Premature monochorionic monoamniotic twins have lower lung compliance at birth than matched dichorionic diamniotic twins

BACKGROUND: Premature infants are born with immature lungs that demonstrate abnormal pulmonary function with differences in passive respiratory system compliance and resistance, and functional residual capacity. To our knowledge, no studies have evaluated differences in neonatal pulmonary function based on the type of twin gestation, or chorionicity. Given the effect of chorionicity on outcomes, we aimed to study the effect of twin type, monochorionic monoamniotic (MCMA) vs dichorionic diamniotic (DCDA), on neonatal early pulmonary function tests. METHODS: In this prospective cohort study, 5 sets of DCDA twins were matched to 5 sets of MCMA twins on gestational age at delivery, latency from antenatal corticosteroid exposure, birthweight, race and gender. Mean values were compared for passive respiratory system compliance and resistance, functional residual capacity, and tidal volume. RESULTS: MCMA infants had a significantly lower compliance (0.64 vs 1.25 mL/cm H2O /kg; p = 0.0001) and significantly higher resistance (0.130 vs 0.087 cm H2O /mL/sec; p = 0.0003) than DCDA infants. Functional residual capacity was lower for MCMA than DCDA infants (17.5 vs 23.4 mL/kg; p = 0.17). Further, 80% of MCMA infants required intubation for surfactant administration compared to 20% of DCDA infants, indicating the clinical significance of these objective measures. CONCLUSIONS: Due to the matched case-control design, causality cannot be established. However, we speculate that these differences in lung function may derive from differential exposure to preterm labor and endogenous maternal corticosteroid exposure. Further study is necessary to establish the true causal relationship.

Breast cancer early detection and diagnostic capacity in Uganda

BACKGROUND

Greater than 80% of women presenting for breast cancer treatment in Uganda have late-stage disease, which is attributable to a dysfunctional referral system and a lack of recognition of the early signs and symptoms among primary health care providers, and compounded by the poor infrastructure and inadequate human capacity. Improving the breast health care system requires a systemic approach beginning with situational analysis to identify systematic gaps that prevent sustainable improvements in outcome.

METHODS

The authors performed a situational analysis of the breast health care system using methods developed by the Breast Health Global Initiative. Based on their findings, they developed a series of recommendations for strengthening the health system for the early diagnosis of breast cancer based on clinical detection, referral, tissue sampling, and diagnosis.

RESULTS

Deficits in the recognition of breast cancer signs and symptoms, the underuse of clinical breast examination as a diagnostic and/or screening tool, the centralization of diagnostic tests (radiology and pathology), reliance on excisional biopsies rather than needle biopsies, and a lack of trained professionals and knowledge of the referral system all contribute to significant health system delays.

CONCLUSIONS

To strengthen referral networks and improve the early diagnosis of breast cancer in Uganda, national referral hospitals should provide educational programs to primary health care providers in community health centers (CHCs), at which the majority of women first present with symptoms. At secondary district-level facilities in which imaging and tissue sampling can be performed, the capacity for diagnostic testing could be increased through task shifting of basic interpretation (abnormal vs normal) from specialists to nonspecialists using networking technology to facilitate remote oversight from specialists at the national referral hospitals.

End-tidal carbon dioxide in critically ill patients during changes in mechanical ventilation

Values of end-tidal CO2 (PETCO2) approximate PaCO2 in spontaneous breathing normal subjects and in stable patients receiving mechanical ventilatory support (MVS). Because marked inequality of ventilation/perfusion ratios in critically ill patients might affect this correlation, we assessed changes of PETCO2 in predicting changes in PaCO2 (delta PaCO2) and changes in minute ventilation (delta Ve) in this patient population. Twenty consecutive intubated patients 38 to 89 yr of age (mean, 70 yr) with respiratory failure while receiving MVS with indwelling arterial lines were studied. Settings on the mechanical ventilator were varied for frequency and tidal volume, and after a minimum of 5 to 10 min equilibration, PaCO2 and PETCO2 were measured. Vt and Ve were recorded from the digital indicator of the pneumotachygraph within the mechanical ventilator and corrected for compression volume in the respirator circuit. A total of 116 simultaneous measurements were performed. PETCO2 correlated well with PaCO2 (r = 0.78, p less than 0.001). The 95% confidence interval for the mean difference in PaCO2-PETCO2 was 4.0 +/- 0.97 mm Hg. However, delta PETCO2 (measured from baseline) did not correlate as well with delta PaCO2 (r = 0.58, p = less than 0.001). In four patients, the trend in their PETCO2 during changes in mechanical ventilation were in the opposite direction from the trend in their PaCO2. Thus, many critically ill patients, who cannto be preidentified, have an inconstant PaCO2-PETCO2 gradient with changes of ventilation. Utilization of PETCO2 as a noninvasive monitoring substitute for trends in PaCO2 in critically ill patients may be misleading despite establishing an initial PaCO2-PETCO2 relationship.