Heated humidified high-flow nasal cannula versus low-flow nasal cannula as weaning mode from nasal CPAP in infants ≤28 weeks of gestation

Despite the paucity of evidence, the practice of weaning nasal continuous positive airway pressure (NCPAP) is widespread. However, the most clinically effective non-invasive ventilatory support strategy remains to be determined. We compared the outcome of very premature infants with respiratory distress syndrome treated with a combination of NCPAP and heated humidified high-flow nasal cannula (HHFNC) versus NCPAP and low-flow nasal cannula (LFNC). Between 2004 and 2008, patients ≤28 weeks of gestation and <1,250 g of birth weight were treated with NCPAP + HHFNC or NCPAP + LFNC. Their respiratory and non-respiratory outcome including cost-effectiveness was compared after matching for antenatal steroid doses, mode of delivery, birth plurality, gestational age, birth weight, gender, surfactant doses, length of mechanical ventilation and clinical risk index for babies-II (CRIB-II) score. Thirty-nine infants received HHFNC + NCPAP, and 40 received NCPAP + LFNC. Median gestational age and birth weight were 27 weeks and 930 g and 27 weeks and 980 g, respectively. The total number of NCPAP days was significantly reduced by 50 % in the HHFNC group. Thirteen percent of the patients on NCPAP suffered from nasal bridge lesions compared to none on HHFNC. Respiratory and non-respiratory outcome was not significantly different otherwise. Combination of NCPAP and HHFNC reduced costs by 33 %. Conclusions: HHFNC shortens NCPAP time without increasing overall length of non-invasive respiratory support in very preterm infants. Unlike NCPAP, HHFNC does not seem to increase the risk of nasal trauma and appears to improve cost-effectiveness whilst producing otherwise equal respiratory and non-respiratory outcomes.     

Mice lacking ghrelin receptors resist the development of diet-induced obesity

Ghrelin is the endogenous ligand for the growth hormone secretagogue receptor (GHSR; ghrelin receptor). Since its discovery, accumulating evidence has suggested that ghrelin may play a role in signaling and reversing states of energy insufficiency. For example, ghrelin levels rise following food deprivation, and ghrelin administration stimulates feeding and increases body weight and adiposity. However, recent loss-of-function studies have raised questions regarding the physiological significance of ghrelin in regulating these processes. Here, we present results of a study using a novel GHSR-null mouse model, in which ghrelin administration fails to acutely stimulate food intake or activate arcuate nucleus neurons. We show that when fed a high-fat diet, both female and male GHSR-null mice eat less food, store less of their consumed calories, preferentially utilize fat as an energy substrate, and accumulate less body weight and adiposity than control mice. Similar effects on body weight and adiposity were also observed in female, but not male, GHSR-null mice fed standard chow. GHSR deletion also affected locomotor activity and levels of glycemia. These findings support the hypothesis that ghrelin-responsive pathways are an important component of coordinated body weight control. Moreover, our data suggest that ghrelin signaling is required for development of the full phenotype of diet-induced obesity.     

Comparison between men and women admitted to an inpatient rehabilitation unit after cardiac surgery

OBJECTIVE: To determine whether there are differences in several factors between men and women who undergo inpatient post-cardiac surgery rehabilitation. DESIGN: A retrospective chart review. Information was collected on a variety of factors: age; previous myocardial infarction; number of days from surgery to admission to rehabilitation; postsurgery, prerehabilitation complications; length of stay on the rehabilitation unit; living arrangements before surgery; disposition; and postdischarge recommendations. SETTING: Community hospital rehabilitation unit associated with a university hospital. PATIENTS: One hundred thirty-eight patients (54 men, 84 women) admitted to an inpatient rehabilitation unit after cardiac surgery. RESULTS: There was a significant relationship between sex and preadmission living arrangements; 56% of women lived alone versus 26% of men (p < .01). There was a statistically significant difference in length of stay on the rehabilitation unit (p < .02). Men stayed longer, with a median stay of 16 days (95% confidence interval, 15 to 20) versus 15 days for women (95% confidence interval, 14 to 15). Ninety-three percent of men were discharged from rehabilitation at 30 days versus 98% of women. No relationship was noted between men and women in age, previous myocardial infarction, number of days from surgery to rehabilitation admission, length of stay on the rehabilitation unit, postsurgery-prerehabilitation complications, complications on the rehabilitation unit, presurgery living arrangements, disposition, and postdischarge therapy recommendations. CONCLUSION: Men and women showed comparable courses after cardiac surgery. Before surgery, women lived alone more frequently than men.     

Evaluation of pulse oximetry as a continuous monitoring technique in the neonatal intensive care unit

We tested a number of pulse oximeters in a neonatal ICU to assess their performance as continuous monitors. Using a computer-based data acquisition system and a movement sensor, we determined the proportion of time that the oximeter was unreliable as the duration of monitored time that the oximeter heart rate (HR) differed from a "true" HR by greater than 10 beat/min using each of the oximeters in both their short and long averaging mode. The tested devices were found to be unreliable for 11.9% to 25% in the short averaging mode, and from 13.8% to 29% in the longer averaging mode. Most of the HR discrepancy was secondary to movement of the extremity. A newer model of one of the devices, which uses ECG R-wave detection to trigger optical pulse scanning, was associated with markedly reduced motion artifact (2.1% to 4.1%) when it accurately interpreted HR. The response of the devices to an acute loss of pulsation revealed differences in design and performance with some oximeters indicating zero saturation and others continuing to display a value while indicating a "low quality signal." Pulse oximeters are a valuable adjunct to clinical oxygen monitoring and, when properly applied and reliably indicating the infant's HR, will accurately reflect arterial saturation (r = .8, p less than .0001). ECG synchronization appears to reduce motion artifact when the ECG R-wave is detected.