The effect of perioperative beta-blockade on the pulmonary function of patients undergoing major arterial surgery.

INTRODUCTION: Concern about the potential detrimental side-effects of beta-blockade on pulmonary function often dissuades against their perioperative use in patients undergoing major arterial surgery (especially in those with chronic obstructive pulmonary disease (COPD)). In this study we aimed to establish prospectively the clinical relevance of these concerns. METHODS: After ethics committee approval and individual informed consent, the pulmonary function of twenty patients (mean age 68.7 years (range 43-82), 11 males) scheduled to undergo non-emergency major vascular surgery was studied by recording symptoms and spirometry before and after institution of effective beta-blockade. Fifteen patients (75%) had significant smoking histories (mean pack years/patient=50), while 12 (60%) had COPD. RESULTS: All patients tolerated effective beta-blockade satisfactorily without developing either subjective deterioration in symptoms or significant change on spirometry. The mean change in FEV1 following adequate beta-blockade was 0.05+/-0.24 liters (95% CI -0.06 to +1.61), p=0.35, giving a mean percentage change of 3.18%+/-11.66 (95% CI -2.26 to 8.62). CONCLUSIONS: Previously held concerns about worsening pulmonary function through the short-term use of beta-blockers should not dissuade their perioperative usage in patients with peripheral vascular disease. Furthermore, the accuracy of pulmonary function tests in preoperative assessment and risk stratification also appears unaffected by this therapy.     

Primary care residents and the management of hypercholesterolemia

A survey of primary care residents' attitudes, beliefs, and knowledge and a medical record audit were used to assess barriers to appropriate detection, identification, and management of hypercholesterolemia. Previous studies have focused on either self-reports or audits alone. This study compares survey results to recorded clinical performance. Family practice and internal medicine residents were compared to determine if previous findings were specialty-specific. The results of the survey indicate that, even prior to the publication of the National Cholesterol Education Program, residents demonstrated positive attitudes and appropriate knowledge of risk levels, in contrast with previous reports on practicing physicians. The medical record audit, however, showed that residents were not providing care that approximated their own recommendations for hypercholesterolemia management. Results of the survey and audit demonstrated little or no difference between specialty groups. The results indicated that training in management skills and reducing practice barriers are important to improve resident physicians' management of patients with hypercholesterolemia. The use of a survey and audit provide a useful needs assessment for designing educational programs.     

A comparative analysis of radiological and surgical placement of central venous catheters

Purpose To compare the differences in practice and outcome of all radiologically and surgically placed central venous catheters retrospectively over a 2-year period simultaneously, at a single institution. Methods A total of 253 Hickman catheters were inserted in 209 patients; 120 were placed radiologically in 102 patients and 133 were placed surgically in 107 patients. The indication was chemotherapy in 76% of radiological and in 47% of surgical cases; the remainder were for total parenteral nutrition and venous access. Results There were 6 (4.5%) primary surgical failures and a further 17 (13%) surgical cases requiring multiple placement attempts. Pneumothorax occurred once (0.8%) surgically and four times (3.3%) radiologically. There were no radiological primary misplacements but there were five (3.7%) surgical ones. Catheter or central vein thrombosis occurred in four (3.3%) radiological and five (3.7%) surgical cases. The rate of infection per 1000 catheter-days was 1.9 in radiologically placed catheters and 4.0 in surgically placed ones (p<0.001). Average catheter life-span was similar for the two placement methods (100±23 days). Conclusion Radiological placement is consistently more reliable than surgical placement. There are fewer placement complications and fewer catheter infections overall.     

In Vivo Proton Spectroscopy of Intracranial Infections and Neoplasms

The chemical characteristics of 10 neoplastic and 11 infectious brain masses were studied by in vivo ¹H magnetic resonance spectroscopy. In tumors, peak height ratios of n-acetyl-L-aspartate to choline were decreased compared to those in normal brain tissue and infectious masses (p < 0.02), but the ratios in normal brains and those with infections did not differ. N-acetyl-L-aspartate—to-creatine/phosphocreatine ratios were significantly lower in infectious masses and tumors compared to normal brain tissue (p = 0.003). However, in progressive multifocal leukoencephalopathy, N-acetyl-L-aspartate appeared relatively unchanged. Lactate was greater than choline in 9 of 11 brains with infection, 0 of 14 control brains, and 1 of 10 tumors. Lactate-to-choline ratios were significantly elevated in infectious masses compared with tumors (p < 0.01). ¹H magnetic resonance spectroscopy is promising for the noninvasive diagnosis of focal brain masses.     

Does Quality Improvement Work? Evaluation of the Organ Donation Breakthrough Collaborative

Objective. The Organ Donation Breakthrough Collaborative is a quality improvement initiative to encourage adoption of "best practices" for identifying potential donors and obtaining consent for deceased organ donation. We evaluate the impact of the first phase on organ donation rates.
Setting. We study donation rates in the 95 hospitals that participated in the first phase and a control group of 125 hospitals.
Design. We use a controlled pre/post design. The preperiod is the year before the start of the Collaborative (September 2002 to August 2003), the postperiod is the final 6 months of the first phase (March 2004 to August 2004).
Data. We use administrative data from the Organ Procurement and Transplantation Network to compute the conversion rate in each hospital group and time period. The conversion rate is the proportion of eligible donors who became actual donors.
Principal Findings. Preperiod conversion rates in Collaborative and control hospitals were similar: 52 and 51 percent, respectively. In the postperiod, the conversion rate increased to 60 percent among Collaborative hospitals and remained at 51 percent among control hospitals. The relative change was 8 percentage points (95 percent confidence interval: 2–13: p <.001).
Conclusions. Our findings suggest that the Breakthrough Collaborative led to an increase in donation rates at participating hospitals.     

Alteration in myelin-associated proteins following spinal cord irradiation in guinea pigs.

The aim of this study was to investigate the pathological and cellular basis for radiation-induced myelopathy in guinea pigs by monitoring biochemical alterations in levels of myelin basic protein and 2',3'-cyclic nucleotide phosphohydrolase. Guinea pigs were irradiated to the lumbar region with various doses of neutrons or cobalt gamma irradiation. The ED50s for paralysis were 17.2 Gy and 67.5 Gy for neutron and cobalt irradiation, respectively, and was histologically associated with demyelination. In spinal cords taken from animals at the onset of paralysis myelin basic protein levels were decreased in direct relationship to the radiation dose. The lowest doses to cause paralysis led to a 25% decrease in MBP levels. In a separate experiment, alterations in MBP were measured in the spinal cords over the time period leading up to paralysis. Surprisingly, decreases in MBP were found immediately after the end of the 4 week irradiation period. These early changes in MBP were not markedly dose dependent and occurred with nonparalyzing doses. Dose-dependent decreases were found only just before the onset of paralysis. CNPase activity measured in the same specimens showed changes that were essentially similar to those for MBP. In the CSF, MBP levels were essentially constant until onset of paralysis. This study showed that demyelination, as assessed by the levels of the myelin-associated proteins MBP and CNPase, can occur soon after spinal cord irradiation but that profound dose-dependent changes are seen only immediately preceding the onset of paralysis. Although increases in MBP in the CSF were associated with the onset of radiation-induced myelopathy, its assay is unlikely to predict this complication of irradiation.