Carbon dioxide narcosis due to inappropriate oxygen delivery: a case report.

BACKGROUND: Oxygen delivery to patients with chronic obstructive pulmonary disease may be challenging because of their potential hypoxic ventilatory drive. However, some oxygen delivery systems such as non-rebreathing face masks with an oxygen reservoir bag require high oxygen flow for adequate oxygenation and to avoid carbon dioxide rebreathing. CASE PRESENTATION: A 72-year-old Caucasian man with severe chronic obstructive pulmonary disease was admitted to the emergency department because of worsening dyspnea and an oxygen saturation of 81% measured by pulse oximetry. Oxygen was administered using a non-rebreathing mask with an oxygen reservoir bag attached. For fear of removing the hypoxic stimulus to respiration the oxygen flow was inappropriately limited to 4L/minute. The patient developed carbon dioxide narcosis and had to be intubated and mechanically ventilated. CONCLUSIONS: Non-rebreathing masks with oxygen reservoir bags must be fed with an oxygen flow exceeding the patient's minute ventilation (>6-10 L/minute.). If not, the amount of oxygen delivered will be too small to effectively increase the arterial oxygen saturation. Moreover, the risk of carbon dioxide rebreathing dramatically increases if the flow of oxygen to a non-rebreathing mask is lower than the minute ventilation, especially in patients with chronic obstructive pulmonary disease and low tidal volumes. Non-rebreathing masks (with oxygen reservoir bags) must be used cautiously by experienced medical staff and with an appropriately high oxygen flow of 10-15 L/minute. Nevertheless, arterial blood gases must be analyzed regularly for early detection of a rise in partial pressure of carbon dioxide in arterial blood in patients with chronic obstructive pulmonary disease and a hypoxic ventilatory drive. These patients are more safely managed using a nasal cannula with an oxygen flow of 1-2L/minute or a simple face mask with an oxygen flow of 5L/minute.

Predicting outcomes in critically ill patients with acute kidney injury undergoing intermittent hemodialysis--a retrospective cohort analysis.

PURPOSE: Despite advances in the management of critically ill patients with acute kidney injury (AKI), the prognosis is poor. The evidence base on risk factors for poor outcomes in these patients is scarce. Our aim was to identify predictors of outcome in AKI patients undergoing intermittent hemodialysis (IHD). METHODS: We retrospectively analyzed patient records from consecutive, critically ill patients with AKI treated with IHD in one teaching secondary care hospital from 2002 to 2006. We used multivariate Cox proportional hazard regression analysis to identify predictors of mortality, hemodynamical instability during hemodialysis and failing renal recovery. RESULTS: Totally, we included 39 patients with a mean APACHE II score of 20.1 (SD 7.5) who had an average of 5.1 +/- 4.8 hemodialysis sessions. All-cause mortality was 35.9% (14/39 patients). In multivariate analysis, pre-existing cardiac co-morbidity (HR 1.92 [0.58-6.47]), metabolic acidosis (2.40 [0-74-7.74]) and presence of ARDS (1.83 [0.52-6.46]) were the strongest predictors. 7 patients (18%) sustained new hemodynamic instability during hemodialysis, for which ARDS (6.42 [0.64-64.03]) was a strong predictor. Among survivors, 20 patients (80%) had partial or complete renal recovery. Preexisting renal insufficiency (3.13 [0.34-29.13]) and high net ultrafiltration quantities (3.30 [0.40-26.90]) were the strongest predictors for failing renal recovery. As a consequence of the small samples size none of the associations was statistically significant. CONCLUSIONS: Presence of ARDS and high net ultrafiltration rates seem to represent key factors affecting prognosis in patients with AKI undergoing IHD. Targeting these risk factors may improve the poor prognosis of these patients.

Prevalence of undernutrition on admission to Swiss hospitals.

BACKGROUND & AIMS: According to the literature, undernutrition is prevalent in 20-60% of patients on hospital admission. The differences in the rate of undernutrition arise from different diagnostic tools used in the studies. We aimed to investigate the prevalence of undernutrition in Swiss hospitals using a standardized screening tool. METHODS: All patients admitted to the departments of internal medicine of 7 Swiss hospitals were screened at entry for nutritional status using the Nutrition Risk Screening 2002 score. Patients with a score of 3 or more, which denotes severe undernutrition or patient "at risk" for undernutrition were analyzed. RESULTS: Between May 2003 and April 2006 32,837 patients were included in the study. 5978 (18.2%) had a score of 3 or more and were classified as severely undernourished or at high risk for undernutrition (age<45 y: 8%; 45-64 y: 11%; 65-84 y: 22%; >85 y: 28%). A nutritional intervention was made in 4175 patients (12.7%). CONCLUSIONS: Nearly one in five patients was severely undernourished or "at risk" for undernutrition. Undernutrition was directly related to age. Patients with a clear indication for nutrition therapy, as suggested by the formal screening procedure, obtained nutritional intervention in 70%.

[The prospective survey of risk interventions and their complications in internal medicine wards]. / Die prospektive Erfassung risikobehafteter Interventionen und ihrer Komplikationen in der stationären Inneren Medizin.

The organization of the heads of hospital departments of the Swiss Society of Internal Medicine is conducting the prospective program "Komplikationenliste" for the registration of type and number of interventions and related complications (both at a case- and statistical level) in patients hospitalized in internal medicine departments. The information collected from the clinics voluntarily participating in the program is periodically commented by field experts and made available in anonymous form to all departments of the country, with the goal to improve patient safety. Through the multi-centric approach, it is also possible to identify the quantitative significance of rare complications, allowing preventive measures also in hospitals where a particular complication has not yet occurred. This system is expected to improve the quality of patient treatment in the whole country. The systematic approach allows that the department heads improve their measures for the reduction of complications of medical interventions, and take responsibility in terms of patient treatment and hospital costs. This program, which has started in 1998, has included 138,320 patients by December 2003.