Effect of hypotension preceding death on the function of lungs from donors with nonbeating hearts

BACKGROUND: A shortage of suitable brain-dead donors continues to severely limit lung transplantation. Use of donors with nonbeating hearts has been suggested as a solution. Lungs are unique, in that aerobic metabolism can continue in the absence of blood circulation because oxygen is present in airways and alveoli. Animal studies have shown reasonable cadaveric graft function up to several hours after sudden death by drug administration. However, hemodynamic instability before death may worsen lung function through activation and pulmonary sequestration of neutrophils and release of inflammatory mediators. Because many potential cadaveric donors experience hypotension before death, this study was undertaken to assess the effect of hypotensive shock on cadaveric lung viability. METHODS: A rat isolated lung reperfusion model was used to assess pulmonary function over 3 hours of reperfusion or until gross pulmonary edema developed. Twenty-five rats were randomly allocated to the following study groups, which were based on status before lung harvest: (1) control: no interventions; (2) hypotensive: 1 hour of hypotension by exsanguination to a mean blood pressure of 30 to 40 mm Hg; (3) cadaver: death by cervical dislocation followed by 3 hours of in situ lung ischemia; (4) hypotensive + 3 hours cadaver: 1 hour of hemorrhagic shock, followed by death and 3 hours of in situ ischemia; (5) hypotensive + 2 hours cadaver: similar to group 4, except the in situ ischemia was abbreviated to 2 hours. RESULTS: No significant differences were found among group 1, 2, or 3 lungs with regard to wet to dry weight ratios, gas exchange, and pulmonary arterial or airway pressures. However, all group 4 lungs became grossly hemorrhagic and developed severe pulmonary edema within 10 minutes of reperfusion. Group 5 lungs fared only marginally better, with two of five lungs tolerating 3 hours of reperfusion. CONCLUSIONS: A period of hypotension before death severely impairs cadaveric lung viability.     

The validity of a nursing assessment and monitoring of signs and symptoms scale in ICU and non-ICU patients

PURPOSE: This study examined the validity of medical-record-based nursing assessment and monitoring of signs and symptoms (nursing surveillance) in predicting patients who were admitted to ICUs and those admitted to non-ICUs. The association of this assessment and monitoring with differences in an intermediate patient outcome, instability at discharge, was also explored. Patients admitted to either setting with a diagnosis of acute myocardial infarction, cerebrovascular accident, congestive heart failure, or pneumonia, were included in the study. METHOD: A secondary analysis was carried out using a subset of data originally collected for a quality-of-care study. Data from the medical records of 11,246 patients (52% female, 48% male) with a mean age of 76.4 years were used in the present study. RESULTS: ICU patients (n = 3969) were found to have a longer length of stay and to be sicker on admission than non-ICU patients (n = 7277). Overall, patients in the ICU received significantly higher nursing assessment and monitoring of signs and symptoms scores than non-ICU patients. Nursing assessment and monitoring of signs and symptoms scores were lower for patients discharged with greater instability for three of the four diseases (cerebrovascular accidents, congestive heart failure, and pneumonia).     

Plaque herniation through an intracoronary stent

We present a case where a Wiktor intracoronary stent was inserted for 'poor angiographic result' following balloon angioplasty. Despite appropriate positioning and repeated dilation of the stent a suboptimal result was achieved because of plaque herniation through the stent. The case emphasizes that the choice of stent used is important and will become more so as the number of choices available increases.