Table 3.

Continuous respiratory rate, effort and blood pressure data analysis and outcome studies

Investigators (respiratory rate)	Study N Site(s)	Inclusion criteria	Results/conclusions
Hofstetter et al.96	33 Single center	23 0/7−27 6/7 weeks	Apnea/hypopnea, bradycardia and hypoxemia episodes decreased with age, but continued at term equivalent, and even after hospital discharge. Infection increased apnea/hypopnea and hypoxemia events.
Fairchild et al.42	1211 Single center	<35 weeks	Number and duration of apnea events decreased with increasing gestational age. ABD events has higher frequency in <31 weeks infants but not increased in infants with severe ROP, BPD and severe IVH after adjusting for GA. ABD events increased before the diagnosis of LOS and NEC.
Tabacaru et al.99	302 Single center	<32 weeks	Intermittent caffeine boluses and discontinuation at 33 weeks PMA were associated with small changes in ABD events.
Patel et al.43	1211 Single center	<35 weeks	Periodic breathing (PB) increases with gestational age and the highest amount was between 30−33 weeks and 2 weeks chronological age. Extreme PB is associated with infection, NEC, caffeine discontinuation and immunizations.
Warburton et al.4	94 Single center	<36 weeks	Tachypnea (RR > 70) is associated with poor growth and respiratory support escalation. >30% tachypnea/day is associated with increased respiratory support in subsequent 3 days.
Mohr et al.95	70 Single center	All infants in the NICU	For 32 weeks gestation infants, PB peaked 7−14 days after birth (6.5%). Infant with death (SIDS) had 40% PB each day and her twin had 15% PB each day.
Investigators (blood pressure)	Study N Site(s)	Inclusion criteria	Results/conclusions
Goldstein et al.117	191 Single center	<1500 g	Metabolic acidosis and respiratory acidosis are related to adverse cognitive, motor and neurologic outcome at 6 months of age, while only metabolic component is related to adverse outcomes at 24 months of age.
Miall-Allen et al.119	33 Single center	<31 weeks	Hypotension (<30 mmHg) for over an hour was associated with IVH, ischemic cerebral lesions and death (within 48 h).
Miall-Allen et al.139	22 Single center	<31 weeks	No association was found between blood pressure fluctuation and IVH in first 36 h of life.
Low et al.122	98 Single center	<34 weeks	Combination of hypotension and hypoxemia in first 96 h of life significantly increased the risk of brain damage and poor outcomes.
Cunningham et al.100	232 Single center	<1500 g	IVH was associated with low or variable BP. PVL and ROP were not associated with BP. BP variability was associated with death.
Bada et al.120	100 Single center	<1500 g	Infants with periventricular IVH had a greater minute to minute BP variability compared to infants with no periventricular IVH.
Perlman et al.140	50 Single center	<1500 g	Fluctuating cerebral blood-flow velocity in infants with RDS increases the risk of IVH.
Soul et al.141	90 Two centers	<1500 g	Cerebral pressure passivity is associated with gestational age and low birth weight, systemic hypotension and maternal hemodynamic factors.
Dacosta et al.142	44 Single center	23 0/7−26 6/7 weeks	Defining the MAP with strongest cerebrovascular activity is feasible and deviations in that increased the risk of IVH and death.
Semenova et al.143	25 Single center	<32 weeks	Normal well-being is associated with nonlinear association between EEG and BP. Presence of weak association with distinctive directionality of information flow is associated with increased mortality.
Hoffman et al.136	61 Single center	23 0/7−28 6/7 weeks	More time with impaired cerebral autoregulation and less time with cerebral reactivity was associated with grade 3-4 IVH.

ABD apnea bradycardia desaturation, BPD bronchopulmonary dysplasia, ROP retinopathy of prematurity, IVH intraventricular hemorrhage, LOS late onset sepsis, NEC necrotizing enterocolitis, GA gestational age, PMA post menstrual age, MAP mean arterial pressure, EEG electroencephalogram, RDS respiratory distress syndrome, PVL periventricular leukomalacia, SIDS sudden infant death syndrome