The Ultrasonographic Changes of Intercostal Muscles and Diaphragm in Mechanically Ventilated Preterm Neonates

Abstract Background Although mechanical ventilation is a lifesaving treatment, abundant evidence indicates that its prolonged use (one week or more) promotes respiratory muscle weakness due to both contractile dysfunction and atrophy. Along with the diaphragm, the intercostal muscles are one of the most important groups of respiratory muscles. In recent years, muscular ultrasound has become a useful bedside tool for the clinician to identify patients with respiratory muscle dysfunction related to critical illness and/or invasive mechanical ventilation. Objective To assess the impact of mechanical ventilation on diaphragm and intercostal muscles using ultrasonography in preterm neonates. Patients and Methods This observational prospective study was conducted at Neonatal Intensive Care Unit (NICU), Children's Hospital Ain Shams University over 6 months from October 2022 to April 2023, It included 60 preterm neonates, divided into two groups; 30 cases of respiratory distress syndrome (RDS) who were on mechanical ventilation for one week or less and 30 preterm infants of matched age and gender who didn’t require respiratory support. Results A total of 60 premature neonates participated in the study. Among them, 30 neonates required mechanical ventilation, whereas the other group consisted of 30 spontaneously breathing neonates of matched age and gender. The mean gestational age of both groups was 33 weeks, there was no statistical significant difference between our two groups as regards weight and gestational age. The relation between the right and left diaphragmatic thickness fraction (DTF) and parasternal intercostals muscle thickness fraction (TFiC) in the ventilated group in day 1 and day 3 was of non significance (p-value = 0.089 in left TFiC, p-value = 0.554 in right DTF), while the relation between them from day 1 to day 5 was significantly decreasing (p-value = 0.019 in left TFiC, p-value = 0.008 in left DTF), demonstrating the relation between the duration of ventilation and muscle function and that prolonged ventilation has a great impact on diaphragmatic effort and amplitude, on the other hand the control group measurements were significantly increasing at both right and left diaphragmatic and intercostals muscle fraction from day 1 to day 5 (p-value = 0.001 in left TFiC, p-value = 0.020 in left DTF). Conclusion Musculoskeletal ultrasound can detect early diaphragm and intercostals muscle atrophy that was observed in most of the patients treated by invasive mechanical ventilation.