Masatoshi Takimoto

Transfer of cefazolin into human milk

phate load will be rapidly excreted by the kidney in the presence of normal glomerular and tubular function, but only in conjunction with a cation to preserve electroneutrality. This is a possible explanation for the large concentration of cations (sodium and potassium) noted in the random urine specimen obtained at the time of the initial admission. In the presence of extracellular volume contraction and increased aldosterone production, a significant proportion of this cation loss could be potassium. The use of enemas, especially hypertonic phosphate enemas, has become routine in pediatrics in preparation for roentgen studies and in the treatment of chronic constipation. Although enemas given to normal individuals usually do not cause electrolyte imbalance, children with abnormal colons or impaired renal function are especially prone to fluid and electrolyte disturbances following the administration of enemas. If the chronic use of enemas cannot be avoided, such patients should be monitored with periodic determinations of serum electrolyte, phosphorus, and calcium concentrations.

Respiratory syncytial virus infection in lower respiratory tract and asthma attack in hospitalized children in North Hokkaido, Japan

Respiratory syncytial virus (RSV) infection is severe and life‐threatening in some infants. To investigate the epidemiology of RSV infection in hospitalized children in North Hokkaido, Japan, we tried to detect RSV antigen in nasopharyngeal aspirates (NPA) from those children with lower respiratory tract infection (LRTI) and asthma attack. From April 1991 to March 1992, 317 patients were hospitalized in our pediatric ward for the treatment of LRTI and asthma attack. The presence of RSV antigen in NPA taken from 283 patients (89.3%) were examined by enzyme immunoassay. RSV antigen was detected in 88 patients (31.1%). RSV LRTI were noted throughout the year, and the epidemic peak was observed in November and December. There was no significant correlation between the RSV antigen positive rate and mean temperature. RSV played an important role in LTRI in children in North Hokkaido, Japan. RSV LRTI in North Hokkaido was not rare in summer, indicating that RSV was transmitted commonly among children throughout the year.

White blood cell count, C‐reactive protein and erythrocyte sedimentation rate in respiratory syncytial virus infection of the lower respiratory tract

Laboratory findings such as white blood cell (WBC) count, C‐reactive protein (CRP) concentration and erythrocyte sedimentation rate (ESR) level in patients with bronchiolitis, bronchopneumonia and lobar pneumonia caused by respiratory syncytial virus (RSV) were studied. The diagnosis of having RSV infection of the lower respiratory tract was made on the presence of RSV antigen in nasopharyngeal specimens by means of enzyme immunoassay, on chest X‐ray appearances and clinical manifestations. The WBC counts in the lobar pneumonia cases (n = 25, 12 288 ± 6296/mm3) were significantly greater than those for the bronchiolitis (n = 52, 9562 ± 2720/mm3) and bronchopneumonia (n = 43, 8369 ± 3714/mm3) cases. The concentrations of CRP in lobar pneumonia cases (n = 25, 6.5 ± 7.3 mg/dL) were significantly greater than those in the bronchiolitis (n = 52, 1.9 ± 2.0 mg/dL) and bronchopneumonia (n = 43, 2.1 ± 2.4 mg/dL) cases. The ESR levels in the lobar pneumonia cases (n = 24, 43.8 ± 29. mm/h) were also significantly higher than those in the bronchiolitis (n = 34, 20.1 ± 12.3 mm/h) and bronchopneumonia (n = 40, 24.7 ± 15.9 mm/h) cases. There were no significant differences in the WBC counts, the CRP concentrations and ESR levels between the bronchiolitis and bronchopneumonia cases. These results suggest that the RSV lobar pneumonia cases are coinfected with some bacterial organisms more heavily than in the RSV bronchiolitis and bronchopneumonia cases.

The role of respiratory syncytial virus in acute bronchiolitis in small children in northern Japan

Respiratory syncytial virus (RSV) plays an important role in acute bronchiolitis, which is life threatening in some infants. We investigated the epidemiology of RSV acute bronchiolitis in children less than 3 years old in northern Japan. From April 1991 to March 1993, 162 infants with acute bronchiolitis were hospitalized in our pediatric wards. The diagnosis of RSV acute bronchiolitis was based on the typical clinical manifestations and the presence of RSV antigen in their nasopharyngeal specimens or the rise of the RSV antibody titer. 124 out of 162 patients (76.5%) were diagnosed as having RSV acute bronchiolitis. 43.5% of patients with RSV acute bronchiolitis were 6 months old or less. The epidemic of RSV acute bronchiolitis commenced in October, peaked in December and ended in summer. RSV is quite prevalent in infants with acute bronchiolitis in northern Japan.

Pharmacokinetics of tobramycin in the newborn.

SummaryFollowing an intramuscular dose of 5.0 mg of tobramycin in eight full-term newborn infants, peak levels averaging 2.69 ± 0.70µg/ml were attained after 30 to 60 minutes. The serum half-life thereafter correlated inversely to postnatal age during the first seven days after birth. Pharmacokinetic analysis revealed that in newborn infants the elimination rate was markedly declined, but the absorption rate was nearly the same as that in older children. Average urinary recovery within eight hours was as low as 26.8%, which suggested accumulation of this antibiotic in the renal tissue.ZusammenfassungBei reifen Neugeborenen betrug nach einer einmaligen Dosis von 5 mg Tobramycin i.m. die maximale Serumkonzentration im Mittel 2,69 ± 0,70µg/ml; sie wurde nach 30–60 Minuten erreicht. Danach korrelierte die Serum-Halbwertzeit innerhalb der ersten sieben Lebenstage reziprok mit dem Lebensalter. Die pharmakokinetische Analyse zeigte, daß bei Neugeborenen die Eliminationsrate wesentlich kleiner, die Absorptionsrate jedoch annähend gleich groß war wie bei einem älteren Kind. Die durchschnittliche Urin-Recovery innerhalb der ersten acht Stunden betrug nur 26,8%, was auf eine Akkumulation des Medikamentes im Nierengewebe hinzuweisen scheint.

Pharmacokinetics of intramuscular carbenicillin in the newborn

SummaryA 500 mg intramuscular dose of carbenicillin produced peak levels averaging 147µg/ml after three hours in the first day full-term newborn infants, and 172µg/ml after one to two hours in infants five days of age. The fall of blood levels thereafter was delayed and serum half-life averaged 4.2 and 2.2 hours in both groups, almost four times and twice as long, respectively, as that reported in adults. Absorption from the injected site was also delayed in young newborns, as was shown by the delayed serum peak and small estimated absorption rate constant. This must be taken into consideration if the intramuscular route is chosen in young newborn infants. On the basis of serum half-life, an administration interval of 12 hours was recommended for newborns younger than four days, and eight hours for those five days of age or more.ZusammenfassungDie intramuskuläre Verabreichung von 500 mg Carbenicillin ergab eine maximale Serumkonzentration von im Mittel 147µg/ml nach drei Stunden bei reifen Neugeborenen am ersten Lebenstag, von 172µg/ml nach ein bis zwei Stunden bei Neugeborenen im Lebensalter von fünf Tagen. Der Abfall der Serumkonzentration war verzögert, die Serumhalbwertzeit betrug durchschnittlich 4,2 bzw. 2,2 Stunden in beiden Gruppen, sie war ungefähr vier- bis zweimal so lang wie der beim Erwachsenen angenommene Wert von etwa einer Stunde. Die Absorption aus der Injektionsstelle war auch beim jungen Neugeborenen verzögert, wie durch die verzögerte maximale Serumkonzentration und niedrige Absorptionsrate gezeigt wurde. Dies muß dann in Betracht gezogen werden, wenn der intramuskuläre Weg bei jungen Neugeborenen gewählt wird. Aufgrund der verlängerten Halbwertzeiten wird ein Dosierungsintervall von 12 Stunden bei Neugeborenen bis zu vier Tagen empfohlen, und ein Intervall von acht Stunden bei denen, die fünf Tage alt oder älter sind.

Acute Phenobarbital Intoxication in an Infant.

Although phenobarbital (PB) is widely used in pediatric practice for sedative and anticonvulsive purposes, there are few reports on acute intoxication in infants and young children in Japan. We describe the case of an infant with acute iatrogenic phenobarbital overdose accompanied by the syndrome of inappropriate secretion of antidiuretic hormone and resulting fluid overload. The plasma level of PB declined following a saturation kinetics scale; the maximum rate of PB elimination was calculated to be 14.6 mg/kg per day.