Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects.

Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest (99m)Tc-sestamibi/(123)I-BMIPP imaging protocol in place of the commonly used sequential rest/stress (99m)Tc-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity and (2) sub-endocardial from transmural defects. We consider cardiac infarcts for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size.

The effect of a respiratory home nurse intervention in patients with chronic obstructive pulmonary disease (COPD).

BACKGROUND: Chronic obstructive pulmomary disease (COPD) is associated with substantial mortality, morbidity, and costs to the health care system. With the increasing interest in outreach care programmes it is important to evaluate their impact upon patients and health services, for conditions such as COPD. AIM: To determine the effectiveness of an outreach respiratory nurse in a shared care approach, with collaboration between general practitioners and hospital services, in the management of patients with severe COPD. METHODS: Patients with severe COPD attending The Queen Elizabeth Hospital, Adelaide participated in a randomised controlled trial of a home based nursing intervention (HBNI) over 12 months with outcome measures including mortality rate, hospital service utilisation, FEV1 and health related quality of life (HRQL) using a modified Dartmouth Primary Care Co-operative Quality of Life questionnaire. RESULTS: There were 48 subjects in each study arm, with no differences in mortality rate (eight deaths in the HBNI group and seven in the control group), hospital admissions, length of stay, number of outpatient and Emergency Service visits. The study had inadequate follow-up of FEV1 and HRQL within the control group. Within the HBNI group, a small improvement in HRQL (in three of ten indices measured) was demonstrated, despite a deterioration in FEV1 (11% reduction, p=0.04) compared to baseline. Quality of life of HBNI subjects' carers did not change. CONCLUSION: An increased level of care given by an outreach respiratory nurse in a shared care approach for patients with severe COPD produced small improvements in HRQL but did not result in the prevention of deaths or reduced health care utilisation.