Esophageal Pressure Measurements Research Articles

Advanced Respiratory Monitoring during Extracorporeal Membrane Oxygenation.

Advanced respiratory monitoring encompasses a diverse range of mini- or noninvasive tools used to evaluate various aspects of respiratory function in patients experiencing acute respiratory failure, including those requiring extracorporeal membrane oxygenation (ECMO) support. Among these techniques, key modalities include esophageal pressure measurement (including derived pressures), lung and respiratory muscle ultrasounds, electrical impedance tomography, the monitoring of diaphragm electrical activity, and assessment of flow index. These tools play a critical role in assessing essential parameters such as lung recruitment and overdistention, lung aeration and morphology, ventilation/perfusion distribution, inspiratory effort, respiratory drive, respiratory muscle contraction, and patient-ventilator synchrony. In contrast to conventional methods, advanced respiratory monitoring offers a deeper understanding of pathological changes in lung aeration caused by underlying diseases. Moreover, it allows for meticulous tracking of responses to therapeutic interventions, aiding in the development of personalized respiratory support strategies aimed at preserving lung function and respiratory muscle integrity. The integration of advanced respiratory monitoring represents a significant advancement in the clinical management of acute respiratory failure. It serves as a cornerstone in scenarios where treatment strategies rely on tailored approaches, empowering clinicians to make informed decisions about intervention selection and adjustment. By enabling real-time assessment and modification of respiratory support, advanced monitoring not only optimizes care for patients with acute respiratory distress syndrome but also contributes to improved outcomes and enhanced patient safety.

Monitoring lung recruitment.

This review explores lung recruitment monitoring, covering techniques, challenges, and future perspectives. Various methodologies, including respiratory system mechanics evaluation, arterial bold gases (ABGs) analysis, lung imaging, and esophageal pressure (Pes) measurement are employed to assess lung recruitment. In support to ABGs analysis, the assessment of respiratory mechanics with hysteresis and recruitment-to-inflation ratio has the potential to evaluate lung recruitment and enhance mechanical ventilation setting. Lung imaging tools, such as computed tomography scanning, lung ultrasound, and electrical impedance tomography (EIT) confirm their utility in following lung recruitment with the advantage of radiation-free and repeatable application at the bedside for sonography and EIT. Pes enables the assessment of dorsal lung tendency to collapse through end-expiratory transpulmonary pressure. Despite their value, these methodologies may require an elevated expertise in their application and data interpretation. However, the information obtained by these methods may be conveyed to build machine learning and artificial intelligence algorithms aimed at improving the clinical decision-making process. Monitoring lung recruitment is a crucial component of managing patients with severe lung conditions, within the framework of a personalized ventilatory strategy. Although challenges persist, emerging technologies offer promise for a personalized approach to care in the future.

Flow starvation during square-flow assisted ventilation detected by supervised deep learning techniques

BackgroundFlow starvation is a type of patient-ventilator asynchrony that occurs when gas delivery does not fully meet the patients’ ventilatory demand due to an insufficient airflow and/or a high inspiratory effort, and it is usually identified by visual inspection of airway pressure waveform. Clinical diagnosis is cumbersome and prone to underdiagnosis, being an opportunity for artificial intelligence. Our objective is to develop a supervised artificial intelligence algorithm for identifying airway pressure deformation during square-flow assisted ventilation and patient-triggered breaths.MethodsMulticenter, observational study. Adult critically ill patients under mechanical ventilation > 24 h on square-flow assisted ventilation were included. As the reference, 5 intensive care experts classified airway pressure deformation severity. Convolutional neural network and recurrent neural network models were trained and evaluated using accuracy, precision, recall and F1 score. In a subgroup of patients with esophageal pressure measurement (ΔPes), we analyzed the association between the intensity of the inspiratory effort and the airway pressure deformation.Results6428 breaths from 28 patients were analyzed, 42% were classified as having normal-mild, 23% moderate, and 34% severe airway pressure deformation. The accuracy of recurrent neural network algorithm and convolutional neural network were 87.9% [87.6–88.3], and 86.8% [86.6–87.4], respectively. Double triggering appeared in 8.8% of breaths, always in the presence of severe airway pressure deformation. The subgroup analysis demonstrated that 74.4% of breaths classified as severe airway pressure deformation had a ΔPes > 10 cmH2O and 37.2% a ΔPes > 15 cmH2O.ConclusionsRecurrent neural network model appears excellent to identify airway pressure deformation due to flow starvation. It could be used as a real-time, 24-h bedside monitoring tool to minimize unrecognized periods of inappropriate patient-ventilator interaction.

Oesophageal pressure monitoring in intubated patients by intensive care units' nurses: An educational study.

Trained ICU nurses may perform oesophageal pressure measurements which may help facilitate its implementation in the usual patient care to better assess lung and chest wall mechanics and easily detect patient-ventilator asynchronies. We thus conducted a prospective educational study aiming to assess the ability of ICU nurses to perform reliable oesophageal pressure measurements after a short dedicated training program. All the 11 nurses who completed the program succeeded their practical evaluation (nine (82%) at the first evaluation and two (18%) at their second attempt). These results show that this training program is feasible and that trained ICU nurses can perform accurate oesophageal pressure measurements in mechanically ventilated patients. Such training program may help to implement this technique in routine ICU care.

Bedside personalized methods based on electrical impedance tomography or respiratory mechanics to set PEEP in ARDS and recruitment-to-inflation ratio: a physiologic study

BackgroundVarious Positive End-Expiratory Pressure (PEEP) titration strategies have been proposed to optimize ventilation in patients with acute respiratory distress syndrome (ARDS). We aimed to compare PEEP titration strategies based on electrical impedance tomography (EIT) to methods derived from respiratory system mechanics with or without esophageal pressure measurements, in terms of PEEP levels and association with recruitability.MethodsNineteen patients with ARDS were enrolled. Recruitability was assessed by the estimated Recruitment-to-Inflation ratio (R/Iest) between PEEP 15 and 5 cmH2O. Then, a decremental PEEP trial from PEEP 20 to 5 cmH2O was performed. PEEP levels determined by the following strategies were studied: (1) plateau pressure 28–30 cmH2O (Express), (2) minimal positive expiratory transpulmonary pressure (Positive PLe), (3) center of ventilation closest to 0.5 (CoV) and (4) intersection of the EIT-based overdistension and lung collapse curves (Crossing Point). In addition, the PEEP levels determined by the Crossing Point strategy were assessed using different PEEP ranges during the decremental PEEP trial.ResultsExpress and CoV strategies led to higher PEEP levels than the Positive PLe and Crossing Point ones (17 [14–17], 20 [17–20], 8 [5–11], 10 [8–11] respectively, p < 0.001). For each strategy, there was no significant association between the optimal PEEP level and R/Iest (Crossing Point: r2 = 0.073, p = 0.263; CoV: r2 < 0.001, p = 0.941; Express: r2 < 0.001, p = 0.920; Positive PLe: r2 = 0.037, p = 0.461). The PEEP level obtained with the Crossing Point strategy was impacted by the PEEP range used during the decremental PEEP trial.ConclusionsCoV and Express strategies led to higher PEEP levels than the Crossing Point and Positive PLe strategies. Optimal PEEP levels proposed by these four methods were not associated with recruitability. Recruitability should be specifically assessed in ARDS patients to optimize PEEP titration.

Estimation of inspiratory effort using airway occlusion maneuvers in ventilated children: a secondary analysis of an ongoing randomized trial testing a lung and diaphragm protective ventilation strategy

BackgroundMonitoring respiratory effort in ventilated patients is important to balance lung and diaphragm protection. Esophageal manometry remains the gold standard for monitoring respiratory effort but is invasive and requires expertise for its measurement and interpretation. Airway pressures during occlusion maneuvers may provide an alternative, although pediatric data are limited. We sought to determine the correlation between change in esophageal pressure during tidal breathing (∆Pes) and airway pressure measured during three airway occlusion maneuvers: (1) expiratory occlusion pressure (Pocc), (2) airway occlusion pressure (P0.1), and (3) respiratory muscle pressure index (PMI) in children. We also sought to explore pediatric threshold values for these pressures to detect excessive or insufficient respiratory effort.MethodsSecondary analysis of physiologic data from children between 1 month and 18 years of age with acute respiratory distress syndrome enrolled in an ongoing randomized clinical trial testing a lung and diaphragm protective ventilation strategy (REDvent, R01HL124666). ∆Pes, Pocc, P0.1, and PMI were measured. Repeated measure correlations were used to investigate correlation coefficients between ∆Pes and the three measures, and linear regression equations were generated to identify potential therapeutic thresholds.ResultsThere were 653 inspiratory and 713 expiratory holds from 97 patients. Pocc had the strongest correlation with ∆Pes (r = 0.68), followed by PMI (r = 0.60) and P0.1 (r = 0.42). ∆Pes could be reliably estimated using the regression equation ∆Pes = 0.66 times Pocc (R2 = 0.82), with Pocc cut-points having high specificity and moderate sensitivity to detect respective ∆Pes thresholds for high and low respiratory effort. There were minimal differences in the relationship between Pocc and ∆Pes based on age (infant, child, adolescent) or mode of ventilation (SIMV versus Pressure Support), although these differences were more apparent with P0.1 and PMI.ConclusionsAirway occlusion maneuvers may be appropriate alternatives to esophageal pressure measurement to estimate the inspiratory effort in children, and Pocc represents the most promising target.Trial registration: NCT03266016; August 23, 2017.

Advanced respiratory mechanics assessment in mechanically ventilated obese and non-obese patients with or without acute respiratory distress syndrome

BackgroundRespiratory mechanics is a key element to monitor mechanically ventilated patients and guide ventilator settings. Besides the usual basic assessments, some more complex explorations may allow to better characterize patients’ respiratory mechanics and individualize ventilation strategies. These advanced respiratory mechanics assessments including esophageal pressure measurements and complete airway closure detection may be particularly relevant in critically ill obese patients. This study aimed to comprehensively assess respiratory mechanics in obese and non-obese ICU patients with or without ARDS and evaluate the contribution of advanced respiratory mechanics assessments compared to basic assessments in these patients.MethodsAll intubated patients admitted in two ICUs for any cause were prospectively included. Gas exchange and respiratory mechanics including esophageal pressure and end-expiratory lung volume (EELV) measurements and low-flow insufflation to detect complete airway closure were assessed in standardized conditions (tidal volume of 6 mL kg−1 predicted body weight (PBW), positive end-expiratory pressure (PEEP) of 5 cmH2O) within 24 h after intubation.ResultsAmong the 149 analyzed patients, 52 (34.9%) were obese and 90 (60.4%) had ARDS (65.4% and 57.8% of obese and non-obese patients, respectively, p = 0.385). A complete airway closure was found in 23.5% of the patients. It was more frequent in obese than in non-obese patients (40.4% vs 14.4%, p < 0.001) and in ARDS than in non-ARDS patients (30% vs. 13.6%, p = 0.029). Respiratory system and lung compliances and EELV/PBW were similarly decreased in obese patients without ARDS and obese or non-obese patients with ARDS. Chest wall compliance was not impacted by obesity or ARDS, but end-expiratory esophageal pressure was higher in obese than in non-obese patients. Chest wall contribution to respiratory system compliance differed widely between patients but was not predictable by their general characteristics.ConclusionsMost respiratory mechanics features are similar in obese non-ARDS and non-obese ARDS patients, but end-expiratory esophageal pressure is higher in obese patients. A complete airway closure can be found in around 25% of critically ill patients ventilated with a PEEP of 5 cmH2O. Advanced explorations may allow to better characterize individual respiratory mechanics and adjust ventilation strategies in some patients.Trial registration NCT03420417 ClinicalTrials.gov (February 5, 2018).

High sensitivity fiber optic esophageal pressure sensor based on OFDR

In this paper, a distributed esophageal pressure measurement sensor is proposed. Optical frequency domain reflection (OFDR) technology is adopted to measure the axial strain change of the optical fiber. By designing a sensitizing structure, the sensing performance can be well improved. The analysis based on finite element simulation of the sensor is carried out and its feasibility is verified. Compared with the solid high-resolution esophageal manometry system widely used at this stage, the proposed sensor is low cost and simple in structure. The sensitivity of the sensor can reach 65.920μɛ/kPa.

Which spontaneous breathing trial to predict effort to breathe after extubation according to five critical illnesses: the cross-over GLOBAL WEAN study protocol

IntroductionReadiness to be freed from ventilatory support can be evaluated by spontaneous breathing trial (SBT) assessing the patient’s ability to sustain respiratory effort after extubation. Current SBT practices are heterogenous...

Hiccup-like Contractions in Mechanically Ventilated Patients: Individualized Treatment Guided by Transpulmonary Pressure.

Hiccups-like contractions, including hiccups, respiratory myoclonus, and diaphragmatic tremor, refer to involuntary, spasmodic, and inspiratory muscle contractions. They have been repeatedly described in mechanically ventilated patients, especially those with central nervous damage. Nevertheless, their effects on patient-ventilator interaction are largely unknown, and even more overlooked is their contribution to lung and diaphragm injury. We describe, for the first time, how the management of hiccup-like contractions was individualized based on esophageal and transpulmonary pressure measurements in three mechanically ventilated patients. The necessity or not of intervention was determined by the effects of these contractions on arterial blood gases, patient-ventilator synchrony, and lung stress. In addition, esophageal pressure permitted the titration of ventilator settings in a patient with hypoxemia and atelectasis secondary to hiccups and in whom sedatives failed to eliminate the contractions and muscle relaxants were contraindicated. This report highlights the importance of esophageal pressure monitoring in the clinical decision making of hiccup-like contractions in mechanically ventilated patients.

The Relationship Between Esophageal Pressure and Diaphragm Thickening Fraction in Spontaneously Breathing Sedated Children: A Feasibility Study.

Diaphragm ultrasound is a novel alternative to esophageal pressure measurements in the evaluation of diaphragm function and activity, but data about its reliability in a pediatric setting are lacking. We aimed to compare the esophageal pressure swing (∆Pes, gold standard) with the diaphragmatic thickening fraction (DTF) as a measure of inspiratory effort in sedated children. Additionally, we studied the effect of positive end-expiratory pressure (PEEP) on the end-expiratory thickness of the diaphragm (DTee). Prospective open-label non-randomized interventional physiological cohort study. Operating room in tertiary academic hospital. Children 28 days to 13 years old scheduled for elective surgery with general anesthesia, spontaneously breathing through a laryngeal mask airway, were eligible for inclusion. Exclusion criteria were disorders or previous surgery of the diaphragm, anticipated difficult airway or acute cardiopulmonary disease. All measurements were performed prior to surgery. Patients were subjected to different levels of respiratory load, PEEP and anesthetic depth in a total of seven respiratory conditions. The esophageal pressure and diaphragm thickening fraction were simultaneously recorded for five breaths at each respiratory condition. The relation between ∆Pes and DTF was studied in a mixed model. We analyzed 407 breaths in 13 patients. Both DTF (p = 0.03) and ∆Pes (p = 0.002) could detect respiratory activity, and ∆Pes and DTF were associated across respiratory conditions (p < 0.001; R2 = 31%). With increasing inspiratory load, ∆Pes increased significantly, while DTF did not (p = 0.08). Additionally, DTee did not differ significantly between 10, 5, and 0 cm H2O PEEP (p = 0.08). In spontaneously breathing sedated children and across different respiratory conditions, DTF could differentiate minimal or no inspiratory effort from substantial inspiratory effort and was associated with ∆Pes. Increased efforts resulted in higher ∆Pes but not larger DTF.

Esophageal manometry: a valuable tool for the comprehensive management of COVID-19-related hypoxic respiratory failure

The optimal management of respiratory failure related to SARS-CoV-2 infection is a subject of heated debates in the scientific community. The lack of solid scientific evidence, combined with the unclear pathophysiology of COVID-19 pneumonia, means that the modalities and duration of ventilator assistance often rely on subjective assessments of the doctor on call. In establishing a suitable respiratory support, it is essential to evaluate the degree of activation of the respiratory muscles as objectively as possible. Among the various methods of evaluating the inspiratory effort, measurement of the phasic variations of esophageal pressure (intended as a surrogate of pleural pressure) represents the gold standard. Esophageal pressure measurement can be implemented in a minimally invasive way in every patient category, does not require sophisticated devices, and provides objective data about respiratory muscle activity. In patients with ongoing COVID-19-related respiratory failure, esophageal pressure monitoring allows i) optimizing the type and settings of noninvasive ventilation, ii) providing objective support in the delicate choice of establishing invasive ventilation in cases in which such an indication is unclear, and iii) monitoring the clinical evolution of COVID-19 pneumonia to allow early interception of cases with progressive worsening of lung function. Esophageal manometry provides a complete and objective assessment of respiratory muscle activity. Its clinical use in patients with respiratory failure in the course of COVID-19 would allow clarifying some pathophysiological aspects of the disease and customizing ventilatory support according to the needs of specific patients.

How hard is it to breathe? Quantification of lung elastance and inspiratory work of breathing in healthy and COPD patients.

Chronic Obstructive Pulmonary Disease (COPD) covers a range of underlying lung conditions. Lung mechanics, particularly airway resistance, are altered, increasing the work of breathing (WOB). Model-based methods to estimate lung parameters may help reduce the clinical burden of diagnosis and monitoring. This analysis presents a modified single compartment model describing lung mechanics and WOB. Plethysmographic data, including derived alveolar pressure, is used to identify inspiratory airway resistance (Rinsp), lung elastance (E), and inspiratory effort (Peff, cmH2O). Four (n=10 each) clinical cohorts comprise subjects who are healthy (young and old) and with COPD (with (FL) and without (NFL) expiratory flow limitation). E and R are correlated (R2 = 0.73) and within the normal range in healthy cohorts (Rinsp <5 cmH2O/L/s, E = 0-6 cmH2O/L), but elevated to R = 5-15 cmH2O/L/s and E = 5 - 12 cmH2O/L in patients with COPD. The peak negative Peff was highest in FL COPD patients, reflecting higher WOB required to overcome E and Rinsp dynamics. Increased Rinsp was more dominant than changes in E in COPD patients. Overall, the modelled Peff match pleural and esophageal pressure measurements in literature. The model presented appears to capture key inspiratory effort dynamics, and is a first step towards a more generalised model for non-invasive clinical diagnosis and monitoring of COPD lung conditions.

Model-Based Estimation of Inspiratory Effort Using Surface EMG.

The quantification of inspiratory patient effort in assisted mechanical ventilation is essential for the adjustment of ventilatory assistance and for assessing patient-ventilator interaction. The inspiratory effort is usually measured via the respiratory muscle pressure (P mus) derived from esophageal pressure (P es) measurements. As yet, no reliable non-invasive and unobtrusive alternatives exist to continuously quantify P mus. We propose a model-based approach to estimate P mus non-invasively during assisted ventilation using surface electromyographic (sEMG) measurements. The method combines the sEMG and ventilator signals to determine the lung elastance and resistance as well as the neuromechanical coupling of the respiratory muscles via a novel regression technique. Using the equation of motion, an estimate for P mus can then be calculated directly from the lung mechanical parameters and the pneumatic ventilator signals. The method was applied to data recorded from a total of 43 ventilated patients and validated against P es-derived P mus. Patient effort was quantified via the P mus pressure-time-product (PTP). The sEMG-derived PTP estimated using the proposed method was highly correlated to P es-derived PTP ([Formula: see text]), and the breath-wise deviation between the two quantities was [Formula: see text]. The estimated, sEMG-derived P mus is closely related to the P es-based reference and allows to reliably quantify inspiratory effort. The proposed technique provides a valuable tool for physicians to assess patients undergoing assisted mechanical ventilation and, thus, may support clinical decision making.

Esophageal Pressure Measurement in Acute Hypercapnic Respiratory Failure Due to Severe COPD Exacerbation Requiring NIV-A Pilot Safety Study.

Esophageal pressure (Pes) measurements could optimise ventilator parameters in acute respiratory failure (ARF) patients requiring noninvasive ventilation (NIV). Consequently, the objectives of our study were to evaluate the safety and accuracy of applying a Pes measuring protocol in ARF patients with AECOPD under NIV in our respiratory intermediate care unit (RICU). An observational cohort study was undertaken. The negative inspiratory swing of Pes (ΔPes) was measured: in an upright/supine position in the presence/absence of NIV at D1 (day of admission), D3 (3rd day of NIV), and DoD (day of discharge). A digital filter for artefact removal was developed. We included 15 patients. The maximum values for ∆Pes were recorded at admission (mean ∆Pes 23.2 cm H2O) in the supine position. ∆Pes decreased from D1 to D3 (p &lt; 0.05), the change being BMI-dependent (p &lt; 0.01). The addition of NIV decreased ∆Pes at D1 and D3 (p &lt; 0.01). The reduction of ∆Pes was more significant in the supine position at D1 (8.8 cm H2O, p &lt; 0.01). Under NIV, ∆Pes values remained higher in the supine versus upright position. Therefore, the measurement of Pes in AECOPD patients requiring NIV can be safely done in an RICU. Under NIV, ∆Pes reduction is most significant within the first 24 h of admission.

Methodological Quality Of The Work Of Breathing During Exercise: A Systematic Review

Measurements of the work of breathing (Wb) during exercise provide useful insights into the energetic demands and mechanics of the respiratory system across a wide range of minute ventilations. The methods used to obtain, compute, and report these Wb measures have yet to be collated and evaluated in the literature. PURPOSE: The aim of this systematic review was to evaluate the quality of methods used to measure Wb during exercise in the published literature. METHODS: An extensive search strategy was designed to retrieve all articles published from database inception until January 12th, 2021, by combining the terms “work of breathing”, “exercise”, “adult humans”, and relevant synonyms in Embase and MEDLINE. Inclusion criteria required articles to be original research with full texts in English, that included measurements of both oesophageal pressure and Wb. Data were extracted on participant characteristics, flow/volume and pressure devices, oesophageal catheters, and Wb measurements. RESULTS: A total of 116 articles were included. Studies predominately investigated healthy individuals (62.9%, N = 73) and used cycling as the primary exercise modality (85.3%, N = 99). The flow sensors used were primarily pneumotachographs (66.4%, N = 83), whereas the most common pressure transducer was of the variable reluctance type (53.0%, N = 61). Oesophageal pressure was most commonly obtained via a balloon-tipped catheter (95.7%, N = 111). Few studies mentioned calibration, frequency responses and dynamic compensation of their measurement devices. The most popular method of measuring the Wb was pressure-volume integration (41.4%, N = 48), followed by the Hedstrand (21.6%, N = 25) and Modified Campbell Diagrams (21.6%, N = 25). Over a third of studies did not report the methods used to process their pressure-volume data, and a majority (>64.0%) of studies used the incorrect Wb units and/or failed to discuss the limitations of their Wb measurements. CONCLUSIONS: This review identified a general lack of transparency in the literature, especially regarding device calibration and methods for obtaining Wb measurements. These findings support the development of a standardized approach for measuring Wb that is informative, practical, and accessible for future researchers.

Development of a Pleural Pressure Catheter via Continuous Fiberoptic Esophageal Pressure Measurements.

There is growing research showing the importance of measuring esophageal pressure as a surrogate for pleural pressure for patients on mechanical ventilators. The most common measurement method uses a balloon catheter, whose accuracy can vary based on patient anatomy, balloon position, balloon inflation, and the presence of other tubes in the esophagus. The authors present the development and initial testing results of a new combination catheter, utilizing fiberoptic pressure sensing to provide more accurate esophageal pressure measurements and allowing for the incorporation of a feeding tube and temperature sensor.

Ventilator management using esophageal balloon pressure measurements

Mechanical ventilation provides essential support for patients with acute respiratory failure and provides time for these patients to recover from the primary disorder. Ventilator strategies need to provide adequate oxygenation and avoid barotrauma. This trauma develops when some regions of the lungs are overinflated and develops when some regions are underinflated and have cyclical opening and closing during the respiratory cycle. The ARDS network trial demonstrated that a low tidal volume and low pressure strategy improved outcomes. Subsequent trials have tried to determine the optimal PEEP level in patients with moderate to severe ARDS. The use of esophageal balloons provides information about the transpulmonary pressure at the end of inspiration and the transpulmonary pressure at the end of expiration. However, available studies to date do not demonstrate a definite improvement in outcomes in patients with ventilator adjustments based on esophageal pressures. Beitler et al. randomized 200 patients with moderate to severe ARDS into one group in which PEEP titration was based on esophageal balloon pressure measurements, and a second group in which PEEP titration was based on a high FiO2/PEEP table studied in earlier trials. There were no differences in mortality between the two groups. Reanalysis of this information after the trial was completed suggested that transpulmonary pressures in the range of -2 to + 2 cm H2O at the end of expiration were associated with improved outcomes compared to pressures outside that range.

Impact of Esophageal Pressure Measurement on Pulmonary Hypertension Diagnosis in Patients With Obesity

Elevated intrathoracic pressure could affect pulmonary vascular pressure measurements and influence pulmonary hypertension (PH) diagnosis and classification. Esophageal pressure (Pes) measurement adjusts for the increase in intrathoracic pressure, better reflecting the pulmonary hemodynamics in patients with obesity. In individuals with obesity, what is the impact of adjusting pulmonary hemodynamic determinations for Pes on PH diagnosis and classification? Can Pes be estimated by positional or respiratory hemodynamic changes? In this prospective cohort study, we included patients with obesity who underwent right heart catheterization and demonstrated elevated pulmonary artery wedge pressure (PAWP;≥ 12mmHg). After placement of an esophageal balloon, we performed pressure determination using an air-filled transducer connected to a regular hemodynamic monitor. We measured pulmonary pressures changes when sitting and the variations during the respiratory cycle. We included 53 patients (mean ± SD age, 59 ± 12 years; mean ± SD BMI, 44.4 ± 10.2kg/m2). Supine end-expiratory pressures revealed a mean pulmonary artery pressure of > 20mmHg in all patients and a PAWP of >15mmHg in most patients (n= 50). The Pes adjustment led to a significant decrease in percentage of patients with postcapillary PH (from 60%to 8%) and combined precapillary and postcapillary PH (from 34%to 11%), at the expense of an increase in percentage of patients with no PH (0%to 23%), isolated precapillary PH (2%to 25%), and undifferentiated PH (4%to 34%). Adjusting pulmonary hemodynamics for Pes in patients with obesity leads to a pronounced reduction in the number of patients who receive a diagnosis of postcapillary PH. Measuring Pes should be considered in patients with obesity, particularly those with elevated PAWP.

Progression of type B intramural hematoma in patients with obstructive sleep apnea

ObjectiveIn the present study, we estimated the influence of obstructive sleep apnea (OSA) on the progression of type B intramural hematoma (IMHB). MethodsA total of 127 patients had undergone sleep evaluations and esophageal pressure measurements. The variables associated with aorta-related adverse events and mortality were summarized by logistic regression analysis and Cox proportional hazard models. A competing risk analysis of death was used to estimate aorta- and non–aorta-related mortality. ResultsThe OSA group had a greater aorta-related adverse events rate (46% vs 4%; P < .001). The mean nighttime systolic pressure (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.11-1.38; P < .001) was associated with aorta-related adverse events during the acute phase. Thoracic endovascular aortic repair (hazard ratio [HR], 16.2; 95% CI, 7.68-34.22, P < .001) and mean morning systolic pressure (HR, 1.43; 95% CI, 1.22-1.68; P < .001) were associated with a higher rate of aorta-related adverse events. OSA (HR, 3.19; 95% CI, 2.57-12.15; P < .001) and mean morning systolic pressure (HR, 1.59; 95% CI, 1.27-2.01; P = .002) were significantly associated with aorta-related mortality. Competing risk analysis revealed significantly higher aorta-related mortality in the OSA group (11.8% vs 2.0%; P = .0412). A neutrophil/lymphocyte ratio >3.52 (specificity, 90.2%; sensitivity, 89.5%) and mean platelet volume/platelet ratio >0.049 (specificity, 98.0%; sensitivity, 98.7%) had diagnostic value for detecting OSA in patients with IMHB. ConclusionsThe presence of OSA led to a higher aorta-related adverse event rate and mortality in patients with IMHB. The variables associated with these outcomes included thoracic endovascular aortic repair, mean morning and nighttime systolic pressure, and OSA. The neutrophil/lymphocyte ratio and platelet volume/platelet ratio are valuable for detecting OSA in patients with IMHB.