Basal ganglia perfusion using dynamic color Doppler sonography in infants with hypoxic ischemic encephalopathy receiving therapeutic hypothermia: a pilot study.

BACKGROUND: The objective of this study was to evaluate the cerebral perfusion of the basal ganglia in infants with hypoxic-ischemic encephalopathy (HIE) receiving hypothermia using dynamic color Doppler sonography (CDS) and investigate for any correlation between these measurements and survival. METHODS: Head ultrasound (HUS) was performed with a 9S4 MHz sector transducer in HIE infants submitted to hypothermia as part of their routine care. Measurements of cerebral perfusion intensity (CPI) with an 11LW4 MHz linear array transducer were performed to obtain static images and DICOM color Doppler videos of the blood flow in the basal ganglia area. Clinical and radiological data were evaluated retrospectively. The video images were analyzed by two radiologists using dedicated software, which allows automatic quantification of color Doppler data from a region of interest (ROI) by dynamically assessing color pixels and flow velocity during the heart cycle. CPI is expressed in cm/sec and is calculated by multiplying the mean velocity of all pixels divided by the area of the ROI. Three videos of 3 seconds each were obtained of the ROI, in the coronal plane, and used to calculate the CPI. Data are presented as mean ± SEM or median (quartiles). RESULTS: A total of 28 infants were included in this study: 16 male, 12 female. HUS was performed within the first 48 hours of therapeutic hypothermia treatment. CPI values were significantly higher in the seven non-survivors when compared to survivors (0.226±0.221 vs. 0.111±0.082 cm/sec; P=0.02). CONCLUSIONS: Increased perfusion intensity of the basal ganglia area within the first 48 of therapeutic hypothermia treatment was associated with poor outcome in neonates with HIE.

Intestinal ultrasonography in infants with moderate or severe hypoxic-ischemic encephalopathy receiving hypothermia.

BACKGROUND: Infants with hypoxic-ischemic encephalopathy (HIE) may develop multiorgan dysfunction, but assessment of intestinal involvement is imprecise and based on nonspecific clinical signs that may occur several days later. Ultrasound imaging has been described as a helpful tool in assessing intestinal involvement in many gastrointestinal disorders. OBJECTIVE: Describe abdominal ultrasonography findings in infants receiving therapeutic hypothermia and investigate its association with the severity of the hypoxic-ischemic insult and death. MATERIALS AND METHODS: Studies were performed within the first 36 h of life to assess intestinal appearance (normal bowel, bowel wall echogenicity and thickness, and sloughed mucosa), free fluid, peristalsis and intramural perfusion. These findings were compared between infants with moderate and severe encephalopathy. Ultrasound findings were also categorized in three major groups and compared with markers of severity of the hypoxic-ischemic insult and with mortality. RESULTS: Nineteen infants with moderate and 9 with severe HIE at admission were studied (17.7 ± 9.5 h of life). Major ultrasonography findings were increased bowel wall echogenicity (78%), free fluid (75%), decreased or absent peristalsis (50%) and sloughing of the intestinal mucosa (21%). Abnormal intestinal findings such as increased bowel wall echogenicity in all quadrants and presence of sloughed mucosa were associated with more severe hypoxic-ischemic insult. All 12 patients with normal bowel appearance or increased bowel wall echogenicity restricted to only one quadrant survived, whereas 7/15 (47%) patients with increased bowel wall echogenicity in all four quadrants died during hospitalization. The presence of sloughed mucosa was associated with increased mortality (P < 0.001). CONCLUSION: In infants receiving therapeutic hypothermia, a high prevalence of intestinal involvement was noted by using ultrasonographic assessment. An association between intestinal findings and severity of hypoxic-ischemic insult was observed. The presence of sloughed mucosa is a potential ultrasonographic sign of severity.

Cooling in the real world: therapeutic hypothermia in hypoxic-ischemic encephalopathy.

BACKGROUND AND AIM: The benefits of therapeutic hypothermia have not been assessed from the perspective of the neurology clinic. We aimed to report the impact of the implementation of a local regional therapeutic hypothermia program on the neurodevelopmental outcomes of surviving hypoxic-ischemic encephalopathy (HIE) infants who were followed in the neonatal neurology clinic. METHODS: Retrospective analysis of term infants referred to the neonatal neurology clinic after having been diagnosed with HIE and meeting eligibility criteria for therapeutic hypothermia between March 1999 and June 2010. Therapeutic hypothermia was implemented in September 2008. Outcome measures were dichotomously defined as: normal or adverse, which included cerebral palsy, global developmental delay, and epilepsy. RESULTS: Thirty infants were included in the pre-therapeutic hypothermia group. Thirty-one infants received therapeutic hypothermia and 27 were adequately followed and included in the post-therapeutic hypothermia group. The frequency of an adverse outcome was significantly higher in the pre-therapeutic hypothermia infants (19/30 [63%] versus 4/27 [15%]; OR = 0.10; 95% CI, 0.03-0.37; P < 0.001). Neonatal clinical seizures were more frequent in the pre-therapeutic hypothermia group (P = 0.012). There were no differences regarding frequency of fetal distress, rate of caesarean sections, Apgar scores, need of resuscitation, cord/initial blood gases, and degrees of encephalopathy between the two groups. CONCLUSIONS: The implementation of a regional therapeutic hypothermia program in our institution has vastly reduced the observed neurological morbidity of surviving HIE infants followed in our neonatal neurology clinic. A similar change in outcomes of infants with HIE can be anticipated by other centers and other clinics adopting this therapy.