Biomedical subjects

Rakesh Sahni

Publications and source records attributed to Rakesh Sahni.

6 recordsLinked to original sources

PubMed2005

Interactions between sleeping position and feeding on cardiorespiratory activity in preterm infants.

Infants sleeping in the prone position are at greater risk for sudden infant death syndrome (SIDS). Sleep position-dependent changes in cardiorespiratory activity may contribute to this increased risk. Cardiorespiratory activity is also affected by feeding. Twenty prematurely-born infants were studied at 31-36 weeks postconceptional age while sleeping in the prone and supine positions. Heart rate, respiratory rate, and patterns of variability were recorded during interfeed intervals, and effects of position and time after feeding were analyzed by repeated measures analyses of variance. There were significant effects of both sleeping position and time after feeding. Heart rate is higher and heart period variability is lower in the prone position, and the effects of sleeping position on cardiac functioning are more pronounced during the middle of the intrafeed interval. In preterm infants, autonomic responses to nutrient processing modulate the cardiorespiratory effects of sleeping position. Prone sleeping risk may vary with time after feeding.

Electrocardiography↗

PubMed2005

Variables associated with the early failure of nasal CPAP in very low birth weight infants.

OBJECTIVE: To identify risk factors and neonatal outcomes associated with the early failure of "bubble" nasal continuous positive airway pressure (CPAP) in very low birth weight (VLBW) infants with respiratory distress syndrome (RDS). STUDY DESIGN: Following resuscitation and stabilization at delivery, a cohort of 261 consecutively inborn infants (birth weight < or = 1250 g) was divided into three groups based on the initial respiratory support modality and outcome at 72 hours of age: "ventilator-started" group, "CPAP-failure" group, and "CPAP-success" group. RESULTS: CPAP was successful in 76% of infants < or = 1250 g birth weight and 50% of infants < or = 750 g birth weight. In analyses adjusted for postmenstrual age (PMA) and small for gestational age (SGA), CPAP failure was associated with need for positive pressure ventilation (PPV) at delivery, alveolar-arterial oxygen tension gradient (A-a DO2) >180 mmHg on the first arterial blood gas (ABG), and severe RDS on the initial chest x-ray (adjusted odds ratio [95% CI] = 2.37 [1.02, 5.52], 2.91 [1.30, 6.55] and 6.42 [2.75, 15.0], respectively). The positive predictive value of these variables ranged from 43% to 55%. In analyses adjusted for PMA and severe RDS, rates of mortality and common premature morbidities were higher in the CPAP-failure group than in the CPAP-success group. CONCLUSION: Although several variables available near birth were strongly associated with early CPAP failure, they proved weak predictors of failure. A prospective controlled trial is needed to determine if extremely premature spontaneously breathing infants are better served by initial management with CPAP or mechanical ventilation.

Birth Weight↗

PubMed2005

Is the new definition of bronchopulmonary dysplasia more useful?

OBJECTIVE: To determine the incidence of bronchopulmonary dysplasia (BPD) in low birth weight (LBW) infants <1251 g managed with early bubble nasal continuous positive airway pressure (NCPAP) and a gentle ventilation strategy using the newly proposed definition for BPD and the previous definitions. METHODS: Needs for supplemental oxygen and positive pressure (positive pressure ventilation or NCPAP) during initial hospitalization were evaluated in 266 inborn LBW infants (birth weight <1251 g). The data were categorized in three weight groups, <751, 751 to 1000 and 1001 to 1250 g and the incidence of BPD was computed in survivors based on oxygen need at 28 days, 36 weeks postmenstrual age (PMA) and the new severity of BPD criteria, that is, mild BPD: need for supplemental oxygen > or =28 days, but not at 36 weeks PMA; moderate BPD: need for supplemental oxygen > or =28 days and <30% at 36 weeks PMA and severe BPD: need for supplemental oxygen > or =28 days, and >30% at 36 weeks PMA and/or positive pressure at 36 weeks PMA. Further, BPD-associated comorbidities and short-term outcome data during hospitalization were compared among the groups, defined by severity of BPD. RESULTS: Among LBW infants <1251 g, the incidences of BPD at 28 days and 36 weeks PMA were 21.1 and 7.4% respectively. Using the newly defined criteria, the incidences of mild, moderate and severe BPD were 13.5, 4.8 and 2.6%, respectively. In total, 64.6% of these infants had mild BPD and 70.8% weighed <751 g at birth. Associated comorbidities correlated significantly with grades of underlying pulmonary disease. Also, significantly longer hospital stay, discharge at a higher PMA and lower growth velocity was observed with increasing grades of BPD. CONCLUSIONS: The new system for grading the severity of BPD offers a better description of underlying pulmonary disease and correlates with the infant's maturity, growth and overall severity of illness. Whether it will have a role in predicting long-term outcome remains to be determined.

Age Factors↗

PubMed2002

Inhaled nitric oxide and gentle ventilation in the treatment of pulmonary hypertension of the newborn--a single-center, 5-year experience.

OBJECTIVE: To evaluate the effect of inhaled nitric oxide (INO) in pulmonary hypertension of the newborn (PH) in a single center over 5 years using gentle ventilation (GV), without hyperventilation or induced alkalosis. METHODS: Data from 229 consecutive infants with PH of varied etiology treated with INO and GV, and from 67 infants with meconium aspiration syndrome (MAS) and primary PH (PPHN) treated with GV alone were reviewed over a 5-year period (86% outborn). INO was initiated at 25 ppm when PH and severe hypoxemia persisted despite maximal optimal ventilation. Hyperventilation or systemic alkalosis were not attempted. RESULTS: Mean duration of ventilation was 9.9 +/- 14 days (median 6.5 days). Average mean airway pressure (MAP) dropped from 17.7 +/- 4.3 cm H(2)O at the referral hospital to 13.2 +/- 2.5 cm H(2)O (p < 0.001) following admission to our unit using conventional settings and GV, before starting INO. Mean oxygenation index (OI) dropped from 46.8 +/- 24.5 to 22.7 +/- 21.4 within 24 hours of INO therapy (p < 0.001). Infants with higher baseline pH and lower baseline OI responded better to INO (p < 0.02). Overall survival was 72%. Patients with MAS and PPHN had the best response, 92% survived and there was a 46% reduction in need for extracorporeal membrane oxygenation (ECMO) compared to historical pre-INO period controls (23.9% vs. 12.8%, p < 0.01). In the infants treated with GV alone, the MAP dropped from 17.2 +/- 4.3 cm H2O at the referral hospital to 12.6+/-2.4 after GV was started in our unit. CONCLUSIONS: We conclude that INO is an effective and well-tolerated therapy for PH in infants receiving GV.

Academic Medical Centers↗

PubMed2002

Newer experience with CPAP.

Progress in neonatal intensive care is closely linked to improvements in the management of respiratory failure in small infants. Current modalities of ventilatory assistance range from more benign continuous positive airway pressure (CPAP) to various modes of mechanical ventilation (including high frequency ventilation). The advent of less invasive methods of delivering CPAP has permitted earlier treatment of infants with respiratory distress syndrome and avoided the need for mechanical ventilation. Children's Hospital of New York (Columbia University) places all spontaneously breathing infants on nasal prong CPAP as the first mode of respiratory support. The early initiation of nasal prong CPAP in combination with a tolerance to elevated PCO(2) levels has reduced the incidence of chronic lung disease to <5% in infants weighing less than 1500g. This report will present an historical review and summarize the experience with CPAP at Columbia and other centres. In addition, it reviews the clinical applications and physiological effects of CPAP in preterm infants with respiratory distress syndrome.

Hospitals, Pediatric↗

PubMed2002

Quality of diet, body position, and time after feeding influence behavioral states in low birth weight infants.

The effects of variations in carbohydrate and fat intake and body position on behavioral activity states were evaluated in 64 healthy, growing low birth weight infants (birth weight, 750-1600 g). The infants, enrolled in a prospective, randomized, double-blind, controlled study of effects of quality of dietary energy, were fed one of the five formulas. These formulas contained fixed intakes of protein (4 g/kg per day) but different intakes of carbohydrate (9.1 to 20.4 g/kg per day) and fat (4.3 to 9.5 g/kg per day). Six-hour daytime sleep studies were performed at 2-wk intervals from time of full enteral intake until discharge (mean postconceptional age at first study, 33.2 +/- 1.8 wk). Infants were randomly assigned to the prone or supine position for the first 3-h postprandial period; the position was reversed during the second 3 h. Behavioral activity state, i.e. quiet sleep (QS), active sleep, indeterminate sleep, awake, or crying was coded each minute throughout the postprandial period. The overall incidence of QS was almost double in the prone position versus the supine (p < 0.0001). In contrast, the probability of being in either of the two wakeful states (awake and crying) was increased when infants were placed in supine position (p < 0.0001). Increased likelihood of being in QS while prone was found only during the 30 min after and before feeding in a 150-min prandial cycle. In contrast, increased amounts of awake and crying in supine position were observed throughout the feeding interval. As carbohydrate intake increased, time spent in QS in supine position increased (from 8.6% to 12.5%, p < 0.02), and a trend in the same direction was noted for the prone position (p = 0.06). However, during postprandial minutes 10-100, when QS is likely to be entrained by the nutrient intake, enhancement of QS was found in the prone position only (p < 0.02). Carbohydrate intake influences the total time spent and the distribution of behavioral activity states within the postprandial period in low birth weight infants. The effect of nutrient intake on sleep profile is dependent on body position and time after feed. Mechanistic hypotheses relating sudden infant death syndrome to sleeping position may need to take these observations into account.

Dietary Carbohydrates↗