PN2 using a manometric Van Slyke apparatus. Venous PN2 remained elevated until 160 min. after decompression indicating still incomplete nitrogen wash-out at least two hours after decompression had been accomplished. Bubble formation is discussed as a cause for prolonged nitrogen elimination. Our data confirm that nitrogen elimination is prolonged after decompression from simulated dives at rest.

[Water rescue. A unique area of emergency medicine with many facets]. / Wasserrettung. Ein notfallmedizinisches Spezialgebiet mit vielen Facetten.

Emergencies on or in water are relatively rare in the rescue service. For this reason, water accident treatment and management does not receive much attention in the training of emergency medicine physicians. Consequently doctors working in emergency medicine often have minimal knowledge in this area. On the other hand, the number of fatal accidents on and in water has increased in recent years. In Germany the number of non-swimmers is also increasing, so it can be assumed that the number of water-related accidents will continue to rise. Drowning accidents and near drowning are important in this context and will be discussed in detail in this review as well as hypothermia (a frequent problem), accompanying injuries and diving accidents.

[Oxygen therapy in diving accidents]. / Sauerstofftherapie nach Tauchunfall.

Diving accidents represent a departure from the routine practice of emergency physicians. The incidence of non-fatal diving accidents is reported as 1-2 per 10,000 dives. Apart from adequate intravenous hydration, oxygen is the only medication with a proven effect in the treatment of diving accidents. After a typical diving accident, administration of oxygen at an inspired concentration (F(I)O(2) 1.0) as high as possible is recommended. Many divers bring along their own oxygen administration systems to the diving sites and these are often better suited for the treatment of diving accidents than the oxygen systems of many emergency responders. Pressure regulators supplying low constant flow oxygen, nasal prongs and inhalation masks are inappropriate. When using artificial ventilation bags with face masks, an oxygen flow of at least 15 l/min should be used. Demand regulators are simple to use and able to deliver a F(I)O2 of 1.0. Their ease of use has earned them high marks in the emergency management of diving accidents and their similarity to standard diving equipment has also aided relatively widespread acceptance. Circulation breathing systems are more technologically complex oxygen delivery systems which permit CO2 absorption and re-breathing at low oxygen flow. In contrast to the demand modules, the likelihood of mistakes during their usage is higher. In diving accidents, the administration of normobaric oxygen, already begun in the field, is the most important therapy and should not be interrupted. Presented with an inadequate supplemental oxygen supply, the inspired oxygen concentration should not be decreased, rather the duration of the oxygen administration should be reduced. Hyperbaric oxygen therapy should be the mainstay of further treatment.

Demographics and respiratory illness prevalence of sport scuba divers.

This study aimed to establish epidemiological data on diving habits and outcome of subjects with respiratory diseases who are considered at increased risk for diving injuries. We conducted a cross-sectional demographics and prevalence study by distribution of an anonymous questionnaire with an issue of a widespread sport diving magazine. The questionnaire was designed to obtain medical and diving history data with an emphasis on respiratory diseases and complaints. The investigational population comprised sport scuba divers of any age and gender from Austria, Germany, and Switzerland. Two hundred and twenty-six male and 96 female divers sent completed questionnaires. Of the respondents 8.7 % indicated that they currently have asthma. Two thirds of asthmatics complained about regular dyspnoea. However, only 42.4 % used drugs relieving or controlling their symptoms regularly and 27.3 % used them in a prophylactic manner before diving. Five percent and 4.7 % of all divers reported a history of respiratory disease other than asthma or dyspnoea respectively. The divers with respiratory illness or complaints had logged a total of 17,386 dives. There were no cases of serious diving injuries. Despite the well-known limitations of postal surveys assessing self reported data, this study indicates that there is a population of subjects diving uneventfully with respiratory diseases that are considered medical contraindications to diving. These subjects deserve particular guidance on related risks and disease management.