The Definition of Acute Perinatal Asphyxia

Carter, Brian S.; Haverkamp, Albert D.; Merenstein, Gerald B.

doi:10.1016/s0095-5108(18)30394-4

Cited by 116 publications

(67 citation statements)

References 57 publications

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“…MA 71 (11) 77 (15) 77 (14) 77 (15) 80 (11) 79 (9) 70 (9) 64 (7) (13) 69 (5) 77 (6) 83 (10) 75 (9) 63 (3) 59 (8) 53 (12) Control 68 (13) 73 (11) 75 (14) 77 (13) 77 (15) 73 (14) 71 (13) 68 (14) 63 (17) Blood glucose concentrations were similar in all groups throughout the experiment, except a momentary increase (ϩ27% at 1 h) after the asphyxic meconium insult (data not shown).…”

Section: Resultsmentioning

confidence: 99%

Asphyxia Aggravates Systemic Hypotension But Not Pulmonary Hypertension in Piglets with Meconium Aspiration

et al. 2003

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Meconium aspiration and birth asphyxia are both separately connected to significant pulmonary and systemic hemodynamic changes in newborns, but, although these insults frequently coexist, their combined effects on the neonatal circulation are still controversial. To determine the pulmonary and systemic circulatory changes induced by pulmonary meconium contamination with concurrent asphyxia, 41 anesthetized and ventilated newborn piglets (10 -12 d) were studied for 6 h. Eleven piglets were instilled with a bolus of human meconium intratracheally, and 10 piglets had meconium instillation with immediate induction of an asphyxic insult. Eight piglets had only asphyxia and 12 ventilated piglets served as controls. Meconium instillation (with and without asphyxia) resulted in a sustained decrease in the oxygenation, which remained, however, on the control level in the asphyxic group. Although meconium insufflation (with and without asphyxia) increased pulmonary artery pressure and vascular resistance progressively during the study period, the meconium-induced hypertensive effect was actually diminished by additional asphyxia. Asphyxia alone did not have any effect on these pulmonary hemodynamic parameters. On the other hand, whereas systemic arterial pressure and vascular resistance remained on the control level after meconium instillation alone, asphyxia (with and without pulmonary meconium insult) resulted in a sustained fall in systemic pressure already by 4 h. Our data thus indicate that although the coexisting asphyxia seems to moderate the meconium aspiration-induced pulmonary hypertensive response, this additional asphyxic insult does not affect the associated hypoxemia, but rather significantly exacerbates systemic hypotension. Abbreviations CO, cardiac output CVP, central venous pressure HR, heart rate MABP, mean arterial blood pressure MAS, meconium aspiration syndrome MPAP, mean pulmonary artery pressure PVR, pulmonary vascular resistance PWP, pulmonary wedge pressure SVR, systemic vascular resistance Aspiration of meconium-stained amniotic fluid frequently produces a severe respiratory failure in term and postterm infants. The clinical MAS has high morbidity and mortality, often linked with the presence of pulmonary hypertension (1-5). The pathophysiology and predisposing factors of the pulmonary hypertensive reaction in MAS are, however, complex and poorly defined. Although abnormal pulmonary arteriolar hypertrophy resulting from intrauterine hypoxia is supposed to play an etiologic role in some fatal cases of hypertensive MAS (6), experimental data indicate that acute intrapulmonary meconium contamination per se is able to cause, in a concentration-dependent manner, progressive pulmonary hypertensive response (2, 7). Alike, there are clinical data suggesting that meconium aspiration and its associated complications, rather than the structural vascular changes, are primarily responsible for the elevated pulmonary vasomotor tone and hypoxemic respiratory failure in newborns (8, 9). Because eventual disturb...

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Section: Resultsmentioning

confidence: 99%

Asphyxia Aggravates Systemic Hypotension But Not Pulmonary Hypertension in Piglets with Meconium Aspiration

et al. 2003

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“…Electronic fetal monitoring of heart rate patterns in labor or the traditional signs of fetal distress have not proved to predict long-term neurological outcome 4 . The same has been observed by meconial fluid analysis, Apgar scores, excess pH and base measurements, and other specific markers of systemic lesions, many of which are still only available in experimental or clinical research centers [5][6][7][8][9][10] . There are also limitations with later indicators of brain injury, such as electroencephalography (EEG), polysomnography, evoked potential, blood flow studies, and neuroimaging, because not all these techniques are widely available, and it is not clear how specific they are for PA or to what extent they reflect primary as opposed to downstream pathology 11 .…”

Section: Introductionmentioning

confidence: 64%

Compensatory rebound of body movements during sleep, after asphyxia in neonatal rats

Suarez

Hoshino

2008

Acta Cir. Bras.

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Purpose:The usefulness of body movements that occur during sleep when assessing perinatal asphyxia and predicting its longterm consequences is contradictory. This study investigated whether neonatal rats manifest these movements in compensatory rebound after asphyxia, and if these alterations play an important role in its pathogenesis. Methods: Eight neonatal rats (aged 6-48h) were implanted with small EMG and EKG electrodes and sleep movements were recorded over a 30-minute control period. Recordings were continued during asphyxia caused by the enclosure of the animal in a polyvinyl sheet for 60 minutes, followed by a 30-minute recovery period. Results: Heart rate was lowered to bradycardic level during asphyxia causing behavioral agitation and increased waking time during the initial phase (30 minutes). Sleep-related movements were also significantly reduced from 12.5 ± 0.5 (median ± SE/2min) to 9.0 ± 0.44 in the final half of the period (Anova, p<0.05). Movement frequency increased in the recovery period to 15.0 ± 0.49 (Anova, p<0.05). Conclusion: These data show that newborn rats present compensatory rebound of body movements during sleep which may help in the diagnosis of asphyxia and other problems related to sleep parameters. Key words: Sleep. Infant, Newborn. Asphyxia. Motor Activity. Rats. RESUMO Objetivo:A utilidade dos movimentos corporais (MC) que ocorrem durante o sono para diagnosticar e predizer as conseqüências, em longo prazo, da asfixia perinatal é contraditório. Este estudo investigou se ratos recém-nascidos (RN) manifestam MC em resposta compensatória à asfixia, e se estas alterações podem ter alguma importância na sua patogênese. Métodos: Oito ratos RN (6-48h de vida) foram submetidos à implantação de pequenos eletrodos para registros da eletromiografia e eletrocardiografia. Os MC e a freqüência cardíaca (FC) foram registrados durante períodos de 30 min: fase controle (F 1 ), fases de asfixia (F 2 ; F 3 ) e fase de recuperação pós-asfixia (F 4 ). A asfixia foi promovida pelo envolvimento completo do animal com uma lâmina de polivinil. Resultados: A FC diminuiu progressivamente durante F 2 e F 3 até a bradicardia. Em F 2 houve grande agitação dos animais e aumento dos períodos de vigília. Em F 3 houve redução significante dos MC de 12,5 ± 0,5 (Md ± SE/2min) para 9,0 ± 0,44 (P<0,05). A freqüência dos MC aumentou em F 4 para 15,0 ± 0,49. Conclusão: Estes dados mostram que ratos RN com asfixia apresentam MC compensatórios durante o sono que podem ajudar no diagnóstico desta afecção e de outros problemas relacionados aos parâmetros do sono. Descritores: Sono. Recém-Nascido. Asfixia. Atividade Motora. Ratos.

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“…Dentre eles o índice de Apgar (IA) que tem a finalidade de verificar de forma rápida o estado clínico do recém-nascido e identificar, aqueles que necessitam de assistência, para avaliar os riscos e prevenir seqüelas de uma provável asfixia. [5][6][7] Ele consta de cinco parâmetros estreitamente relacionados com hipóxia perinatal: a freqüência cardíaca, a respiração, o tônus muscular, a irritabilidade reflexa e a coloração da pele do recém-nascido. Numa escala de 0 a 10 se o seu valor for menor que sete, será diagnosticada hipóxia fetal.…”

Section: Resultsunclassified