Distinct pattern of microsusceptibility changes on brain magnetic resonance imaging (MRI) in critically ill patients on mechanical ventilation/oxygenation

Purpose

Over the years, interesting SWI abnormalities in patients from intensive care units (ICU) were observed, not attributable to a specific cause and with uncertain clinical significance. Recently, multiple SWI-hypointense foci were mentioned related to neurological complications of SARS-COV-2 infection. The purpose of the study was to describe the patterns of susceptibility brain changes in critically-ill patients who underwent mechanical ventilation and/or extracorporeal membrane oxygenation (ECMO).

Methods

An institutional board-approved, retrospective study was conducted on 250 ICU patients in whom brain MRI was performed between January 2011 and May 2020. Out of 48 patients who underwent mechanical ventilation/ECMO, in fifteen patients (median age 47.7 years), the presence of SWI abnormalities was observed and described.

Results

Microsusceptibilities were located in white-gray matter interface, in subcortical white matter (U-fibers), and surrounding subcortical nuclei in 13/14 (92,8%) patients. In 8/14 (57,1%) patients, SWI foci were seen infratentorially. The corpus callosum was affected in ten (71,4%), internal capsule in five (35,7%), and midbrain/pons in six (42,8%) patients.

Conclusion

We showed distinct patterns of diffuse brain SWI susceptibilities in critically-ill patients who underwent mechanical ventilation/ECMO. The etiology of these foci remains uncertain, but the association with mechanical ventilation, prolonged respiratory failure, and hypoxemia seems probable explanations.

Recommendations for extracorporeal membrane oxygenation (ECMO) in COVID-19 patients : Consensus paper of the Medical University of Vienna

The pandemic from the SARS-CoV‑2 virus is currently challenging healthcare systems all over the world. Maintaining appropriate staffing and resources in healthcare facilities is essential to guarantee a safe working environment for healthcare personnel and safe patient care. Extracorporeal membrane oxygenation (ECMO) represents a valuable therapeutic option in patients with severe heart or lung failure. Although only a limited proportion of COVID-19 patients develop respiratory or circulatory failure that is refractory to conventional treatment, it is of utmost importance to clearly define criteria for the use of ECMO in this steadily growing patient population. The ECMO working group of the Medical University of Vienna has established the following recommendations for ECMO support in COVID-19 patients.

[Recommendations for Extracorporeal Membrane Oxygenation (ECMO) in COVID-19 Patients]

The pandemic from the SARS-CoV‑2 Virus is currently challenging health care systems all over the world. Maintaining appropriate staffing and resources in healthcare facilities is essential to guarantee a safe work environment for healthcare personnel and safe patient care. Extracorporeal membrane oxygenation (ECMO) represents a valuable therapeutic option in patients with severe heart or lung failure. Although only a limited proportion of COVID-19 patients develops respiratory or circulatory failure that is refractory to conventional therapies, it is of utmost importance to clearly define criteria for the use of ECMOs in this steadily growing patient population. The ECMO working group of the Medical University of Vienna has established the following recommendations for ECMO support in COVID-19 patients.

Can Venous Blood Gas Be Used as an Alternative to Arterial Blood Gas in Intubated Patients at Admission to the Emergency Department? A Retrospective Study

Objective

Blood gas analysis plays an important role in both diagnosis and subsequent treatment of critically ill patients in the emergency department and the ICU. Historically, arterial blood is predominantly used for blood gas analysis. The puncture is painful and complications may occur. The purpose of the present study was to evaluate the agreement between arterial and venous blood gas analysis and whether the sole use of venous blood gas analysis would have changed therapy.

Methods

Adult patients who were intubated in the field and received an arterial and venous blood gas analysis within 15 mins after admission to the ED were eligible for inclusion. The values for pH, pCO₂, HCO₃-, base excess and lactate levels were collected retrospectively. Mean differences were calculated by subtracting venous from arterial values. The agreement between venous and arterial measurements was assessed using the method of Bland and Altman. Blood gases were assessed by two independent physicians using a standardized questionnaire to determine whether the use of venous blood gases would have led to a different interpretation of the situation (other diagnostic path) or a change of therapy (eg. respirator adjustment). Acceptable limits were defined before the collection of data started.

Results

Fifty patients (62% male, median age 63years) who were treated at the Emergency Department between June 1, 2014 and December 31, 2014 were included in the study. Following average differences and limits of agreement (LOA) were documented: pH 0.02312 with LOA from −0.048 to 0.094; pCO₂ −3.612 mmHg with LOA from −15 to 8.1 mmHg; BE −0.154 mmol/l with LOA from −3.7 to 3.4 mmol/l; HCO₃−0.338 mmol/l with LOA from −2.27 to 2.9 mmol/l; Lactate −0.124 mg/dl with LOA from −2.28 to 2.03 mg/dl. Using venous blood gas results 100% of the patients with metabolic alkalosis were correctly diagnosed. Metabolic acidosis was detected with a high sensitivity (80.64%), specificity (89.47%) and positive predictive value (92.59%). The answers to lactate and acidosis due to AKI showed a specificity and positive predictive value of 100%. The respiratory adjustment showed a high sensitivity (91.89%) but a low specificity (38.46%).

Conclusion

For pH, bicarbonate, BE and lactate venous blood gases can be used as surrogates for arterial measurements. Venous pCO₂ can be used for screening of hypercapnia and trending. Respirator adjustments may be done too often if the venous blood gas is used.

Evaluation of coagulation markers for early diagnosis of acute coronary syndromes in the emergency room

BACKGROUND

Diagnosis of acute coronary syndromes (ACS) is a major challenge for emergency physicians. Because soluble fibrin (sF) has been suggested as a potential early marker of impending myocardial ischemia, we were interested whether a sF bedside test could help in early identification of patients with ACS in the emergency department.

METHODS

We evaluated plasma coagulation markers, including a newly developed sF bedside test, prothrombin fragment (F(1+2)), sF, and D-dimer, in a cross-sectional trial with 184 patients suggestive of ACS.

RESULTS

Whereas 76% (13 of 17) of patients with unstable angina pectoris (UAP) had a positive sF bedside test, only 10 of 33 patients (30%) with non-ST-segment-elevation myocardial infarction and 10 of 44 patients (23%) with ST-elevation myocardial infarction tested positive. Three percent of controls (1 of 33) and 11% of patients (6 of 57) with preexisting stable angina had a positive sF bedside test (P <0.001 for noncardiac chest pain vs ACS), yielding an overall specificity of 92% and a sensitivity of 35%. The sensitivity of the established coagulation markers was significantly less to detect ACS (11% for F(1+2), 20% for thrombus precursor protein, and 18% for D-dimer; P <0.02 vs sF bedside test). The sF bedside test presented the earliest objective indicator of impending myocardial damage in the majority (10 of 13) of ACS patients with a normal or nondiagnostic electrocardiogram (ECG).

CONCLUSIONS

A sF bedside test offers a specific tool for early identification of patients with ACS in an emergency department setting, although its sensitivity seems sufficient only for the early identification of patients with UAP. A sF bedside test could be useful, particularly in UAP patients with a nondiagnostic ECG.

C-reactive protein and mortality in patients with acute aortic disease

OBJECTIVE

The association of acute-phase reaction and outcome of patients with acute vascular diseases is controversial. The prognostic value of admission C-reactive protein (CRP) in patients with acute aortic aneurysm or dissection has not yet been investigated.

DESIGN AND SETTING

Cohort study including 255 consecutive patients from an aneurysm registry with symptomatic thoracic or abdominal aortic aneurysm and/or dissection in an emergency department of a tertiary care university hospital.

PATIENTS

Patients were included who had symptoms of aortic disease admitted between 1 January 1992 and 31 November 1998 and were followed up until 31 December 1999 for survival.

MEASUREMENTS

Admission CRP (mg/dl) levels were categorized in quartiles: quartile 1, less than 0.5; quartile 2, 0.50-1.30; quartile 3, 1.31-6.30; quartile 4, higher than 6.30. Each group contained about 60 patients.

RESULTS

Cumulative mortality 1, 3, and 6 months after presentation was 32%, 37%, and 40%, respectively. Increased CRP levels were independently associated with mortality, adjusted for age, sex, hemodynamic shock, mechanical ventilation, coronary artery disease, aortic rupture, hemoglobin, diabetes, and treatment strategy (surgery vs. conservative). Hazard ratios in patients with CRP levels in quartiles 2-4 compared to quartile 1 were 0.7, 1.8, and 2.6, respectively.

CONCLUSIONS

Elevated admission CRP values in patients with symptomatic aortic aneurysm/dissection were independently associated with poor prognosis. CRP levels higher than 6.3 mg/dl indicate a high risk for short-term mortality.

Severe accidental hypothermia with or without hemodynamic instability: rewarming without the use of extracorporeal circulation

BACKGROUND

The optimal rewarming technique for patients in deep accidental hypothermia with core temperatures below 28 degrees C is not established. Several authors believe that extracorporeal rewarming is essential, especially for patients with hemodynamic instability. Others believe that invasive rewarming ought to be reserved for patients in cardiac arrest. We describe our experience with a strictly conservative technique without the use of invasive rewarming devices in patients with severe accidental hypothermia and a sustained perfusion rhythm.

METHODS

A cohort study extending from 1991 to 2000, including all patients received at the emergency department of the University Hospital of Vienna with severe hypothermia, a core temperature of maximum 28 degrees C and no preclinical cardiac arrest.

RESULTS

36 patients with deep hypothermia were included in the study. Their core temperatures ranged from 20.2 degrees C to 28 degrees C; the median temperature was 25.75 degrees C (25th and 75th percentile, 24.2/27.3). Fourteen patients were intoxicated and their multimorbidity was high. All of 19 patients with stable hemodynamics and 14 of 17 patients with unstable hemodynamics were successfully rewarmed to normothermia with warmed infusions, inhalation rewarming and forced air rewarming. The rewarming process took 9.5 hours (8/10.5) and required a volume load of 4820 ml (2735/5770). The rewarming rate was 1.09 degrees C per hour (0.94/1.25). Although 92% of the patients were successfully rewarmed to normothermia, in-hospital mortality was 42%, but was largely related to comorbidity.

DISCUSSION

A conservative approach is highly successful in achieving normothermia in patients with deep hypothermia with or without stable hemodynamics. In-hospital mortality of severe accidental hypothermia in urban conditions is high; comorbidity might play a major role. The influence of the rewarming strategy on late in-hospital mortality remains unclear.

Plasma endothelin in patients with acute aortic disease

PURPOSE AND BACKGROUND

We investigated the plasma levels of endothelin 1/2 in patients with acute symptoms relating to a known or newly diagnosed aortic aneurysm in order to investigate the possible role of peptides in the development of the disease.

METHODS

Endothelin 1/2 plasma levels were determined in patients admitted to the emergency unit with suspected acute aortic disease. The history, type of aneurysm, outcome and laboratory findings were determined and compared to endothelin 1/2 levels collected on admission.

RESULTS

In patients with ruptured aneurysm (n=27) or acute aortic dissection (n=18) the endothelin 1/2 median levels were higher 1.1 (25th and 75th quartile 0.7, 1.7) fmol/ml than in patients (n=20) with pre-existing aneurysm 0.7 (0.4, 1.1) fmol/ml (P=0.013). Patients who died had significantly higher endothelin levels 1.3 (0.8, 1.9) fmol/ml than the survivors 0.8 (0.5, 1.4) fmol/ml (P=0.04). In a logistic regression analysis, only a higher blood pressure on admission was an independent predictor of survival.

CONCLUSION

Endothelin 1/2 levels are elevated in patients with acute dissection or ruptured aneurysm, but they are not an independent predictor of survival.

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.

[Physical exercise impairs the acute stage of adaptation to moderate altitude]

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.

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.

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

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]

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.

Bronchoscopy via a redesigned Combitube in the esophageal position. A clinical evaluation

BACKGROUND

The esophageal-tracheal Combitube (Kendall-Sheridan Catheter Corp., Argyle, NY) is an effective device for providing adequate gas exchange. However, tracheal suctioning is impossible with the Combitube placed in the esophageal position. To eliminate this disadvantage, the Combitube was redesigned by creating an enlarged hole in the pharyngeal lumen that allows fiberoptic access, tracheal suctioning, and tube exchange over a guide wire.

METHODS

The two anterior, proximal perforations of regular Combitubes were replaced by a larger, ellipsoid-shaped hole. After the study was approved by the institutional review board, 20 patients with normal airways (Mallampati I or II) were studied. During general anesthesia, patients were esophageally intubated with the Combitube. A flexible bronchoscope was inserted and guided via the modified hole and glottic opening down the trachea. For the replacement procedure, a J tip guide wire was introduced through the bronchoscope. The bronchoscope and the Combitube were removed and a standard endotracheal tube was advanced over a guide catheter.

RESULTS

Bronchoscopic evaluation of the trachea and guided replacement of the Combitube by an endotracheal tube was successful in all 20 study patients. The average time needed to perform airway exchange was 90 +/- 20 s (mean +/- SD). Arterial oxygen saturation and end-tidal carbon dioxide levels remained normal in all patients. No case of laryngeal trauma was observed during intubation or the airway exchange procedure.

CONCLUSIONS

The redesigned Combitube enables fiberoptic bronchoscopy, fine-tuning of its position in the esophagus, and guided airway exchange in patients with normal airways. Further studies are warranted to demonstrate its value in patients with abnormal airways.

Conservative management of foreign bodies in the gastrointestinal tract

There are at present no clear guidelines whether foreign body ingestion in the gastrointestinal tract should be managed conservatively, endoscopically or surgically. Retrospectively we have, therefore, analyzed 78 foreign body ingestion's in 42 patients (age 15-72 years) admitted to the Emergency Department of the University Hospital in Vienna. Our intention was to assess the value of a conservative management, defined as daily follow-up visits until the foreign body spontaneously appeared in the feces and to find criteria when endoscopic or surgical management is required. Of 78 foreign bodies, 67 (86%) passed the gastrointestinal tract spontaneously without complications, 9 (11%) were removed endoscopically, and only 2 (3%) required surgery. There were no gastrointestinal perforations. Even foreign bodies with a maximal length of 13.5 cm appeared in the feces spontaneously within a few days. Our data suggests that more than 80% of adults with foreign body ingestion can be managed safely as outpatients by means of conservative treatment. Endoscopic or surgical removal is only indicated in very rare circumstances.

[Results of critical care management of patients after bone marrow transplantation]

In a retrospective study we investigated the clinical course of patients who required intensive care support after bone marrow transplantation. Out of 25 patients only 5 (20%) survived treatment in the intensive care unit (ICU) and this group showed a significantly lower age, lower APACHE III and organ-failure scores and higher serum albumin values, as well as a longer interval between bone marrow transplantation and admission to intensive care. However, no patient requiring mechanical ventilation primarily for pneumonia or other infections arising as a complication of bone marrow transplantation survived intensive care. All patients requiring ventilation for more than 24 hours died in hospital. Of the 5 patients surviving ICU treatment only 3 were eventually discharged from hospital and only one single patient was alive after 6 months. Hence, current intensive care management appears to be indicated in only a small group of patients after bone marrow transplantation.

[Emergency respirator therapy in intermediate altitude with the Ambu Matic]

Portable emergency ventilators are commonly used in a pre-hospital setting in the transport of critically ill patients also in hypobaric environments. The aim of our trial was to evaluate the influence of moderate altitude at 2700 m compared to 171 m altitude on minute ventilation and blood gas analysis in healthy volunteers during mechanical ventilation with the Ambu Matic ventilator. At 2700 m altitude, the delivered minute volume increased by 13.8%. paCO2 decreased by 9.2% (p < 0.01 for all reported changes). No statistical change in paO2 at 2700 m altitude was observed. These changes are of sufficient magnitude and importance to require monitoring of minute volume to prevent volutrauma or barotrauma.

[Bronchiolitis obliterans organizing pneumonia with acute respiratory insufficiency]

A 22-year-old woman was hospitalized because of fever of 39 degrees C and increasing dyspnoea. The chest radiograph demonstrated coarse confluent opacities bilaterally. Despite antibiotic treatment the condition deteriorated acutely after 2 days. All efforts to find an infectious agent, including immunological tests, were unsuccessful. Artificial ventilation became necessary because of increasing respiratory failure with an arterial oxygen partial pressure of 56 mm Hg, CO2 of 41 mm Hg and a respiratory rate of 60/min. Histological examination of a transthoracic lung biopsy revealed bronchiolitis obliterans organizing pneumonia, which was treated with prednisolone. The initial dose was 500 mg/d, gradually reduced to 12.5 mg/d over 2 weeks. The clinical and radiological findings improved markedly after 2 days and the patient discharged herself after 3 weeks and there was no follow-up.

[Emergency intubation with the Combitube in a patient with persistent vomiting]

Prompt establishment of a patient airway and effective ventilation are the major goals during initiation of cardiopulmonary resuscitation in patients with cardiac arrest. Endotracheal intubation is the definitive method to maintain an optimal airway. However, endotracheal intubation is not always possible, even for the skilled physician. The Combitube has been developed to overcome this disadvantage. Studies have proved the effectivity of ventilation with this device. A case is reported where a patient suffered from acute respiratory failure and attempts at endotracheal intubation failed due to continued vomiting rendering fibre-optical visualisation of the vocal cords impossible. Blind insertion of the Combitube led to successful ventilation, and hence replacement by an endotracheal airway could be performed without danger of aspiration.

Magnetic resonance imaging of the heart during positive end-expiratory pressure ventilation in normal subjects

OBJECTIVES

Magnetic resonance imaging was used to assess the effects of ventilation with positive end-expiratory pressure (PEEP) on cardiac volumes, especially on atrial volumes as well as to determine semiquantitative measurements of spatial interactions between heart, lungs and chest.

DESIGN

Prospective study with healthy volunteers undergoing mechanical ventilation with different levels of PEEP during magnetic resonance imaging.

SETTING

Magnetic resonance unit, Institute of Diagnostic Imaging, Rudolfinerhaus Hospital.

SUBJECTS

Twelve healthy volunteers.

INTERVENTIONS

Volunteers were imaged, using a multislice-multiphase technique during spontaneous breathing and with PEEP values of 0, 7, and 15 cm H2O.

MEASUREMENTS AND MAIN RESULTS

Atrial as well as ventricular volumes, chest diameters, and midventricular contact between the heart and anterior chest wall were determined on transverse-oblique sections. Atrial volumes showed a progressive decline beginning at a PEEP of 7 cm H2O. Diastolic filling of both ventricles was reduced. A PEEP level of 15 cm H2O induced a significant increase in the sagittal-oblique but not in the transverse-oblique chest diameter. PEEP values of 7 and 15 cm H2O shortened the length of the midventricular contact between the heart and anterior chest wall.

CONCLUSIONS

Left and right ventricular end-diastolic volumes and stroke volumes decreased significantly during ventilation with PEEP at 15 cm H2O, as did end-systolic atrial volumes. Volume changes in association with changes of chest and heart configuration suggest external cardiac compression by the expanding lungs. Furthermore, this study illustrates the feasibility of magnetic resonance imaging in mechanically ventilated patients.

[Prevalence of alcohol drinking in Alpine skiing]

Previous investigations showed direct correlation between the degree of alcoholization and the severity of injuries after ski accidents. The aim of our study was to investigate the prevalence of alcohol use on slopes and on ski tours.

RESULTS

The examination of breath in 414 probands proved 30% alcohol positive ski tourists. A significantly higher frequency of alcohol positive skiers was found on tours, if an open mountain hut was located on the tour, but the mean degree of alcoholization was significantly higher on slopes.

Emergency intubation with the Combitube in a grossly obese patient with bull neck

A grossly obese patient with bull neck required immediate intubation. Endotracheal intubation failed because visualization of the vocal cords was not possible. As an alternative, the Combitube was inserted without difficulty and the patients lungs were ventilated via the Combitube until tracheotomy was performed on the following day. The patient survived and was discharged alive from the hospital 5 weeks later. The Combitube has gained worldwide interest and is now included in the Guidelines of the American Heart Association and the American Society of Anesthesiologists.

Emergency intubation with the Combitube: comparison with the endotracheal airway

STUDY OBJECTIVE

To evaluate the safety and effectiveness of the Combitude as used by ICU nurses under medical supervision compared with endotracheal airway established by ICU physicians during CPR.

DESIGN

Prospective study of ICU patients over a seven-month period.

SETTING

Medical ICU.

PARTICIPANTS

Thirty-seven patients suffering from cardiac arrest.

INTERVENTIONS

Emergency intubation with either the Combitube by nurses or the endotracheal airway by physicians and subsequent mechanical ventilation.

MEASUREMENTS AND MAIN RESULTS

Evaluation of blood gases after 20 minutes of mechanical ventilation. Intubation time was shorter for the Combitube (P < .001). Blood gases for each device showed comparable results; PaO2 was slightly higher during ventilation with the Combitube (P < .001).

CONCLUSION

The Combitube as used by ICU nurses was as effective as establishment of the endotracheal airway by intensivists during CPR. The Combitube may be used whenever endotracheal intubation cannot be performed immediately.

[Amphetamine doping in leisure-time mountain climbing at a medium altitude in the Alps]

Although doping in leisure sports may potentially be of relevance for medical emergency situations, it has attracted much less attention than doping in elite athletes. The aim of our study was to evaluate the prevalence of amphetamine consumption in medium altitude mountaineering. Urine samples were taken from 253 males after a successful ascent. Analysis for amphetamines proved positive for 7.1% of mountaineers climbing above 3300 m. On peaks between 2500 to 3300 meters above sea level, 2.7% of the mountaineers we examined had amphetamines residues in their urine. Below 2500 meters, no positive sample was detected. For tourists living outside of the Alpine range, we noticed a significantly higher proportion of positive analyses. We conclude that attempts to induce a higher performance level by pharmacological means are not overly uncommon in leisure mountaineering. Such a behaviour may be of medical relevance in emergency situations.

A rare complication of a central venous catheter system (Port-a-Cath). A case report of a catheter embolization after catheter fracture during power training

A 36 year old patient received an implantable central venous catheter system for a bone marrow transplantation. One year after the successful transplantation, embolization of the catheter was discovered by a routine x-ray three weeks after beginning of an exercise program with a spring expander including arm exercises. The catheter was removed without further complication via the vena femoralis. We assume that the cause for this incident was material fatigue due to pressure between clavicula and first rib possibly caused by strength training. We suggest as a consequence that patients with an implanted catheter system should before starting exercise consult a sports medicine specialist who would in turn cooperate with the specialist responsible for the catheter, so that an adequate and safe training program can be selected.

Is the incidence of acute mountain sickness (AMS) at medium altitude in the Austrian Alps influenced by the height of home residence of the alpinist?

In previous studies the incidence of acute mountain sickness (AMS) at medium altitude was examined in the Austrian Alps, where many tourists come from low parts of Europe. This study assesses the influence of the height of home residence on the incidence of AMS at medium altitude. The severity of high-altitude adaptation disorder was quantified by using a scoring system after an interview and a clinical examination in 84 lowlanders, mainly those from Hungary. Forty-two alpinists with a home residence of 800 to 1000 m served as control. The incidence of AMS was 1.4% at 2000 m and 7.4% in 3000 m. The most frequent symptoms were slight headache and peripheral or periorbital oedema. The AMS-score of the Hungarian alpinists did not differ significantly from that of the alpinists with a home residence of height 800 to 1000 m.

CONCLUSION

in contrast to the situation at high altitude, at medium height tourists from lowlands are not at higher risk of AMS than other alpinists.