David L. Jackson

Childhood lead poisoning: a controlled trial of the effect of dust-control measures on blood lead levels

Lead-contaminated house dust is one factor in childhood lead poisoning; however, most lead-reduction programs do not emphasize the control of house dust. We studied whether lead-reduction plus dust-control measures would lower blood lead levels in children with Class II or III poisoning (blood lead levels, 30 to 49 micrograms per deciliter) more effectively than lead reduction alone. An experimental group of 14 children and a control group of 35 children whose homes had already been treated were studied. In experimental homes, sites with elevated lead levels (greater than 100 micrograms per 930 cm2) were wet-mopped twice monthly and families were encouraged to clean and to wash the childs hands frequently. After one year blood lead levels fell an average of 6.9 micrograms per deciliter in the experimental group, as compared with 0.7 micrograms per deciliter in controls (P less than 0.001). Children in the experimental group with the highest blood lead levels had the most marked reduction. Four children in the control group (and none in the experimental group) required chelation therapy for blood levels greater than 50 micrograms per deciliter. These results show that a focused dust-control program can reduce blood lead levels more than standard lead removal in the home.

Patient autonomy and 'death with dignity'. Some clinical caveats

THE rapid advance in medical technology over the past two decades has raised serious questions about patient autonomy and the right to die with dignity. This article will attempt to examine psychol...

Clinical characteristics and resource utilization of ICU patients: implications for organization of intensive care.

We reviewed the clinical characteristics and resource utilization of 391 medical (M) and 315 surgical (S) ICU patients. In general, MICU patients had more physiologic derangement, as determined by the admission, maximal, and average acute physiology scores (APS). SICU patients had more frequent therapeutic interventions as measured by admission, maximal, and average therapeutic intervention scoring system values. Notably, 40% of MICU and 30% of SICU patients never received any active interventions and were admitted strictly for monitoring purposes.Patients on admission with APS ≤ 10 had markedly shorter ICU stays, with almost 50% less treatment than patients with APS over 10. Fifty-six percent of patients with APS ≤ 10 did not require any active intervention. In contrast, 83% of patients with APS greater than 10 had considerable intensive interventions. These patients required mechanical ventilation, invasive monitoring, and vasoactive drugs more than twice as often as patients with lower APS scores. Consideration should be given, therefore, to the organization of ICUs according to the patients severity of illness.

Discharge decision-making in a medical ICU: characteristics of unexpected readmissions

To identify those patients most likely to be readmitted to a Medical ICU (MICU), we studied 512 MICU admissions during a 1-yr period. There were 36 readmissions within the same hospitalization in that interval. When ICU deaths and short-term drug overdoses were excluded, these 36 readmissions comprised 12% of all patients discharged from MICU. The mortality rate of this group was 58%, greater than twice the overall mortality rate for the year. Fifty-three % of the patients were readmitted because of recurrence of their initial disease on admission, with septicemia being the most common disease. Another 30% were readmitted because of a new complication, one-half of which were medication toxicities.We have attempted to delineate diseases, medications, and complications which may predict the high-risk discharge from MICU. Further studies to identify high-risk and low-risk admissions and discharges will effect better use of intensive care.

Clinical experience with the use of xenon-enhanced CT blood flow mapping in cerebral vascular disease.

Cerebral blood flow mapping with the xenon-enhanced/CT method has become a useful clinical tool in the management of patients with occlusive cerebral vascular disease. Studies involving 4-5 minutes of inhaling a xenon/oxygen mixture (=£ 35%) can now be performed routinely with acceptable patient tolerance and compliance. Four cases with acute and chronic ischemlc injuries are reported here to illustrate the manner in which this method has been used to characterize flow pattern in such patients and the relevance of this flow information to clinical patient management. Stroke Vol 15, No 3, 1984

Measurement of cerebral blood flow during xenon inhalation as measured by the microspheres method.

Measurements of cerebral blood flow (CBF) were performed using the microsphere technique in non-human primates (baboons) to assess the effect of non-radioactive xenon gas inhalation on CBF. Blood flows in small tissue volumes (approximately 1 cm3) were directly measured before and during the inhalation of xenon/oxygen gas mixtures. The results of these studies demonstrated that when inhaled in relatively high concentrations, xenon gas does increase CBF, but the changes are more global than tissue-specific. The problems and limitations of such evaluations are discussed.

Implications of DRG payments for medical intensive care.

Patients in the most prevalent DRGs in a Medical Intensive Care Unit (MICU) were compared with their counterparts who received only routine hospital care on adjusted total hospital costs and length of stay. Costs for both groups were compared with estimated DRG payments under an allpayer system. For patients in three DRGs, measures of severity of illness were examined as predictors of costs. Significant differences between MICU and routine care patients were found in 10 of 13 DRGs studied; intensive care costs were substantially above overall payment rates. The severity of illness measures varied widely in their correlation with costs, depending on DRG and whether the patients were MICU or routine care. These apparent differences in accounting costs may result in hospital decisions to restrict the number of MICU beds. Severity of illness adjustments to DRGs might produce more equitable payments. The most useful measure of severity may differ, however, depending on DRG.

Simultaneous measurements of cerebral blood flow by the xenon/CT method and the microsphere method. A comparison

Simultaneous measurements of cerebral blood flow have been performed in baboons to assess the correlation between the acute and invasive nondiffusible microsphere technique and the noninvasive xenon-enhanced CT method. Blood flows in small tissue volumes (approximately 1 cm3) were directly compared. The results of these studies demonstrate a statistically significant association between the two methods (P less than .001). Similar correlations were obtained by both the Kendall tau (tau) and the Spearman (r) methods. The problems and limitations of such correlations are discussed.

No correlation between cerebral blood flow and neurologic recovery after reversible total cerebral ischemia in the dog

This study was conducted to determine if regional cerebral flow during the first day after total cerebral ischemia was correlated with neurologic deficit and eventual survival. Dogs were subjected to 11 min of total cerebral ischemia (TCI) produced by an arterial and venous double balloon occlusion method. Recovery was allowed for up to 7 days after reperfusion, whereupon it was reassessed in survivors. Blood flow, determined by the radiolabeled microsphere method, was determined before TCI and at times up to 24 h after reperfusion. Blood flow during reperfusion after TCI followed the expected pattern of immediate hyperperfusion followed by prolonged hypoperfusion. TCI of 11 min duration resulted in a 50% mortality rate by 1 week. No positive correlation between magnitude or duration of hypoperfusion and neurologic deficit or mortality was found. It was concluded that improved postischemic blood flow cannot be used as a criterion for assessing drug therapy without reference to metabolic demand. The observation of a statistical correlation between dogs that survived and lower hematocrit was reported. It was suggested that the prolonged hypoperfusion encountered after TCI was not pathological, but rather served as a mechanism to limit oxygen exposure to the brain during a vulnerable period and, thus, was part of a controlled attempt at recovery of function by the central nervous system.

Profile of medical ICU vs. ward patients in an acute care hospital.

Demographic characteristics, severity of illness, resource utilization, and outcome were compared for 351 medical ICU (MICU) and 329 ward patients of a large, urban, tertiary care hospital. Patients were similar in age, race, sex, and insurance coverage. Both MICU and ward patients had similar health status distrubutions 3 to 6 months before hospitalization. Severity of illness, as measured by the Acute Physiology Score was significantly higher in the MICU patients, although there was considerable overlap in the distributions. Resource utilization, as measured by the Therapeutic Intervention Scoring System (TISS), was also significantly higher in the MICU; again, the distributions of the two groups overlapped, although mostly for low values of TISS. Of the MICU sample, 28% to 30% never required active therapeutic interventions; 11% of the ward sample received active treatment. The significant overlap between MICU and ward distributions of severity of illness and resource utilization has implications for admission and discharge policies.