Elevated S100B protein as an early indicator of intracranial haemorrhage in infants subjected to extracorporeal membrane oxygenation

The aim of this investigation was to verify whether plasma S100B could be a useful tool in identifying which infants subjected to extracorporeal membrane oxygenation (ECMO) might develop intracranial haemorrhage (ICH). A case-control study of eight infants who developed ICH during ECMO was conducted. Plasma samples collected daily after ECMO insertion were assessed for S100B and compared with those obtained from eight infants supported by ECMO who did not develop ICH. Cerebral ultrasound and Doppler velocimetry waveform patterns in the middle cerebral artery (MCA PI) were also recorded at the same time as blood sampling. S100B blood concentrations were significantly higher in the group of infants with ICH 72 h before any signs of haemorrhage could be detected by ultrasound (ICH: 2.91 +/- 0.91 microg/L vs. control: 0.53 +/- 0.15 microg/L), reaching their peak at day 6, when cerebral ultrasound scan patterns were suggestive of intracranial haemorrhage (ICH: 3.50 +/- 1.03 microg/L vs. control: 0.66 +/- 0.27 microg/L) (p < 0.05, for both). The highest S100B levels were observed in the three ICH infants who expired during the ECMO procedure (3.43 microg/L, 4.0 microg/L, 4.12 microg/L, respectively). MCA PI values in the ICH group were also significantly higher, but only 24 h before any ultrasound pattern of bleeding was detected (ICH: 2.31 +/- 0.22 vs control: 1.81 +/- 0.24) (p < 0.05). CONCLUSION: This study suggests that blood S100B measurement could be a promising tool for the identification of infants at risk of ICH when imaging assessment and clinical symptoms of haemorrhage might still be silent.     

Recombinant human erythropoietin: analysis of a policy of treatment in an hospital based population of very-low-birthweight infants]

AIM OF THE STUDY: To evaluate a policy of treatment with human recombinant erythropoietin (rhEPO) and to describe factors related to red blood cell transfusions (RBCTs) in treated neonates. STUDY: Prospective, observative study. PATIENTS AND METHODS: One-hundred and sixty-five neonates with gestational age (GA) < 30 weeks and/or birthweight < 1000g admitted between may 1998 and october 1999. Ninety were excluded (congenital malformations n = 6, deaths n = 16, referral to a general hospital before discharge n = 67, ECMO n = 1). Data about the characteristics of the population, the severity of the neonatal period, hemoglobin at birth, blood loses, treatment with rhEPO, number of red blood cells transfusions (RBCTs) and donors were recorded in all infants. RESULTS: Thirty-eight in seventy-five (51%) neonates received 112 blood transfusions. Eighty-eight were prescribed after day 15. In most of the cases (n = 68), RBCTs were done according to the protocol. In 20 cases (23%) infants were transfused during a late-onset infection. No difference was observed between the non-transfused (group I) and the transfused neonates (group II) with regards to the drug administration: first dose on day 3 +/- 2, number of injections (17 +/- 4 vs 18 +/- 1, ns). The start of oral supplementation with iron was late (12j +/- 8 vs 19j +/- 10, ns). Infants in group II had a lower birthweight (850 +/- 240 vs 1050 +/- 160 g, p < 0,01) for a similar GA (28 +/- 1SA vs 28 +/- 2SA, ns) in association with an increased number of small for date babies (p = 0.03). Antenatal stero?ds administration (89 vs 74%, ns), administration of surfactant (59 vs 81%, ns) were similar in the two groups. The Clinical Risk Index for Babies was higher in group II: 5 +/- 3 vs 2 +/- 1 (p < 0,001) as was the duration of oxygen delivery (53 +/- 44 vs 14 +/- 20 days, p < 0,01) and postnatal administration of corticostero?ds ( 38% vs 3%, p < 0.01). CONCLUSION: The quality of iron administration, RBCTs and the limitation of donors could be improved in our population. Transfusions among neonates born before 30 weeks and/or with a birthweight of less than 1000 g and treated with rhEPO are associated with intrauterine malnutrition and a worse clinical condition on admission. Early identification of at risk neonates could improve prevention of RBCTs and the efficacy of rhEPO administration to preterm infants.     

Effect of maternal administration of thyrotropin releasing hormone on the preterm fetal pituitary-thyroid axis

We evaluated the response of preterm fetuses to maternal intravenous injection of 400 micrograms of thyrotropin releasing hormone (TRH) between 30 minutes and 5 hours before delivery (n = 12). An additional seven mothers received saline solution and served as control subjects. There were no statistically significant differences in gestational age, birth weight, or Apgar scores between groups. At delivery, concentrations of maternal thyrotropin were elevated in the TRH group compared with the control group (12.0 +/- 1.6 vs 5.6 +/- 0.5 mU/L; p less than 0.005); however, maternal triiodothyronine (T3) values remained unchanged. Significant elevations of fetal thyrotropin and T3 were observed after maternal administration of TRH compared with control subjects (45.8 +/- 7.7 vs 8.4 +/- 0.9 mU/L (p less than 0.002) and 1.3 +/- 0.07 vs 0.7 +/- 0.04 nmol/L or 87 +/- 5 vs 49 +/- 3 ng/dl (p less than 0.001), respectively). Fetal thyroxine (T4) and prolactin values were also elevated after exposure to TRH (135 +/- 5 vs 86 +/- 10 nmol/L or 10.5 +/- 0.4 vs 6.7 +/- 0.8 micrograms/dl (p less than 0.001) and 212 +/- 31 vs 105 +/- 28 micrograms/L (p less than 0.05), respectively). Two hours after birth, a significant increase in T3 but not T4 levels was observed in both groups of infants. These data indicate that fetal exposure to a single dose of TRH via maternal administration of this hormone results in marked stimulation of the preterm fetal pituitary-thyroid axis, as in the fetus at term, and that this treatment does not inhibit the early postnatal surge of T3.     

Effect of BCG vaccination in asthmatic schoolchildren

Recent studies have explored the effect of Bacilli Calmette-Guerin (BCG) or Mycobacterium vaccae vaccination in asthmatic patients, yielding conflicting results. We investigated the effect of BCG vaccination in asthmatic schoolchildren, especially focusing on the cytokine pattern released by mononuclear cells. After a 1-yr run-in period, 67 asthmatic schoolchildren received intradermal immunization with BCG (33 patients) or placebo (34 patients). Both groups were followed during 1 yr. Serum immunoglobulin E (IgE) levels did not change after BCG (407.1 +/- 86.6 vs. 415.1 +/- 86.7 IU/ml, mean +/- s.e.m.), but increased after placebo (406.7 +/- 67.0 vs. 619.7 +/- 90.7 IU/ml, p = 0.001) administration. Interleukin (IL)-4 and interferon (IFN)-gamma measured in the supernatant of stimulated cultured blood mononuclear cells did not change in the BCG group (10.8 +/- 2.3 vs. 17.9 +/- 5.7 pg/ml, and 348.6 +/- 118.0 vs. 354.8 +/- 139.0 pg/ml, respectively), while in the control group IL-4 increased (from 6.7 +/- 1.3 to 16.1 +/- 6.0 pg/ml, p < 0.05), and IFN-gamma decreased (from 279.9 +/- 82.1 to 232.1 +/- 109.6 pg/ml, p = 0.01). In comparison with their initial status, most patients maintained the same asthma severity and the same proportion of emergency room visits at the end of the study. The proportion of those in whom asthma improved or worsened was the same in both groups. We concluded that, contrary to the common hypothesis, BCG vaccination in asthmatic children was unable to cause a long-term reinforcement of Th(1) response, although it could avoid the increased Th(2) response observed in control patients.     

Changes in cardiac function during extracorporeal membrane oxygenation for persistent pulmonary hypertension in the newborn infant

The effects of extracorporeal membrane oxygenation (ECMO) on cardiac function and its determinants (preload, afterload, contractility, and heart rate) are largely unknown, although some evidence exists that function may decrease. To determine whether cardiac function decreases and what changes in the determinants take place during and after ECMO, we observed 26 newborn infants with persistent pulmonary hypertension. Serial echocardiograms were performed before ECMO, during maximum cardiopulmonary bypass, and after ECMO. Cardiac function was assessed by using standard echographic ejection phase indices (shortening fraction and cardiac output). Heart rate, preload (left ventricular end-diastolic dimension and area), afterload (left ventricular end-systolic wall stress), and contractility (relationship between velocity of circumferential fiber shortening and wall stress) were also measured. Ejection phase indices significantly decreased during ECMO (shortening fraction 33% to 25%, cardiac output 205 to 113 ml/kg/min; p less than 0.05) and returned to normal after ECMO (shortening fraction 26% to 34%, cardiac output 107 to 240 ml/kg/per minute; p less than 0.05). Heart rate also significantly decreased during ECMO (158 to 118 beats/min; p less than 0.05). Preload significantly increased after ECMO (left ventricular end-diastolic dimension 1.4 to 1.6 cm, left ventricular end-diastolic area 1.9 to 2.2 cm2; p less than 0.05). There were no significant changes in contractility and afterload during any study period. We conclude that, although left ventricular ejection phase indices and heart rate decreased during ECMO, these changes were transient and resolved when bypass was terminated. Contractility and afterload did not appear affected by bypass.     

Hemodynamic responses to upright exercise of adolescent cardiac transplant recipients.

To characterize the hemodynamic response to exercise after cardiac transplantation, we asked seven adolescent transplant patients (aged 15.1 +/- 0.7 years; mean +/- SE) to perform upright discontinuous exercise to volitional exhaustion on a mechanically braked cycle ergometer. Data were compared with those of seven control subjects matched for age, gender, body mass, percentage of fat, and body surface area. The transplant group had lower peak power output values (92 +/- 13 vs 146 +/- 30 watts; p less than or equal to 0.001) and maximum oxygen consumption values (22 +/- 8 vs 32 +/- 8 ml/kg per minute; p less than or equal to 0.03), despite achieving the same peak venous lactic acid concentration (6.2 +/- 3 vs 5.9 +/- 3 mEq/L; p = not significant). The transplant group had a diminished heart rate in response to exercise--44% lower than the control group had (delta = 49 +/- 6.4 vs 87 +/- 9.1 beats/min; p = 0.005). The cardiac output response to exercise was maintained in the transplant group (delta = 6.5 +/- 1.5 vs 4.6 +/- 0.8 L/min; p = not significant) by an augmented stroke volume response (delta = 31 +/- 10 vs -4 +/- 3.4 ml; p = 0.01), which may relate to a greater decrease in systemic vascular resistance during exercise (delta = -13.7 +/- 2.2 vs -6.3 +/- 1.2 Wood units; p = 0.02). Thus adolescents who have undergone cardiac transplantation have a normal cardiac output response to upright exercise. This is accomplished, despite a blunted heart rate response, by an augmented stroke volume that may relate to the greater decrease in systemic resistance during exercise.     

Role of circulating complement and polymorphonuclear leukocyte transfusion in treatment and outcome in critically ill neonates with sepsis

We examined the effects of early administration of polymorphonuclear leukocyte (PMN) transfusions in neonates with sepsis by prospectively randomizing 35 consecutive critically ill infants with sepsis, 21 of whom received PMN transfusions in addition to supportive care, one transfusion every 12 hours for a total of five transfusions. Each transfusion consisted of 15 mL/kg containing 0.5 to 1.0 X 10(9) PMN with less than 10% lymphocytes, and was subjected to 1500 rads. PMNs were obtained by continuous-flow centrifugation leukopheresis. Pretreatment values that did not significantly affect survival included weight, gestational age, sex, prematurity, C-reactive protein, initial hematocrit, platelet count and absolute granulocyte count (AGC less than or equal to 1500/mm3), IgM, IgG, IgA, neutrophil supply pool depletion, hypoxia, acidosis, and hypotension. Postnatal age was significantly lower in the nontransfused group than in the transfused group; 2.3 +/- 0.6 vs 6.1 +/- 2.2, (P less than 0.001). Positive blood cultures were obtained in 80% of both groups. Low circulating levels of total hemolytic complement were associated with a poor outcome and higher mortality: 56 +/- 4.0 IU in survivors vs 31 +/- 4.4 IU in nonsurvivors (P less than 0.01). Survival was significantly greater in the PMN transfused group than in the nontransfused group: 20 (95%) of 21 vs nine (64%) of 14 (P less than or equal to 0.05). No untoward effects were attributable to PMN transfusions, either during the study or on subsequent follow-up visits. These preliminary data suggest that early treatment with PMN transfusions improves survival in neonates with overwhelming sepsis. In addition, depleted or low circulating levels of complement may influence prognosis and thus future treatment strategies for neonatal sepsis.     

Biliary lipid composition in patients with cystic fibrosis

Lipid composition of gallbladder bile was determined in 20 patients with cystic fibrosis (CF) (9 females and 11 males, ranging in age from 3 to 18 years). The results were compared with 47 normal subjects matched for age, sex, and pubertal stage. In patients with CF, bile was undersaturated with cholesterol before puberty in both sexes and no differences with normal controls could be observed. After puberty, a similar increase in cholesterol saturation was noted in females with CF (85 +/- 15% vs. 130 +/- 38%, p less than 0.01) and normal controls (82 +/- 11% vs. 138 +/- 31%, p less than 0.01). No change in cholesterol saturation could be observed in male patients and controls after puberty. Molar percentage of chenodeoxycholic acid (CDCA) was lower (p less than 0.05) in postpubertal females (31 +/- 9%) and males (36 +/- 7%) with CF compared to controls (42 +/- 8% and 40 +/- 5%, respectively), while cholic acid (CA) was higher in all patients with CF. In females with CF, lithocholic acid (LCA) increased after puberty (2.2 +/- 0.8% vs. 5.3 +/- 2.6%, p less than 0.05) and was higher compared to controls (2.2 +/- 0.8%, p less than 0.001). An increase was also noted for deoxycholic acid (DCA) in postpubertal females with CF (1.7 +/- 2.6% vs. 10.8 +/- 7%, p less than 0.05), but it was lower in both sexes after puberty than in respective controls. The present results suggest that cholesterol saturation of bile in patients with CF is not different from respective controls.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hypoxaemia in infants with respiratory tract infections

Nineteen infants who were graduates from special care baby units underwent two overnight tape recordings of oxygen saturation (SaO2) and breathing movements; one during an upper (n = 12) or lower (n = 7) respiratory tract infection and the other when free of infection. Baseline SaO2 was lower during infection (median 99.6 vs 100%, p less than 0.01), with four patients having values (84.3-95.5%) below the normal lower limit for full-term infants (97%). The median number of apnoeic pauses was also lower during respiratory tract infection (4.7 vs 15.7/h, p less than 0.02). The median number of episodic desaturations (SaO2 less than or equal to 80%) did not change significantly (1.3 vs 1.9/h, p greater than 0.05), with the exception of one patient who had extremely increased values during infection for both apnoeic pauses (63/h) and desaturations (112/h). No infant, however, was considered clinically hypoxaemic. Clinically unsuspected hypoxaemia may thus occur during respiratory tract infection in a proportion of infants graduating from special care baby units. Such hypoxaemia may have potentially deleterious effects.     

Recombinant erythropoietin compared with erythrocyte transfusion in the treatment of anemia of prematurity

To assess the risks and benefits of erythropoietin versus erythrocyte transfusion in the treatment of the anemia of prematurity, we randomly assigned 19 anemic preterm infants (birth weight 988 +/- 227 gm; gestational age 27.6 +/- 1.2 weeks; age 41 +/- 15 days; all values mean +/- SD) to receive either transfusion or subcutaneously administered erythropoietin (200 units/kg every other day for 10 doses). In the 10 erythropoietin recipients, corrected reticulocyte counts increased from 2% +/- 1% to 7% +/- 2% (p less than 0.001) and hematocrits increased from 27% +/- 2% to 30% +/- 4% (p less than 0.05). In the nine infants who underwent transfusion, reticulocyte counts did not increase, but hematocrits increased from 28% +/- 4% to 41% +/- 2% after initial transfusion (p less than 0.001) and had decreased to 34% +/- 5% by day 20. Signs attributed to anemia (tachycardia, apnea with bradycardia, and poor weight gain) declined in both the erythropoietin recipients and those who underwent transfusion. However, five of nine infants who underwent transfusion had symptoms within 10 to 14 days and were given further transfusions. Marrow aspiration performed after 7 to 10 days of treatment showed that infants receiving erythropoietin had greater percentages of erythropoietic precursors (p less than 0.01), greater concentrations of mature erythroid progenitors (p less than 0.001), and higher cycling rates of erythroid progenitors (p less than 0.001). The percentage of mature stored neutrophils in marrow was lower in the erythropoietin group than in the transfusion group, resulting in an inverse myeloid/erythroid ratio (0.5:1 vs 6.2:1; p less than 0.001). After 20 days, absolute blood neutrophil counts were lower in the erythropoietin recipients (1.8 +/- 0.9 x 10(3) cells/microliters) than in the infants who underwent transfusion (3.9 +/- 1.9 x 10(3) cells/microliters; p less than 0.05). Administration of erythropoietin thus stimulated erythropoiesis and relieved signs attributed to anemia; the significance of the relative neutropenia remains to be determined. We conclude that erythropoietin administration offers promise as an alternative to erythrocyte transfusion in neonates with symptomatic anemia of prematurity.     

Improved erythrocyte survival with combined vitamin E and selenium therapy in children with glucose-6-phosphate dehydrogenase deficiency and mild chronic hemolysis

To study the antioxidant effect of high-dose vitamin E alone and in combination with selenium in patients with glucose-6-phosphate dehydrogenase deficiency with mild chronic hemolysis, 36 male children with such manifestations were enrolled consecutively into two equal groups. Group 1 received 800 IU vitamin E daily, and group 2 received 800 IU vitamin E in combination with 25 micrograms selenium. Hematologic status before and 2 months after treatment was evaluated. After treatment there was a significant change toward normal in both groups. The mean red cell half-life increased in group 1 from 16.9 to 22.8 days (P less than 0.01), and in group 2 from 15.6 to 24.3 days (P less than 0.01). A comparison of the mean difference of paired values in the two groups revealed a more significant increase in hemoglobin (0.9 +/- 0.1 gm/dl vs 1.2 +/- 0.2 gm/dl, P less than 0.05), hematocrit (2.4% +/- 0.4% vs 3.8% +/- 0.3%, P less than 0.05), and red cell half-life (5.9 +/- 3.0 days vs 9.1 +/- 4.4 days, P less than 0.01), and more significant reduction in reticulocytes (-0.7% +/- 0.2% vs -1.5% +/- 0.4%, P less than 0.01) in group 2. Clinical assessment and follow-up indicated no side effects related to the drugs.     

Effect of zinc supplementation on growth hormone secretion, IGF-I, IGFBP-3, somatomedin generation, alkaline phosphatase, osteocalcin and growth in prepubertal children with idiopathic short stature

Controversy exists about the effect of zinc on growth and the GH-IGF system. Zinc supplementation has been shown to stimulate linear growth in zinc-deficient children. However the mechanism of this effect has not been well characterized. Furthermore, the effect of zinc supplementation on non-zinc-deficient short children is unknown. We investigated the effect of zinc supplementation on endogenous GH secretion, serum IGF-I and IGFBP-3 concentrations, IGF-I and IGFBP-3 generation in response to exogenous GH, bone formation markers, and linear growth of non-zinc-deficient children with idiopathic short stature. We analyzed prospectively serum zinc, IGF-I, IGFBP-3, alkaline phosphatase, osteocalcin, and GH response to clonidine test, and performed a somatomedin generation test before and 6 weeks after zinc supplementation in 22 (16 M, 6 F) prepubertal children with idiopathic short stature. Serum IGF-I increased from 67.4+/-70.6 to 98.2+/-77.3 ng/ml (p <0.001), IGFBP-3 from 2326+/-770 to 2758+/-826 ng/ml (p <0.001), alkaline phosphatase from 525+/-136 to 666+/-197 U/l (p <0.0001), and osteocalcin from 16.8+/-10.6 to 25.8+/-12.8 ng/ml (p <0.05) after zinc supplementation despite there being no difference in GH response to clonidine after zinc supplementation (peak GH 11.6+/-6.9 vs 13.4+/-7.8 ng/ml, GH area under the curve during clonidine test 689+/-395 vs 761+/-468, NS). Percent change in IGF-I and IGFBP-3 during the somatomedin generation test was not significantly affected by zinc supplementation (118% vs 136% and 57% vs 44%, respectively). There was no significant correlation between percentage increase in zinc levels and percentage increase in parameters tested. Height SDS or weight SDS did not improve significantly in 17 patients who continued on zinc supplementation for at least 6 months (6-12 months) (-2.59 vs -2.53 SDS and -1.80 vs -1.67 SDS, respectively). Zinc supplementation increased basal IGF-I, IGFBP-3, alkaline phosphatase and osteocalcin without changing GH response to clonidine. Zinc supplementation did not affect sensitivity to exogenous GH as tested by IGF-I and IGFBP-3 generation test. These results suggest a direct stimulatory effect of zinc on serum IGF-IGFBP-3, alkaline phosphatase and osteocalcin. Despite improvements in the above parameters, zinc supplementation to children with idiopathic short stature with normal serum zinc levels did not significantly change height or weight SDS during 6-12 months follow-up.     

Regulation of placental glucose transfer and consumption by fetal glucose production

We studied ten normoglycemic [maternal glucose (GA) = 70 mg/dL] and six insulin-induced hypoglycemic (GA = 22 mg/dL) pregnant sheep to test the hypothesis that development of fetal glucose production (GPR) could help maintain fetal glucose concentration, limit uteroplacental-fetal glucose transfer (UPGT), and sustain uteroplacental glucose consumption (UPGC). Compared with the normoglycemic group, the hypoglycemic group demonstrated the following values: fetal glucose concentration (Ga) was 9.8 +/- 0.8 mg/dL (51% lower, p less than 0.01), uterine glucose uptake (UtGU) was 16.7 +/- 1.4 mg/min (54% lower, p less than 0.01), UPGT was 3.1 +/- 0.6 mg/min (81% lower, p less than 0.001), and UPGC was 13.6 +/- 1.4 mg/min (30% lower, p less than 0.05). The reduction in UPGC was significantly less (p less than 0.05) than the reductions in UPGT and UtGU. Fetal glucose utilization rate (GUR) was decreased 20% (p less than 0.05) to 3.99 +/- 0.35 mg/min/kg. A further decrease in GUR was prevented by the appearance of fetal GPR of 2.82 +/- 0.32 mg/min/kg (p less than 0.05) compared with negligible GPR in the normoglycemic group. UPGT and UPGC in both groups were not influenced by maternal or fetal insulin infusions as long as Ga did not change; however, fetal glucose infusion that increased Ga increased UPGC in both groups. We conclude that, during chronic maternal hypoglycemia, increased fetal GPR limits the simultaneous decrease in fetal GUR and glucose concentration. By sustaining Ga fetal GPR limits UPGT to a significantly greater extent than UtGU, diverting UtGU to UPGC. Thus, fetal GPR promotes placental as well as fetal metabolic autonomy when the maternal supply of glucose is reduced.     

Sleep quality in children with asthma treated with theophylline or cromolyn sodium

The effect of theophylline and cromolyn sodium on sleep was studied in 10 children with asthma who were 10 to 17 years of age (mean 13.5 +/- 2.4 years). Theophylline or cromolyn sodium was taken for 14 days in a double-blind, crossover, placebo-controlled trial. Theophylline blood levels before sleep were 10.2 +/- 4 micrograms/ml during the theophylline period. There was no difference in pulmonary function between the two periods. Theophylline did not disrupt sleep as measured by sleep latency, total sleep time, sleep efficiency, movement time, microarousals, and arousals. Apneic episodes (greater than or equal to 10 seconds) were of central origin and less frequent during the theophylline period (p less than 0.05). Arterial oxygen desaturation (greater than 5% decrease from baseline saturation when awake) was less frequent during the theophylline treatment (p less than 0.05). We conclude that theophylline treatment of the children's asthma did not disrupt sleep and appeared to have a protective effect in regard to apnea, hypopnea, and arterial oxygen saturation.     

Thermal responses and heart rates of low-birth-weight premature babies during daily care on a heated, water-filled mattress

Body temperatures, heart rates and resting oxygen consumptions were examined during routine nursing care in 12 premature babies treated alternately in incubators or on a heated, water-filled mattress (HWM). The mean temperatures were significantly higher in the axilla (0.3 degree C; p less than or equal to 0.05) and the foot (1.4 degrees C; p less than 0.001) during HWM care. The degree of maximal fall in various body temperatures during routine nursing procedures was the same for both treatments, whereas the time taken for the foot temperature to fall was 13 min shorter during HWM care (p less than 0.001). The proportion of heart rates below 160 bpm when the babies were not disturbed was 7.4% greater during HWM treatment (p less than 0.01). The resting oxygen consumption in babies treated on HWM was slightly lower (6.2 +/- 0.4 vs 6.4 +/- 0.5 ml/kg/min; p less than 0.05). Treatment on the HWM seems to promote calm and comfort, since it reduces the amount of thermal stress and prolongs quiet resting periods.     

Phentolamine administration increases blood S100B protein levels in pediatric open-heart surgery patients

AIM: Phentolamine administration during open-heart surgery shortens the cooling and rewarming phases of cardiopulmonary bypass (CPB) and hastens weaning from mechanical ventilation and extubation. Data on the effects of phentolamine on cerebral circulation and function in this setting are lacking. This study reports the cerebral effects of phentolamine using blood S100B protein levels and the middle cerebral artery pulsatility index (MCA PI). METHODS: Sixty pediatric patients undergoing congenital heart disease repair were randomly assigned to receive either phentolamine 0.2 mg kg(-1) i.v. (n = 30) or placebo (n = 30) before the cooling and rewarming phases of CPB. Samples for S100B measurement were collected at seven predetermined time-points before, during and after surgery. MCA PI values were recorded at the same times as sampling. RESULTS: S100B blood levels were higher in the phentolamine-treated group than in controls after rewarming (3.53 +/- 1.88 vs 1.58 +/- 0.53 microg l(-1); p < 0.001), remained persistently higher at the end of surgery (2.95 +/- 0.91 vs 0.79 +/- 0.21 microg l(-1); p < 0.001) and returned to normal ranges 12 h later than in the placebo group (p > 0.05). MCA PI values were also significantly higher at the end of surgery in the phentolamine-treated group (1.83 +/- 0.50 vs 1.22 +/- 0.34; p < 0.01). Cooling and rewarming times were shorter in the phentolamine-treated group (p < 0.01, for all). CONCLUSION: Despite improved peripheral vasodilatation and perfusion, phentolamine administration in pediatric open-heart surgery is correlated with increased cerebrovascular resistance and brain damage.     

Oxygen desaturation during sleep in infants and young children with congenital heart disease.

Oxygen saturation (SaO2) during sleep and pulmonary functions were evaluated in 19 infants with congenital heart disease, aged 6 +/- 4 months, and in 11 normal infants, aged 8 +/- 5 months, to determine whether infants with congenital heart disease have more frequent oxygen desaturation during sleep and, if so, its relationship to underlying pulmonary function. Infants with congenital heart disease were classified as acyanotic (n = 11) or cyanotic (n = 8) on the basis of their aortic SaO2 at the time of cardiac catheterization (greater or less than 90% SaO2). Pulmonary function tests included respiratory rate, functional residual capacity, total respiratory system compliance, and maximal flows at functional residual capacity. Significant differences were found in the values for the lowest SaO2 of each 5-minute epoch (SaO2L) averaged during the entire sleep time (normal 94% +/- 2%, acyanotic 90% +/- 3%, and cyanotic 74% +/- 4%; p less than 0.01). The three groups also differed significantly in frequency distributions of percentage of total sleep time with SaO2L less than 90% (SaO2%T) (normal 10% +/- 17%, acyanotic 36% +/- 34%, and cyanotic 97% +/- 4%; p less than 0.05). Compared with the control group, the acyanotic group had a higher respiratory rate (66 +/- 19 breaths/min vs 35 +/- 6 breaths/min; p less than 0.01), a lower tidal volume (65% +/- 29% predicted vs 105% +/- 18% predicted; p less than 0.01), and a lower total respiratory compliance (59% +/- 18% predicted vs 106% +/- 30% predicted; p less than 0.01). A negative correlation existed between SaO2%T and aortic SaO2 (R2 = 0.64; p less than 0.01). We conclude that oxygen desaturation occurs during sleep in infants with congenital heart disease; the presence of desaturation appears to be related to the initial degree of hypoxemia and the presence of abnormal pulmonary function.     

Postnatal nicotine exposure does not further compromise hypoxia defense mechanisms in prenatally nicotine-exposed lambs

AIMS: To determine whether combined pre- and postnatal nicotine exposure compared with prenatal exposure alone results in more compromised postnatal hypoxia defense mechanisms and further alteration of the postnatal breathing pattern (reduced tidal volume and increased respiratory rate). METHODS: Seven lambs exposed to nicotine prenatally (pN) (approximate maternal dose: 0.5 mg/kg/d) and seven lambs exposed to nicotine pre- and postnatally (ppN) (postnatal dose: 1.6-2 mg/kg/d) were studied without sedation at an average age of 5 d and 21 d during resting (room air) conditions, during exposure to 10% O2 and during a brief exposure to 100% O2. RESULTS: Resting minute ventilation, occlusion pressure, effective impedance, heart rate and mean arterial blood pressure were similar in the two groups during wakefulness and quiet sleep. Resting tidal volume was significantly higher in ppN than in pN lambs during wakefulness (9.4 +/- 0.7 vs 7.7 +/- 1.4 ml/kg, p < 0.05) and quiet sleep (9.8 +/- 0.6 vs 7.6 +/- 1.5 ml/kg, p < 0.01) at 5 d and also at 21 d during wakefulness (7.7 +/- 1.0 vs 6.2 +/- 1.1 ml/kg, p < 0.05). The ventilatory, heart rate and blood pressure responses to hypoxia were comparable in the two groups during both activity states. Time to arousal from quiet sleep in response to hypoxia was equivalent in the two groups. The ventilatory response to hyperoxia was not significantly different in the two groups during either activity state. CONCLUSION: Continued postnatal nicotine exposure after prenatal exposure did not further compromise hypoxia defense mechanisms after birth.     

Infantile hypertrophic pyloric stenosis: evaluation of sonographic criteria

Sonography has become an important diagnostic adjunct in the evaluation of vomiting infants who are suspected to have infantile hypertrophic pyloric stenosis (IHPS). Two commonly used sonographic criteria, viz. pyloric diameter (D) and pyloric muscle wall thickness (T) were evaluated in 14 consecutive vomiting infants. The D and T were significantly larger in the IHPS group compared to the non IHPS group (1.40 +/- 0.34 cm vs 0.95 +/- 0.19 cm, p = 0.04; 4.4 +/- 1.1 mm vs 2.5 +/- 0.6 mm, p less than 0.01). By a combination of sonographic criteria (D greater than or equal to 1.2 cm & T greater than or equal to 3 mm), all the 4 non IHPS patients and 9 out of 10 IHPS patients were correctly diagnosed. The positive and negative predictive values were 1.00 and 0.80, respectively. However, using reported diagnostic criteria of D greater than or equal to 1.5 cm or T greater than or equal to 4 mm would have missed 60% and 20% of the IHPS cases, respectively. With proper choice of diagnostic criteria, sonography is a useful diagnostic tool in the evaluation of vomiting infants for IHPS patients.     

Extracorporeal membrane oxygenation after stage I reconstruction for hypoplastic left heart syndrome.

OBJECTIVE: Although extracorporeal membrane oxygenation (ECMO) is an acceptable strategy for children with refractory cardiac dysfunction after cardiac surgery, its role after stage I reconstruction for hypoplastic left heart syndrome and its variants is controversial. Our objective is to describe the outcome of "nonelective" ECMO after stage I reconstruction. DESIGN: Retrospective case series. SETTING: Pediatric cardiac intensive care unit. PATIENTS: Infants placed on ECMO after stage I reconstruction from January 1998 to May 2005. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 382 infants who underwent stage I reconstruction during the study period, 36 (9.4%) required ECMO in the postoperative period. There were 22 infants with hypoplastic left heart syndrome. Indications for ECMO included inability to separate from cardiopulmonary bypass in 14 and cardiac arrest in 22. Fourteen infants (38.8%) survived to hospital discharge. Nonsurvivors had longer cardiopulmonary bypass time (150.1 +/- 70.0 mins vs. 103.9 +/- 30.0 mins, p =. 01). 9/14 infants (64%) supported with ECMO> than 24 hrs after stage I reconstruction survived while only 5/22 infants (22%) requiring ECMO< 24 hrs of stage I reconstruction survived (p =. 02). Of note, all five infants diagnosed with an acute shunt thrombosis were early survivors. Mean duration of ECMO was 50.1 +/- 12.5 hrs for survivors and 125.2 +/- 25.0 for nonsurvivors (p =. 01). 7/14 early survivors are alive at a median follow-up of 20 months (2-78 months). CONCLUSIONS: In our experience, ECMO after stage I reconstruction can be life saving in about a third of infants with otherwise fatal conditions. It is particularly useful in potentially reversible conditions such as acute shunt thrombosis and transient depression of ventricular function.