Clinical features of late-onset circulatory dysfunction in premature infants

Figures & data

Figure 1 Relationship between incidence of LCD and gestational age at birth.

Note: The incidence of LCD was inversely correlated with gestational age at birth, except for at 22 and 23 weeks, and was highest at 24 weeks (14/58, 24.1%).

Table 1 Incidence of LCD according to institution

Institution	Number of infants	Infants with LCD	Incidence (%)
A	203	36	17.7
B	208	16	7.7
C	138	7	5.1
D	127	1	0.8
E	85	2	2.4
F	109	0	0.0
G	48	10	20.8
H	29	1	3.4
I	57	0	0.0
Total	1,004	73	7.3

Notes: The incidence of LCD differed significantly among the 9 institutions (P<0.0001).

Abbreviation: LCD, late-onset circulatory dysfunction of premature infants.

Table 2 Clinical characteristics of the LCD and control groups

Clinical features	LCD (n=73)	Control (n=73)	P
Birth-related factors
Gestational age^#	26 w 3 d (~24 w 4 d–28 w 6 d)	26 w 5 d (~25 w 1 d–29 w 2 d)	0.43
Birth weight (g)^#	850 (~668.5–1,067)	852 (~728–1,100)	0.24
Outborn	1	6	0.12
C-section	61	48	0.013
Male:female	38:35	38:35	1
Light-for-date	14	12	0.67
APGAR score (1 minute)^#	3 (~2–6)	4 (~2–7)	0.35
APGAR score (5 minutes)^#	6 (~4–8)	7 (~5–9)	0.09
Chorioamnionitis	36/67	26/68	0.07
Clinical data on the day before LCD diagnosis
Body weight/birth weight ratio	1.00±0.19	1.00±0.18	0.83
Water intake (mL/kg/day)	119.5±41.7	127.4±61.7	0.37
Heart rate (beats/min)	158.7±11.5	151.9±10.3	0.0002
Na <130 mEq/L	24/66	3/39	0.001
K >5.5 mEq/L	13/65	2/39	0.037
Blood glucose (mg/dL)	104.3±42.3	99.2±35.4	0.52
Respiratory status at LCD diagnosis
Spontaneous respiration (room air)	7	12	0.22
Spontaneous respiration (O2 supplementation)	6	17	0.0125
Respiratory support	60	44	0.0034
n-CPAP	24	17	0.2
IMV	16	20	0.44
HFOV	20	7	0.0056
Deterioration of respiratory status <24 hours before diagnosis	36	6	<0.0001
Medication
Perinatal
Prenatal steroid treatment	27	22	0.38
Postnatal steroid infusion before LCD diagnosis	13	9	0.35
<day 7	8	8	1.00
≧day 7	7	1	0.027
Indometacin for symptomatic PDA	15	22	0.18
At LCD diagnosis
Diuretics	14	5	0.027
Theophylline and/or caffeine	54	45	0.011
Doxapram	10	15	0.27
Steroid inhalation	3	2	0.65
Oral Na supplementation	27	27	1
Complications
Respiratory distress syndrome	56	51	0.349
Pulmonary hemorrhage	5	2	0.25
IVH (grade III and IV)	8	4	0.23
O2 requirement (days)^#	64 (~45–88.5)	61 (~26.5–79.5)	0.13
O2 dependence at 28 days of age	66	54	0.009
O2 dependence at 36 weeks of post conceptional age	36	28	0.21
PVL	14	4	0.012
ROP	33	23	0.1
Died	1	1	1

Notes: Data in the LCD at the time of LCD diagnosis were compared with data in the control group at the same age.

# median (interquartile range).

Abbreviations: C-section, cesarean section; HFOV, high-frequency oscillatory ventilation; HOT, home oxygen therapy; IMV, intermittent mandatory ventilation; IVH, intraventricular hemorrhage; LCD, late-onset circulatory dysfunction of premature infants; n-CPAP, nasal continuous positive airway pressure; PDA, patent ductus arteriosus; PVL, periventricular leukomalacia; ROP, retinopathy of prematurity; w, weeks; d, days.

Table 3 ACTH and cortisol concentrations at LCD diagnosis

LCD	Age at LCD diagnosis (days)	Gestational age at birth	Birth weight (g)	ACTH (pg/mL)	Cortisol (μg/dL)
1	23	24 w 2 d	826	11	12.8
2	5	25 w 0 d	753	13.3	8.8
3	7	25 w 3 d	595	20.9	4.4
4	6	25 w 3 d	733	13.5	5.9
5	23	25 w 4 d	1,028	83	9.8
6	16	26 w 3 d	982	36.8	6.9
7	37	26 w 5 d	850	150	6.5
8	19	29 w 6 d	1,306	61	7.1
9	15	30 w 0 d	904	nd	5.4
10	10	30 w 5 d	1,352	35.6	5.1
11	5	30 w 6 d	1,130	63.3	5.6

Abbreviations: ACTH, adrenocorticotropic hormone; LCD, late-onset circulatory dysfunction of premature infants; nd, no data; w, weeks; d, days.

Table 4 Multivariate logistic regression analysis of clinical characteristics

Clinical features (outcome: LCD)	Regression coefficient	Odds ratio (95% CI)	P
Outborn	0.280	1.749 (0.075–18.152)	0.663
C-section	0.724	4.252 (1.301–15.597)	0.021
Gestational age at birth	0.195	5.973 (0.305–137.129)	0.247
Apgar score (5 minutes)	0.087	1.191 (0.450–3.166)	0.724
Chorioamnionitis	0.511	2.781 (1.075–7.592)	0.039
O2 dependence at 28 days old	−0.170	0.711 (0.115–4.355)	0.711
Deterioration of respiratory status <24 hours before diagnosis	1.218	11.433 (3.871–40.559)	<0.0001
PVL	0.756	4.536 (1.137–21.927)	0.042
ROP	0.047	1.098 (0.396–3.015)	0.855
Postnatal steroid infusion before LCD diagnosis (≧day 7)	0.631	3.529 (0.355–83.760)	0.328
Respiratory support	0.597	3.298 (0.815–15.278)	0.105
Diuretics at onset	0.506	2.752 (0.722–11.949)	0.152
Theophylline or caffeine at onset	0.258	1.675 (0.646–4.490)	0.294

Abbreviations: C-section, cesarean section; CI, confidence interval; LCD, late-onset circulatory dysfunction of premature infants; PVL, periventricular leukomalacia; ROP, retinopathy of prematurity.