Response Of Preterm Infants Research Articles

Response of premature infants with severe respiratory failure to inhaled nitric oxide

Response of premature infants with severe respiratory failure to inhaled nitric oxide

Electrical Stimulation of Acupuncture Meridians May Blunt Salivary Cortisol Stress Response in Premature Infants. 1039

Electrical Stimulation of Acupuncture Meridians May Blunt Salivary Cortisol Stress Response in Premature Infants. 1039

Relieving pain with sugar

There may be sweet solutions to pain response in premature infants, according to two recent studies in the March 1996 Archives of Disease in Childhood, Fetal and Neonatal Edition. In the first study, 15 healthy premature infants, 32 to 34 weeks postmenstrual age and no more than 24 hours old, received 1 ml of either 25 percent sucrose solution or sterile water by syringe on the anterior tongue approximately two minutes before undergoing heel pricks for glucose or bilirubin tests. Among infants receiving the sucrose, there was a significant reduction in: duration of the first cry; percentage of time spent crying within five minutes after heel prick; and perceived pain (based on scoring facial expressions and crying).

Secretory immune responses of ventilated preterms to gentle/light and systematic stroking

The premature infant is more vulnerable to infection and more prone to respiratory complications than the healthy term counterparts. Secretary Immunoglobulin A (SIgA) protects againts respiratory tract infections and the secretory immune responses of premature infants to tactile stimulation were examined in this study. A pre-test/post-test counterbalanced design examined developmental effects of gentle/light systematic stroking (TAC-TIC therapy) on SIgA secretion. Unstimulated saliva was obtained from six (2M;4F) very/extrenely low birthweight (<1.2kgs), ventilated infants before and after TAC-TIC (n=14) or a control period (n=15). A one-way repeated measures ANOVA indicated that SIgA concentrations were higher (NS) after the intervention and significantly lower (DF = 1; F=4.11; p<0.05) following the control period. Based on the rationale of the ‘Equilibrium Model’ the intervention may be facilitating ‘coactions’ amongst various infant systems through self-regulatory mechanisms, and it is possibly acting as a modulator of the immune system.

Responses of Premature Infants to Routine Nursing Interventions and Noise in the NICU

This study documents the effects of routine nursing procedures and loud noise events on the behavioral and physiological responses of premature infants in the neonatal intensive care unit (NICU). The subjects were 55 premature infants ranging in weight from 480 to 1930 g and in age from 23 to 37 weeks gestation. Nineteen nursing activities common in the NICU as well as loud noises such as alarms, telephones, loud speech, or infant crying were recorded every 5 minutes. The infants' physiological and behavioral responses were recorded at 5-minute intervals for 2 hours in the morning and 2 hours in the evening. Nursing interventions and noise resulted in significant changes in both the behavioral and physiological responses of infants. The presence of noise alone and nursing interventions alone resulted in similar physiological responses; however, the combination of these events was not cumulative. Infants changed their behavioral states an average of six times each hour during the 12 observation periods, and the number of enduring states (10 minutes or longer) averaged 10 times in the 48 observation periods of 4 hours.

Special Needs of Preterm Infants in the Management of Pain and Discomfort

Most infants born preterm are admitted to hospital neonatal intensive care units, where they undergo repeated multiple diagnostic and therapeutic procedures that result in pain and discomfort. Although there is convincing evidence to support the preterm infant's neurologic capacity for pain, management of pain often is not optimal. Accurate and reliable assessment of the preterm infant's pain is an important prerequisite for effective pain management. Pain assessment is a challenge for health professionals because the preterm infant's responses are less vigorous, more variable, and less consistent than are the responses of term neonates and older infants. Few reliable and valid assessment measures exist for this age group. There also is uncertainty in implementing pain-relieving intervention because of inadequate information on their safety and effectiveness and preconceived attitudes and beliefs of health professionals. The special needs of preterm infants related to the assessment and management of pain are discussed.

Oxidant Stress Responses in Premature Infants during Exposure to Hyperoxia

To assess oxidant stress responses in newborn infants treated with elevated concentrations of oxygen, we measured plasma concentrations of glutathione (GSH) and glutathione disulfide (GSSG) in newborn infants ranging from 23 to 42 wk gestational age. All infants recruited into the study were mechanically ventilated and had catheters placed in their umbilical arteries as part of their normal clinical management. Blood samples were obtained on d 1, 3, and 5 and weekly thereafter or until the catheters were removed. We observed plasma concentrations of GSSG in these infants that were frequently an order of magnitude higher than the 0.1 to 0.3 microM we find in adults. Interestingly, plasma GSSG concentrations were inversely correlated to the inspired oxygen tensions. This effect appeared to arise from the patient selection criteria whereby, of the infants studied, those breathing the lowest partial pressures of oxygen were the smallest and gestationally youngest. A second observation was that plasma concentrations of GSH in the premature infants were substantially, indeed often dramatically, lower than we have observed in adult humans (6 to 10 microM). Finally, we found that in patients with both umbilical arterial and umbilical venous catheters arterial GSSG concentrations were consistently higher than venous concentrations; conversely, arterial GSH concentrations were lower than venous concentrations. The elevated GSSG concentrations we observed in these infants indicate marked oxidant stress responses in prematurely born infants, even in those infants exposed only to room air. The positive arteriovenous gradients of GSSG concentrations across the lungs of these infants suggest that at least some of the increased plasma GSSG originates in the lung.(ABSTRACT TRUNCATED AT 250 WORDS)

The physiological responses of premature infants to heelstick blood sampling

The physiological responses of premature infants to heelstick blood sampling

Neuromotor Behavior and Cardiorespiratory Responses of Premature Infants with Bronchopulmonary Dysplasia

Neuromotor behavior and cardiorespiratory changes in response to movement and handling in ten infants with braonchopulmonary dysplasia were compared to those of eleven health age-matched infants at sixteen weeks corrected age. Arm responses to midline stimuli, retention of infants reflexes and automatic reaction were scored bases on direct observation and analysis of videotapes recordings. Compared to the control infants, the infants with bronchopulmonary dysplasia performed less than half the arm midline activity, were less skilled in prone and had greater retention of infant reflexes. Muscle tone was similar in both groups. The infants with bronchopulmonary dysplasia weighted significantly less than the control infants and had signs of respiratory insufficiency, yet tolerated movement and handling with minimal cardiorespiratory changes. Implications of these preliminary results are discussed.

Developmental and prognostic study on cerebral evoked responses in premature infants

Developmental and prognostic study on cerebral evoked responses in premature infants

1255 LIPID INFUSION ENHANCES GLUCONEOGENESIS FROM AMINO ACIDS IN PREMATURE INFANTS

Glucose production in premature neonates depends upon available gluconeogenic substrates and intact enzymatic and hormonal systems. To determine whether lipid alone or in concert with amino acids alters glucoregulation, we determined the glycemic response from intravenous lipid in 8 premature infants (BW 1226 ± 100 g, GA 28.6±1.4 wks). At 4±2 days of age, we administered either Intralipid (L) alone (.25 g/kg over 20 min followed by .5 gm/kg/hr × 100 min) or an identical Intralipid dose plus amino acids (Aminosyn, .5 gm/kg over 4 hrs) (LA). All infants received concurrent glucose at 5-6 mg/kg/min throughout the study. Free fatty acid concentrations increased within 10 min of infusion and peak values were equivalent in L and LA infants (4345 vs 3100 μ Eq/L). LA infants demonstrated a brisk glycemic response compared to L infants (23±3 vs 7±2% increase at 10 min). In addition, LA infusion resulted in a far greater increase at 150 min compared to L (65±11 vs 30±7%). Preliminary data in infants receiving A alone suggest a limited glycemic response relative to L and LA infants. Insulin responded appropriately in L and LA infants increasing from 10 to 75 μU/ml in response to increasing glucose, while glucagon demonstrated no consistent pattern in either group. L infusion results in a mild glycemic response in premature infants, while LA administration more promptly increases glucose. These data suggest that lipids enhance gluconeogenesis from amino acids in premature infants.

Postnatal changes in erythropoietin levels in untransfused premature infants

The purpose of this study was to determine whether an inappropriately low erythropoietin response in premature infants might be a basis for the anemia of prematurity. Erythropoietin was measured by radioimmunoassay in conjunction with hemoglobin and reticulocyte count in untransfused premature infants between birth and 60 days of age. The 27 infants had a mean gestational age of 31 weeks and a mean birth weight of 1378 gm. Between 2 and 30 days, mean erythropoietin concentration was 9.7 mU/ml, significantly and substantially lower than 15.2 mU/ml in 15 concurrently studied healthy adults (P less than 0.01). Subsequently, from 30 to 60 days, values rose gradually to a mean of 17.2 mU/ml, which did not differ significantly from the mean value in adults. Hemoglobin values fell from a mean of 12.9 gm/dl during the first month to 9.0 gm/dl between 30 and 60 days. Thus, during the second postnatal month, preterm infants had essentially the same erythropoietin values as in adults despite a mean hemoglobin concentration that averaged less than two thirds the adult value. This failure to mount a greater erythropoietin response may help to explain why hemoglobin declines to such low values at 2 months of age.

Depressed phytohemagglutinin and concanavalin A responses in premature infants

Lymphocyte responses to phytohemagglutinin (PHA) and concanavalin A (Con A) were studied, using whole blood cultures, in 54 preterm infants weighing 800 to 2500 g, in 17 infants weighing > 2500 g, and in five small-for-dates weighing 520 to 1820 g. All samples studied were collected within 12 h after the delivery. Half of the infants weighing < 1000 g had abnormally low responses to PHA and Con A. The responsiveness increased with the increasing birth weight, being similar to that of the full-term newborns already in infants with a birth weight of 1251–1500 g. Seven of the low responders were studied again at the age of 4–13 days. All the responses were then normal, suggesting a role for immunosuppressive factors in the plasma.

Diminished Response to Carbon Dioxide in Premature Infants

Reduced ventilatory response to CO&lt;sub&gt;2&lt;/sub&gt; (less than 50 cm&lt;sup&gt;3&lt;/sup&gt;/min/mm Hg increase in minute ventilation) has been demonstrated in premature infants of 28–32 weeks postconceptional age. Diminished ventilatory response to CO&lt;sub&gt;2&lt;/sub&gt; may be due either to mechanical limitations on respiratory work or true loss of chemosensitivity. Although premature infants are neurologically immature they have been shown to have chemoreceptor activity for oxygen. They are also known to have stiff lungs and high total pulmonary resistance. The present study was undertaken to determine if mechanical or neurological factors limited CO&lt;sub&gt;2&lt;/sub&gt; response of premature infants. Adult patients have been shown to increase work during CO&lt;sub&gt;2&lt;/sub&gt; stimulation even though they do not increase minute ventilation as much as healthy subjects. Pulmonary work was therefore calculated from tracings of tidal volume and intraesophageal pressure during rebreathing of 5%CO&lt;sub&gt;2&lt;/sub&gt; – 40% O&lt;sub&gt;2&lt;/sub&gt; on 13 occasions in 12 infants. Evidence of CO&lt;sub&gt;2&lt;/sub&gt; sensitivity, demonstrated by increased respiratory work, was found in 5 of 7 infants who failed to increase minute volume in response to CO&lt;sub&gt;2&lt;/sub&gt;. Two infants increased neither minute volume nor respiratory work, suggesting true absence of chemoreceptor activity. Both mechanical and neurological factors may limit the response to CO&lt;sub&gt;2&lt;/sub&gt; in premature infants.

Brain stem auditory-evoked responses in premature infants.

Brain stem auditory-evoked responses were recorded in 24 infants ranging in age from six-weeks premature to term. At a given age, the latency of the response increased with decreasing stimulus intensity. Further, as age increased, there was a systematic decrease in latency of the response at each sound intensity level. The response was shown not to be fatigue or sleep stage. It may, therefore, be of use for evaluating auditory function in high-risk newborn infants.

REDUCED SENSITIVITY TO CO2 IN PREMATURE INFANTS

Reduced ventilatory response to CO2 (less than a 50cc/min/mmHg Pco2 increase in minute ventilation has been demonstrated in premature infants of 28-32 weeks post-conceptional age. Diminished ventilatory response to CO2 may be due to either mechanical limits on ventilatory work or true loss of CO2 sensitivity. Though premature infants are neurologically immature, they have been shown to possess chemoreceptor tone for oxygen. They also have small, stiff lungs and high total pulmonary resistance. The present study was undertaken to determine if mechanical or neurological factors limit the CO2 response of these infants. Adult patients with pulmonary disease have been shown to increase respiratory work during CO2 stimulation even though their minute volume fails to increase. Pulmonary work was therefore calculated from tracings of tidal volume and intraesophageal pressure during rebreathing of 5%CO2-40%O2 (Read, Austral.Ann.Med. 16:20 '67) on 13 occasions in 12 premature infants. Evidence of CO2 sensitivity, as demonstrated by increased respiratory work, was found in 5 of 7 infants whose ventilatory response to CO2 was less than 50cc/min/mmHg Pco2. Two infants showed no evidence of CO2 sensitivity by failing to increase either work or ventilation, suggesting true absence of chemoreceptor tone. Both neurological and mechanical factors may limit the CO2 response in premature infants, and may influence the course of hyaline membrane disease and the occurrence of “crib death” (SIDS).

The maturation and interrelationship of EEG patterns and auditory evoked responses in premature infants

In a longitudinal neonatal study, biweekly EEGs and summed auditory evoked responses (AERs) were recorded during sleep from 23 premature infants between the ages of 28 and 41 weeks post-conception. Seventy-eight EEG tracings were obtained and 60–74 min of each were visually analyzed. Each 20 sec epoch was classified into one of 6 EEG patterns according to specific criteria relating to amplitude, frequency, and persistence or intermittancy of activity. With increasing post-conceptional age, the relative and absolute occurrences of 3 patterns decreased and 2 patterns increased significantly in a general linear fashion. During each EEG session, 9–12 summed AERs to loud click stimuli were recorded from the vertex with combined ears as the reference electrode. The amplitude and latency of the N 1 and P 2 potentials were, in general, positively related to 3 intermittent, relatively immature EEG patterns, and negatively related to a high voltage continuous pattern, but significant relationships were noted mainly in subjects older than 34 weeks post-connection. Post-conceptional and gestational age but not post-natal age influenced the relationship between EEG patterns and AER measurements. The average regression coefficients between AER measurements and some EEG patterns were determined for every 2 week age period permitting a quantitative estimate of these relationships related to age post-conception. The intra-subject, intra-recording variability in amplitude and latency of 2 major waves of the neonatal AER recorded from premature infants was therefore related to two measurable variables, background EEG and age post-conception.

Developmental study of photic evoked responses in premature infants

Developmental study of photic evoked responses in premature infants

Light-evoked cortical and retinal responses in premature infants.

Recordings of cortical and retinal responses to a series of light flashes were obtained from 50 premature infants and a smaller number of newborns and older infants and children. Data revealed a gradual evolution of the cortical-evoked response with advancing age. The electroretinogram, recorded simultaneously, remained essentially unchanged.

Internal anal sphincter. Observations on development and mechanism of inhibitory responses in premature infants and children with Hirschprung's disease.

Internal anal sphincter. Observations on development and mechanism of inhibitory responses in premature infants and children with Hirschprung's disease.