C. Heath Gauss

The effects of hypercapnia on cerebral autoregulation in ventilated very low birth weight infants.

Permissive hypercapnia, a strategy allowing high Paco2, is widely used by neonatologists to minimize lung damage in ventilated very low birth weight (VLBW) infants. While hypercapnia increases cerebral blood flow (CBF), its effects on cerebral autoregulation of VLBW infants are unknown. Monitoring of mean CBF velocity (mCBFv), Paco2, and mean arterial blood pressure (MABP) from 43 ventilated VLBW infants during the first week of life was performed during and after 117 tracheal suctioning procedures. Autoregulation status was determined during tracheal suctioning because it perturbs cerebral and systemic hemodynamics. The slope of the relationship between mCBFv and MABP was estimated when Paco2 was fixed at 30, 35, 40, 45, 50, 55, and 60 mm Hg. A slope near or equal to 0 suggests intact autoregulation, i.e. CBF is not influenced by MABP. Increasing values >0 indicate progressively impaired autoregulation. Infants weighed 905 ± 259 g and were 26.9 ± 2.3 wk gestation. The autoregulatory slope increased as Paco2 increased from 30 to 60 mm Hg. While the slopes for Paco2 values of 30 to 40 mm Hg were not statistically different from 0, slopes for Paco2 ≥45 mm Hg indicated a progressive loss of cerebral autoregulation. The autoregulatory slope increases with increasing Paco2, suggesting the cerebral circulation becomes progressively pressure passive with hypercapnia. These data raise concerns regarding the use of permissive hypercapnia in ventilated VLBW infants during the first week of life, as impaired autoregulation during this period may be associated with increased vulnerability to brain injury.

Parental Recognition of Overweight in School-age Children

Objective: Examine the accuracy of parental weight perceptions of overweight children before and after the implementation of childhood obesity legislation that included BMI screening and feedback.

Changes in School Environments With Implementation of Arkansas Act 1220 of 2003

Changes in school nutrition and physical activity policies and environments are important to combat childhood obesity. Arkansas Act 1220 of 2003 was among the first and most comprehensive statewide legislative initiatives to combat childhood obesity through school‐based change. Annual surveys of principals and superintendents have been analyzed to document substantial and important changes in school environments, policies, and practices. For example, results indicate that schools are more likely to require that healthy options be provided for student parties (4.5% in 2004, 36.9% in 2008; P ≤ 0.0001) and concession stands (1.6% in 2004, 19.6% in 2008; P ≤ 0.0001), ban commercial advertising by food or beverage companies (31.7% in 2005, 42.6% in 2008; P ≤ 0.0001), and offer skim milk options for students in cafeterias (white milk: 26.1% in 2004, 41.0% in 2008, P ≤ 0.0001; chocolate milk: 9.0% in 2004, 24.0% in 2008, P ≤ 0.0001). They are less likely to have vending machines available during the lunch period (72.3% in 2004, 37.2% in 2008; P ≤ 0.0001) and to include sodas in vending machines (83.8% in 2004, 73.5% in 2008; P ≤ 0.0001). Other changes were noted in foods and beverages offered in the cafeteria, in classrooms, and at school events, as well as in fund‐raising and physical activity practices. A significant number of school districts have modified physical education requirements for elementary schools and developed policies prohibiting the use of physical activity as a punishment. We conclude that Arkansas Act 1220 of 2003 is associated with a number of changes in school environments and policies, resulting from both statewide and local initiatives spawned by the Act.

Impact of a smoke-free hospital campus policy on employee and consumer behavior.

Objective. Although smoke-free hospital campuses can provide a strong health message and protect patients, they are few in number due to employee retention and public relations concerns. We evaluated the effects of implementing a clean air policy on employee attitudes, recruitment, and retention; hospital utilization; and consumer satisfaction in 2003 through 2005. Methods. We conducted research at a university hospital campus with supplemental data from an affiliated hospital campus. Our evaluation included (1) measurement of employee attitudes during the year before and year after policy implementation using a cross-sectional, anonymous survey; (2) focus group discussions held with supervisors and security personnel; and (3) key informant interviews conducted with administrators. Secondary analysis included review of employment records and exit interviews, and monitoring of hospital utilization and patient satisfaction data. Results. Employee attitudes toward the policy were supportive (83.3%) at both institutions and increased significantly (89.8%) at post-test at the university hospital campus. Qualitatively, administrator and supervisor attitudes were similarly favorable. There was no evidence on either campus of an increase in employee separations or a decrease in new hiring after the policy was implemented. On neither campus was there a change in bed occupancy or mean daily census. Standard measures of consumer satisfaction were also unchanged at both sites. Conclusion. A campus-wide smoke-free policy had no detrimental effect on measures of employee or consumer attitudes or behaviors.

Cerebral blood flow velocities in extremely low birth weight infants with hypotension and infants with normal blood pressure.

OBJECTIVE To determine whether extremely low birth weight (ELBW) infants with hypotension have similar cerebral hemodynamics when compared with control subjects with normal blood pressure. We hypothesized that ELBW infants with low or normal blood pressure have similar cerebral blood flow (CBF) velocity. STUDY DESIGN In this case control study, CBF velocity (with Doppler ultrasound scanning), PCO2, and mean arterial blood pressure (MABP) were continuously monitored twice daily before intensive care procedures. If an infant became hypotensive (MABP < or = gestational age in weeks), additional monitoring was performed for 10 to 20 minutes, before treatment with dopamine. Thirty ELBW infants were enrolled (637 +/- 140 g, 24.2 +/- 1.1 weeks); 15 had hypotension, and 15 were gestational age/birth weight-matched control subjects with normal blood pressure. CBF velocity was compared by use of the Mann-Whitney U test. RESULTS The groups did not differ significantly in gestational age, birth weight, race, sex, PCO2, Apgar scores, or occurrence of severe intraventricular hemorrhage. There was no difference in mean CBF velocity (P = .934) in infants with hypotension (MABP: 23 [20-24.9] mm Hg) compared with infants with normal blood pressure (MABP: 32.6 [27.5-35.7] mm Hg). CONCLUSION Despite having hypotension, ELBW infants (before treatment) had similar CBF velocity compared with control subjects with normal blood pressure. On the basis of these results, hypotension may not indicate decreased CBF.

Evaluating the Effect of Hospital and Insurance Type on the Risk of 1-Year Mortality of Very Low Birth Weight Infants: Controlling for Selection Bias

Objectives:We examined the effect of hospital type and medical coverage on the risk of 1-year mortality of very low birth weight (VLBW) infants while adjusting for possible selection bias. Methods:The study population was limited to singleton live birth infants having birth weight between 500 and 1500 g with no congenital anomalies who were born in Arkansas hospitals between 2001 and 2007. Propensity score (PS) matching and PS covariate adjustment were used to mitigate selection bias. In addition, a conventional multivariable logistic regression model was used for comparison purposes. Results:Generally, all 3 analytical approaches provided consistent results in terms of the estimated relative risk, absolute risk reduction, and the number needed to treat. Using the PS matching method, VLBW infants delivered at a hospital with a neonatal intensive care unit (NICU) were associated with a 35% relative decrease (95% bootstrap confidence interval, 18.5%–48.9%) in the risk of 1-year mortality as compared with those infants delivered at non-NICU hospitals. Furthermore, our results showed that on average, 16 VLBW infants (95% bootstrap confidence interval, 11–32), would need to be delivered at a hospital with an NICU to prevent 1 additional death at 1 year. However, there was not a difference in the risk of 1-year mortality between VLBW infants born to Medicaid-insured versus non–Medicaid-insured women. Conclusions:Estimated relative risk of infant mortality was significantly lower for births that occurred in hospitals with an NICU; therefore, greater efforts should be made to deliver VLBW neonates in an NICU hospital.

The Diastolic Closing Margin Is Associated with Intraventricular Hemorrhage in Premature Infants.

Premature infants are at an increased risk of intraventricular hemorrhage (IVH). The roles of hypotension and hyperemia are still debated. Critical closing pressure (CrCP) is the arterial blood pressure (ABP) at which cerebral blood flow (CBF) ceases. When diastolic ABP is equal to CrCP, CBF occurs only during systole. The difference between diastolic ABP and CrCP is the diastolic closing margin (DCM). We hypothesized that a low DCM was associated with IVH. One hundred eighty-six premature infants, with a gestational age (GA) range of 23-33 weeks, were monitored with umbilical artery catheters and transcranial Doppler insonation of middle cerebral artery flow velocity for 1-h sessions over the first week of life. CrCP was calculated linearly and using an impedance model. A multivariate generalized linear regression model was used to determine associations with severe IVH (grades 3-4). An elevated DCM by either method was associated with IVH (p < 0.0001 for the linear method; p < 0.001 for the impedance model). Lower 5-min Apgar scores, elevated mean CBF velocity, and lower mean ABP were also associated with IVH (p < 0.0001). Elevated DCM, not low DCM, was associated with severe IVH in this cohort.

Reach and Adoption of a Randomized Weight Loss Maintenance Trial in Rural African Americans of Faith: The WORD (Wholeness, Oneness, Righteousness, Deliverance)

Purpose: There is minimal information regarding the Reach and Adoption of evidence-based weight loss maintenance interventions for African Americans of faith. Design: The WORD (Wholeness, Oneness, Righteousness, Deliverance) was an 18-month, cluster randomized trial designed to reduce and maintain weight loss in African American adults of faith. Participants received the Diabetes Prevention Program adapted core weight loss program for 6 months, and churches were subsequently randomized to 12-month maintenance treatment or control. All participants underwent body weight and associated behavioral and psychosocial assessments at baseline, 6, 12, and 18 months. The current article focuses on assessing Reach and Adoption at baseline and 6 months using the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework. Setting: Lower Mississippi Delta. Participants: Thirty churches, 61 WORD Leaders (WLs), and 426 participants. Intervention: Group delivered by trained community members (WLs). Measures: Body mass index and percentage weight lost from baseline to 6-month follow-up were measured. Reach was assessed at participant, WL, and church levels through calculating participation rates and sociodemographics of each level. Adoption was assessed at church and WL levels. Analysis: Descriptive statistics summarized baseline characteristics of each level. Continuous and categorical end point comparisons were made. Results: Participants’ participation rate was 0.84 (n = 437 agreed to participate, n = 519 eligible invited to participate); they were predominantly female, employed, and had a mean age of 49.8. Dropouts by 6 months were younger, had differential marital status, and religious attendance compared with retained participants. Church participation rate was 0.63 (n = 30 enrolled, n = 48 eligible approached) and the majority reported ≤100 active members. The WL participation rate was 0.61 (n = 61 implemented intervention, n = 100 eligible approached); they were primarily female and aged 53.9 (mean). Conclusion: Recruitment, engagement, and delivery strategies employed by the WORD show promise of sustained engagement and adoption in other faith-based behavioral weight management programs for African Americans.

CBF velocity in newborns 23–24 weeks' gestation during the first week of life

Objective: The aim of this prospective observational trial was to generate reference values of middle cerebral artery cerebral blood flow velocity (CBFv) in normotensive, ventilated newborn survivors born at 23–24 weeks’ gestation during the first week (with normal cranial ultrasounds during the hospitalization), and to analyze how reference values may be affected by PCO2. Methods: Baseline systolic, diastolic, and mean CBFv were determined for 12 infants born at 23–24 weeks’ gestation (birth weight 643± 68 g) using transcranial Doppler ultrasound during several monitoring sessions during the first week, prior to intensive care procedures. Mean and 95% CI reference curves were generated using a locally weighted regression technique. Results: Mean CBFv increased from ∼10 to 21 cm/sec, and when baseline PCO2 was adjusted to 40, 50, and 60 mmHg, increased from ∼8.5 to 9, ∼12.5 to 16, and ∼16.5 to 23 cm/sec during the first week, respectively. Conclusion: Reference curves for middle cerebral artery CBFv for normotensive ventilated newborns born at 23–24 weeks’ gestation (with normal cranial ultrasounds) are presented for the first time. Since PCO2 is a potent regulator of CBF, when reporting cerebral hemodynamic values in the future, investigators must also report PCO2.