Oxygen saturation and breathing patterns in preterm infants with cyanotic episodes

Samuels, M. P.; Poets, CF; Stebbens, V A; Alexander, J. R.; Southall, D P

doi:10.1111/j.1651-2227.1992.tb12127.x

Cited by 18 publications

(10 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This decrease in body oxygen stores, in conjunction with the observed increase in total body oxygen consumption and increased total body oxygen extraction, may, as we argue below, be a key predisposing factor in the onset of rapidly developing cyanosis during feeding. The cyclic pattern of Sa,Oµ desaturation and resaturation, coupled with a sustained decrease in Sv,Oµ during feeding, closely resembles the pattern of Sa,Oµ and Sv,Oµ observed during repetitive apnoea (Fletcher et al 1989;Poets & Southall, 1991;Samuels, Poets, Stebbens, Alexander & Southall, 1992;Poets, Stebbens, Samuels & Southall, 1993;Wilkinson et al 1995 Total body oxygen consumption (ýOµ) increased during the nonsucking periods of feeding and remained elevated into the recovery period (P û 0·05). Systemic oxygen transport (SOT) was unchanged while total body oxygen extraction (TBOE) increased significantly (P û 0·05).…”

Section: Discussionsupporting

confidence: 64%

Oxygen Transport and Utilization during Feeding in the Young Lamb

Grant¹,

Fewell²,

Walker³

et al. 1997

The Journal of Physiology

View full text Add to dashboard Cite

Five lambs (19–27 days old) were studied to determine the effects of feeding on cardiorespiratory function. Each lamb was instrumented to record cardiac output, aortic and pulmonary artery pressure and arterial and mixed venous oxyhaemoglobin saturations (Sa,O2 and Sv,O2). During feeding, arterial haemoglobin desaturated and resaturated sequentially during the periods of sucking and non‐sucking. The nadir of these Sa,O2 desaturations (83 ± 2%, mean ±s.e.m.) was significantly lower than the baseline value (92 ± 2%, P≤ 0.05, ANOVA). Sa,O2 returned to the baseline level between periods of sucking. Sv,O2 also decreased (55 ± 3% baseline, 46 ± 3% sucking, P≤ 0.05) but, in contrast to Sa,O2, it remained significantly lower than baseline levels in the pauses between periods of sucking. Arterial pressure increased during feeding (94 ± 4 mmHg baseline, 113 ± 6 mmHg feeding, P≤ 0.05), while heart rate and cardiac index did not change. Total body oxygen consumption rose during the pauses between sucking periods (10.9 ± 1.1 ml O2 min−1 kg−1 baseline, 13.9 ± 1.2 ml O2 min−1 kg−1 non‐sucking, P≤ 0.05) and was provided for by a significant increase in total body oxygen extraction as systemic oxygen transport was unchanged. Our results reveal that during feeding in young lambs oxygen consumption increases and body stores of oxygen (e.g. Sv,O2) become depleted; this combination may promote rapid arterial desaturation and cyanosis during feeding.

show abstract

Section: Discussionsupporting

confidence: 64%

Oxygen Transport and Utilization during Feeding in the Young Lamb

Grant¹,

Fewell²,

Walker³

et al. 1997

The Journal of Physiology

View full text Add to dashboard Cite

show abstract

“…3). Such episodes have been observed in preterm infants with recurrent cyanotic episodes of unknown cause [25], in term infants with respiratory tract infections [26], and also in asymptomatic pre term infants [27]. In the first group, measure ments of the slope of desaturation during epi sodes with continued ventilation showed that hypoxaemia progressed 2-3 times faster than during isolated apnoeic pauses in the same infant [25].…”

Section: Pathophysiology Of Apnoea and Hypoxaemia In Preterm Infantsmentioning

confidence: 98%

“…Such episodes have been observed in preterm infants with recurrent cyanotic episodes of unknown cause [25], in term infants with respiratory tract infections [26], and also in asymptomatic pre term infants [27]. In the first group, measure ments of the slope of desaturation during epi sodes with continued ventilation showed that hypoxaemia progressed 2-3 times faster than during isolated apnoeic pauses in the same infant [25]. This latter observation makes it extremely unlikely that the desaturations de spite continuous breathing were solely due to hypoventilation; they are more likely to result from a sudden intrapulmonary shunt [22], Non-apnoeic mechanisms contributing to apnoea-induced hypoxaemia have also been demonstrated during periodic apnoea in pre term infants.…”

Section: Pathophysiology Of Apnoea and Hypoxaemia In Preterm Infantsmentioning

confidence: 99%

Epidemiology and Pathophysiology of Apnoea of Prematurity

1994

View full text Add to dashboard Cite

In preterm infants, reliance on the detection of apnoeic pauses and/or bradycardia results in significant amounts of hypoxaemia remaining undetected. In addition, recordings of breathing movements and ECG do not have predictive value for subsequent sudden infant death. In recent years, the ability to continuously monitor and record arterial oxygen saturation (SaO₂) has produced important information regarding the mechanisms for respiratory events in the preterm population. Normal data on SaO₂ (Nellcor N-200) and breathing movements have been collected in 160 preterm infants. Median baseline SaO₂ during regular breathing was 99.5% (range 88.7-100) at the time of discharge from SCBU and 100% (95.3–100) at follow-up 6 weeks later. Episodic desaturations (SaO₂ < 80% for ≥4s) ranged between 0 and 355 episodes per 12-hour recording. In a study of a separate group of 16 preterm infants with recurrent cyanotic episodes of unknown cause, the total number of abnormal hypoxaemic episodes was markedly increased. These hypoxaemic episodes were associated with three breathing pattern: (i) absent breathing movements; (ii) continued breathing movements, but absent airflow, and (iii) continuous airflow and breathing movements. Thus, preterm infants with cyanotic episodes have an increased number of clinically unapparent hypoxaemic episodes, some of which occur with continued breathing and airflow. In another study of 79 patients who had been born preterm and had a history of an apparent life-threatening event, 43 (54%) had abnormal oxygenation on multichannel recordings, including 23% with clinically undetected baseline hypoxaemia. Continuous additional inspired oxygen was given to 27 patients with recorded abnormalities in oxygenation and a history of recurrent ALTE needing cardiopulmonary resuscitation: in 25, episodes stopped or markedly reduced in frequency. Home PO₂ monitoring has been undertaken in 73 patients for a median duration of 7.1 months. Recognition and treatment of abnormalities in episodic or baseline hypoxaemia may reduce the risk for recurrent cyanotic episodes or subsequent apparent life-threatening events at home. In infants with a history of such episodes, the use of additional inspired oxygen and home PO₂ monitoring are helpful in management. The finding of abnormal hypoxaemia may be relevant to the increased risk of sudden death found in preterm infants.

show abstract

“…These events, usually termed 'apnoea', become less clinically apparent by 36 weeks postmenstrual age (PMA) although a degree of apnoea persists to discharge [2][3][4]. For a small proportion of infants, persistent apnoea may delay hospital discharge usually because of concerns regarding associated cyanosis or the need for resuscitation [5].…”

Section: Introductionmentioning

confidence: 98%