Ventilation Maneuvers Research Articles

Successful application of airway pressure release ventilation in a child with severe acute respiratory distress syndrome induced by trauma: a case report

BackgroundTrauma has been identified as one of the risk factors for acute respiratory distress syndrome. Respiratory support can be further complicated by comorbidities of trauma such as primary or secondary lung injury. Conventional ventilation strategies may not be suitable for all trauma-related acute respiratory distress syndrome. Airway pressure release ventilation has emerged as a potential rescue method for patients with acute respiratory distress syndrome and hypoxemia refractory to conventional mechanical ventilation. However, there is a lack of research on the use of airway pressure release ventilation in children with trauma-related acute respiratory distress syndrome. We report a case of airway pressure release ventilation applied to a child with falling injury, severe acute respiratory distress syndrome, hemorrhagic shock, and bilateral hemopneumothorax. We hope this case report presents a potential option for trauma-related acute respiratory distress syndrome and serves as a basis for future research.Case presentationA 15-year-old female with falling injury who developed severe acute respiratory distress syndrome, hemorrhagic shock, and bilateral hemopneumothorax was admitted to the surgical intensive care unit. She presented refractory hypoxemia despite the treatment of conventional ventilation with deep analgesia, sedation, and muscular relaxation. Lung recruitment was ineffective and prone positioning was contraindicated. Her oxygenation significantly improved after the use of airway pressure release ventilation. She was eventually extubated after 12 days of admission and discharged after 42 days of hospitalization.ConclusionAirway pressure release ventilation may be considered early in the management of trauma patients with severe acute respiratory distress syndrome when prone position ventilation cannot be performed and refractory hypoxemia persists despite conventional ventilation and lung recruitment maneuvers.

Pressure- and time-dependent alveolar recruitment/derecruitment in a spatially resolved patient-specific computational model for injured human lungs.

We present a novel computational model for the dynamics of alveolar recruitment/derecruitment (RD), which reproduces the underlying characteristics typically observed in injured lungs. The basic idea is a pressure- and time-dependent variation of the stress-free reference volume in reduced dimensional viscoelastic elements representing the acinar tissue. We choose a variable reference volume triggered by critical opening and closing pressures in a time-dependent manner from a straightforward mechanical point of view. In the case of (partially and progressively) collapsing alveolar structures, the volume available for expansion during breathing reduces and vice versa, eventually enabling consideration of alveolar collapse and reopening in our model. We further introduce a method for patient-specific determination of the underlying critical parameters of the new alveolar RD dynamics when integrated into the tissue elements, referred to as terminal units, of a spatially resolved physics-based lung model that simulates the human respiratory system in an anatomically correct manner. Relevant patient-specific parameters of the terminal units are herein determined based on medical image data and the macromechanical behavior of the lung during artificial ventilation. We test the whole modeling approach for a real-life scenario by applying it to the clinical data of a mechanically ventilated patient. The generated lung model is capable of reproducing clinical measurements such as tidal volume and pleural pressure during various ventilation maneuvers. We conclude that this new model is an important step toward personalized treatment of ARDS patients by considering potentially harmful mechanisms-such as cyclic RD and overdistension-and might help in the development of relevant protective ventilation strategies to reduce ventilator-induced lung injury (VILI).

Natural shear wave measurements detect changes in operational stiffness induced by mechanical ventilation in sheep

Abstract Shear wave elastography (SWE) has the potential to non-invasively measure myocardial stiffness, based on the propagation speed of shear waves traveling through the myocardium after valve closure. However, shear wave propagation speed (SWS) is related to the operational stiffness of the heart, which is defined by the slope of the end-diastolic stress-strain relationship at the operating volume/pressure. Therefore, operational stiffness can be altered by both changes in intrinsic myocardial stiffness and myocardial loading conditions. We aimed to investigate whether SWE can detect differences in operational stiffness induced by loading changes during mechanical ventilation, and whether SWE combined with respiratory hold manoeuvres could detect an evolution in stiffness during the course of ischemic cardiomyopathy (ICM). We assessed SWS in 8 sedated and mechanically ventilated sheep: 1 healthy control, 3 within 8 weeks, and 4 after at least 16 weeks following left coronary artery ligation (early vs. late ICM). Left ventricular parasternal long-axis views were acquired with a state-of-the-art ultrasound scanner with high frame rate technology (> 1100 Hz). Shear waves after mitral valve closure were considered during an inspiratory hold at 30 cmH2O and 15 cmH2O and expiratory hold at 0 cmH2O (atmospheric pressure). We used linear regression to assess the trend of the SWS during ventilation manoeuvres per animal and a two-tailed Student’s T-test to assess changes between ICM stages and their respective response to ventilation manoeuvres. In all but one sheep, SWS declined with higher inspiratory pressures (see fig. 1), possibly due to a reduction in preload at higher inspiratory pressures resulting in a shift towards a reduced slope on the myocardial stress-strain relation. The sheep with a positive slope was excluded from further analyses. SWS during expiratory hold at atmospheric pressure was 3.4 m/s in the healthy control and was significantly lower in early vs. late ICM (mean±SD 4.0±0.6 vs. 9.0±1.7 m/s; p=0.007). Furthermore, the change in SWS was larger in late vs. early ICM (slope of regression line -0.16 vs. -0.05 m/s/cmH2O; p=0.03). These observations suggest loading on a steeper part of the end-diastolic stress strain relationship in late ICM. In conclusion, our results suggest that SWE is able to detect differences in operational stiffness induced by mechanical ventilation. Secondly, SWE appears to distinguish between different time points in the course of ICM based on the magnitude of the SWS during expiratory hold at atmospheric pressure, but also on the magnitude of the SWS change during loading alterations induced by mechanical ventilation. Further work should assess whether SWE combined with respiratory hold manoeuvres could contribute to differentiate intrinsic from hemodynamic stiffening, and to exploit its full potential as a non-invasive bedside method for the assessment of operational stiffness.

A meta-analysis of conventional assisted ventilation versus continuous lung recruitment maneuver in preterm infants.

A meta-analysis of conventional assisted ventilation versus continuous lung recruitment maneuver in preterm infants.

Rebounds of sevoflurane concentration during simulated trigger-free pediatric and adult anesthesia

BackgroundIn trigger-free anesthesia a volatile anesthetic concentration of 5 parts per million (ppm) should not be exceeded. According to European Malignant Hyperthermia Group (EMHG) guideline, this may be achieved by removing the vapor, changing the anesthetic breathing circuit and renewing the soda lime canister followed by flushing with O2 or air for a workstation specific time. Reduction of the fresh gas flow (FGF) or stand-by modes are known to cause rebound effects. In this study, simulated trigger-free pediatric and adult ventilation was carried out on test lungs including ventilation maneuvers commonly used in clinical practice. The goal of this study was to evaluate whether rebounds of sevoflurane develop during trigger-free anesthesia.MethodsA Dräger® Primus® was contaminated with decreasing concentrations of sevoflurane for 120 min. Then, the machine was prepared for trigger-free anesthesia according to EMHG guideline by changing recommended parts and flushing the breathing circuits using 10 or 18 l⋅min− 1 FGF. The machine was neither switched off after preparation nor was FGF reduced. Simulated trigger-free ventilation was performed with volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) including various ventilation maneuvers like pressure support ventilation (PSV), apnea, decreased lung compliance (DLC), recruitment maneuvers, prolonged expiration and manual ventilation (MV). A high-resolution ion mobility spectrometer with gas chromatographic pre-separation was used to measure sevoflurane in the ventilation gas mixture in a 20 s interval.ResultsImmediately after start of simulated anesthesia, there was an initial peak of 11–18 ppm sevoflurane in all experiments. The concentration dropped below 5 ppm after 2–3 min during adult and 4–18 min during pediatric ventilation. Other rebounds of sevoflurane > 5 ppm occurred after apnea, DLC and PSV. MV resulted in a decrease of sevoflurane < 5 ppm within 1 min.ConclusionThis study shows that after guideline-compliant preparation for trigger-free ventilation anesthetic machines may develop rebounds of sevoflurane > 5 ppm during typical maneuvers used in clinical practice. The changes in rate and direction of internal gas flow during different ventilation modes and maneuvers are possible explanations. Therefore, manufacturers should provide machine-specific washout protocols or emphasize the use of active charcoal filters (ACF) for trigger-free anesthesia.

Ultrasound-Guided Popliteal Artery Cannulation: An Alternative for Emergency Arterial Cannulation During Prone Position

ABSTRACT Arterial cannulation is an essential procedure for invasive blood pressure measurement as well as repeated arterial blood gas sampling in intensive care unit setting. Common sites for placing an arterial cannula are the radial artery, femoral artery, brachial artery, and dorsalispedis artery. In certain situations such as in the case of prone ventilation, arterial cannula from common peripheral sites may get accidentally disconnected and it becomes very difficult for even a senior anesthesiologist to place an arterial cannula in the prone position. In those circumstances, an alternate site such as the popliteal artery may serve as a site for arterial cannulation. Therefore, here we present three cases of severe acute respiratory distress syndrome, whose arterial cannula was accidentally dislodged during prone ventilation maneuver and were successfully managed by ultrasound-guided popliteal artery cannulation.

The effectiveness of the respiratory muscles in children with oncohematological diseases after hematopoietic stem cell transplantation

The article analyzes the effectiveness of the respiratory muscles by measuring inspiratory mouth occlusion pressure at 0.1 seconds during quiet breathing (P0.1) and maximum voluntary ventilation maneuver (P0.1 max ) in children with acute leukemia and acquired idiopathic aplastic anemia after allogeneic hematopoietic stem cell transplantation (HSCT). We carried out a comparative analysis of the Р0.1 and Р0.1 max values measured before HSCТ and on days +30, +90, +180 and +360. In a group of patients with acquired idiopathic aplastic anemia, we revealed a significant decrease in these values starting from day +30, followed by a recovery to baseline values by one year of follow-up. In children with acute leukemia, effectiveness of the respiratory muscles was increased after 360 days of transplantation as a result of the aggravation of impaired ventilation. This method for measuring airway occlusion pressure can be used in a comprehensive assessment of the functional state of the respiratory system for the timely diagnosis of pulmonary complications after HSCT. The study was approved by the Independent Ethics Committee and the Scientific Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation.

PO-02-106 GENERAL ANESTHESIA VERSUS CONSCIOUS SEDATION WITH LOCOREGIONAL ANESTHESIA IN S-ICD IMPLANTATION: A MONOCENTRIC RETROSPECTIVE ANALYSIS

In patients not requiring pacing, the subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as a safe and effective alternative to the transvenous implantable cardioverter-defibrillator (TV-ICD) for the treatment of life-threatening ventricular arrhythmias. The S-ICD’s larger size requires a larger pocket for insertion and peri-procedural lead tunnelling carries high nociceptive potential, resulting historically in 65% of S-ICD implantations being performed under general anesthesia (GA). This study seeks to demonstrate that conscious sedation with locoregional anesthesia (CS-LA) is a safe and effective alternative to general anesthesia (GA) in S-ICD implantation. A total of 138 S-ICD implantations (90 under CS-LA) at our institution between 2013 and 2020 were studied The CS-LA technique was performed with conscious sedation, local anesthesia of the pocket and xyphoid incision sites, and post-procedural intercostal nerve blocade of the 4th to 7th intercostal spaces with a mixture of 10mL of 0.5% bupivacaine and 20mL of 2% lidocaine without epinephrine. Analgesic efficacy in the 24 post-operative hours was evaluated by Numerical Pain Rating Scale (NPRS) score and by total analgesic medication dosage received. Safety was evaluated by comparing the incidence of significant adverse events (AE): hypotension <80 mmHg or requiring vasopressors, bradycardia <40 bpm, or desaturation <90% for more than two minutes or requiring non-invasive ventilation maneuvers. Post-procedural pain at 15 minutes and at 24 hours was significantly less in the CS-LA group, with a difference of -0.90 (p=0.04) and -1.21 (p=0.004) respectively. Post-procedural opioid consumption was 10.64mg of per os morphine equivalents (p=0.046) lower than in the CS-LA group. No significant difference in the likelihood of at least one adverse event occurring was noted, with CS-LA demonstrating OR 1.95 (95% CI [0.86, 4.40], p=0.11) for at least one AE. Only one patient in the CS-LA arm required conversion to GA, due to excessive agitation during the procedure. S-ICD implantation under CS-LA was superior at 15 minutes and 24 hours to GA in terms of analgesic efficacy and post-procedural patient comfort. CS-LA’s safety profile was similar to GA, with no significantly increased risk of suffering at least one adverse event.

Real-Time Intubation and Ventilation Feedback: A Randomized Controlled Simulation Study.

This study aimed to determine the best educational application of a respiratory function monitor and a video laryngoscope. This study was a randomized controlled simulation-based trial, including 167 medical students. Participants had to execute ventilation and intubation maneuvers on a newborn manikin. Participants were randomized into 3 groups. In group A (no-access), the feedback devices were not visible but recording. In group B (supervisor-access), the feedback devices were visible to the supervisor only. In group C (full-access), both the participant and the supervisor had visual access. The two main outcome variables were the percentage of ventilations within the tidal volume target range (4-8mL/kg) and the number of intubation attempts. Group C achieved the highest percentage of ventilations within the tidal volume target range (full-access 63.6%, supervisor-access 51.0%, no-access 31.1%, P < .001) and the lowest mask leakage (full-access 34.9%, supervisor-access 46.6%, no-access 61.6%; A to B: P < .001, A to C: P < .001, B to C: P = .003). Overall, group C achieved superior ventilation quality regarding primary and secondary outcome measures. The number of intubation attempts until success was lowest in the full-access group (full-access: 1.29, supervisor-access: 1.77, no-access: 2.43; A to B: P = .001, A to C: P < .001, B to C: P = .015). Our findings confirm that direct visual access to feedback devices for supervisor and trainees alike considerably benefits outcomes and can contribute to the future of clinical education.

Retrocardiac Pneumomediastinum: Description of an Unusual Case and Review of Literature

Retrocardiac pneumomediastinum (RP) is the consequence of air trapping in the inferior and posterior mediastinum. It is characterized by the presence of a right or left para-sagittal infrahilar oval or pyramidal air collection on a chest X-ray. It is usually detected in neonates because of alveolar rupture after invasive ventilation or invasive manoeuvres applied on airways or the digestive tract. A healthy child came to the emergency department (ED) for acute respiratory failure due to viral bronchiolitis when he was 2 months old. Because of his clinical condition, he underwent helmet continuous positive airway pressure (HCPAP). When the condition allowed, he was discharged and sent home. He was re-admitted into the hospital for asthmatic bronchitis 3 months later. A frontal chest X-ray taken during the second hospitalization showed an oval-shaped retrocardiac air lucency not previously detected. Differential diagnosis including digestive and lung malformations was made. Finally, the diagnosis of RP was made. We report an unusual case of retrocardiac pneumomediastinum in a 5-month-old male infant after the application of continuous positive pressure via a helmet. RP presentation after the administration of non-invasive ventilatory support beyond the neonatal age is unusual. Although surgical drainage is curative, conservative treatment can be considered in hemodynamically stable patients.

Volume-controlled ventilation versus pressure-controlled ventilation and recruitment maneuvers in video-assisted thoracoscopic surgery

Volume-controlled ventilation versus pressure-controlled ventilation and recruitment maneuvers in video-assisted thoracoscopic surgery

Successful Recovery After Veno-Arterio-Venous Extracorporeal Membrane Oxygenation Immediately Before Liver Transplantation in Multi-Organ Failure Including Acute Respiratory Distress Syndrome: A Case Report

Extracorporeal membrane oxygenation (ECMO) has emerged as an alternative treatment to conventional ventilation maneuvers in the nontransplantation literature to support acute respiratory distress syndrome. However, the role of ECMO in transplant is unclear, and few case reports have described using ECMO pretransplant. We discuss the successful use of veno-arteriovenous ECMO as a bridge therapy to deceased donor liver transplant (LT) in acute respiratory distress syndrome. Because the incidence of severe pulmonary complications resulting in acute respiratory distress syndrome with multiorgan failure is rare before LT, determining the usefulness of ECMO is challenging. However, in acute but reversible respiratory failure and cardiovascular failure, veno-arteriovenous ECMO provides a useful therapeutic option as a bridge for patients awaiting LT and should be considered if available even in multiorgan failure.

Analysis of the impact of pronation maneuver in patients on mechanical ventilation with diagnosis of pneumonia by Covid-19 and acute respiratory distress syndrome

Objective: To analyze the profile of patients on invasive mechanical ventilation with SARS-CoV-2 pneumonia who were pronated and who developed acute respiratory distress syndrome. Methods: Historical cohort study through the analysis of a database containing 282 patients hospitalized in a large university hospital in the city of Porto Alegre, Brazil. The population studied included individuals infected with SARS-CoV-2 and with a clinical course marked by severe pneumonia and, mainly, by acute respiratory distress syndrome, submitted to mechanical ventilation and invasive pronation maneuver. Results: Database analysis showed a high mortality rate for all patient groups and a high case fatality rate, especially in elderly patients and in individuals with active oncologic disease or with chronic kidney disease. Conclusions: The high overall mortality rate, as well as the high lethality, especially in elderly patients and in individuals with active oncologic disease or with chronic kidney disease, suggests that, for certain specific population groups, the prone maneuver is not effective in reducing high. mortality caused by acute respiratory distress syndrome associated with COVID-19.

Advanced maneuvers in neonatal resuscitation at a hospital in the amazon region: associated factors

Objective: To analyze among newborns that required resuscitation the probability of chances between the need for advanced procedures and demographic and obstetric characteristics, use of substances and intercurrences during pregnancy. Methods: Descriptive and multivariate analytical study, carried out in a maternity hospital in the Amazon region. All medical records of newborns in 2018 were researched, and those with missing data and Cook’s distance &lt;0,20 were excluded. The remaining were divided by the intervention performed: positive pressure ventilation or advanced maneuvers (orotracheal intubation, direct laryngoscopy, cardiac massage, drugs or CPAP mask). The variables analyzed were demographic and obstetric characteristics, use of substances and intercurrences during pregnancy. Logistic regression was used to derive unadjusted and adjusted odds ratios and 95% confidence intervals. Results: 1611 infants went through resuscitation. Out of them, 217 were excluded, due to missing data and Cook’s distance &lt;0,20. 41,2% of the the remaining 1394 required advanced maneuvers. Adjusted odds ratio revealed significant association between needing advanced resuscitation and low gestational age (5 times higher chances), 5th minute Apgar &lt;7 (28 times higher chances), tobacco (9 times higher chances), small for gestational age (6 times higher chances), low birth weight (4-5 times higher chances), meconium (double chances), not specified gestational intercurrences (3 times higher chances) and absence of gestational diabetes (6 times higher chances). Conclusions: Prematurity, low birth weight, 5th minute Apgar &lt;7, small for gestational age, meconium and tobacco were associated with higher chances of advanced maneuvers.

Lung Transplant for Patients with COVID-19 Bridged with VV ECMO: Initial Experience

PurposeDuring the COVID-19 pandemic, veno-venous Extracorporeal Membrane Oxygenation (VV ECMO) has been used extensively for respiratory failure refractory to conventional mechanical ventilation (MV) and rescue maneuvers. However, the worldwide experience with COVID-19 patients undergoing lung transplant (LTx) with pre-LTx VV ECMO support is limited. Therefore, we sought to report our institution's early experience with COVID-19 patients who underwent LTx after VV ECMO.MethodsWe retrospectively identified 5 COVID-19 patients who underwent LTx after VV ECMO support. Patients were required to have a negative nasopharyngeal swab and a negative bronchoalveolar lavage for COVID-19 prior to LTx listing. We analyzed preoperative and operative characteristics, details of VV ECMO support and early post-transplant outcomes.ResultsThe mean age of our cohort was 50 years (range 39-57 years) and all patients were male. Mean recipient BMI was 30 (range 22-37). Mean duration of VV ECMO pre-Ltx was 60 days (range 44-72 days). At the time of the LTx operation, 60% (3/5) of patients were on VV ECMO, 20% (1/5) were on mechanical ventilation (MV), and 20% (1/5) were on supplemental oxygen only. Preoperatively, 80% (4/5) had acute kidney injury and 20% (2/5) were on dialysis. LTx was performed via clamshell approach with intraoperative venoaterial ECMO support in all cases. For 60% (3/5) patients, VV ECMO support was continued after LTx and discontinued on postoperative days 0, 1 and 6, respectively. All-cause mortality was 40% (2/5), related to sepsis and multi-organ failure, and both deaths occurred an average of 115 days post-LTx. Mean length of stay for surviving patients was 59 days (range 22-117). In the first 3 months postop-LTx, grade A2 acute cellular rejection was noted in 2 patients, A1 in 2 patients, and antibody-mediated rejection in 1 patient.ConclusionOur early experience with LTx for COVID-19 patients supported with VV ECMO support is notable for 1) prolonged VV-ECMO duration and significant morbidity pre-LTx, and 2) early mortalities related to sepsis and multiple organ failure. These data highlight a uniquely complex patient population that carries high risk of multi-organ failure and other comorbidities dictating careful selection for transplant.

Continuous measurement of arterial oxygenation in mechanically ventilated horses.

The possibility of accurately and continuously measuring arterial oxygen partial pressure (PaO2 ) in horses may facilitate the management of hypoxaemia during general anaesthesia. The aim of this study was to evaluate the ability of a novel fibreoptic sensor to measure PaO2 (PaO2Sensor ) continuously and in real time in horses undergoing ventilatory manoeuvres during general anaesthesia. In vivo experimental study. Six adult healthy horses were anaesthetised and mechanically ventilated in dorsal recumbency. A fibreoptic sensor was placed in one of the facial arteries through a catheter to continuously measure and record PaO2Sensor . After an alveolar recruitment manoeuvre, a decremental positive end-expiratory pressure (PEEP) titration using 20-minute steps of 5cmH2 O from 20 to 0cmH2 O was performed. An arterial blood sample was collected at 15minutes of ventilation at each PEEP level for PaO2 measurement using an automated blood gas machine (PaO2Ref ). The agreement between PaO2Sensor and PaO2Ref was assessed by Pearson's correlation, Bland-Altman plot and four-quadrant plot analysis. In the last minute of ventilation at each PEEP level, a slow tidal inflation/deflation manoeuvre was performed. The mean relative bias between PaO2Sensor and PaO2Ref was 4% with limits of agreement between -17% and 29%. The correlation coefficient between PaO2Sensor and PaO2Ref was 0.98 (P<.001). The PaO2Sensor and PaO2Ref concordance rate for changes was 95%. Measurements of PaO2Sensor during the slow inflation/deflation manoeuvre at PEEP 15 and 10cmH2 O were not possible because of significant noise on the PaO2 signal generated by a small blood clot. Small sample size. The tested fibreoptic probe was able to accurately and continuously measure PaO2Sensor in anaesthetised horses undergoing ventilatory manoeuvres. A heparinised system in the catheter used by the fibreoptic sensor should be used to avoid blood clots and artefacts in the PaO2 measurements.

Qual o conhecimento em ressuscitação cardiopulmonar e uso do desfibrilador externo automático por estudantes de medicina?

Cardiopulmonary resuscitation (CPR) consists of a procedure where there is a combination of chest compressions and ventilation maneuvers, to reverse cardiac arrest (CRA). The medical student's knowledge in CPR identification, CPR maneuvers and AED use is important to be evaluated, allowing to verify their emergency care skills, contributing to save lives, besides making them potential knowledge multipliers. The aim of the present study was to evaluate medical students' knowledge regarding the parameters for CPR identification and CPR performance. This was an observational and cross-sectional study of medical students' theoretical knowledge of CPR, using an anonymous short-answer questionnaire and data analysis using Excel and Minitab software. It was possible to observe that most students considered themselves capable of identifying a victim in CPR. However, half of the total number of interviewees did not consider themselves capable of performing CPR. It is observed that there is a need for the implementation of practical training modules for these students, to increase their safety for action.

GENERAL ANESTHESIA VERSUS CONSCIOUS SEDATION WITH LOCOREGIONAL ANESTHESIA IN S-ICD IMPLANTATION: A MONOCENTRIC RETROSPECTIVE ANALYSIS

GENERAL ANESTHESIA VERSUS CONSCIOUS SEDATION WITH LOCOREGIONAL ANESTHESIA IN S-ICD IMPLANTATION: A MONOCENTRIC RETROSPECTIVE ANALYSIS

Effect Of Controlled Ventilatory Maneuver On Military Performance In The Basic Military Shooting Test

Effect Of Controlled Ventilatory Maneuver On Military Performance In The Basic Military Shooting Test

SLL-PEEP Ventilation to Improve Exposure in Minimally Invasive Right Anterolateral Minithoracotomy Aortic Valve Replacement.

An accepted landmark to assess feasibility of surgical aortic valve replacement (SAVR) via right anterolateral minithoracotomy (RALT) is the aortic-midpoint to right-sternal-edge distance. We aimed to evaluate single left lung positive-end-expiratory-pressure (SLL-PEEP) ventilation inducing an intraoperative rightward shift of the ascending aorta to improve exposure. Nineteen patients with aortic stenosis undergoing SAVR via RALT were prospectively analyzed. SLL-PEEP ventilation (20,395 cmH2O) via a double-lumen endotracheal tube was applied immediately before transthoracic aortic cross-clamping, thereby inducing rightward shift of the ascending aorta to enhance exposure. We analyzed preoperative computed tomography (CT) reconstructions and intraoperative video recordings. Primary endpoint was extent of rightward shift induced by SLL-PEEP ventilation; secondary endpoints were procedure times and safety events. Mean age was 61 ± 14.8 years and 6 of 19 (31.6%) were female. Mean EuroSCORE II was 0.81% ± 0.04%, STS-PROM was 1.13% ± 0.74%, and mean aortic rightward shift induced by SLL-PEEP ventilation was 10.32 ± 4.14 mm (4 to 17 mm; P = 0.003). Median shift in the group considered suitable for the RALT approach by preoperative CT-scan evaluation was 14.2 mm (IQR 11) and in the less suitable group 11.5 mm (IQR 5). Mean procedure time was 167 ± 28.9 min, CPB time was 105.7 ± 18.4 min, and cross-clamp time was 64.5 ± 13 min. Fifteen patients (79%) received SAVR via RALT with implantation of a bioprosthesis, whereas a rapid-deployment-prosthesis was used in 4 patients (21%). Ten of 19 (53%) patients who were classified as less suitable preoperatively received SAVR via RALT after SLL-PEEP ventilation. No strokes were observed. The SLL-PEEP ventilation maneuver during SAVR via RALT significantly enhances aortic exposure. There were no safety events associated with this maneuver and we were able to demonstrate significant rightward aortic shift in every single patient.