PubMed Health⌕ Search

Biomedical subjects

I Hamon

Publications and source records attributed to I Hamon.

18 recordsLinked to original sources
PubMed2005

The safety and efficacy of nitric oxide therapy in premature infants.

OBJECTIVES: To assess the safety-efficacy balance of low-dose inhaled nitric oxide (iNO) in hypoxemic premature infants because no sustained beneficial effect has been demonstrated clearly and there are concerns about side effects. STUDY DESIGN: Eight hundred and sixty infants <32 weeks were randomized at birth to receive 5 ppm iNO or placebo when they presented with hypoxemic respiratory failure (HRF) defined by a requirement for mechanical ventilation, fraction of inspired oxygen (FIO 2 ) >40%, and arterio-alveolar ratio in oxygen (aAO 2 ) <0.22. The primary end point was intact survival at 28 days of age. RESULTS: Sixty-one of 415 infants presented with HRF and were compared with 84 of 445 controls who presented with HRF. There was no difference in the primary end point (61.4% in infants [23% with HRF who were treated with iNO] vs 61.1% in controls [21.4% in controls with HRF]; P = .943). For the infants with HRF who were treated with iNO, there was no significant difference from controls for intraventricular hemorrhage (IVH) (6% vs 7%), necrotizing enterocolitis (8% vs 6 %), or patent ductus arteriosus (PDA) (34% vs 37%). Compared with nonhypoxemic infants, the risk of bronchopulmonary displasia (BPD) increased significantly in HRF controls (OR = 3.264 [CI 1.461-7.292]) but not in infants with HRF who were treated with iNO (OR = 1.626 [CI 0.633-4.178]). CONCLUSIONS: iNO appears to be safe in premature infants but did not lead to a significant improvement in intact survival on day 28.

Administration, Inhalation↗
PubMed2004

[Sudden death of neonates in the delivery room].

Healthy newborn death in the delivery room is uncommon. Unlike for sudden infant death syndrome well described in infants between 2 and 6 months of age, few publications have studied this event. We report two cases of asymptomatic term newborns who died unexpectedly in the delivery room. Noteworthy, these newborns were sleeping in prone position on their mother. The Agence Nationale d'Accreditation et d'Evaluation en Sante (ANAES) published recommendations to promote breast-feeding including uninterrupted early contact between the infant and his mother. However, immediately after birth, the newborn may be particularly vulnerable. The application of this recommendation unwisely could be dangerous for newborns allowed to stay on their mother without any monitoring, or medical supervision. We would like to point out the importance of healthy newborn supervision within the first hours of life that can be done without interfering with the mother-child bonding.

Breast Feeding↗
PubMed2002

[Massive fetomaternal transfusion after induction of labor by oxytocin].

UNLABELLED: Severe fetomaternal transfusions are seldom, but may lead to neonatal morbidity or death. CASE REPORT: We report a case of lethal fetomaternal transfusion in which a failure to induce labour, at term, can be suspected. COMMENTS: We emphasize the need of a close monitoring of the fetal well-being in cases of failed induced labour at term.

Adult↗
PubMed2002

[Management of severe neonatal Rh disease following in utero exchange transfusion: towards a new strategy].

Important changes in the prevention, diagnosis, and in utero treatment, of Rhesus allo-immunization in the past 30 years, have led to new neonatal clinical presentations. Based upon the analysis of 14 successive pregnancies with severe hemolytic disease, requiring in utero exchange-transfusion, it appears that the current management is no longer adapted to the new resulting clinical postnatal presentations. In the acute phase, intensive phototherapy associated with regular blood cell transfusion as required, appears to be a better policy than traditional postnatal systematic exchange transfusions. In addition endogenous erythropoiesis stimulation should be included in order to avoid any unnecessary transfusion.

Adult↗
PubMed2001

Chronic oxygen dependency in infants born at less than 32 weeks' gestation: incidence and risk factors.

OBJECTIVE: To assess incidence and clinical risk factors of chronic oxygen dependency (COD) among survivors who were born at or before 31 weeks' gestation. METHODS: This prospective, multicenter study enrolled 802 infants who were born at or before 31 weeks' gestation and admitted to 8 level III neonatal intensive care units in northern and eastern France from January 1 through December 31, 1997. Need for oxygen to maintain oxygen saturation between 92% and 96% was assessed at 28 days of life and at 36 and 42 weeks' postconceptional age (PCA). Stepwise logistic regression analysis was used to identify the incidence of COD and the risk factors related to its occurrence. RESULTS: The mortality rate was 14%. Antenatal corticotherapy was administered to 51% of patients, surfactant therapy to 76% of the ventilated patients, and high-frequency oscillatory ventilation at day 1 to 32%. At 28 days and 36 and 42 weeks' PCA, respectively, 25%, 15%, and 6% of survivors had COD. After adjustment for intercenter variations, we identified the significant risk factors for COD at these dates: a low gestational age, a high score on the Clinical Risk Index for Infants, intrauterine growth restriction, and surfactant treatment. CONCLUSION: COD incidence was high at 28 days of life but decreased dramatically by 42 weeks' PCA. This study confirmed previously reported risk factors and underlined the importance of intrauterine growth restriction and the Clinical Risk Index for Infants as significant risk factors.

Bronchopulmonary Dysplasia↗
PubMed2001

[Perinatal corticotherapy: updates].

The beneficial effects of antenatal corticosteroid treatment are now well established. Likewise, a functional pulmonary improvement has been demonstrated when corticosteroids are used in neonates with chronic lung disease. However, several questions remain to be answered. This review of recent data suggest the need for an updated policy of treatment to improve prognosis. In our population, antenatal maturation has reached a level of 77% below 32 weeks gestation and is associated with a 50% reduction of the risk of severe respiratory distress syndrome. Antenatal steroids have been shown to be beneficial as soon as 23 weeks gestation, but the indication for treatment needs to be carefully evaluated since side effects appear to overcome benefits above 3 repeated courses of treatment. An optimal interval between each course can be set at 10 to 15 days according to the severity of premature labor and gestational age. Since several experimental and clinical studies suggest an increased risk of neurological disability with dexamethasone as compared with betamethasone, it seems consistent to favor the exclusive use of antenatal betamethasone as well as its postnatal choice when indicated. Postnatal use should be restricted to severe chronic lung disease and pulse therapy is now the optimal choice to reduce side effects.

Adrenal Cortex Hormones↗
PubMed2001

[Limits of antenatal management: technical and ethical aspects].

The lower limit for elective delivery depends on technical and ethical issues. Elective delivery is usually accepted after 26 weeks gestation with a 60% survival rate and a 30% handicap rate. Decision making requires close coordination between obstetricians and pediatricians. Sufficient time must be devoted to providing the parents with adequate information. The physician plays a crucial role in decision making, but parent's information and consent are essential.

Delivery, Obstetric↗
PubMed2000

Risks and benefits of therapies for apnoea in premature infants.

Apnoea in infants can result from a wide range of causes, and requires thorough evaluation before deciding on appropriate treatment. Continuous monitoring of premature infants with apnoea is mandatory in order to define the pathophysiology and type of apnoea; selection of treatment involves careful assessment of aetiology, as well as efficacy and tolerability in each individual case. The objective of treatment is to prevent the deleterious consequences of apnoeas that last >20 seconds and/or are associated with bradycardia, cyanosis or pallor, and occur more often than once an hour over a 12-hour period. Apnoea management involves both pharmacological and nonpharmacological treatment. We suggest methylxanthines as first-line therapy for idiopathic apnoeas; evidence suggests that caffeine is better tolerated and as efficacious as theophylline (since it is particularly efficacious against the 'central' component of idiopathic apnoea of prematurity). If treatment fails, additional measures such as doxapram may be appropriate when hypoventilation is present, or nasal continuous positive airway pressure when upper airway instability or obstructive apnoeas are predominant. Apnoea prophylaxis is an additional reason to advocate prenatal maturation with betamethasone. Weaning from treatment is attempted 4 to 5 days after complete resolution of apnoea, beginning with the last treatment introduced. Monitoring should be maintained for 4 to 5 days to detect any relapse of recurrent and severe apnoeas, which would lead to the resumption of the most recently withdrawn treatment.

Apnea↗
PubMed1999

[Efficacy and limits of rescue high-frequency oscillatory ventilation in the treatment of hyaline membrane disease in preterm newborns].

UNLABELLED: Conflicting reports of high-frequency oscillatory ventilation (HFOV) use as an alternative to conventional mechanical ventilation have been published. This retrospective study has evaluated the efficacy and safety of rescue HFOV in preterm infants with severe hyaline membrane disease (HMD) after the failure of conventional mechanical ventilation (CMV). POPULATION AND METHODS: All newborns hospitalized in our neonatal intensive care unit (NICU) from 10.1.1993 to 15.4.1995 with CMV failure, defined as the need for more than 55% FiO2 without any improvement for at least six hours, have been retrospectively studied. The infants were shared according to the absence (Gr I) or the presence (Gr II) of persistent pulmonary hypertension of neonate (PPHN) in addition to HMD before HFOV. RESULTS: Gestational age (GA) was 29.2 +/- 3.7 weeks (mean +/- SD) in Gr I and 30.3 +/- 2.8 in Gr II. Birth weight was 1379 +/- 750 g and 1471 +/- 612 g, respectively. As soon as three hours after the onset of HFOV in both groups, a dramatic improvement was observed with a FiO2 drop from 82 +/- 20% to 64.8 +/- 25.5% (P < 0.01). Among the infants, 62% survived without any major disability and 28% died (46% in Gr II vs 12% in Gr I, P < 0.01). A trend towards a worsening of pre-existing brain lesions has been noticed. An increased risk of mortality was observed when a secondary worsening in O2 requirements occurred 24 hours after the onset of HFOV, despite an initial significant improvement. SGA was also associated with a poor prognosis (46% of the deaths vs 29% for AGA infants, P < 0.05). CONCLUSION: HFOV has been successfully used in premature infants with severe respiratory disease and failure of CMV. Criteria of poor prognosis were PPHN and SGA, or a secondary worsening in oxygen requirements after initial improvement. A trend towards aggravation of pre-existing brain lesions has been noticed after HFOV. This aggravation is more frequent when PPHN is associated with HMD. This observation suggests caution for HFOV use when these conditions are present in premature infants.

Female↗
PubMed1997

[Liquid ventilation: a new mode of ventilation in neonatology?].

Liquid ventilation is based on perfluorocarbons capacity to transport O2 and CO2. Almost 30 years of experimental studies have shown its feasibility and high performances. Results of the first clinical applications in severe neonatal respiratory failure are encouraging. Results of larger randomized and controlled studies, actually in preparation, are awaited with interest.

Animals↗
PubMed1997

Analgesia after caesarean section: patient-controlled intravenous morphine vs epidural morphine.

In a randomized, double-blind study, conducted in 60 patients after caesarean section, we compared epidural morphine (5 mg) with intravenous morphine patient-controlled analgesia (PCA). Efficacy of pain relief (visual analogue scale), comfort, satisfaction and side-effects were studied. In the PCA group, pain scores were higher (P < 0.005) from the third hour onward. The degree of comfort was similar. Overall satisfaction for the first 24 postoperative hours was higher in the epidural group when assessed on a graded scale from 0 to 10, but equal when assessed using qualitative terms. Haemodynamic and respiratory tolerance were identical without any episodes of respiratory depression or oxygen desaturation in either group. The epidural morphine group showed a higher incidence of pruritus requiring specific treatment (P < 0.005). Nausea was reported to be equal in the two groups. Consumption of morphine was higher in the PCA group. We conclude that epidural morphine analgesia, though of good quality, was associated with more pruritus. Morphine PCA, although producing a lesser degree of analgesia compared to epidural morphine, gave good satisfaction.

Clinical Trial↗
PubMed1996

[Anatomical route of pain in premature newborn infants].

Recent research about nociceptive pathways in newborn infants have shown that, even very immature, preterm infants have all the anatomical and functional components required for the perception of painful stimuli. However, the perception of pain in preterm infants is thought to be slightly different from that of term infants: because of a lack of myelination of their sensitive fibers and a still immature cortical organization of the somatosensory system, painful stimuli are perceived more widespread and durable. In addition, the threshold of pain seems to be lower in premature infants, probably due to a lack of protection of their spinal and supraspinal inhibitory pathways. Finally, abnormal behavioural imprinting secondary to early painful stimuli is now suggested. Thus in contrast with the former misconception of "insensitivity towards pain", premature infants must be now considered as "hypersensitive" and vulnerable.

Humans↗
PubMed1996

Effects of fentanyl administration on general and cerebral haemodynamics in sick newborn infants.

Despite the wide use of fentanyl for analgesia in newborns, concerns have been raised about potential haemodynamic side-effects. Since sick newborns may lose their cerebral blood flow autoregulation, a drug-induced haemodynamic instability could lead to brain injury. We assessed the effects of a 15-min infusion of fentanyl (3 micrograms/kg) on the general and cerebral haemodynamics in 15 newborns (median gestational age 29 weeks, 25th-75th percentile, range 28-31 weeks; birthweight 1170 g, range 955-1790 g). The heart rate and mean arterial blood pressure were continuously recorded. Mean cerebral blood flow velocity and pulsatility index were measured using pulsed Doppler ultrasound before, during and up to 60 min after the onset fentanyl administration. No significant modification of general or cerebral haemodynamics was observed. In conclusion, the infusion of 3 micrograms/kg of fentanyl did not lead to any deleterious effect on the general or cerebral haemodynamics in sick normovolaemic newborns.

Analgesics, Opioid↗
PubMed1995

Sheep lung cytochrome P4501A1 (CYP1A1): cDNA cloning and transcriptional regulation by oxygen tension.

Lung cytochrome P450 activity has been linked to neoplasia and may produce reactive oxidant species and potent arachidonic acid metabolites. In lamb lung, oxygen breathing increases lung P450 activity, and inhibition of lung cytochrome P450 activity reduces oxygen-induced lung injury. The P4501A1 (CYP1A1) isozyme is present in many lung cells, including endothelial cells, and may therefore be involved in the pathogenesis of hyperoxic injury to microvascular endothelium. Therefore, to test the hypothesis that oxygen regulates P4501A1 gene expression in the lung, we cloned the sheep P4501A1 cDNA, and examined its regulation by oxygen breathing significantly increased lung P4501A1 RNA levels and that this increase preceded the increase in isozyme activity. Oxygen exposure also promptly increased P4501A1 RNA levels in cultured lamb lung microvascular endothelial cells but not in endothelial cells isolated from the main pulmonary artery or in lung smooth muscle cells. The oxygen-stimulated increase in P4501A1 RNA levels was not serum dependent, was unaffected by cycloheximide treatment, and could not be mimicked by treatment of the cells with oxygenated medium, conditioned medium, or by chemical oxidants. By nuclear run-on assay in cultured lung endothelial cells, oxygen increased the transcription rate of P4501A1 by almost fourfold after 90 min of oxygen exposure but had no significant effect on P4501A1 RNA stability. We conclude that oxygen tension, but not chemical oxidants, increases P4501A1 gene expression pretranslationally in lung microvascular endothelial cells. We speculate that oxygen induction of P450 activity in these cells may contribute to microvascular injury during oxygen breathing.

Animals↗
PubMed1994

Patent foramen ovale with left to right shunt in bronchopulmonary dysplasia: coincidental or associated complication?

Despite the use of exogenous surfactants, the incidence of bronchopulmonary dysplasia (BPD) has not decreased as much as expected. Of 208 newborns involved in trials with Exosurf at our center, 51 had BPD. Among these newborns, 8 were found retrospectively to have secondary worsening of respiratory distress syndrome after initial improvement with surfactant treatment. Oxygen requirements decreased from 89 +/- 15% to 58 +/- 16% (mean +/- SD), respectively, before and 48 h after surfactant, and then reached a plateau of 34 +/- 10% before dramatic deterioration at 22 +/- 9 days of life. The patients had signs of cardiac failure and increased oxygen requirements of up to 76 +/- 19% within 6 h. A patent foramen ovale (PFO) was demonstrated at echocardiography with a left to right shunt at Doppler. No other cause of worsening was found. Five infants had significant improvement when treated with digoxin and furosemide. This retrospective study raises questions about the relationship between PFO and BPD that should be explored in a prospective study.

Bronchopulmonary Dysplasia↗
PubMed1994

Effects of phenobarbital on cerebral blood flow during hypoxia.

Phenobarbital (PB), at anticonvulsant dosages, has been used in an attempt to reduce hypoxic brain injury in asphyxiated newborn infants. The effects of PB pretreatment on the cerebral blood flow (CBF) response in hypoxia were studied in 15 curarized and mechanically ventilated piglets: 7 animals were pretreated with 20 mg/kg of PB (group 1) and 8 served as untreated controls (group 2). Successive aliquots (25 ml) of carbon monoxide were introduced into a closed ventilator circuit and CBF (measured with radiolabelled microspheres), arterial blood pressure, blood gases, arterial pH and PaO2 were subsequently determined at different levels of hypoxia. The amount of hemoglobin available for oxygen transport (i.e. total Hb-HbCO) was used to express hypoxic aggression and decreased from grade I (> 2 mmol/l) to grade II (1-2 mmol/l) to grade III (< 1 mmol/l). In the control group, CBF increased during grade-I hypoxia and continuously remained above baseline values during grade-II and grade-III hypoxia. In pretreated animals, however, only grade-II hypoxia was associated with a significant increase in CBF above baseline. In addition during grade-III hypoxia, CBF decreased to the prehypoxic values despite a fall in cerebral oxygen delivery and cardiac index. These data suggest that PB should be used with caution to prevent brain damage in the asphyxiated newborn infants.

Animals↗