RESUMO
Infants with bronchopulmonary dysplasia (BFD) often have difficulty achieving coordinated suckle feeding. To analyze rhythmic differences during feeding in infants with BPD we performed weekly studies of 14 infants with BPD (eight male, six female; postmenstrual age [PMA] 32.1 to 39.7 weeks); and a PMA-matched control group without BPD (n=20), from initiation of bottle feeding until discharge, with simultaneous digital recordings of pharyngeal and nipple (teat) pressure. Unlike the control group, there was no significant correlation between PMA and stability of suckle rhythm, aggregation of suckles or swallows into runs, or length of suckle runs. Comparing those infants >35 weeks' PMA, the group with BPD had significantly decreased stability of suckle rhythm (increased coefficient of variation of suckle-suckle intervals: 0.34, SE 0.02 vs 0.254, SE 0.014; p=0.003), decreased aggregation into suckle runs (71.1, SE 3.4% vs 85.4, SE 2%;p=0.001), and decreased length of suckle runs (7.2, SE 0.9 vs 13.1, SE 1.9 suckles/run; p=0.003). Percentage of swallows in runs was also decreased in the cohort with BPD (58, SE 3.8% vs 77.2, SE 3.5%; p<0.001), as was length of swallow run (5.3, SE 0.5 vs 10.7, SE 1.1;p<0.001). Thus, in infants with BPD, anticipated maturational patterns of suckle and swallow rhythms did not occur. Delay in attainment of stable suckle and swallow rhythms in preterm infants, especially after 35 weeks' PMA, may predict subsequent feeding and neurological problems.
Assuntos
Displasia Broncopulmonar/complicações , Transtornos de Deglutição/etiologia , Deglutição/fisiologia , Recém-Nascido Prematuro , Comportamento de Sucção , Estudos de Casos e Controles , Desenvolvimento Infantil , Feminino , Humanos , Recém-Nascido , Masculino , PrognósticoRESUMO
Twenty healthy preterm infants (gestational age 26 to 33 weeks, postmenstrual age [PMA] 32.1 to 39.6 weeks, postnatal age [PNA] 2.0 to 11.6 weeks) were studied weekly from initiation of bottle feeding until discharge, with simultaneous digital recordings of pharyngeal and nipple (teat) pressure and nasal thermistor and thoracic strain gauge readings. The percentage of sucks aggregated into 'runs' (defined as > or = 3 sucks with < or = 2 seconds between suck peaks) increased over time and correlated significantly with PMA (r=0.601, p<0.001). The length of the sucking-runs also correlated significantly with PMA (r=0.613, p<0.001). The stability of sucking rhythm, defined as a function of the mean/SD of the suck interval, was also directly correlated with increasing PMA (r=0.503, p=0.002), as was increasing suck rate (r=0.379, p<0.03). None of these measures was correlated with PNA. Similarly, increasing PMA, but not PNA, correlated with a higher percentage of swallows in runs (r=0.364, p<0.03). Stability of swallow rhythm did not change significantly from 32 to 40 weeks' PMA. In low-risk preterm infants, increasing PMA is correlated with a faster and more stable sucking rhythm and with increasing organization into longer suck and swallow runs. Stable swallow rhythm appears to be established earlier than suck rhythm. The fact that PMA is a better predictor than PNA of these patterns lends support to the concept that these patterns are innate rather than learned behaviors. Quantitative assessment of the stability of suck and swallow rhythms in preterm infants may allow prediction of subsequent feeding dysfunction as well as more general underlying neurological impairment. Knowledge of the normal ontogeny of the rhythms of suck and swallow may also enable us to differentiate immature (but normal) feeding patterns in preterm infants from dysmature (abnormal) patterns, allowing more appropriate intervention measures.
Assuntos
Recém-Nascido Prematuro , Comportamento de Sucção/fisiologia , Desenvolvimento Infantil , Deglutição/fisiologia , Transtornos de Deglutição , Feminino , Humanos , Lactente , Recém-Nascido , MasculinoRESUMO
OBJECTIVES: To assess the frequency and clinical significance of asystole (sinus arrest > or = 2.0 seconds) and the incidence of bradycardia in infants prescribed home cardiorespiratory monitors and to test the hypothesis that asystoles are more likely to occur in preterm infants. DESIGN: Prospective, consecutive sample of monitor printouts. METHODS: All 291 printouts from the memory monitors of 161 patients received during a 2-month period were analyzed. SETTING: University hospital providing primary and referral care. MAIN OUTCOME MEASURES: Asystoles and bradycardias; clinical course of patients with asystoles. RESULTS: Eight patients (5.0%) had 32 episodes of asystole lasting 2.0 to 4.3 seconds (group 1). Fifty-three patients (32.9%) had true bradycardia alarms but no asystoles (group 2). One hundred patients (62.1%) had neither asystoles nor bradycardias (group 3). Preterm infants constituted 88% of group 1 and 81% of group 2 but only 58% of group 3. Infants were more likely to be full-term in group 3 than in the other 2 groups (chi 2, P = .02). Birth weights were lower in group 1 than in group 3 (P < .05, 1-tailed t test). There were 479 true bradycardias; 72.2% lasted 10 seconds or less, 26.3% were longer than 10 seconds but no more than 20 seconds, and 1.5% were longer than 20 seconds. None of the 8 patients with asystoles required resuscitation for their asystoles; all survived and were free of any life-threatening events after their monitors were discontinued and up until their first birthday. CONCLUSIONS: Asystoles occur more commonly in preterm infants; those pauses in the 2.0- to 4.0-second range seem to be benign. Studies of long-term recordings are needed to redefine asystole in both normal preterm and fullterm infants. These data would help further refine current guidelines for pacemaker implantation during infancy.
Assuntos
Bradicardia/diagnóstico , Eletrocardiografia , Parada Cardíaca/diagnóstico , Serviços de Assistência Domiciliar , Recém-Nascido Prematuro , Peso ao Nascer , Bradicardia/etiologia , Idade Gestacional , Parada Cardíaca/etiologia , Humanos , Incidência , Lactente , Recém-Nascido , Monitorização Fisiológica , Estudos Prospectivos , Fatores de RiscoRESUMO
Pharyngeal swallows during infant suckle-feeding are associated with a characteristic sequence of sounds audible by stethoscope or by an accelerometer or microphone held over the larynx. In rhythmically feeding term-born neonates, the delineating acoustic elements are discrete sounds which precede and succeed pharyngeal swallows. Digital signal processing shows similarities in morphological detail between the discrete sounds preceding swallows and between those succeeding swallows; those succeeding swallows are more variable in temporal relation to swallows, amplitude and morphological detail. Variations in the pattern of interswallow respiration, including apnea, are correlated with variations in the discrete sounds. Specification of physiological correlates of these internal feeding sounds increases the utility of cervical auscultation as a method of investigation and of clinical observation of feeding.
Assuntos
Auscultação , Deglutição/fisiologia , Recém-Nascido/fisiologia , Espectrografia do Som , Comportamento de Sucção/fisiologia , Ingestão de Alimentos/fisiologia , Humanos , Monitorização Fisiológica , Pescoço , Sons Respiratórios , Processamento de Sinais Assistido por Computador , Gravação em FitaRESUMO
The authors recorded the sound signals during suckle feeding of six normal infants within the first two postnatal days. The sounds were recorded onto a cassette tape-recorder from a small microphone attached to the infant's neck, then displayed on an oscilloscope and analysed by digital signal processing techniques. These displays demonstrated acoustic patterns and temporal relationships which are not otherwise audible. The method and findings are described in detail, and the method should be useful in the clinical investigation of feeding and swallowing problems associated with more subtle neurological impairment and preterm birth.