Factors associated with the use of supplemental oxygen or positive pressure ventilation in the delivery room,in infants born with a gestational age ≥ 34 weeks

Background

Approximately 5–10 % of newborns require some form of resuscitationupon delivery; several factors, such as maternal abnormal conditions, gestational age and type of delivery could be responsible for this trend. This study aimed to describe the factors associated with the need for positive pressure ventilation (PPV) via a mask or endotracheal tube and the use of supplemental O2 in newborns with a gestational age greater than 34 weeks in Brazil.

Methods

We performed a cross-sectional study and obtained data from the Birth in Brazil Survey. The inclusion criterion was a gestational age ≥34 weeks. Exclusion criteria were newborns with congenital malformations, and cases with undetermined gestational age or type of delivery (vaginal, pre labor cesarean section and cesarean section during labor). The primary outcomes were need of PPV via a mask or endotracheal tube and the use of supplemental oxygen without PPV. Confounding variables, including maternal age, source of birth payment, years of maternal schooling, previous birth, newborn presentation, multiple pregnancy, and maternal obstetric risk, were analyzed.

Results

We included 22,720 newborns. Of these, 2974 (13.1 %) required supplementary oxygen. PPV with a bag and mask was used for 727 (3.2 %) newborns and tracheal intubation for 192 (0.8 %) newborns. Chest compression was necessary for 136 (0.6 %) newborns and drugs administered in 114 (0.5 %). 51.3 % of newborns were delivered by cesarean section, with the majority of cesarean sections (88.7 %) being performed prior to labor. Gestational age (late preterm infants: (Relative Risk-(RR) 2.46; 95 % (Confidence interval-CI 1.79–3.39), maternal obstetric risk (RR 1.59; 95 % CI1.30–1.94), and maternal age of 12–19 years old (RR 1.36; 95 % CI1.06–1.74) contributed to rates of PPV in the logistic regression analysis. Newborns aged between 37–38 weeks of gestaional age weren´t less likely to require PPV compared with those aged 39–41 weeks of gestational age.

Conclusions

Late preterm infants, previous maternal obstetric risks and maternal age contributed to the higher needs of PPV and use of O2 in the delivery room. These variables need to be considered in planning care in the delivery room.

     

Hypercapnia modulates cAMP signalling and cystic fibrosis transmembrane conductance regulator‐dependent anion and fluid secretion in airway epithelia

Key points

• Raised arterial blood CO₂ (hypercapnia) is a feature of many lung diseases.
• CO₂ has been shown to act as a cell signalling molecule in human cells, notably by influencing the levels of cell signalling second messengers: cAMP and Ca²⁺.
• Hypercapnia reduced cAMP‐stimulated cystic fibrosis transmembrane conductance regulator‐dependent anion and fluid transport in Calu‐3 cells and primary human airway epithelia but did not affect cAMP‐regulated HCO₃ ⁻ transport via pendrin or Na⁺/HCO₃ ⁻ cotransporters.
• These results further support the role of CO₂ as a cell signalling molecule and suggests CO₂‐induced reductions in airway anion and fluid transport may impair innate defence mechanisms of the lungs.

Abstract

Hypercapnia is clinically defined as an arterial blood partial pressure of CO₂ of above 40 mmHg and is a feature of chronic lung disease. In previous studies we have demonstrated that hypercapnia modulates agonist‐stimulated cAMP levels through effects on transmembrane adenylyl cyclase activity. In the airways, cAMP is known to regulate cystic fibrosis transmembrane conductance regulator (CFTR)‐mediated anion and fluid secretion, which contributes to airway surface liquid homeostasis. The aim of the current work was to investigate if hypercapnia could modulate cAMP‐regulated ion and fluid transport in human airway epithelial cells. We found that acute exposure to hypercapnia significantly reduced forskolin‐stimulated elevations in intracellular cAMP as well as both adenosine‐ and forskolin‐stimulated increases in CFTR‐dependent transepithelial short‐circuit current, in polarised cultures of Calu‐3 human airway cells. This CO₂‐induced reduction in anion secretion was not due to a decrease in HCO₃ ⁻ transport given that neither a change in CFTR‐dependent HCO₃ ⁻ efflux nor Na⁺/HCO₃ ⁻ cotransporter‐dependent HCO₃ ⁻ influx were CO₂‐sensitive. Hypercapnia also reduced the volume of forskolin‐stimulated fluid secretion over 24 h, yet had no effect on the HCO₃ ⁻ content of the secreted fluid. Our data reveal that hypercapnia reduces CFTR‐dependent, electrogenic Cl⁻ and fluid secretion, but not CFTR‐dependent HCO₃ ⁻ secretion, which highlights a differential sensitivity of Cl⁻ and HCO₃ ⁻ transporters to raised CO₂ in Calu‐3 cells. Hypercapnia also reduced forskolin‐stimulated CFTR‐dependent anion secretion in primary human airway epithelia. Based on current models of airways biology, a reduction in fluid secretion, associated with hypercapnia, would be predicted to have important consequences for airways hydration and the innate defence mechanisms of the lungs.     

Use of central venous catheter-related bloodstream infection prevention practices by US hospitals

OBJECTIVE: To examine the extent to which US acute care hospitals have adopted recommended practices to prevent central venous catheter-related bloodstream infections (CR-BSIs). PARTICIPANTS AND METHODS: Between March 16, 2005, and August 1, 2005, a survey of infection control coordinators was conducted at a national random sample of nonfederal hospitals with an intensive care unit and more than 50 hospital beds (n=600) and at all Department of Veterans Affairs (VA) medical centers (n=119). Primary outcomes were regular use of 5 specific practices and a composite approach for preventing CR-BSIs. RESULTS: The overall survey response rate was 72% (n=516). A higher percentage of VA compared to non-VA hospitals reported using maximal sterile barrier precautions (84% vs 71%; P=.01); chlorhexidine gluconate for insertion site antisepsis (91% vs 69%; P<.001); and a composite approach (62% vs 44%; P=.003) combining concurrent use of maximal sterile barrier precautions, chlorhexidine gluconate, and avoidance of routine central line changes. Those hospitals having a higher safety culture score, having a certified infection control professional, and participating in an infection prevention collaborative were more likely to use CR-BSI prevention practices. CONCLUSION: Most US hospitals are using maximal sterile barrier precautions and chlorhexidine gluconate, 2 of the most strongly recommended practices to prevent CR-BSIs. However, fewer than half of non-VA US hospitals reported concurrent use of maximal sterile barrier precautions, chlorhexidine gluconate, and avoidance of routine central line changes. Wider use of CR-BSI prevention practices by hospitals could be encouraged by fostering a culture of safety, participating in infection prevention collaboratives, and promoting infection control professional certification.