Cardiac arrest due to accidental hypothermia--a 20 year review of a rare condition in an urban area.

BACKGROUND: Accidental hypothermic cardiac arrest is associated with unfortunate prognosis and large studies are rare. We therefore have performed an outcome analysis in patients that were admitted to Vienna University Hospital with the diagnosis of accidental hypothermic cardiac arrest. METHODS: This study employed a retrospective outcome analysis of prospectively collected data in a selected cohort of hypothermic cardiac arrest patients. We screened 3800 cardiac arrest patients, treated at our department between 1991 and 2010, for eligibility. Inclusion criteria were cardiac arrest with a body core temperature ≤28 °C and return of spontaneous circulation. RESULTS: A total of 18 patients who achieved return of spontaneous circulation were analysed. Nine patients (50%) achieved survival in good neurologic condition (defined as cerebral performance category CPC 1 or 2). Accidental hypothermia with consecutive cardiac arrest was caused by intoxication in most cases (67%). These patients had a better outcome than patients with other causes of accidental hypothermic cardiac arrest (OR=28; 95%KI 2-37.9; p<0.01). Hypothermia associated typical ECG changes after return of spontaneous circulation (Osborne waves) were more frequent in the surviving population (OR 16; 95%KI 1.3-19.5; p=0.05). CONCLUSIONS: Accidental hypothermic cardiac arrest in a central European urban area is rare. Prognosis was excellent in patients where hypothermic cardiac arrest was caused by intoxication.

Effects of indomethacin on the L-selectin expression in humans.

Based on an in vitro study and an uncontrolled in vivo trial we examined the effects of indomethacin on the expression of L-selectin by leukocytes in healthy volunteers. Eight subjects received infusions of 0.7 mg/kg indomethacin and placebo t.i.d. (three times daily) in a randomized, controlled trial. Indomethacin decreased the mean fluorescence intensity of the L-selectin expression on isolated neutrophils incubated with toxic indomethacin concentrations. However, indomethacin did not lower the L-selectin expression in whole blood or in-vivo. Thus, therapeutic doses of the cyclo-oxygenase inhibitor indomethacin do not lower the L-selectin expression on leukocytes. Hence, the inhibition of cyclo-oxygenase cannot explain the previously observed dexamethasone-induced decrease in L-selectin.

Sepsis-associated purpura fulminans in adults.

Sepsis-associated purpura fulminans is defined as septicemia, shock, disseminated intravascular coagulation and circulatory failure leading to multiple organ dysfunction. 40-70% of patients with sepsis-associated purpura fulminans die. Early prognostic factors in adults have not been well delineated yet. Aim of our study was 1) to evaluate currently used scoring systems for meningococcal septicemia in the setting of sepsis-associated purpura fulminans and 2) to assess if other parameters are feasible as early prognostic factors. From 1.1 1994-31.12.1998 twelve patients (female: 7; mean age: 31 (21; 43) years) were studied. Six patients (50%) died within 2 hours and 7 days after admission despite standard intensive treatment. On admission non-survivors had a more pronounced degree of disseminated intravascular coagulation compared to survivors (platelet count 18000 (15000; 45000) G/l vs. 119.000 (111000; 152000) G/l, (p = 0.03); fibrinogen 67 (50; 108) mg/dl vs. 356 (234; 483) mg/dl, (p = 0.02); PTZ 28% (20%; 30%) vs. 44% (35%; 51%), (p = 0.05); aPTT 120 (120; 128) sec vs. 46 (44; 69) sec, (p = 0.001). Severity of lactic acidosis was significantly higher in non-survivors than in survivors (pH 7.08 (6.92; 7.21) vs. pH 7.4 (7.25; 7.4), (p = 0.02); lactate 13.5 (11; 15) mval/l vs. 6.0 (4.4; 6) mval/l, (p = 0.02); data presented as median (25-75% interquartile range). In our patients the Glasgow Meningococcal Septicemia Prognostic Score (GMSPS) and the Niklasson-Score failed to distinguish between survivors and non-survivors (GMSPS 7 (6; 11) vs 7.5 (7; 9) out of 15; predicted mortality according to Niklasson-Score 73% vs 88%). There was no difference in the APACHE II Score (22 (18.5, 24) vs 22 (20.25, 26)). The severity of disseminated intravascular coagulation assessed by routine laboratory parameters and the degree of lactic acidosis on admission were the strongest predictors of outcome in patients with sepsis-associated purpura fulminans. Scoring systems developed for patients with meningococcal septicemia are of limited value in the setting of sepsis-associated purpura fulminans.

L-Tryptophan does not influence acute ventilatory response at moderate altitude.

Altitude induced insomnia is a very common symptom in mountaineering. Conventional hypnotics such as benzodiazepines potentially can be associated with untoward side effects because they can impair ventilatory adaptation to hypoxia at altitude. The objective of our study was to evaluate the effect of a alternative potentially sedative drug, L-tryptophan on ventilation at moderate altitude. STUDY DESIGN, METHODS AND RELEVANT RESULTS: Randomised, double blind, placebo controlled crossover trial. Blood gas analysis of 8 healthy subjects was performed before and one hour after oral administration of 500 mg L-tryptophan or placebo at altitudes of 171 m and at 3,000 m. PaO2 and PaCO2 before and after L-Tryptophan or placebo medication did not change significantly at neither level of altitude investigated. CONCLUSION: L-tryptophan does not impair ventilatory adaptation to mild hypoxia at moderate altitude.

[Physical exercise impairs the acute stage of adaptation to moderate altitude]. / Körperliche Belastung beeinträchtigt die akute Anpassung in mittlerer Höhenlage.

UNLABELLED: A recent study has reported the impairment of high altitude adaptation capacity by physical exercise in a decompression chamber. The aim of our protocol was to evaluate if physical exercise at moderate altitude in the Alps would show a similar effect. 8 alpinists were examined in a randomised cross-over trial at 171 m and at 3000 m altitude under sedentary and under exercise condition (50% maximal workload on the bicycle ergometer four times 30 minutes during the first 6 hours of an 8 hour observation period at each altitude). At the beginning and at the end of each observation period AMS scores and arterial oxygen saturation SaO2 were measured. The differences of the AMS scores and the differences of SaO2 at both test conditions were compared at both altitudes. RESULTS: In comparison to sedentary condition, the differences between initial and final AMS scores at 3000 m altitude were significantly higher (-0.38 +/- 0.52 vs. -1.25 +/- 0.46, diff 0.88, 95% CI 0.58 to 1.17, p < 0.01), as well as the difference between initial and final SaO2 (-0.25 +/- 0.71% vs. 2.25 +/- 1.04%, diff. -2.5%, 95% CI for the diff. -3.59 to -1.41, p < 0.01). AMS score and SaO2 did not change after exercise at 171 m altitude. CONCLUSION: Physical exercise impairs the acute stage of adaptation to moderate altitude. This is mainly due to the exercise-induced exaggeration of arterial hypoxaemia.

Correlation between raised body temperature and acute mountain sickness score at moderate altitude.

UNLABELLED: In high altitude mountaineering, a rise in body temperature has long been associated with acute mountain sickness. No data exist on the situation at moderate altitudes in the Austrian Alps. The objective of this study was to investigate a potential relationship between an increase in body temperature and acute mountain sickness (AMS) and hypoxemia at moderate altitude. Body temperature and arterial oxygen saturation (SaO2) were measured in 40 alpinists at 1000 m altitude and after ascent to 3100 m altitude, and the AMS score was measured at 3100 m altitude. At 3100 m altitude, 3 alpinists with AMS (score 3) experienced a 0.87 +/- 0.12 degree C rise in body temperature and a 10.67 +/- 1.15% reduction in SaO2. In 8 moderately affected alpinists, temperature increased by 0.49 +/- 0.16 degree C and SaO2 was reduced by 6.75 +/- 1.75%. In 29 alpinists without signs of AMS, temperature did not change (difference 0.02 +/- 0.14 degree C) and SaO2 decreased by 4.59 +/- 0.82%. The difference between temperatures at the two altitudes correlated significantly with the SaO2 difference between the two altitudes (rs = 0.408, p < 0.01) and with the AMS scores (rs = 0.814, p < 0.01). CONCLUSION: Comparable with maximal forms of AMS at high altitude, our data provide reason to speculate that systemic inflammatory disease could also be causal in less severe forms of acute mountain sickness. Therefore, in cases of fever at moderate altitude, the differential diagnosis must include acute mountain sickness.

[Recollections of ventilated patients after a stay in the intensive care unit]. / Erinnerungsreste beatmeter Patienten nach Aufenthalt an der Intensivstation.

UNLABELLED: A review of the literature reveals only scarce data and observations concerning the recollections of patients treated in a intensive care unit, although intraoperative awareness under general anaesthesia has been extensively reported. In the present study we investigated the recollections of patients who had undergone artificial ventilation in intensive care units. METHODS: Fifty patients who had undergone mechanical ventilation in intensive care units at the University Hospital of Vienna were retrospectively interviewed in regard of their experience during the treatment. A score was used to quantify discomfort. RESULTS: All patients remembered having been treated at the intensive care unit. The most unpleasant experience was tracheal suctioning which was remembered by 60%. The next most unpleasant experience was extubation; 52% remembered this intervention. Eighty-four per cent of patients remembered the medical staff, 90% of them had confidence in them, 86% remembered the nursing staff and 91% had confidence in them. CONCLUSION: In spite of unpleasant memories of intensive care treatment, of which tracheal suctioning was perceived as most unpleasant, the majority of patients expressed a positive evaluation of their treatment at the intensive care unit.

Comparison of oxygen cost of breathing with pressure-support ventilation and biphasic intermittent positive airway pressure ventilation.

OBJECTIVE: To assess the oxygen cost of breathing with either pressure-support ventilation (PSV) or biphasic intermittent positive airway pressure ventilation (BIPAP). DESIGN: Prospective, randomized, crossover study. SETTING: Medical intensive care unit of a university hospital. PATIENTS: Twenty clinically stable and spontaneously breathing patients after long-term mechanical ventilation. INTERVENTIONS: Patients were randomized to start on either PSV or BIPAP, and measurements were performed after an adaptation period of 30 mins. Immediately after, the ventilatory mode was changed and after another 30-min adaptation period, the same measurements were performed. MEASUREMENTS AND MAIN RESULTS: Indirect calorimetry was performed during each ventilatory mode for a period of 30 mins. Oxygen consumption, energy expenditure, CO2 production, and respiratory quotient did not differ significantly between the two ventilatory modes, regardless of the patients' randomization. There were no statistically significant differences with regard to respiratory rate, minute volume, and blood gas analysis. All patients tolerated both ventilatory modes without any signs of discomfort. CONCLUSIONS: Pressure support ventilation and BIPAP are both used for weaning patients gradually from the ventilator. BIPAP may be advantageous in patients not breathing sufficiently with PSV, since no patient effort is necessary with use of this ventilatory mode.

Exogenous surfactant therapy in a patient with adult respiratory distress syndrome after near drowning.

A 24-year-old woman developed adult respiratory distress syndrome (ARDS) after near-drowning due to attempted suicide. Conventional mechanical ventilation together with prone positioning and inhaled nitric oxide could not provide sufficient oxygenation. Surface tension data (gamma min = 27 dyn/cm, stability index = 0.341) from a lavage sample supported the hypothesis that the surfactant function of this patient was drastically reduced due to a washout effect by aspiration of fresh water. Porcine surfactant (Curosurf, 50 mg/kg for each lung) was instilled via fibreoptic bronchoscope. The partial arterial carbon dioxide pressure (paCO2) and fraction of inspired oxygen (FiO2) ratio as well as shunt fraction (Qs/Qt) improved impressively. When respiratory situation deteriorated again, surfactant application was repeated. Altogether, six bolus instillations of surfactant (total dose 300 mg/kg = 18,000 mg) were administered until the respiratory situation had stabilized and oxygenation could be maintained by conventional mechanical ventilation. The radiological findings did not show substantial amelioration. The patient developed septic shock and died 12 days after admission. Surfactant application apparently led to a significant improvement of the respiratory function. However, the outcome could not be influenced positively. The high cost of surfactant therapy prevents the more widespread early administration in patients at risk.

Fatal pulmonary edema after nitric acid inhalation.

We report a case of acute inhalation injury of nitric acid in a 56-year old white male. The patient presented conscious and dyspnoic at the emergency department after cleaning a copper chandelier with nitric acid. He had to be intubated 2 h after admission and mechanically ventilated because of fulminant respiratory insufficiency. As all sources of mechanical ventilation failed, extracorporeal membrane oxygenation had to be established 7 h after admission. With the additional use of surfactant and low dose inhalation therapy with nitric oxide (NO), the patient could be stabilised for 3 days and lung function improved temporarily. Despite all efforts the patient died at the fourth day from refactory respiratory failure. Pathologic examination revealed massive pulmonary edema without signs of inflammation. Thus, nitric acid inhalation induced pulmonary edema appears to be a most severe situation in which even most modern therapeutic interventions fail. As, in respect of recent literature and our case no promising therapy for nitric acid inhalation pulmonary edema is available, our efforts have to be directed towards prevention of nitric acid exposure.