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Biomedical subjects

J H Khan

Publications and source records attributed to J H Khan.

24 records · Page 2Linked to original sources

Bronchial carcinoid tumor: experience over 20 years.

Nineteen cases of bronchial carcinoid tumor seen over 20 years in a 1,000-bed, tertiary medical center were retrospectively reviewed. They consisted of 0.4 per cent of all patients with lung tumors. Initial complaints were hemoptysis, persistent pulmonary infection, chest pain, and diarrhea. Two of the five patients with atypical carcinoid tumors came to the hospital with diarrhea as a result of their chemically active tumors. However, seven patients (36%) were asymptomatic and were diagnosed after an abnormal chest radiograph was noted incidentally. Of 13 patients receiving bronchoscopic examination, 9 (69%) had visible tumors. Bronchial biopsy was performed in 7 patients and led to a diagnosis in all seven. Significant bleeding was noted in 3 patients as a result of biopsy. Lobectomy was the most common surgical procedure in this series. Follow-up of these patients was from 6 months to 15 years. The general outcome for patients with typical carcinoid was good. However, all patients with atypical carcinoid died as a result of dissemination.

Academic Medical Centers↗

Brachiocephalic revascularization: a comparison between carotid-subclavian artery bypass and axilloaxillary artery bypass.

Sixty-seven patients who underwent carotid-subclavian bypass (CSBP) (28 CSBPs only and eight with carotid endarterectomy) or axilloaxillary artery bypass (n = 31) with polytetrafluoroethylene grafts were followed up for a mean of 69.2 and 71.9 months, respectively. Indications for surgery in the CSBP group included hemispheric transient ischemic attack (TIA)/cerebrovascular accident in five, nonhemispheric TIA in seven, upper extremity ischemia in 15, and combined TIA and arm ischemia in nine patients. In the axilloaxillary artery group, two patients had hemispheric TIA, five had nonhemispheric TIA, 12 had upper extremity ischemia, and 12 had combined TIA and arm ischemia. Graft patency was determined clinically and confirmed by segmental Doppler pressures, duplex ultrasonography, or angiography. The 30-day mortality rate was approximately 3% in both groups. The 30-day complication rate was 3% for the axilloaxillary artery group and 8% for the CSBP group (not statistically significant). Relief of symptoms was achieved in 100% of patients in both groups; however, 20% of the patients in the axilloaxillary artery group had a recurrence of symptoms, in contrast to 5.6% in the CSBP group. The cumulative 10-year primary and secondary patency rates, calculated by life-table analysis, were 66% and 84.6% for the axilloaxillary artery procedures and 93.8% and 93.8% for the CSBP procedures, respectively (statistically significant). Concomitant carotid endarterectomy with CSBP did not influence graft patency. In conclusion, both bypasses have comparable morbidity and mortality rates; however, the CSBP has a statistically significantly better primary patency rate than the axilloaxillary artery bypass. Therefore CSBP should be the procedure of choice and the axilloaxillary artery bypass should be restricted to high-risk patients.

Arterial Occlusive Diseases↗

Risk factors for chronic lung disease in infants with birth weights of 751 to 1000 grams.

We performed a multicenter, historical-cohort analysis to identify factors associated with chronic lung disease (CLD) in extremely low birth weight infants. The 235 infants who were born in 1984 with birth weights of 751 to 1000 gm and admitted to any of 10 participating neonatal intensive care units comprised the study population. We analyzed demographic characteristics, status at birth, severity of acute atelectasis, and early respiratory treatment in relation to CLD, which we defined as having received oxygen at age 30 days. By univariate analysis, CLD was associated with lower gestational age (p less than 0.001), male sex (p = 0.004), more severe acute atelectasis as indicated by a higher roentgenographic score (p less than 0.001), a higher ventilation rate at 96 hours (p = 0.012), and lower PaCO2 at 48 hours (p = 0.04). Infants receiving mechanical ventilation whose highest PaCO2 levels at 48 or 96 hour were less than 40 mm Hg were 1.45 times as likely to develop CLD as those whose highest PaCO2 levels were greater than 50 mm Hg (95% confidence interval 1.04 to 2.01). CLD rates by center were inversely related to mean PaCO2 levels in infants receiving mechanical ventilation at 48 and 96 hours (Spearman rank correlations 0.60 and 0.55; p less than 0.001). A logistic risk model that included sex, PaCO2 at 48 hours, roentgenographic score, gestational age, and race showed only male sex (p = 0.009) and lower PaCO2 at 48 hours (p = 0.04) to be independent predictors of CLD. We conclude that mechanical ventilation that results in PaCO2 levels above the physiologic range may decrease the risk of CLD in extremely low birth weight infants.

Carbon Dioxide↗

Interruption of persistent ductus arteriosus with metal clips.

Persistent ductus arteriosus was interrupted with Hemoclips (Weck) in two children, 4 and 6 years of age, and four premature infants. After follow-up of 14 to 19 months, there were no recurrences. The use of Hemoclips to interrupt the persistent ductus arteriosus appears to be a safe procedure.

Child↗