Positional effects on lung mechanics of ventilated preterm infants with acute and chronic lung disease

BACKGROUND

The role of prone position in preterm infants has not been completely clarified. We investigated prone versus supine posture-related changes in respiratory system resistance (Rrs) and reactance (Xrs) measured by the Forced Oscillation Technique (FOT) in mechanically ventilated preterm newborns.

METHODS

Patients were studied in the supine versus prone positions in random order. Oxygen saturation, transcutaneous partial pressure of oxygen (ptcO2 ), carbon dioxide (ptcCO2 ), Rrs and Xrs were measured in each position.

RESULTS

Nine patients with respiratory distress syndrome (RDS) and nine with evolving broncho-pulmonary dysplasia (BPD) were studied. Rrs was, on average, 9.8 (1.3, 18.3 as 95%CI) cmH2 O*s/l lower in the prone compared to the supine position (P = 0.02), while no differences in Xrs, ptcO2 , ptcCO2 , and breathing pattern were observed between postures. Only patients with evolving BPD showed a significant reduction of Rrs from 69.0 ± 27.4 to 53.0 ± 16.7 cmH2 O*s/l, P = 0.01. No significant correlations were found between changes in lung mechanics and ptcO2 , ptcCO2 , or breathing pattern.

CONCLUSIONS

On short-term basis, prone positioning does not offer significant advantages in lung mechanics in mechanically ventilated infants with RDS, while it is associated with lower Rrs values in patients with evolving BPD.

[Therapy with high-flow nasal prongs in preterm infants]

Despite of improved survival of premature infants, the incidence of long-term pulmonary complications, mostly associated with ventilation-induced lung injury, remains high. Non invasive ventilation (NIV) is able to reduce the adverse effects of mechanical ventilation. Although nasal continuous positive airway pressure (NCPAP) is an effective mode of NIV, traumatic nasal complications and intolerance of the nasal interface are common. Recently high flow nasal cannula (HFNC) is emerging as an efficient, better tolerated form of NIV, allowing better access to the baby's face, which may improve nursing, feeding and bonding. The aim of this review is to discuss the available evidence of effectiveness and safety of HFNC in preterm newborns with respiratory distress syndrome (RDS). It is known that distending pressure generated by HFNC increases with increasing flow rate and decreasing infant size and varies according to the amount of leaks by nose and mouth. The effects of HFNC on lung mechanics, its clinical efficacy and safety are still insufficiently investigated. In conclusion, there is a growing evidence of the feasibility of HFNC as an alternative mode of NIV. However, further larger randomized trials are required, before being able to recommend HFNC in the treatment of moderate respiratory distress of preterm infants.

Diagnosis of BPH and treatment of LUTS among GPs: a European survey

AIMS OF THE STUDY

This survey was conducted in France, Germany, Italy, Spain and UK, with the aim to assess diagnosis and therapy of BPH patients in clinical practice.

METHODS USED TO CONDUCT THE STUDY

A selected cohort of 455 general practitioners (GPs) in Europe were asked to report information on BPH patients with lower urinary tract symptoms (LUTS), including patient characteristics, diagnostic procedures, severity of illness, symptoms duration and underlying conditions. The GPs provided data relating to 886 patients.

RESULTS OF THE STUDY

The diagnostic work-up included description of symptoms (74.9-85.1%), rectal examination (55.4-82.1%) and the determination of PSA (79.1-94.7%). Transrectal sonography was popular in Italy and France (51.1% and 55.9%, respectively), less so in Germany (15.3%) and Spain (13.1%) and not at all in the UK (2.3%). At diagnosis, the most common symptom was nocturia (71-88%), followed by frequency (15-79%), urgency (43-68%) and weak stream (47-64%). The most common combination was the triad nocturia-frequency-feeling of incomplete emptying (22-31%). The mean ± SD LUTS severity score was similar in all countries: The main aim of treatment was the resolution of nocturia, which had an average score that reflected an important need (> 3.5) closely followed by frequency (3.3-3.9).

CONCLUSIONS DRAWN FROM THE STUDY AND CLINICAL IMPLICATIONS

This survey has shown that the most common LUTS is nocturia. Analyses of the symptoms' pattern revealed that the most common combination appears to be the triad nocturia-frequency-feeling of incomplete emptying. An association between LUTS and heart disease, diabetes and hypertension suggests that the pharmacological treatment should be devoid of effects on the cardiovascular system. With alpha blockers as first line treatment of LUTS, respondents were more concerned with hypotensive episodes resulting in falls, rather than about other typical side effects (e.g. ejaculation disorders and lowered libido). The survey highlights educational needs in diagnostics.