[Hyperkalemia].

PURPOSE: The use of bowel segments as bladder substitutes may result in chronic, impaired vitamin D and calcium metabolism, and ultimately in bone demineralization. MATERIALS AND METHODS: Bone metabolism was examined in 14 patients who lived for 5 to 8 years with an ileal low pressure bladder substitute after radical cystectomy for bladder cancer. Bone mineral density was measured using dual energy x-ray absorptiometry of the total skeleton, lumbar spine, femoral neck, and tibial epiphysis and diaphysis. Laboratory studies included serum levels of 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D, intact parathyroid hormone, plasma alkaline phosphatase, electrolytes, creatinine and blood gas analysis. RESULTS: Bone mineral density was normal in all patients. There was no evidence of deficient vitamin D stores. There was a tendency toward slightly elevated serum creatinine values in patients with preexisting impaired renal function, including 1 who also had slight acidosis. No patient had hyperchloremia. CONCLUSIONS: We found no evidence of osteomalacia, osteoporosis or significant metabolic acidosis in 14 patients with an ileal bladder substitute for 5 to 8 years. However, it is not known whether the absence of osteopenia would also apply to patients with poor renal function, to those not followed meticulously and, thus, at risk for major long-term functional or metabolic disturbances from the ileal bladder substitute or to patients with orthotopic bladder substitutes made from longer or other bowel segments than we used.

Acidosis↗

PubMed1995

Neonatal cerebral arterial flow velocity waveforms in term infants with and without metabolic acidosis at delivery.

To define the effects of acid base status at delivery on neonatal cerebral artery flow velocity waveform patterns obtained using Doppler ultrasound during the first week of life, a longitudinal comparative study of neonates born at term with and without evidence of metabolic acidosis in the umbilical artery was undertaken. Eighty-two appropriate for gestational age infants delivered after uncomplicated pregnancies with non-acidotic umbilical artery blood gases and in whom no neonatal complications were noted were studied to establish reference values of neonatal cerebral arterial vascular resistance index (RI) in normal term infants during the first week of life. A further 189 infants were grouped according to the presence and severity of metabolic acidosis at delivery, and also the presence of high risk features in the antenatal period. In the normal non-acidotic infants, over the first 24 h of life, there was a significant fall in the cerebral arterial resistance index (RI) in all the vessels examined, after which a steady state value was attained with no significant changes in vascular resistance index being noted during the remainder of the study period. The fall in RI between 12 and 24 h of age was consistent in all study groups. Infants with metabolic acidosis at delivery had blood flow patterns compatible with decreased resistance to flow in both anterior and middle cerebral arteries which persisted throughout the first week of life. This reduction in cerebral vascular resistance was most marked in those infants with severe metabolic acidosis. The majority of severely acidotic infants had a benign clinical outcome in the first week of life and all infants had normal cerebral ultrasound scans during the neonatal period. These findings suggest that metabolic acidosis at birth is associated with changes in neonatal cerebral arterial vascular resistance during the first week of life, and in the presence of benign clinical course the significance of this observation with regard to neurodevelopmental outcome requires evaluation.

Acidosis↗