Systemic and Cerebral Effects of Physiotherapy in Mechanically Ventilated Subjects

Effects of Positive Expiratory Pressure on Gas Exchange, Atelectasis, Hemodynamics, and Dyspnea in Spontaneously Breathing Critically Ill Subjects

Background: The EzPAP Positive Airway Pressure System (EzPAP) is a noninvasive positive expiratory pressure (PEP) device designed to promote lung expansion. The aim of this study was to evaluate the effects of PEP on gas exchange. Secondary objectives included assessing the early effects of PEP on radiological atelectasis score (RAS), hemodynamics, and dyspnea. These outcomes were compared between spontaneously breathing subjects with and without tracheostomy. Methods: This observational single-center study was conducted at a university hospital. Inclusion criteria were spontaneously breathing adult subjects with RAS ≥ 2 and a worsened PaO2/FIO2. Exclusion criteria included life-threatening conditions, intracranial hypertension, hemodynamic instability, and pneumothorax. Gas-exchange, hemodynamic parameters, and dyspnea measured with the Respiratory Distress Observation Scale (RDOS) were assessed at 3 time points: T0 (before PEP), T1 (immediately after PEP), and T2 (2 h after PEP). RAS was assessed at T0 and 1-week post treatment (T3). Results: Of 213 patients assessed for eligibility, 186 were excluded for various reasons, leaving 27 subjects (19 without and 8 with tracheostomy) enrolled in the study. The median [interquartile range] age was 65 [58-74] y, with 66.7% being male. In the overall sample and in subjects without tracheostomy, PaO2/FIO2 did not differ significantly between T1 and T0 (P = .52 and P = .54, respectively) or between T2 and T0 (P = .47 and P = .85, respectively). In subjects with tracheostomy, PaO2/FIO2was higher at T1 compared to T0 (P = .039) but not between T2 and T0 (P = .58). Arterial PaO2 and hemodynamic parameters remained unchanged in the overall cohort. The RAS improved within 1 week of treatment in the overall cohort (T3 vs T0, P < .001) and in subjects without tracheostomy (T3 vs T0, P = .001). However, PEP therapy did not improve RDOS. Conclusions: In critically ill, spontaneously breathing subjects, PEP therapy significantly improved RAS without affecting hemodynamic stability or respiratory symptoms.

Protocolized strategies to encourage early mobilization of critical care patients: challenges and success

Technological advances and interprofessional teamwork have significantly improved survival rates of critically ill patients. However, this progress has also introduced new challenges, such as intensive care unit-acquired weakness, which can contribute to postintensive care syndrome. Both conditions are associated with increased morbidity and mortality, prolonged length of hospital stay, higher social and health care costs, and reduced quality of life for patients and their families. Timely physical therapy plays a crucial role in mitigating intensive care unit-acquired weakness and postintensive care syndrome. Key recommendations for the effective rehabilitation of patients in the intensive care unit include education and training, communication and collaboration, patient screening, planning of activities, distribution of functions focused on teamwork, patient cooperation, safety assessments, patient positioning, functional mobilization, and documentation of outcomes. This narrative review aims to update the current understanding of the influence of physical therapy and critical care teamwork on intensive care unit patients and to provide evidence-based recommendations for promoting early mobilization in the intensive care unit setting.

The Neurological and Hemodynamics Safety of an Airway Clearance Technique in Patients with Acute Brain Injury: An Analysis of Intracranial Pressure Pulse Morphology Using a Non-Invasive Sensor

Patients with acute brain injury (ACI) often require mechanical ventilation (MV) and are subject to pulmonary complications, thus justifying the use of Airway Clearance Techniques (ACTs), but their effects on intracranial pressure (ICP) are unknown. This study investigates the neurological and hemodynamics safety of an ACT called ventilator hyperinflation (VHI) in patients with ACI. This was a randomized clinical equivalence trial, which included patients aged ≥ 18 years with a clinical diagnosis of hemorrhagic stroke, with symptom onset within 48 h. The participants were randomly allocated to the Experimental Group (EG, n = 15), which underwent VHI followed by tracheal aspiration (TA), and the Control Group (CG, n = 15), which underwent TA only. Neurological safety was verified by analyzing the morphology of the ICP wave through the non-invasive B4C sensor, which detects bone deformation of the skull, resulting in a P2/P1 ratio and TTP, and hemodynamics through a multi-parameter monitor. Evaluations were recorded during five instances: T1 (baseline/pre-VHI), T2 (post-VHI and before TA), T3 (post-TA), T4 and T5 (monitoring 10 and 20 min after T3). The comparison between groups showed that there was no effect of the technique on the neurological variables with a mean P2/P1 ratio [F (4,112) = 1.871; p = 0.120; np2 = 0.063] and TTP [F (4,112) = 2.252; p = 0.068; np2 = 0.074], and for hemodynamics, heart rate [F (4,112) = 1.920; p = 0.112; np2 = 0.064] and mean arterial pressure [F(2.73, 76.57) = 0.799; p = 0.488; np2 = 0.028]. Our results showed that VHI did not pose a neurological or hemodynamics risk in neurocritical patients after ACI.

Electrical impedance tomography: Usefulness for respiratory physiotherapy in critical illnesses

Respiratory physiotherapy, including the management of invasive mechanical ventilation (MV) and noninvasive mechanical ventilation (NIV), is a key supportive intervention for critically ill patients. MV has potential for inducing ventilator-induced lung injury (VILI) as well as long-term complications related to prolonged bed rest, such as post-intensive care syndrome and intensive care unit acquired weakness. Physical and respiratory therapy, developed by the critical care team, in a timely manner, has been shown to prevent these complications. In this pathway, real-time bedside monitoring of changes in pulmonary aeration and alveolar gas distribution associated with postural positioning, respiratory physiotherapy techniques and changes in MV strategies can be crucial in guiding these procedures, providing safe therapy and prevention of potential harm to the patient. Along this path, electrical impedance tomography (EIT) has emerged as a new key non-invasive bedside strategy free of radiation, to allow visualization of lung recruitment. This review article presents the main and potential applications of EIT in relation to physiotherapy techniques in the ICU setting.

Effects of positive end-expiratory pressure on intracranial pressure, cerebral perfusion pressure, and brain oxygenation in acute brain injury: Friend or foe? A scoping review

Background

Patients with acute brain injury (ABI) are a peculiar population because ABI does not only affect the brain but also other organs such as the lungs, as theorized in brain-lung crosstalk models. ABI patients often require mechanical ventilation (MV) to avoid the complications of impaired respiratory function that can follow ABI; MV should be settled with meticulousness owing to its effects on the intracranial compartment, especially regarding positive end-expiratory pressure (PEEP). This scoping review aimed to (1) describe the physiological basis and mechanisms related to the effects of PEEP in ABI; (2) examine how clinical research is conducted on this topic; (3) identify methods for setting PEEP in ABI; and (4) investigate the impact of the application of PEEP in ABI on the outcome.

Methods

The five-stage paradigm devised by Peters et al. and expanded by Arksey and O'Malley, Levac et al., and the Joanna Briggs Institute was used for methodology. We also adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension criteria. Inclusion criteria: we compiled all scientific data from peer-reviewed journals and studies that discussed the application of PEEP and its impact on intracranial pressure, cerebral perfusion pressure, and brain oxygenation in adult patients with ABI. Exclusion criteria: studies that only examined a pediatric patient group (those under the age of 18), experiments conducted solely on animals; studies without intracranial pressure and/or cerebral perfusion pressure determinations, and studies with incomplete information. Two authors searched and screened for inclusion in papers published up to July 2023 using the PubMed-indexed online database. Data were presented in narrative and tubular form.

Results

The initial search yielded 330 references on the application of PEEP in ABI, of which 36 met our inclusion criteria. PEEP has recognized beneficial effects on gas exchange, but it produces hemodynamic changes that should be predicted to avoid undesired consequences on cerebral blood flow and intracranial pressure. Moreover, the elastic properties of the lungs influence the transmission of the forces applied by MV over the brain so they should be taken into consideration. Currently, there are no specific tools that can predict the effect of PEEP on the brain, but there is an established need for a comprehensive monitoring approach for these patients, acknowledging the etiology of ABI and the measurable variables to personalize MV.

Conclusion

PEEP can be safely used in patients with ABI to improve gas exchange keeping in mind its potentially harmful effects, which can be predicted with adequate monitoring supported by bedside non-invasive neuromonitoring tools.