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Article Excerpt
Intraventricular hemorrhage (IVH) remains a significant problem for pre-term infants, potentially leading to increased length of hospital stay, overall long-term health care costs, long-term neurologic impairment, and decreased survival (Inder, Warfield, Wang, Huppi, & Volpe, 2005; Ward & Beachy, 2003). Early identification of infants at risk for IVH is therefore needed to reduce costs (Chang, Lin, Lin, & Yeh, 2000) and long-term impairments (Vohr, O'Shea, & Wright, 2003; Vollmer et al., 2003). The purpose of this study was to investigate heart rate variability (HRV) as a tool for early identification of infants at risk for IVH by comparing normative changes in HRV (obtained by spectral analysis) to that of one infant diagnosed with IVH.
Management begins in the perinatal period, with the prevention of pre-term birth, birth asphyxia, and birth trauma. Prompt resuscitation at birth minimizes hypoxemia and hypercarbia, which can alter cerebral autoregulation during the initiation of an intraventricular or periventricular bleed (Blackburn, 1998; Bassan et al., 2006). Activities that increase intracranial pressure or cause wide swings in pressure are minimized in the first 72 hours of life--if possible. Specific interventions to reduce or prevent the risk of increased pressure include avoiding hypoxic events, rapid alterations in cerebral blood flow, and systemic blood pressure. These include positioning the head in the midline and with the head of the bed elevated; avoiding tight bands around the head; avoiding rapid infusion for volume expansion; frequent monitoring of blood pressure; suctioning of the endotracheal tube only when needed; maintaining the infant within the neutral thermal range; avoiding interventions that cause crying, such as frequent venipunctures; excessive manipulation or handling; using analgesics for stressful procedures; and avoiding interventions that cause hypoxia (Blackburn, 1998). Early initiations of such measures, however, require identification of increased intracranial pressure.
More than 90% of infants with increased intracranial pressure secondary to IVH are identified by head ultrasound within the first 72 hours after birth, with 50% identified during the first 24 hours after birth (Blackburn, 1998). However, because the signs and symptoms of IVH vary widely and are sometimes subtle, a referral for head ultrasound frequently does not occur until after a catastrophic bleed has been identified. Volpe (1987) has described three clinical syndromes: silent, catastrophic, and saltatory (Blackburn, 1998). Most infants are at the silent end of this continuum, where there are no clinical signs. The catastrophic syndrome involves major hemorrhages that evolve rapidly over minutes to hours. Clinical findings include stupor progressing to coma, and respiratory distress progressing to apnea, seizures, decerebrate posturing, fixation of pupils, and flaccid quadriparesis. This is associated with a decreasing hematocrit, bulging anterior fontanelle, hypotension, bradycardia, and hypoglycemia. The saltatory pattern is associated with small hemorrhages that develop over hours to days. Signs and symptoms are subtle and irregular. Some clinical signs may include hypotonia, abnormal eye movements or positions, and an unexplained decrease...
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