Impact of intrauterine growth restriction on cerebral and renal oxygenation and perfusion during the first 3 days after birth.

Intrauterine growth restriction (IUGR) is associated with a higher incidence of perinatal complications as well as cardiovascular and renal diseases later on. A better insight into the disease mechanisms underlying these sequalae is important in order to identify which IUGR infants are at a higher risk and find strategies to improve their outcome. In this prospective case-control study we examined whether IUGR had any effect on renal and cerebral perfusion and oxygen saturation in term neonates. We integrated near-infrared spectroscopy (NIRS), echocardiographic, Doppler and renal function data of 105 IUGR infants and 105 age/gender-matched controls. Cerebral and renal regional oxygen saturation values were measured by NIRS during the first 12 h after birth. Echocardiography alongside Doppler assessment of renal and anterior cerebral arteries were performed at 6, 24, 48 and 72 h of age. Glomerular and tubular functions were also assessed. We found a left ventricular dysfunction together with a higher cerebral oxygen saturation and perfusion values in the IUGR group. IUGR term infants showed a higher renal oxygen saturation and a reduced oxygen extraction together with a subclinical renal damage, as indicated by higher values of urinary neutrophil gelatinase-associated lipocalin and microalbumin. These data suggest that some of the haemodynamic changes present in growth-restricted foetuses may persist postnatally. The increased cerebral oxygenation may suggest an impaired transition to normal autoregulation as a consequence of intra-uterine chronic hypoxia. The higher renal oxygenation may reflect a reduced renal oxygen consumption due to a subclinical kidney damage.

Auditory cortex hypoperfusion: a metabolic hallmark in Beta Thalassemia.

BACKGROUND: Sensorineural hearing loss in beta-thalassemia is common and it is generally associated with iron chelation therapy. However, data are scarce, especially on adult populations, and a possible involvement of the central auditory areas has not been investigated yet. We performed a multicenter cross-sectional audiological and single-center 3Tesla brain perfusion MRI study enrolling 77 transfusion-dependent/non transfusion-dependent adult patients and 56 healthy controls. Pure tone audiometry, demographics, clinical/laboratory and cognitive functioning data were recorded. RESULTS: Half of patients (52%) presented with high-frequency hearing deficit, with overt hypoacusia (Pure Tone Average (PTA) > 25 dB) in 35%, irrespective of iron chelation or clinical phenotype. Bilateral voxel clusters of significant relative hypoperfusion were found in the auditory cortex of beta-thalassemia patients, regardless of clinical phenotype. In controls and transfusion-dependent (but not in non-transfusion-dependent) patients, the relative auditory cortex perfusion values increased linearly with age (p < 0.04). Relative auditory cortex perfusion values showed a significant U-shaped correlation with PTA values among hearing loss patients, and a linear correlation with the full scale intelligence quotient (right side p = 0.01, left side p = 0.02) with its domain related to communication skills (right side p = 0.04, left side p = 0.07) in controls but not in beta-thalassemia patients. Audiometric test results did not correlate to cognitive test scores in any subgroup. CONCLUSIONS: In conclusion, primary auditory cortex perfusion changes are a metabolic hallmark of adult beta-thalassemia, thus suggesting complex remodeling of the hearing function, that occurs regardless of chelation therapy and before clinically manifest hearing loss. The cognitive impact of perfusion changes is intriguing but requires further investigations.

Continuous glucose monitoring profile during therapeutic hypothermia in encephalopathic infants with unfavorable outcome.

BACKGROUND: The relation between glucose homeostasis and outcome in hypoxic-ischemic encephalopathy (HIE) is unclear. To investigate whether glucose abnormalities assessed by using continuous interstitial glucose monitoring (CGM) correlate with later neurological outcomes in HIE. METHODS: Prospective cohort study recruiting full-term neonates who received therapeutic hypothermia for HIE. CGM devices were placed soon after birth and recorded glucose profile for 3 days. The association between hypoglycemia (≤50 mg/dL), hyperglycemia (>144 mg/dL) and primary outcome defined as death or moderate or severe disability was examined with generalized estimating equations adjusted for Apgar scores, umbilical artery pH and base deficit. Neurodevelopmental outcome was assessed between 18 and 24 months. RESULTS: Fifty-four neonates had outcome data available for the analysis; 19 of them (35%) had adverse outcome. Longer duration of hypoglycemia (OR 7.1, 95% CI 1.8-20.3, P < 0.001) and hyperglycemia (OR 5.4, 95% CI 1.6-15.7, P < 0.001), a greater area under the hypoglycemic (OR 2.6, 95% CI 1.4-4.6, P = 0.04) and hyperglycemic (OR 6.4, 95% CI 1.9-16.3, P < 0.001) curve were significantly associated with adverse outcomes. CONCLUSION: Both hyper and hypoglycemia may be associated with adverse outcome in neonates with HIE. Future studies are needed to assess their prognostic association with neurological outcome. IMPACT: Glucose abnormalities during therapeutic hypothermia are associated with later neurological outcomes.Increased glucose variability correlates to the neurological outcome between 18 and 24 months.This study provides the first data on the continuous glucose profile in a group of HIE infants followed up to 2 years of age.Glucose homeostasis represents a key point in the management of HIE patients.Further research is needed to find the appropriate glycemic target in this population.