Exchange transfusion in acute chloramphenicol toxicity

Updates in the general approach to the pediatric poisoned patient

Poison prevention remains essential to prevent the most vulnerable population from becoming exposed to potentially lethal toxins. The evaluation of a child presumed to have been exposed to a toxic substance should include a precise history of the exposure, a physical examination, and knowledge of current ingestions and recreational practices. New treatments and research guiding therapy continue to evolve. Poison centers and medical toxicologists can be consulted to assist with the diagnosis of medicinal/drug overdoses, for advice about the pitfalls inherent in stabilizing children who have been exposed to toxic compounds, and for treatment recommendations based on the latest research.

Neonatal exchange transfusion: a Jordanian experience

The aetiology and complications of exchange transfusion (ET) were studied over a 6-year period in northern Jordan. During that time, 336 neonates (0.46% of total live births) underwent 386 ETs. There was a yearly reduction in the number of ETs, varying from 8.2% in the 1st year of the study to 2.7% in the last year. Thirty-nine (11.9%) required more than one ET. Twenty-five (7.4%) were preterm babies and the remainder full-term. The commonest cause of ET overall was G6PD deficiency, either alone or concomitant with ABO incompatibility (38.1%). ET complications occurred in 51 neonates (15.2%), the commonest being anaemia and bradycardia. Septicaemia occurred in only 3% of cases. Only one baby died. G6PD deficiency, either alone or concomitant with ABO isoimmunization, is the most common cause of ET in northern Jordan. Fewer preterm babies require ET and there is a low incidence of septicaemia following ET.

Chloramphenicol toxicity associated with severe cardiac dysfunction

A 9-month-old infant experienced severe chloramphenicol toxicity associated with high serum levels (313 micrograms/ml). Cardiovascular collapse with cardiomyopathic changes and impaired left ventricular function was documented by echocardiography. Serial echocardiographic evaluation showed resolution of the cardiomyopathic findings as the chloramphenicol levels were spontaneously cleared. Clinical course was complicated by the development of liver disease and coagulopathy compatible with disseminated intravascular consumption. Patient's recovery was complete and uneventful, nevertheless, chloramphenicol toxicity in childhood is associated with a significant mortality rate of 40%. The related impaired cardiac function, although reversible, appears to play a major role in the pathogenesis and eventual outcome in this syndrome.

Exchange transfusion and multidose activated charcoal following vancomycin overdose

The inadvertent administration of a concentrated vancomycin solution to a 47 day-old premature male twin resulted in extremely high vancomycin levels and altered renal function. A 1.5 volume exchange transfusion did not change the measured vancomycin level. Multiple doses of oral activated charcoal, 1 g/kg, were administered beginning 5 h after the exchange transfusion. A calculated half-life of vancomycin before the exchange transfusion was 35 h. The half-life after the exchange transfusion and during charcoal administration was calculated to be 12 h. The only apparent adverse effect of this vancomycin overdose was reversible nephrotoxicity. The infant's hearing, tested by brainstem auditory responses, was normal. The higher volume of distribution of vancomycin in infants may preclude removing significant amounts of this drug by exchange transfusion. Gastrointestinal dialysis with activated charcoal warrants consideration in cases of vancomycin overdose in neonates.

Antimicrobial therapy for pediatric patients

New antimicrobial agents are being introduced for clinical use at an increasingly rapid rate. This has required physicians continually to review relevant data and determine unique properties that might guide selection among any new antibiotics as well as older ones. Efficacy, potential toxicity, and comparative cost (in that order) generally guide selection. The present comprehensive review examines currently available antibiotics along with some under investigation, emphasizing these three basic areas of consideration.

Acidosis as a presenting feature of chloramphenicol toxicity

Metabolic acidosis has previously been described in the gray baby syndrome, but has not been documented as a presenting feature. Four seriously ill children (bronchiolitis, hypoaldosteronism, dysautonomia, Reye syndrome), ages 4 months to 11 years, received chloramphenicol (CAP) intravenously. After initial stabilization, unexplained metabolic acidosis occurred 40 to 81 hours after beginning CAP. Serum CAP concentrations were 84, 62, 80, and 30 micrograms/ml, respectively, when acidosis was recognized. Hypotension, hypothermia, and abdominal distension occurred a mean of 23 hours after the onset of acidosis. Acidosis resolved and signs of the gray baby syndrome cleared with the decrease in serum CAP concentrations. Metabolic acidosis should be considered an early sign of CAP toxicity, and CAP should be used in reduced doses in severely ill patients, especially those with liver dysfunction.

Chloramphenicol toxicity in neonates: its incidence and prevention

The incidence of dose related chloramphenicol toxicity was determined in 64 neonates from 12 hospitals. Ten of the 64 exhibited symptoms attributed clinically to chloramphenicol toxicity. Nine received the dose prescribed and one an overdose. Symptoms of the grey baby syndrome were observed in five of the 10 babies; four babies suffered reversible haematological reactions; and one baby was described as very grey. Peak serum chloramphenicol concentrations in these 10 babies ranged from 28 to 180 mg/l and trough concentrations from 19 to 47 mg/l. Serum chloramphenicol concentrations above the therapeutic range (15-25 mg/l) were observed in a further 27 neonates (two had received a 10-fold overdose), none of whom showed signs of toxicity. Serious toxicity was associated with either prescription of dosages greater than that recommended or overdosage of chloramphenicol. High concentrations in young neonates may be avoided by prescribing and giving the recommended dose and then careful monitoring; concentrations should be maintained between 15 and 25 mg/l. No babies with concentrations within this range showed clinical signs of toxicity.