Color Doppler imaging of the ocular ischemic syndrome.

PURPOSE: This study describes hemodynamic characteristics of the ophthalmic, central retinal, and posterior ciliary arteries in 16 eyes of 11 patients with the ocular ischemic syndrome. Understanding the hemodynamic characteristics of the retrobulbar circulation may elucidate the natural history and pathophysiology of the ocular ischemic syndrome and perhaps form the basis for rational treatment of this condition. METHODS: Color Doppler imaging, a procedure that permits rapid noninvasive imaging of the ophthalmic, central retinal, and posterior ciliary arteries, was used to quantitate peak systolic blood flow velocities and vascular resistance (pulsatility index) within these vessels in study group eyes and in an age-matched control population. RESULTS: We demonstrated markedly reduced ocular ischemic syndrome central retinal and posterior ciliary artery peak systolic velocities compared with control group eyes. Central retinal and posterior ciliary artery vascular resistance (pulsatility index) was greater in ocular ischemic eyes versus control group eyes. Reversal of ophthalmic artery blood flow was detected in 12 of 16 ocular ischemic syndrome eyes. Study group eyes with poor vision had no detectable posterior ciliary arterial blood flow. CONCLUSION: Color Doppler imaging quantitates hemodynamic characteristics of the retrobulbar circulation in the ocular ischemic syndrome. There is markedly reduced peak systolic velocity and increased vascular resistance in ocular end arteries such as the central retinal and posterior ciliary arteries. Ophthalmic artery reversal of flow seems to represent collateral blood flow to lower resistance vascular beds. Posterior ciliary artery hypoperfusion may correlate with poor vision in the ocular ischemic syndrome.     

Modeling two dimensions of patient satisfaction: a panel study.

Measurement of patient satisfaction is an essential part of health outcome assessment. The purpose of this study is (a) to compare the stability of an aggregate summary measure and two separate summary measures of patient satisfaction; and, (b) to examine causal effects between two separate summary measures at two points in time. Data were collected from 1,451 Medicare HMO beneficiaries. In conclusion, (a) separate summary measures are recommended for constructing the measure of patient satisfaction and (b) moderate causal relationships and cross-lagged effects between the patient satisfaction measures of qualify of care and access to care were found.     

The role of ostiomeatal complex obstruction in maxillary fungus ball.

OBJECTIVE: The aim of this study was to clarify the role of ostiomeatal complex obstruction in maxillary fungus ball. STUDY DESIGN AND SETTING: Comparative study in a hospital setting of the mean Lund-Mackay scores for the anterior ethmoid and frontal sinuses of 54 versus 48 patients with maxillary fungus ball versus chronic unilateral rhinosinusitis, respectively. RESULTS: In cases with partial opacification in the maxillary sinus, the anterior ethmoid and frontal sinuses were diseased in the chronic unilateral rhinosinusitis group but not in the maxillary fungus ball group. In cases with total opacification in the maxillary sinuses, all anterior ethmoid and frontal sinuses in both groups were diseased, but the disease condition of the frontal sinuses was significantly less severe in the maxillary fungus ball group (P < 0.001). CONCLUSION AND SIGNIFICANCE: In this era of evidence-based medicine, we provide statistical data supporting the principle that maxillary fungus ball is not associated with osteomeatal complex obstruction and that another as-yet-unexplained mechanism must be responsible. EBM rating: B-3b.     

The hepatitis B immunization programme in Singapore

A voluntary immunization programme to prevent perinatal transmission of hepatitis B virus (HBV) infection in Singapore was implemented on 1 October 1985 as an integral component of the national childhood immunization programme. Up to April 1988, a total of 68,845 mothers who attended government maternal and child health clinics were screened for the disease. Of these, 2432 (3.5%) were positive for hepatitis B surface antigen (HBsAg) and 904 (1.3%) for hepatitis B e antigen (HBeAg). Virtually all the babies born to carrier mothers completed the full immunization schedule; and in addition, those of HBeAg-positive mothers were given a dose of hepatitis B immunoglobulin at birth. The hepatitis B immunization programme was extended on 1 September 1987 to cover all newborns. About 90% of the 15,943 babies delivered in government institutions from September 1987 to April 1988 were immunized at birth, with the subsequent doses being administered at maternal and child health clinics at 4-6 weeks and 5 months later. More than 85% of the children given the full course of plasma-derived and yeast-derived hepatitis B vaccine from birth continued to have protective antibody to HBV two years after immunization. The programme is being closely monitored to assess the duration of immunity and the need for booster doses, while seronegative adults are also being encouraged to be vaccinated.     

Treatment of persistent and recurrent nasopharyngeal carcinoma by brachytherapy

The early results of brachytherapy for persistent and recurrent nasopharyngeal carcinoma in 30 patients is presented. Fifteen patients were treated by intracavitary caesium, 12 patients were treated by interstitial gold grain implant using the split-palate approach and three patients were treated by both intracavitary caesium and interstitial gold grain implant for the first and second relapse in the nasopharynx, respectively. The overall tumour control rate for intracavitary caesium was 5/18 (28%) with median follow-up of 25.2 months, and for interstitial gold grain implant it was 9/14 (64%) with median follow-up of 16.5 months. Interstitial gold grain implantation appears to be effective in the treatment of persistent and recurrent nasopharyngeal carcinoma.     

Oxygen Reverses Deficits of Cognitive Function and Memory and Increased Heart Rate Induced by Acute Severe Isovolemic Anemia

Background: Erythrocytes are transfused to improve oxygen delivery and prevent or treat inadequate oxygenation of tissues. Acute isovolemic anemia subtly slows human data processing and degrades memory, increases heart rate, and decreases self-assessed energy level. Erythrocyte transfusion is efficacious in reversing these effects of acute anemia. We tested the hypothesis that increasing arterial oxygen pressure (Pao2) to 350 mmHg or greater would supply sufficient oxygen to be equivalent to augmenting hemoglobin concentration by 2-3 g/dl and thus reverse the effects of acute anemia.

Methods: Thirty-one healthy volunteers, aged 28 +/- 4 yr (mean +/- SD), were tested with verbal memory and standard, computerized neuropsychologic tests before and twice after acute isovolemic reduction of their hemoglobin concentration to 5.7 +/- 0.3 g/dl. Two sets of tests were performed in randomized order at the lower hemoglobin concentration: with the volunteer breathing room air or oxygen. The subject and those administering the tests and recording the results were unaware which gas was administered. As an additional control for duration of the experiment, 10 of these volunteers also completed the same tests on a separate day, without alteration of hemoglobin concentration, at times of the day similar to those on the experimental day. Heart rate, mean arterial blood pressure, and self-assessed sense of energy were recorded at the time of each test.

Results: Reaction time for digit-symbol substitution test increased, delayed memory was degraded, mean arterial pressure and energy level decreased, and heart rate increased at a hemoglobin concentration of 5.7 g/dl (all P < 0.05). Increasing Pao2 to 406 +/- 47 mmHg reversed the digit-symbol substitution test result and the delayed memory changes to values not different from those at the baseline hemoglobin concentration of 12.7 +/- 1.0 g/dl, and decreased heart rate (P < 0.05). However, mean arterial pressure and energy level changes were not altered with increased Pao2 during acute anemia.