Antibiotic treatment for urinary tract infections in pediatric patients.

This review focuses on antibiotic treatment of acute urinary tract infections (UTIs) in children who are neurologically and anatomically intact. Neonates younger than 28 days with a febrile UTI should be hospitalized, given supportive care and treated with parenteral amoxicillin and cefotaxime. Following a good response to 3 to 4 days of parenteral antibacterial therapy, outpatient treatment with an oral antibiotic should be given to complete 14 days of therapy. Infants from 28 days to 3 months who appear clinically ill with a febrile UTI should be hospitalized, receive supportive care and parenteral administration of a 3(rd) generation cephalosporin or gentamicin. When these infants are clinically improved and afebrile for 24 hours they should be discharged to complete 14 days of therapy with an oral antibiotic. Infants from 28 days to 3 months of age who are not acutely ill with a febrile UTI may be managed as outpatients. Ceftriaxone or gentamicin should be administered parenterally and given each 24 h until the infant is afebrile for 24 hours. Fourteen days of therapy should be completed with an oral antibiotic. Children with complicated pyelonephritis should be hospitalized, receive supportive care and parenteral ceftriaxone or gentamicin each 24 hours until clinically improved and without fever for 24 hours. They should then complete 10 to 14 days of therapy with an oral antibiotic as an outpatient. Children with uncomplicated pyelonephritis should be rehydrated in the outpatient department (if necessary) and receive parenteral ceftriaxone or gentamicin each 24 hours until without fever for 24 hours. If clinically improved they should receive an oral antibiotic to complete 10 to 14 days of therapy. Children with cystitis who are only mildly symptomatic should be managed with supportive care until the result of the urine culture and sensitivity are available. Children with cystitis who are moderately to severely symptomatic should receive an oral antibiotic and supportive care immediately. If the therapy is effective, children with cystitis should show a good clinical response in 2 to 3 days. If the response is satisfactory and the culture shows an organism susceptible to the antibiotic used, complete 5 to 7 days of treatment with the oral antibiotic.

Correlates of pregnancy oestrogen, progesterone and sex hormone-binding globulin in the USA and China.

The objective of this study is to examine perinatal correlates of oestradiol (E2), oestriol (E3), progesterone and sex hormone-binding globulin (SHBG) among pregnant women in the USA and China. Three hundred and four Caucasian women in Boston and 335 Chinese women in Shanghai were studied. Levels of E2, E3, progesterone and SHBG were measured in maternal blood at weeks 16 and 27 of gestation, and correlated with maternal, gestational and perinatal characteristics. Height, weight and body mass index (BMI) before pregnancy is inversely associated with E2 and SHBG, whereas E3 is inversely associated with height and progesterone is inversely associated with weight and BMI. A previous live birth is associated with lower E2 and SHBG in the index pregnancy. Total gestation duration is inversely associated with E2, E3 and progesterone, whereas weight gain during pregnancy is inversely associated with progesterone and SHBG. In the US, pregnancies with female fetuses are characterized by significantly reduced progesterone. Pregnancy hormones are associated with several maternal, gestational and neonatal characteristics.

Reducing infections among women undergoing cesarean section in Colombia by means of continuous quality improvement methods.

BACKGROUND: Improving obstetric care in resource-limited countries is a major international health priority. OBJECTIVE: To reduce infection rates after cesarean section by optimizing systems of obstetric care for low-income women in Colombia by means of quality improvement methods. METHODS: Multidisciplinary teams in 2 hospitals used simple methods to improve their systems for prescribing and administering perioperative antibiotic prophylaxis. Process indicators were the percentage of women in whom prophylaxis was administered and the percentage of these women in whom it was administered in a timely fashion. The outcome indicator was the surgical site infection rate. RESULTS: Before improvement, prophylaxis was administered to 71% of women in hospital A; 24% received prophylaxis in a timely fashion. Corresponding figures in hospital B were 36% and 50%. Systems improvements included implementing protocols to administer prophylaxis to all women and increasing the availability of the antibiotic in the operating room. These improvements were associated with increases in overall and timely administration of prophylaxis (P<.001) in both hospitals by time series analysis, with adjustment for volume and case mix. After improvement, overall and timely administration of prophylaxis was 95% and 96% in hospital A and 89% and 96% in hospital B. In hospital A, the surgical site infection rate decreased immediately after the improvements (P<.001). In hospital B, the infection rate began a downward trend before the improvements that continued after their implementation (P =.04). CONCLUSION: Simple quality improvement methods can be used to optimize obstetric services and improve outcomes of care in resource-limited settings.

Creatinine excretion rates for renal clearance studies.

A total of 637 timed-urine collections for creatinine excretion rates obtained from 295 children over 14 years have been analyzed. The children ranged in age from 2.8 to 21.7 years at the time of the clearance study. The data analyzed included only one study from a child during any 6-month period. The objective is to provide data defining the expected range of creatinine excretion for renal clearance studies. One hundred forty-two studies were conducted on children not pretreated with cimetidine and 495 on those pretreated with cimetidine. Analysis showed that pretreatment with cimetidine for creatinine clearance studies does not alter creatinine excretion rates (P=0.080; 95% CI -0.03 to 1.61). Creatinine excretion rates in urine collections obtained at home (roughly 24-h collections) were compared with 2-h supervised collections in the Children's Kidney Center. The supervised urine collections resulted in creatinine excretion rates 1.38 mg/kg/24 h greater than home collections (P=0.001; 95% CI 0.76-2.00). Using regression equations for creatinine excretion rate with age, tables have been prepared showing the expected rate of creatinine excretion for renal clearance studies in children 3-21 years of age.

Long-term consequences of urinary tract infections.

The past several years have brought marked changes in our understanding of the consequences of urinary tract infections (UTIs). Studies of infants with intrauterine dilatation of the urinary tract show that many children previously thought to have incurred kidney damage after an infection actually have congenital renal damage. The importance of vesicoureteric reflux (VUR) in the pathogenesis of acute pyelonephritis has been downgraded with the recognition of the frequency with which kidney infection occurs in the absence of VUR. Some infants with intrauterine VUR and no history of UTI have impaired kidney function or hypertension secondary to renal hypoplasia or dysplasia.

The long-term consequences of urinary tract infections: a historic and contemporary perspective.

The long-term adverse consequences of UTI in childhood are hypertension, impaired renal function, end-stage renal disease, and complications during pregnancy. These adverse effects of UTIs are a result of renal parenchymal damage. Currently, these complications are unusual among patients in industrialized countries, unless kidney damage is present at birth. VUR, the most common abnormality encountered in infants and young children with UTIs, is not a diagnostic entity, but reflects a spectrum of underlying conditions. There may be nonobstructive VUR with no other urinary tract abnormality. VUR may be associated with voiding dysfunction and frequent UTIs. It may be present with bladder outlet obstruction, hydronephrosis, and intrauterine renal damage. Children with intrauterine renal damage are those most likely to develop hypertension and those at greatest risk for progression to end-stage renal disease. Acquired renal injury as a cause of adverse long-term consequences due to UTI is much less common than it was early in this century, probably as a result of improved health care.

Autosomal dominant inheritance of multicystic dysplastic kidney.

Unilateral multicystic dysplastic kidney (MCDK) in a normal infant is believed to be a sporadic disorder, with an incidence of about 1 in 4,300 live births. Isolated unilateral MCDK occurring in a family without other genitourinary abnormalities has not been described. We report a family in which isolated unilateral MCDK occurred in a woman and her two children. The mother presented with a palpable abdominal mass during infancy, which on excision was found to be a MCDK. Both the children were found to have MCDK on prenatal ultrasonography, which was later confirmed on postnatal evaluation. The MCDK in the children continues to involute on follow-up urinary tract ultrasonography. The inheritance of MCDK appears to be autosomal dominant in this family.

Maternal pregnancy hormone levels in an area with a high incidence (Boston, USA) and in an area with a low incidence (Shanghai, China) of breast cancer.

Characteristics probably associated with the fetal hormonal milieu have recently been shown to increase (birth size indicators, prematurity, neonatal jaundice) or decrease (pregnancy toxaemia) breast cancer risk in the female offspring. However, it is unknown whether differences in pregnancy hormone levels may contribute to the marked geographical variation in breast cancer incidence. We have compared, in a highly standardized manner, pregnancy hormone levels in a population with high incidence and one with low incidence of breast cancer. Three hundred and four pregnant Caucasian women in Boston and 334 pregnant Chinese women in Shanghai were enrolled from March 1994 to October 1995. Levels of oestradiol, oestriol, prolactin, progesterone, human growth hormone, albumin and sex hormone-binding globulin were measured in maternal blood at weeks 16 and 27 of gestation and compared between the two study sites using non-parametric Wilcoxon's rank-sum test. Demographical, anthropometrical and pregnancy characteristics were ascertained through interview, and relevant variables concerning delivery and the newborn were abstracted from medical records and paediatric charts. During the first visit, median serum levels of all studied hormones were statistically significant, and in most instances substantially, higher among Chinese women, who have a low incidence of breast cancer, compared with American women, who have a high incidence of breast cancer. An analogous pattern was evident during the second visit, although the relative differences tended to be smaller. Further research is needed to identify lifestyle or other exogenous determinants of pregnancy hormone levels, as well as possible mechanisms by which they may influence carcinogenic processes in the breast and possibly other organs.

Urinary tract infections per se do not cause end-stage kidney disease.

The objective of this study was to determine the frequency with which urinary tract infection (UTI) in the absence of concomitant underlying abnormalities caused end-stage renal disease (ESRD). The records of 102 patients with ESRD (disease necessitating dialysis and/or transplant) seen at Children's Mercy Hospital during a 10-year period (1986- 1995) were reviewed. Obstructive uropathy, aplastic/hypoplastic/dysplastic kidneys, polycystic kidney disease, congenital nephrotic syndrome, acquired glomerulonephritis, idiopathic interstitial nephritis, hemolytic uremic syndrome, and a variety of systemic conditions were the cause of ESRD in 99 children; 3 children had reflux nephropathy, 1 of whom had no history of a UTI and another who had a single, afebrile UTI. A girl with a history of recurrent UTIs since 4 years of age had an elevated serum creatinine and grade II-III bilateral vesicoureteric reflux when evaluated at 8 years of age. She had ureteral reimplantations and control of the infections, but progressed to ESRD. This child appears to be the only 1 of 102 children who developed ESRD because of acquired renal injury in which UTIs were an important contributing factor.

Urinary tract infections in children: why they occur and how to prevent them.

Urinary tract infections (UTIs) usually occur as a consequence of colonization of the periurethral area by a virulent organism that subsequently gains access to the bladder. During the first few months of life, uncircumcised male infants are at increased risk for UTIs, but thereafter UTIs predominate in females. An important risk factor for UTIs in girls is antibiotic therapy, which disrupts the normal periurethral flora and fosters the growth of uropathogenic bacteria. Another risk factor is voiding dysfunction. Currently, the most effective intervention for preventing recurrent UTIs in children is the identification and treatment of voiding dysfunction. Imaging evaluation of the urinary tract following a UTI should be individualized, based on the child's clinical presentation and on clinical judgment. Both bladder and upper urinary tract imaging with ultrasonography and a voiding cystourethrogram should be obtained in an infant or child with acute pyelonephritis. Imaging studies may not be required, however, in older children with cystitis who respond promptly to treatment.

Creatinine clearance following cimetidine for estimation of glomerular filtration rate.

Simultaneous inulin (C[in]) and creatinine clearance (C[Cr]) studies were performed on 53 pediatric renal patients using a cimetidine protocol. Since cimetidine blocks the tubular secretion of creatinine, it was hypothesized that C(Cr) measured following cimetidine would closely approximate the C(in). C(in) was compared with C(Cr) with the latter calculated from: (1) a 24-h urine collection, (2) plasma creatinine, height, and a proportionality constant, (3) the same plasma and urine specimens used for calculating C(in), and (4) from the plasma and urine specimens of the four 30-min clearance periods treated as a single 2-h clearance. The C(in) was very closely approximated by the C(Cr) calculated from the same specimens used for the C(in) and by the 2-h clearance. The cimetidine protocol, with C(Cr) derived from a 2-h urine collection obtained under supervision in the office or clinic, provides a convenient and inexpensive procedure for estimation of glomerular filtration rate in a clinical setting.

Urinary tract infections. Old and new concepts.

The recommendations for evaluation and management of pediatric patients with UTIs are summarized in Table 5. These recommendations were designed to minimize the risk of kidney damage in children with UTIs based on current perceptions of the pathogenesis of renal injury. The children at greatest risk for kidney damage are the infants and young children with febrile UTIs in whom effective treatment is delayed, those with gross VUR, and those with anatomic or neurogenic urinary tract obstruction. These recommendations likely will be modified as more is learned about the pathogenesis of renal injury associated with UTIs, as new therapeutic approaches are developed, and as imaging technology improves.

"Low-dose" growth hormone therapy during peritoneal dialysis or following renal transplantation.

The minimal effective dose of growth hormone (GH) to promote growth in children on dialysis or following renal transplantation remains unsettled. In order to study the issue, "low-dose" GH was administered to children with end-stage renal disease (ESRD) receiving chronic automated peritoneal dialysis (APD, n = 6, 4 males, 2 females) or following renal transplantation (T, n = 9, 8 males, 1 female). No APD patient was GH deficient, while 1 T patient (no. 2) had data consistent with GH deficiency, although he was obese (body mass index = 34 kg/m2). The mean dose of GH after 6 and 12 months of treatment was 0.16 +/- 0.02 and 0.22 +/- 0.07 versus 0.16 +/- 0.03 and 0.27 +/- 0.21 mg/kg per week for APD and T patients, respectively. When analyzing all patients, there were no significant differences before or after 6 and 12 months of GH therapy within or between the two groups, in terms of height velocity, bone age, renal function (in the T group) and height Z-scores (Z-Ht). However, the height velocity Z-score (Z-HV) increased significantly at 6 and 12 months compared with baseline in the APD patients only (P < 0.05). When the 2 T patients with the most impaired renal function were excluded from the analysis, Z-HV also increased significantly in the T patients after 12 months of GH (P < 0.02). We conclude that following "low-dose" GH therapy, children with ESRD treated with APD or T have similar increases in HV, allowing maintenance of Z-Ht but not "catch-up" growth.

The impact of extreme prematurity and congenital anomalies on the interpretation of international comparisons of infant mortality.

OBJECTIVE: To identify the potential impact that different definitions of live births and practice patterns have on infant mortality rates in England and Wales, France, Japan, and the United States. METHODS: United States data were obtained from the 1986 linked national birth-infant death cohort, and those for the other countries came from either published sources or directly from the Ministries of Health. RESULTS: In 1986 in the United States, infants weighing less than 1 kg accounted for 36% of deaths (32% white and 46% black); 32% resulted from fatal congenital anomalies. These rates were much higher in both categories than in England and Wales in 1990 (24 and 22%, respectively), France in 1990 (15 and 25%, respectively), and Japan in 1991 (9% for infants weighing less than 1 kg, percentage of fatal congenital anomalies unknown). These cases are more likely to be excluded from infant mortality statistics in their countries than in the United States. CONCLUSIONS: In 1990, the United States infant mortality rate was 9.2 per 1000 live births, ranking the United States 19th internationally. However, infant mortality provides a poor comparative measure of reproductive outcome because there are enormous regional and international differences in clinical practices and in the way live births are classified. Future international and state comparisons of reproductive health should standardize the definition of a live birth and fatal congenital anomaly, and use weight-specific fetal-infant mortality ratios and perinatal statistics.

Vitamin status of infants receiving long-term peritoneal dialysis.

The oral vitamin intakes and blood vitamin concentrations of seven infants receiving long-term peritoneal dialysis were measured. The serum concentrations of vitamin A, vitamin B12, vitamin C and folic acid were determined. Thiamine and riboflavin were assessed by the activation of erythrocyte transketolase and erythrocyte glutathione reductase, respectively. Vitamin B6 was measured as plasma pyridoxal phosphate. All patients received a daily vitamin supplement devoid of vitamin A. Dietary vitamin intake was derived from infant formula. In all cases, the patients' blood concentrations of the water-soluble vitamins were equal to or greater than normal infant values. Serum vitamin A levels were elevated despite the lack of supplementation. The combined dietary/supplemental water-soluble vitamin intake of the patients exceeded the recommended daily allowance in all but one patient. These preliminary data emphasize the need to further evaluate the vitamin requirements of infants receiving long-term peritoneal dialysis.