Clinical review: bedside assessment of alveolar recruitment

Recruitment is a dynamic physiological process that refers to the reopening of previously gasless lung units. Cumulating evidence has led to a better understanding of the rules that govern both recruitment and derecruitment during mechanical ventilation of patients with acute respiratory distress syndrome. Therefore not only the positive end-expiratory pressure, but also the tidal volume, the inspired oxygen fraction, repeated tracheal suctioning as well as sedation and paralysis may affect recruitment of acute respiratory distress syndrome lungs that are particularly prone to alveolar instability. In the present article, we review the recently reported data concerning the physiological significance of the pressure-volume curve and its use to assess alveolar recruitment. We also describe alternate techniques that have been proposed to assess recruitment at the bedside. Whether recruitment should be optimized remains an ongoing controversy that warrants further clinical investigation

Clinical review: bedside assessment of alveolar recruitment

Recruitment is a dynamic physiological process that refers to the reopening of previously gasless lung units. Cumulating evidence has led to a better understanding of the rules that govern both recruitment and derecruitment during mechanical ventilation of patients with acute respiratory distress syndrome. Therefore not only the positive end-expiratory pressure, but also the tidal volume, the inspired oxygen fraction, repeated tracheal suctioning as well as sedation and paralysis may affect recruitment of acute respiratory distress syndrome lungs that are particularly prone to alveolar instability. In the present article, we review the recently reported data concerning the physiological significance of the pressure-volume curve and its use to assess alveolar recruitment. We also describe alternate techniques that have been proposed to assess recruitment at the bedside. Whether recruitment should be optimized remains an ongoing controversy that warrants further clinical investigation

Year in review in Intensive Care Medicine 2012. II: Pneumonia and infection, sepsis, coagulation, hemodynamics, cardiovascular and microcirculation, critical care organization, imaging, ethics and legal issues.

Journal ArticleSCOPUS: re.jSCOPUS: re.jinfo:eu-repo/semantics/publishe

Noninvasive respiratory support in the perioperative setting: a narrative review

The application of preoperative noninvasive respiratory support (NRS) has been expanding with increasing recognition of its potential role in this setting as a physiological optimization for patients with a high risk of developing atelectasis and postoperative pulmonary complications (PPC). The increased availability of high-performance anesthesia ventilator machines providing an easy way for NRS support in patients with reduced lung function should not be under-evaluated. This support can reduce hypoxia, restore lung volumes and theoretically reduce atelectasis formation after general anesthesia. Therapeutic purposes should also be considered in the perioperative setting, such as preoperative NRS to optimize treatment of patients’ pre-existing diseases, e.g., sleep-disordered breathing. Finally, the recent guidelines for airway management suggest preoperative NRS application before anesthesia induction in difficult airway management to prolong the time needed to secure the airway with an orotracheal tube. This narrative review aims to revise all these aspects and to provide some practical notes to maximize the efficacy of perioperative noninvasive respiratory support

A rare case of a patient with cystinosis and COVID-19 pneumonia with difficult weaning from mechanical ventilation: the "pocus force"

Here, we describe the case of a 39-year-old woman with cystinosis who already suffered from an extra parenchymal pattern of restrictive lung disease and, after SARS-CoV-2-related respiratory failure, had a difficult weaning from mechanical ventilation and required tracheostomy. In this rare disease, due to the mutation of the CTNS-gene located on chromosome 17p13, cystine accumulation in the distal muscle has been reported, even in the absence of manifest muscle fatigue. We were able to evaluate diaphragmatic weakness in this patient through the ultrasonographic evaluation of the diaphragm. We believe that diaphragm ultrasonography could be helpful to identify causes of difficult weaning thus supporting clinical decisions

Postoperative pulmonary compensation after lung cancer surgery: a shift towards a modern and comprehensive model—a narrative review

Background and Objective: Pulmonary lobectomies result in permanent tissue loss and postoperative compensatory adaptations of the remaining lung volume. The structural remodelling processes of the tracheobronchial tree significantly influence postoperative functional tests and predispose to complex scenarios such as redistribution of the pulmonary airflow rate and steno-obstructive phenomena affecting patients’ quality of life. Moreover, in the context of a second primary lung neoplasm, the reduced adult pulmonary parenchymal plasticity and residual exercise intolerance due to postoperative changes rises anaesthesiologic challenges in case of need for surgical re-intervention. The aim of this unsystematic narrative review is to highlight correlations between morpho-dynamic changes of the tracheobronchial tree and postoperative steno-obstructive symptoms in patients undergoing lung surgery. Methods: An unsystematic narrative review of published article about post-operative pulmonary compensation after lobectomies for non-small cell lung cancer (NSCLC) by querying PubMed and Scopus databases was conducted. According to the Medical Subject Heading (MeSH) items, search terms were: pulmonary compensation or remodel; lung cancer; surgery; post-operative pulmonary function; anatomic changes; lung mechanics; ventilation; one-lung ventilation; post-operative pulmonary tests. Inclusion criteria were: papers written in English about post-resectional anatomic and dynamic pulmonary compensation [2010–2023]. Key Content and Findings: This review will focus on pathophysiological and clinical challenges about of postoperative pulmonary compensations in NSCLC patients undergoing lobectomy. Conclusions: Postoperative pulmonary adaptive response involves morpho-structural and dynamic compensations of air-flow redistribution resource in response to surgical stress as the epiphenomenon of a complex cooperation between the host response, recruitment of alveolar-capillary reserves and fluid dynamics influencing postoperative respiratory function and medium-long term sequelae in surgical NSCLC patients

Phenotypes of Patients with COVID-19 Who Have a Positive Clinical Response to Helmet Noninvasive Ventilation

In patients with COVID-19 and moderate-to-severe hypoxemic respiratory failure, high-flow oxygen is as effective as helmet noninvasive ventilation in patients who show PaO2/[FiO2*VAS dyspnea]≥30 and/or PaCO2≥35 mmHg under conventional oxygen, while helmet noninvasive ventilation as applied in the HENIVOT trial may improve clinical outcome among subjects exhibiting PaO2/[FiO2*VAS dyspnea]<30 and/or PaCO2<35 mmHg

Physiological effects of high-flow oxygen in tracheostomized patients

High-flow oxygen therapy via nasal cannula (HFOTNASAL) increases airway pressure, ameliorates oxygenation and reduces work of breathing. High-flow oxygen can be delivered through tracheostomy (HFOTTRACHEAL), but its physiological effects have not been systematically described. We conducted a cross-over study to elucidate the effects of increasing flow rates of HFOTTRACHEAL on gas exchange, respiratory rate and endotracheal pressure and to compare lower airway pressure produced by HFOTNASAL and HFOTTRACHEAL. METHODS: Twenty-six tracheostomized patients underwent standard oxygen therapy through a conventional heat and moisture exchanger, and then HFOTTRACHEAL through a heated humidifier, with gas flow set at 10, 30 and 50 L/min. Each step lasted 30 min; gas flow sequence during HFOTTRACHEAL was randomized. In five patients, measurements were repeated during HFOTTRACHEAL before tracheostomy decannulation and immediately after during HFOTNASAL. In each step, arterial blood gases, respiratory rate, and tracheal pressure were measured

Diaphragmatic morphological post-mortem findings in critically ill COVID-19 patients: an observational study

: Our study investigates the post-mortem findings of the diaphragm's muscular structural changes in mechanically ventilated COVID-19 patients. Diaphragm samples of the right side from 42 COVID-19 critically ill patients were analyzed and correlated with the type and length of mechanical ventilation (MV), ventilatory parameters, prone positioning, and use of sedative drugs. The mean number of fibers was 550±626. The cross-sectional area was 4120±3280 μm2, while the muscular fraction was 0.607±0.126. The overall population was clustered into two distinct populations (clusters 1 and 2). Cluster 1 showed a lower percentage of slow myosin fiber and higher fast fiber content than cluster 2, 68% versus 82%, p<0.00001, and 29.8% versus 18.8%, p=0.00045 respectively. The median duration of MV was 180 (41-346) hours. In cluster 1, a relationship between assisted ventilation and fast myosin fiber percentage (R2=-0.355, p=0.014) was found. In cluster 2, fast fiber content increased with increasing the length of the controlled MV (R2=0.446, p=0.006). A high grade of fibrosis was reported. Cluster 1 was characterized by fibers' atrophy and cluster 2 by hypertrophy, supposing different effects of ventilation on the diaphragm but without excluding a possible direct viral effect on diaphragmatic fibers