HFNC and non-invasive ventilation: effects on alveolar recruitment-overdistention

We have read with great interest a study recently published in ERJ Open Research that analysed the ability of high-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) to induce pulmonary expansion in acute hypoxaemic respiratory failure [1]. We would like to congratulate Artaud-Macariet al. [1] for their interesting observation using end-expiratory electrical lung impedance as a measuring tool. NIV certainly affects both dependent and non-dependent lung regions, which could increase tidal volume (V_T) to >9.5 mL per kg predicted body weight and potentially exacerbate acute hypoxaemic respiratory failure. The authors concluded that, compared to NIV, HFNC contributes to lower risk of overdistension and fewer deleterious effects on global and regional V_T, because the end-expiratory electrical lung impedance does not increase in non-dependent regions. Other studies, however, argue that HFNC may have similar negative effects to NIV, supported by four well-known determinants, as follows.

Both high-flow nasal cannula and noninvasive ventilation are subject to pulmonary complicationshttps://bit.ly/3jFCSG9

Recurrent pneumothorax after cesarean delivery in the critically ill pregnant with severe COVID-19 ARDS: a case report

OBJECTIVE

Few data are available on the ICU management and on the possible respiratory complications of invasively ventilated pregnant patients affected by COVID-19 pneumonia, especially in the early phase of pregnancy. Tension pneumothorax has been previously described as a rare cause of respiratory failure after delivery, but its occurrence in the postpartum of COVID-19 patient has not been reported yet. We hereby describe the ICU management of a 23rd gestational week pregnant woman who underwent invasive mechanical ventilation, prone positioning, and cesarean delivery during her ICU stay for COVID-19 related pneumonia. Moreover, we focused on the occurrence and management of recurrent tension pneumothorax after the cesarean delivery.

CASE REPORT

A 23rd gestational week pregnant woman was admitted to the ICU for a COVID-19 bilateral pneumonia and underwent invasive mechanical ventilation and prone positioning. Cesarean delivery was planned during the ICU stay, while the patient was receiving invasive mechanical ventilation. After delivery, the patient experienced a recurrent pneumothorax that required the positioning of multiple chest drains.

CONCLUSIONS

In pregnant critically ill COVID-19 patients, mechanical ventilation management is particularly challenging, especially in the postpartum period. Prone positioning is feasible and can improve oxygenation and respiratory system compliance, while tension pneumothorax must be suspected if the respiratory function suddenly deteriorates after delivery.

Non-invasive ventilation in patients with an altered level of consciousness. A clinical review and practical insights

Non-invasive ventilation has gained an increasingly pivotal role in the treatment of acute hypoxemic and/or hypercapnic respira-tory failure and offers multiple advantages over invasive mechanical ventilation. Some of these advantages include the preserva-tion of airway defense mechanisms, a reduced need for sedation, and an avoidance of complications related to endotracheal intubation. Despite its advantages, non-invasive ventilation has some contraindications that include, among them, severe encephalopathy. In this review article, the rationale, evidence, and drawbacks of the use of noninvasive ventilation in the context of hypercapnic and non-hypercapnic patients with an altered level of consciousness are analyzed.