Outcome of Neonates with Meconium Aspiration Syndrome on High Frequency Oscillatory Ventilation in NICU of Tertiary Care Centre

Background: Meconium Aspiration Syndrome (MAS) is a complex respiratory disease of the term and near-term neonate. Inhalation of meconium causes airway obstruction, atelectasis, epithelial injury, surfactant inhibition and pulmonary hypertension, the chief clinical manifestations of which are hypoxemia and poor lung compliance. Supplemental oxygen is the mainstay of therapy of MAS, with around one-third of infants requiring mechanical ventilation. For those ventilated, high ventilator pressures, as well as relatively long inspiratory time and slow ventilatory rate, may be necessary to achieve adequate oxygenation. High frequency ventilation may offer a benefit in infants with refractory hypoxemia and/or gas trapping. High-frequency oscillatory ventilation (HFOV) is a lung-protective strategy that can be utilized in the full spectrum of patient populations ranging from neonatal to adults with acute lung injury. HFOV uses low tidal volumes and constant mean airway pressures in conjunction with high respiratory rates to provide beneficial effects on oxygenation and ventilation, while eliminating the traumatic “inflate–deflate” cycle imposed by CV. Few studies have shown that, HFOV can effectively improve lung ventilation and oxygenation function, shorten ventilator treatment time and reduce the incidence of air leakage for neonatal MAS, making it a safe and effective treatment method. Objective:To study the Outcome of Neonates with Meconium Aspiration Syndrome on High Frequency Oscillatory Ventilation (HFVO).Material & Methods:It is a Prospective Observational Study of 10 neonates >34 weeks of gestation and birth weight >1500gm with meconium-stained liquor with respiratory distress requiring mechanical ventilation. Study was conducted over a period of 10months from August 2021 to May 2022. These neonates requiring mechanical ventilation were electively first hand put on SensorMedics 3100A High Frequency Oscillatory Ventilator after taking informed written consent from parents and given appropriate Intensive care. Data was analyzed at the end of the study duration and looked for outcome in the form of successful weaning from mechanical ventilation and discharge from NICU, and Death.Results:8 out of 10 (80%) neonates with MAS that were ventilated via HFOV were successfully weaned from mechanical ventilation and discharged, while death was reported in 2 out of 10 (20%) of the neonates included in the study.Conclusion:80% of neonates with MAS that were provided mechanical ventilation in the form of HFOV were effectively weaned off from mechanical ventilation, whereas 20% neonates died. This shows clinical effectiveness of HFOV in MAS making it a safe and effective treatment modality in neonates with MAS.

Outcome of neonates receiving high frequency oscillation ventilation in a tertiary care institution

Background: High-frequency ventilation is defined as ventilation at a frequency greater than four times normal respiratory rate. HFOV has been used as alternative to conventional ventilation and in respiratory failure of various etiologies. The aim of the study was to identify the indications of neonates receiving HFOV, following failure of conventional ventilation.Methods: Total 93 neonates were enrolled in the study who received HFOV. The criteria for starting HFOV, the ventilator settings, CBG and ABG analysis, oxygenation index (OI), duration of ventilation and complications of ventilation were recorded during CMV and subsequently when shifted over to HFOV. Outcomes such as oxygenation, lung recruitment and ventilation and survival were monitored.Results: Total 66 neonates (71%) were term babies. Among the 27 preterm 18 (18.4%) were 33-34'6 weeks of gestational age. Male were 50 in number (53.8%) and female were 43 (46.2%). The male: female ratio was 50:43. Disease specific survival analysis revealed more than 50% survival in cases of pneumonia, collapse, air leak, MAS and pulmonary hemorrhage. 16 out of 33 babies (48.5%) with PPHN survived. All 3 babies with CDH expired. Of the 93 neonates included in the study, 53 (57%) of them were discharged home. The major complications noted while on HFOV were- 38 neonates (40.8%) had air leaks. Instead of, ventilator associated pneumonia was present in 42 of them (45.1%) and none of them developed IVH or NTB (Necrotising tracheo bronchitis).Conclusions: HFOV is a safe and effective technique in the treatment of neonates with respiratory failure in whom CMV fails. The results of present study show that rescue HFOV improved oxygenation, ventilation and lung recruitment and there was no increased incidence of IVH.

A Case of Severe Air Leak Syndrome Treated with High - Frequency Oscillatory Ventilation ( HFOV )

In air leak syndrome, a significant portion of the volume delivered during a positive pressure breath can be lost through the leak. HFOV can achieve adequate ventilation at lower peak and/or mean intrapulmonary pressure than conventional mechanical ventilation (CMV) and has been an effective treatment of already established air leak syndrome. We report a 1-day-old male infant with severe respiratory failure from pneumothorax and pneumomediastinum, who was refractory to CMV with chest tube drainage. HFOV was applied to this patient for 114 hours, and improvement of oxygenation and ventilation as well as significant reduction of pneumothorax followed.

The Comparison of Histopathology of Cats Received Conventional Mechanical Ventilation and High Frequency Oscillation Ventilation / 영남의대학술지

The tracheobronchial histopathologic findings in 7 healthy cats used with high frequency oscillation ventilation (HFOV) were compared with those in 6 cats used with conventional mechanical ventilation (CMV). 4-point, 9-variable scoring system was used to evaluate the injury in the trachea, right & left main bronchi and parenchyma. The following results were obtained; 1) The tracheobronchial tree received HFOV had no significant damage compared with CMV (P>0.05). 2) Intraepithelial mucus loss and emphysema were slightly more prominent in CMV groups. As above results; the tracheobronchial histopathologic difference was not prominent between CMV and HFOV groups received with relatively short period, however, the cellular of function and barotrauma may be more prominent in CMV groups. From now on, as causes of tracheobronchial injury in HFV, interaction between humidification and mechanical trauma considers further study.