Manfred Weninger

Spontaneous localized intestinal perforation in very-low-birth-weight infants:: a distinct clinical entity different from necrotizing enterocolitis

BACKGROUND Idiopathic spontaneous intestinal perforation (SIP), a distinct clinical entity different from necrotizing enterocolitis (NEC), has an increasing prevalence in very-low-birth-weight infants. The aims of our study were to define patient characteristics and potential risk factors for premature infants with SIP compared with infants subjected to surgical treatment for NEC. STUDY DESIGN The medical records of 29 premature infants with either SIP (n = 13) or NEC (n = 16) were reviewed retrospectively. RESULTS Infants who experienced SIP were smaller at birth, had lower Apgar scores, and required more intensive neonatal resuscitation. An increased rate of premature rupture of membranes in infants with SIP (8/13 versus 6/16) was not associated with a higher rate of infection in mothers or infants. The onset of illness in SIP was significantly earlier than in NEC (p = 0.022). In contrast to patients with NEC (7/16), 11 of 13 patients in the SIP group had received indomethacin (p = 0.02). Bluish discoloration of the abdomen (8/13), a gasless abdomen (8/13), and the absence of pneumatosis intestinalis (0/13) were further significant markers in infants with SIP. At operation, SIP was always located in the terminal ileum in an antimesenteric position (13/13), and the remaining bowel appeared grossly normal. In most cases of SIP (10/13), the histologic investigation revealed an area of hemorrhagic necrosis without the typical coagulation necrosis seen predominantly in NEC. CONCLUSIONS Based on clinical presentation and radiologic and intraoperative findings, SIP is a distinct pathologic entity in very-low-birth-weight infants and can be differentiated from classic NEC. Detected early, SIP can be treated by simple procedures (sutures, or resection and primary anastomosis) with a low rate of morbidity and mortality.

Evaluation of the Cerebral Function Monitor as a tool for neurophysiological surveillance in neonatal intensive care patients

Abstract. Background: Cerebral function in critically ill infants is difficult to assess and would certainly require continuous monitoring. Therefore, this study was performed to evaluate the Cerebral Function Monitor (CFM) as a tool for continuous neurophysiological surveillance in the Neonatal Intensive Care Unit (NICU). Patients: A total of 40 neurological risk neonates were included in the study. They were classified on the basis of their primary diagnoses as infants with clinically manifest seizures, suspected seizure activity, intracranial hemorrhage (ICH) and hypoxic-ischemic encephalopathy (HIE). A group of 20 neurologically normal (preterm and full-term) infants served as controls. Results and conclusion: All patients with seizures showed pathologic patterns in both the CFM and the conventional EEG tracings. The patients with ICH showed depressed amplitudes, an increase in discontinuous activity, and a high incidence of seizure activity. The patients with HIE were characterized by depressed activities correlating with the severity of the pathology. Our results indicate that the CFM is a very helpful tool for neurophysiological surveillance in high-risk neonates.

Effects of umbilical arterial catheterization on mesenteric hemodynamics

Impairment of mesenteric blood flow due to the use of umbilical artery catheters (UAC) may increase the risk of necrotizing enterocolitis (NEC) in newborn infants. We used Duplex Doppler sonography to investigate the degree of vessel obstruction due to UAC and their effect on visceral hemodynamics in 12 newborn infants. Ultrasonography was performed before and immediately after removal of the UAC, which was positioned above the ostia of the celiac and superior mesenteric arteries (SMA). Vessel diameter, peak systolic blood flow velocity (PSFV), end diastolic blood flow velocity (EDFV), and Pourcelots resistance index (RI) were measured in the celiac trunk and the SMA within 1 cm of their origins. Removal of the UAC led to a significant increase in mean PSFV (celiac trunk: 50 cm/s ± 15 vs 62 cm/s ± 0.22,P < 0.05; SMA: 52 cm/s ± 0.17 vs 72 cm./s ± 0.21,P < 0.05). RI increased from 0.7 ± 0.14 to 0.74 ± 0.13 and from 0.73 ± 0.1 to 0.76 ± 0.13 for the celiac trunk and SMA, respectively. The EDFV and vessel diameters did not change significantly after UAC removal. Our results suggest that UAC cause a decrease in mesenteric blood flow. Therefore, their use in hemodynamically unstable neonates or in those with gastrointestinal disease should be very carefully considered.

Abdominal aortic aneurysm in a premature neonate with disseminated candidiasis: ultrasound and angiography

When using ultrasound for detection of kidney enlargement, we found an acute abdominal aortic aneurysm secondary to aortitis following umbilical artery catheterisation in a premature neonate with systemic candidiasis. Aortography was performed to provide vascular details such as involvement of celiac, renal, iliac and femoral arteries.

Sonographic detection of internal jugular vein thrombosis after central venous catheterization in the newborn period

We sonographically investigated the internal jugular veins of 40 children who had undergone catheterization of the vein (group A: silastic catheter,n-24; group B: polyurethane catheter,n=16) in the neonatal period. The average age at catheter implantation was 43±73 days, the average birthweight 2414±1145 g, and the average gestational age 34.8±5.0 weeks. We performed follow-up longitudinal and transverse high resolution sonographic scans including routine examination of the contralateral jugular vein at a mean age of 3.7±1.5 years. In group A thrombotic alterations were detected in 8 aut of 24 patients. In three of these patients we found mild clinical symptoms. In group B thrombotic alterations were detected in 1 aut of 16 patients without clinical symptoms. Mean birthweight (1815 versus 3313 g) and mean gestational age (32.3 versus 38 weeks) were significantly lower and indwelling time of the catheters (18 versus 11 days) was significantly longer in group A. Our results indicate that jugular vein thrombosis is a frequent long-term complication in neonates after jugular vein catheterization. High resolution ultrasonography is an adequate method for detecting jugular vein thrombosis and should therefore routinely be performed for long-term follow-up.

A very low birth weight infant with Candida nephritis with fungus balls. Full recovery after pyelotomy and antifungal combination therapy

We report on the use of antifungal combination therapy with fluconazole and 5-fluorocytosine, as a safer alternative to the standard therapy with amphotericin-B, together with pyelotomy, in the successful treatment of a very low birth weight infant who developed Candida septicaemia with bilateral obstructive renal fungus balls and biopsy proven intraparenchymal Candida infiltration. The male infant was delivered by caesarean section at 29 weeks of gestation with a birth weight of 1034 g. Broad spectrum antibiotics were administered for recurrent infections until day 35. On this day the infant developed respiratory and cardiac failure requiring inotropic support and mechanical ventilation. He was in renal failure (serum creatinine 1.9-mg/dl, blood urea nitrogen 49 mg/dl) with anuria. Renal ultrasound revealed markedly dilated renal pelvices partially filled with inhomogeneous echogenic material. On day 37, bilateral pyelotomy and the insertion of pyelostomy catheters was performed. Renal biopsies showed intraparenchymal Candida myceles and ovoids. Systemic antifungal treatment with fluconazole (Diflucan, Pfizer; 6 mg/kg per day) and 5-fluorocytosine (Ancotil, Roche; 100 mg/kgper day) was given. Following the removal of the fungal balls and antifungal treatment, diuresis resumed immediately. Blood urea nitrogen and creatinine levels had returned to within normal range after about 1 week. Fluconazole and 5-fluorocytosine were sustained until day 48 to prevent relapse, despite negative urine cultures from day 15. Pyelostomy catheters were removed on the 23rd post-operative day. Serial ultrasound follow-ups showed complete normalisation of all areas of the kidneys. Creatinine clearance and dimercaptosuccinic acid scintigraphy 8 weeks after the operation revealed normal kidney function. At 1 year of age he has normal renal function. Reports in the literature indicate that Candida colonisation has been found in 34% of all infants on neonatal intensive care units, with septicaemia developing in 7.7% of these infants [1]. Renal involvement has been reported in up to 70% of all infants with Candida sepsis [1]. Candida myceles forming fungus balls, as evidenced by echogenic masses within the urinary tract on renal ultrasound, may obstruct the renal pelvis leading to anuria and acute renal failure [4]. Therapeutic approaches in the literature include various combinations of antifungal drugs with or without percutaneous or open pyelostomy [3, 4,7]. In this case, the presence of bilateral urinary tract obstruction, together with renal insufficiency, justified pyelotomy. Amphotericin-B is highly effective in eliminating fungi from the kidney [6], however, it is often associated with nephrotoxicity due to its accumulation in the kidney, a feature which may be even more pronounced in premature infants with immature organ functions [5]. Liposomal amphotericin-B represents a less toxic alternative [7]. Besides relative high costs, this drug may also cause electrolyte imbalance and in some cases bone marrow suppression. Fluconazole has proven efficacious in treating renal Candida infections, although somewhat less than amphotericin-B [5,7]. It has a high bioavailability, a good tissue penetration and no nephrotoxicity [5]. Successful treatment of neonatal candidiasis with 5-fluorocytosine has been reported in the past [3, 4, 6]. Anuria, especially when it is of nephrogenic origin, precludes the use of nephrotoxic drugs. The combination of fluconazole and 5-fluorocytosine in this case was considered the most efficacious with the least likelihood of nephrotoxicity [2,5]. To our knowledge this is the first Eur J Pediatr (2003) 162: 642–643 DOI 10.1007/s00431-002-0935-7

Pharmacokinetics of intra-arterial indomethacin treatment for patent ductus arteriosus

SummaryWe present pharmacokinetic data of prolonged, intra-arterial indomethacin treatment (i.e. induction plus maintenance dose) for symptomatic patent ductus arteriosus (sPDA) in 26 ventilated premature infants. sPDA was assessed by two-dimensional and pulsed Doppler echocardiography. Permanent ductal closure occurred in 20 (76%) infants. Plasma levels of indomethacin were 1.18±0.74; 1.8±1.0; 1.51±0.93 and 1.25±0.98 μg/ml (mean±SD) at 12, 24, 48 and 72 h after initial dose administration. All except one patient who responded with ductal closure, showed plasma levels above 0.25 μg/ml throughout the 3 day treatment period and no case of sPDA reopening was noted. Although target concentrations over time were not defined, the data indicate that the maintenance levels measured were within the therapeutic range. A negative correlation was found for plasma drug levels and postnatal age (r=0.52;P<0.01). Volume of drug distribution was 0.23±0.18l/kg, total clearance 0.1±0.11 ml/min and elimination constant 0.06±0.05h−1 (mean±SD). The great variation in pharmacokinetic data reflects the heterogeneity of the population studied with respect to extracellular fluid space, cardiovascular status, serum protein and other parameters.

Cerebral blood flow in newborn infants with and without mechanical ventilation

The influence of mechanical ventilation with low mena airway pressure (MAP) on cerebral blood flow (CBF) veolocity in newborn infants was assessed in fifteen ventilated infants by Duplex Doppler Sonography (Duplex DS). As a control, CBF velocities were examined in 15 age and weight matched non-ventilated infants. For quantitation, maximal systolic velocity, enddiastolic velocity and the semiquantitative Pourcelot index were determined as representative flow variables. There was no significant difference of these flow variables between ventilated and non-ventilated infants. The pH, pO2 and pCO2 did not differ significantly between the two groups and there was no correlation between the flow variables, pH, pO2, pCO2 or MAP. Mechanical ventilation with low MAP is not associated with adverse effects on cerebral hemodynamics in newborn infants when significant alterations of the blood gases are avoided.