Chyong-Hsin Hsu

Comparison of hemocytometer leukocyte counts and standard urinalyses for predicting urinary tract infections in febrile infants.

Objectives. To compare the accuracy of standard and hemocytometer white blood cell (WBC) counts and urinalyses for predicting urinary tract infection (UTI) in febrile infants. Methods. Enrolled were 230 febrile infants <12 months of age. All urine specimens were obtained by suprapubic bladder aspiration and microscopically analyzed by the standard urinalysis (UA) and by hemocytometer WBC counts simultaneously, and quantitative urine cultures were performed. Receiver‐operating characteristic (ROC) curves were constructed for each method of UA. The optimal cutoff point of the UA test in predicting UTI was determined by ROC analysis. Results. There were 37 positive urine cultures of at least 1000 CFU/ml. Of these 37 patients, 9 females and 28 males, 1 had a positive blood culture (Escherichia coli). Thirty (81%) of the positive urine cultures had a bacterial colony count ≧100 000 colony‐forming units/ml, whereas the remaining had between 1000 and 50 000 colony‐forming units/ml. The area under the ROC curve for standard UA was 0.790 ± 0.053, compared with 0.900 ± 0.039 for hemocytometer WBC counts (P < 0.05). For hemocytometer WBC counts, the presence of ≧10 WBC/&mgr;l appeared to be the most useful cutoff point, yielding a high sensitivity (83.8%) and specificity (89.6%). Standard UA, with a cutoff point of 5 WBC/high power field, had a lower sensitivity (64.9%) and similar specificity (88.1%). The hemocytometer WBC counts showed significantly greater sensitivity and positive predictive value (83.8 and 60.8%, respectively) than the standard urinalysis (64.9 and 51.1%, respectively) (P < 0.05). The accuracy, specificity and likelihood ratio of hemocytometer WBC counts were also greater than that of standard UA (88.7, 89.6 and 8.08%vs. 84.3, 88.1 and 5.44%). Conclusion. Hemocytometer WBC counts provide more valid and precise prediction of UTI in febrile infants than standard UA. The presence of ≧10 WBC/&mgr;l in suprapubic aspiration specimens is the optimum cutoff value for identifying febrile infants for whom urine culture is warranted.

Urinary Tract Infection in Infants Less Than 2 Months of Age

Ninety-five infants, less than 2 months of age, diagnosed as urinary tract infections, from July 1984 to June 1991, were reviewed. Their urinary cultures, obtained either by suprapubic puncture or via catheterization, all had bacterial colony counts of over 10(5)/ml. In this survey, males predominated (91.6%). Fever and gastrointestinal problems were the two most prevalent signs. E. coli was the most common causative organism, and gentamicin was the most effective antibiotic. Vesicoureteral reflux (VUR), the most common anomaly, was found in one-third (25/76) of patients on voiding cystourethrography, with 20% being high grade (Gr. IV or Gr. V). Eleven cases (11%) had bacteremia, and one case had bacterial meningitis. Sixty-seven cases were followed up in our hospital and seven of them had second infections within a year of their first UTI. The mean period between episodes was less than two months. All these patients had urinary tract anomalies and received oral chemoprophylactic drugs for variable lengths of time. Five of the seven recurrences were caused by resistant bacilli. Continuous oral antibiotic prophylaxis and regular follow-up examinations were the rules of prevention for further infection and future renal impairment. These preventive methods are especially important in young infants with UTI.

Home oxygen therapy for chronic lung disease in very low-birth-weight infants.

Prolonged hospitalization in infants suffering from chronic lung disease who require continuous oxygen therapy can be avoided by oxygen administration at home. In the period from August 1995 to September 1996, 155 very low-birth-weight (VLBW) infants were consecutively admitted to the neonatal intensive care unit of Mackay Memorial Hospital. Of the 155 infants, 72% (111/155) survived to discharge. However, 34% (38/111) of the survivors developed chronic lung disease. Twenty-three infants with chronic lung disease underwent home oxygen therapy after 107.0 +/- 43.6 days of hospitalization. The mean duration of home oxygen therapy was 4.3 +/- 3.4 months. In the first year after discharge, 91% of the patients required rehospitalization. One patient died during the fourth hospitalization. Follow-up information on growth and development at one year of corrected age was available for 19 patients. Five of the 19 patients had a body weight below the 5th percentile. Five of the 19 infants were mentally retarded and 12 of the 19 patients had significantly delayed motor development. In conclusion, carefully supervised home oxygen therapy permits safe early discharge of selected VLBW infants with chronic lung disease. Their somatic and psychomotor development should be carefully followed up.

Clinical experience with early enteral feeding in very-low-birth-weight infants.

The primary objective of this study was to evaluate the safety and benefit of early enteral feeding in very-low-birth-weight (VLBW) infants without parenteral nutrition. Weight gain, feeding intolerance, nosocomial infection rate and a postnatal growth curve were recorded for 61 VLBW premature infants who were admitted to the Neonatal Intensive Care Unit of Mackay Memorial Hospital from September 1, 1995 to February 28, 1997. Nine infants were unable to complete the study and three were excluded because of severe bronchopulmonary dysplasia; therefore only 49 infants could be evaluated. They were divided into two groups based on birth weight: 1001 gm to 1250 gm (Group A, mean birth weight 1153 +/- 64 gm, mean gestational age 29.0 +/- 2.2 weeks), and less than or equal to 1000 gm (Group B, mean birth weight 911 +/- 82 gm, mean gestational age 27.1 +/- 1.5 weeks). They received breast milk or premature formula by intermittent nasogastric or continuous nasogastric feeding. Growth was followed over the first 30 postnatal days. Group A reached 100 kcal/kg/day of enteral feeding at a mean age of 17 days as compared with a mean age of 20 days for group B. Infants regained their birth weight at 20 and 25 days in Groups A and B, respectively. By the 30th postnatal day, weight gain exceeded birth weight by 218.2 +/- 143.1 gm and 95.3 +/- 81.5 gm in groups A and B respectively. No definite episodes of necrotizing enterocolitis (NEC) developed. Two cases of Escherichia coli sepsis and one of Klebsiella sepsis occurred. The conclusion was that early enteral feeding in very-low-birth-weight infants does not increase the risk of NEC. It was also demonstrated that enteral feeding alone can produce biphasic postnatal growth curves in very-low-birth-weight infants. Although early enteral feeding was well tolerated in the study infants, the occurrence of feeding intolerance in some (36%) would suggest that additional parenteral nutrition may benefit some infants until full enteral feeding can be achieved.

The VATER association: analysis of forty six cases without karyotyping.

Forty-six patients with two or more features of the VATER association admitted to the Mackay Memorial Hospital from May, 1983 to Mar, 1992 were retrospectively enrolled in this study. We compared the incidence of major features with that reported in the literature. Imperforate anus, congenital heart disease, and renal anomalies were the three most common major features in our study. Thirteen patients died. Heart failure was the major cause of mortality. We noted many patients associated minor features, and among them there was a relatively high ratio of cleft lip, cleft palate, and hypospadius. The overall outcome and development were good among the survivals. We suggest that children who have any congenital anomaly included in the VATER association should get a careful examination and evaluation of their heart, genitourinary tract, limbs and vertebrae. Early correction if possible is indicated in such patients.