Mitigation of Exercise Oscillatory Ventilation Score by Cardiac Resynchronization Therapy.

BACKGROUND: Exercise oscillatory ventilation (EOV) is a consequence of ventilatory control system instability and is commonly observed in patients with advanced heart failure (HF); it is associated with adverse prognosis. The goal of this study was to evaluate the effects of cardiac resynchronization therapy (CRT) on oscillatory ventilation as quantified by a proposed EOV score. METHODS AND RESULTS: Consecutive patients with HF (N = 35) who underwent clinically indicated CRT, cardiopulmonary exercise testing and carbon dioxide (CO2) chemosensitivity by rebreathe before and 4-6 months after CRT were included in this post hoc analysis. With CRT, EOV scores improved in 22 patients (63%). In these patients, left ventricular ejection fraction, left atrial volume, brain natriuretic peptide concentration, and CO2 chemosensitivity significantly improved after CRT (P < 0.05). Furthermore, minute ventilation per unit CO2 production significantly decreased, and end-tidal CO2 increased at rest and at peak exercise post-CRT. Multiple regression analysis showed only the change of CO2 chemosensitivity to be significantly associated with the improvement of the EOV score (b = 0.64; F = 11.3; P = 0.004). In the group without EOV score improvement (n = 13), though left ventricular ejection fraction significantly increased with CRT (P = 0.015), no significant changes in ventilation or gas exchange were observed. CONCLUSION: The EOV score was mitigated by CRT and was associated with decreased CO2 chemosensitivity.

Transbronchial biopsy from the upper pulmonary lobes is associated with increased risk of pneumothorax - a retrospective study.

BACKGROUND: Pneumothorax (PTX) is one of the most common complications of transbronchial biopsy (TBB). Previous research suggests that upper pulmonary lobe TBB may be associated with increased risk of PTX development. The aim of this study was to compare the risk of PTX after TBB performed from different pulmonary lobes. METHODS: All bronchoscopic records from the period January 1st, 2015 - December 31st, 2017 (from the Department of Respiratory Diseases, University Hospital Brno, Czech Republic) were retrospectively analyzed. Of the 3542 bronchoscopic records, 796 patients underwent TBB and were further analyzed. Basic demographic data, TBB procedure-related factors, smoking history and radiological features were analyzed. Furthermore, in patients who developed PTX, PTX onset, PTX symptoms, distribution of the abnormal radiological findings and duration of hospitalization were also analyzed. RESULTS: Patients who developed PTX had significantly lower body mass index (BMI) and more than 4 samples taken during procedure (all p < 0.05). TBB performed from the left upper pulmonary lobe was associated with a significant risk of PTX development (OR 2.27; 95% CI 1.18-4.35; p = 0.02). On the contrary, TBB performed from the right lower lobe was associated with a significant reduction of risk of developing PTX (OR 0.47; 95% CI 0.22-0.98; p = 0.04). Logistic regression analysis showed BMI (OR 1.08; 95% CI 1.02-1.16; p = 0.01), left upper lobe as sampling site (OR 2.15; 95% CI 1.13-4.11; p = 0.02) and more than 4 samples taken (OR 1.91; 95% CI 1.04-3.49; p = 0.04) to be significantly associated with PTX development. CONCLUSIONS: We conclude that TBB from the left upper pulmonary lobe is associated with significantly increased risk of post-procedural PTX. The right lower pulmonary lobe seems to be the safest sampling site to perform TBB. In patients with diffuse-type pulmonary disease, TBB should be performed preferably from the right lower lobe in order to decrease the risk of post-procedural PTX.

Ventilatory Efficiency Identifies Patients Prone to Hypoxemia During One-Lung Ventilation.

OBJECTIVES: One-lung ventilation (OLV) may be complicated by hypoxemia. Ventilatory efficiency, defined as the ratio of minute ventilation to carbon dioxide output (VE/VCO2), is increased with ventilation/perfusion mismatch and pulmonary artery hypertension, both of which may be associated with hypoxemia. Hence, the authors hypothesized increased VE/VCO2 will predict hypoxemia during OLV. DESIGN: Prospective observational study. SETTING: Single-center, university, tertiary care hospital. PARTICIPANTS: The study comprised 50 consecutive lung resection candidates. INTERVENTIONS: All patients underwent cardiopulmonary exercise testing before surgery. Patients who required inspired oxygen fraction (FiO2) ≥0.7 to maintain arterial oxygen (O2) saturation >90% after 30 minutes of OLV were considered to be hypoxemic. The Student t or Mann-Whitney U test were used for comparison of patients who became hypoxemic and those who did not. Multiple regression analysis adjusted for age, sex, and body mass index was used to evaluate which parameters were associated with the VE/VCO2 slope. Data are summarized as mean ± standard deviation. MEASUREMENTS AND MAIN RESULTS: Twenty-four patients (48%) developed hypoxemia. There was no significant difference in age, sex, and body mass index between hypoxemic and nonhypoxemic patients. However, patients with hypoxemia had a significantly higher VE/VCO2 slope (30 ± 5 v 27 ± 4; p = 0.04) with exercise and lower partial pressure of oxygen/FiO2 (129 ± 92 v 168 ± 88; p = 0.01), higher mean positive end-expiratory pressure (6.6 ± 1.5 v 5.6 ± 0.9 cmH2O; p = 0.02), and lower mean pulse oximetry O2 saturation/FiO2 index (127 ± 20 v 174 ± 17; p < 0.01) during OLV. Multiple regression showed VE/VCO2 to be independently associated with the mean pulse oximetry O2 saturation/FiO2 index (b = -0.28; F = 3.1; p = 0.05). CONCLUSIONS: An increased VE/VCO2 slope may predict hypoxemia development in patients who undergo OLV.

Low leptin concentration may identify heart failure patients with central sleep apnea.

Low leptin concentration has been shown to be associated with central sleep apnea in heart failure patients. We hypothesized that low leptin concentration predicts central sleep apnea. Consecutive ambulatory New York Heart Association (NYHA) classes I-IV heart failure patients were studied prospectively, including measurement of serum leptin, echocardiography and polysomnography. Sleep apnea was defined by type (central/mixed/obstructive) and by apnea-hypopnea index ≥5 by polysomnography. Subjects were divided into four groups by polysomnography: (1) central sleep apnea, (2) mixed apnea, (3) no apnea and (4) obstructive sleep apnea. Fifty-six subjects were included. Eighteen subjects were diagnosed with central sleep apnea, 15 with mixed apnea, 12 with obstructive apnea and 11 with no sleep apnea. Leptin concentration was significantly lower in central sleep apnea compared to obstructive apnea (8 ± 10.7 ng mL-1 versus 19.7 ± 14.7 ng mL-1 , P Ë‚ 0.01) or no sleep apnea (8 ± 10.7 ng mL-1 versus 17.1 ± 8.4 ng mL-1 , P Ë‚ 0.01). Logistic regression showed leptin to be associated independently with central sleep apnea [odds ratio (OR): 0.19; 95% confidence interval (CI): 0.06-0.62; area under the curve (AUC): 0.80, P < 0.01]. For the detection of central sleep apnea, a cut-off value for leptin concentration 5 ng mL-1 yielded a sensitivity of 50% and specificity of 89%. In conclusion, a low leptin concentration may have utility for the screening of heart failure patients for central sleep apnea.

Is it intestinal tuberculosis again? Case report.

This case report focuses on an immigrant admitted to the Department of Respiratory Diseases, University Hospital Brno due to suspicion of relapsing intestinal tuberculosis. The patient presented with fever, night sweat, weight loss, diarrhea, and a history of several tuberculosis attacks in the last few years. None of the examinations confirmed the presence of active tuberculosis but raised suspicion of hematological malignancy. Pancytopenia was present in the peripheral blood. However, bone marrow examination and flowcytometry excluded the presence of a hematological malignancy. The results pointed to the possibility of vitamin B12 or folate deficiency that were both confirmed consequently by serum biochemical tests. Cobalamin and folate deficiency were caused by short bowel syndrome that developed after a major intestinal resection that the patient underwent in his past. Combined treatment including vitamins, pancreatic enzymes substitution, antidiarrhoics and spasmolytics was administered. The general health status of the patient improved rapidly with restitution of hematopoiesis, weight gain, and a decrease by 80% in daily number of stools. Clinical appearance of intestinal tuberculosis, short bowel syndrome and of cobalamin and folate deficiency as well as pathophysiology, diagnosis and treatment of these uncommon or even rare diseases are discussed in this case report.Key words: intestinal tuberculosis - pancytopenia - short bowel syndrome - vitamin B12 deficiency.

Modulation of ventilatory reflex control by cardiac resynchronization therapy.

BACKGROUND: Heart failure (HF) is characterized by heightened sensitivities of the CO2 chemoreflex and the ergoreflex which promote increased ventilatory drive manifested as increased minute ventilation per volume of expired CO2 (VE/VCO2). The aims of this study were to evaluate the effects of cardiac resynchronization therapy (CRT) on carbon dioxide (CO2) chemosensitivity and the arterial CO2 setpoint. METHODS AND RESULTS: Consecutive HF patients (n = 35) who underwent clinically indicated CRT were investigated by means of cardiopulmonary exercise testing and CO2 chemosensitivity evaluation with the use of a rebreathe method before and 4-6 months after CRT. Pre- and post-CRT measures were compared with the use of either paired t test or Wilcoxon test. Decreased peak VE/VCO2 (44 ± 10 vs 40 ± 8; P < .01), CO2 chemosensitivity (2.2 ± 1.1 vs 1.7 ± 0.8 L min(-1) mm Hg(-1); P = .04), and increased peak end-tidal CO2 (29 ± 5 vs 31 ± 5 mm Hg; P < .01) were also observed after CRT. Multivariate analysis adjusted for age and sex showed the decrease of peak VE/VCO2 from before to after CRT to be most strongly associated with the increase of peak end-tidal CO2 (ß = -0.84; F = 21.5; P < .0001). CONCLUSIONS: Decrease of VE/VCO2 after CRT is associated with decreased CO2 chemosensitivity and increase of the arterial CO2 setpoint, which is consistent with decreased activation of both the CO2 chemoreflex and the ergoreflex.

The impact of sedation on pulse pressure variation.

OBJECTIVE: Pulse pressure variations (PPV) are mainly influenced by ventilation. The impact of sedation on PPV is not known. The aim of the study was to test the influence of sedation on pulse pressure variation in mechanically ventilated critically ill patients and to compare PPV in critically ill and brain dead patients. Beside the absolute value of PPV, the adjusted values of pulse pressure were used to eliminate influence of ventilation. DESIGN AND INTERVENTION: Mechanically ventilated patients received four different breath frequencies. At each frequency airway pressure was adjusted to keep the end-tidal CO2 stable. In critically ill patients the frequencies were applied at basal (bispectral index - BIS median 38) and deeper sedation (BIS 29). MAIN OUTCOME MEASURES: Simultaneous haemodynamic and respiratory data including oesophageal pressure were recorded, adjusted PPV were calculated as PPV/VT, PPV/dPair, PPV/dPes where VT is tidal volume, dPair and dPes are airway and oesophageal driving pressures. SETTING: University Hospital, ICU. PARTICIPANTS: 30 critically ill and 23 patients with a diagnosis of brain death. RESULTS: The pulse pressure variation did not change significantly during deep sedation compared to basal sedation (median 10.3 vs 10.9%) whereas PPV/dPair increased from 0.7 to 0.8%/cmH2O and PPV/dPes from 1.9%/cmH2O to 2.4%/cmH2O (p=0.04). Patients with a diagnosis of brain death had higher PPV and adjusted PPV than critically ill patients. CONCLUSION: Deeper sedation increases values of adjusted pulse pressure variation.

Subpleural pulmonary nodule marking with patent blue V dye prior to surgical resection.

Background and objective: Subpleural located pulmonary nodules are perioperatively invisible to the surgeon. Their precise identification is conventionally possible by palpation, but often at the cost of performing a thoracotomy. The aim of the study was to evaluate the success rate and feasibility of the pre-operative CT-guided marking subpleural localized nodule using a mixture of Patent Blue V and an iodine contrast agent prior to the extra-anatomical video-assisted thoracoscopic surgery (VATS) resection in patients for whom the primary anatomical resection in terms of segmentectomy or lobectomy was not indicated. Methods: The data of consecutive patients with pulmonary nodules located ≤ 30 mm from the parietal pleura, who were indicated for VATS extra-anatomical resection between 2017 to 2023, were retrospectively reviewed and analyzed. All patients indicated for VATS resection underwent color marking of the area with the pulmonary lesion under CT-guided control immediately before the surgery. The primary outcome was the marking success. Morphological lesion characteristics, time from marking to the surgery, procedure related complications, final histology findings and 30day mortality were analyzed. Additionally, we assessed the association of the successful marking and the patient's smoking history. Results: A total of 62 lesions were marked. The successful marking was observed in 56/62 (90.3%) patients. The median time from the lesion marking to the beginning of surgery was 75.0 (IQR 65.0-85.0) minutes. The procedure related pneumothorax was observed in 6 (9.7%) patients, intraparenchymal hematoma in 1 (1.6%) patient. No statistically significant association of the depth of the subpleural lesion's location, occurrence of complications or time from the marking to surgery and the successful marking was observed. The 30day mortality was zero. No association of smoking and successful marking was observed. Conclusions: The method of marking the subpleural pulmonary lesions under CT-guided control with a mixture of Patent Blue V and iodine contrast agent is a safe and effective method with minimal complications. It provides surgeons the precise visualization of the affected pulmonary parenchyma before the planned extra-anatomical VATS resection.

The relationship between leptin and ventilatory control in heart failure.

BACKGROUND: Increased serum leptin concentration has been linked to increased ventilation in patients with mild heart failure (HF). However, in animal models the absence of leptin has also been associated with increased ventilation. This study evaluated the relationship of circulating leptin concentration with exercise ventilation in HF patients. METHODS AND RESULTS: Fifty-eight consecutive ambulatory HF patients were stratified by quintiles of leptin concentration, with a lowest quintile of mean leptin concentration of 1.8 ± 8.9 ng/mL and a highest of 33.3 ± 30.3 ng/mL. Peak exercise ventilatory efficiency (VE/VCO2) was significantly elevated in the lowest (46 ± 6 vs 34 ± 4; P < .01) as well as in the highest (38 ± 8 vs 34 ± 4; P < .05) leptin concentration quintiles compared with the reference middle quintile. Multiple regression analysis adjusted for confounders such as age, sex, and body mass index showed leptin concentration to be independently inversely correlated to VE/VCO2 in the low-to-normal quintiles (ß = -0.64; P < .01), positively in the normal-to-high quintiles (ß = 0.52; P = .02), and positively correlated to PETCO2 in the low-to-normal quintiles (ß = 0.59; P = .01) and inversely in the normal-to-high quintiles (ß = -0.53; P = .02). CONCLUSIONS: In HF patients, both high and low leptin concentrations are associated with increased VE/VCO2 and decreased PETCO2 with a nonlinear U-shaped relationship, suggesting that either leptin deficiency or leptin resistance may modulate ventilatory control in HF patients.

Temperature corrected thromboelastography in hypothermia: is it necessary?

CONTEXT: Hypothermia is known to influence thromboelastography (TEG). TEG reproducibility is generally low. OBJECTIVE: The aim of this study was to evaluate the rationale of TEG temperature adjustment in patients during hypothermia. We hypothesised that temperature adjustment would not be important because of low TEG reproducibility. DESIGN: Prospective observational study. SETTING: Single-centre, secondary care study performed 01/2009 to 07/2010. PATIENTS: Survivors of cardiopulmonary resuscitation in whom therapeutic hypothermia (32 to 34°C) was indicated for 24 h were recruited to the study which lasted 36 h. Four hundred samples from 30 patients (22 men and eight women) were obtained. No specific exclusion criteria were defined. MAIN OUTCOME MEASURES: Temperature adjusted and non-adjusted Kaolin-Heparinase and Rapid-TEG were done at 12-h intervals during the first 36 h. RESULTS: Bland-Altman plots were used for analysis. During hypothermia, the bias of adjusted measurements was greater in clot formation variables for both Kaolin-Heparinase-TEG (from -15 to -19%) and Rapid-TEG (-9 to -25%) compared to normothermia (from -3 to 3% for Kaolin-Heparinase-TEG and -10 to 2% for Rapid-TEG). Bias of clot strength variables was not influenced by temperature adjustment (median -1%). The 95% limits of agreement were wide for clot formation variables and independent of temperature. In Kaolin-Heparinase-TEG (R -42 to 40% normothermia, -47 to 18% hypothermia) and in Rapid-TEG (R -117 to 97% normothermia, -114 to 95% hypothermia). Limits of agreement of clot strength variables were narrower and independent of temperature in Kaolin-Heparinase-TEG (MA -16 to 13% normothermia, -9 to 10% hypothermia) and also in Rapid-TEG (MA -27 to 24% normothermia, -18 to 20% hypothermia). CONCLUSION: Although TEG analysis with temperature adjusted to the in-vivo value during hypothermia yields results with small systematic bias, the importance of temperature adjustment in clinical routine is low because of the precision limits of TEG measurement itself. Therefore, we see no need to perform TEG analysis at the in-vivo temperature.

Endobronchial cryobiopsy may shorten the time to cancer diagnosis: a retrospective study.

Endobronchial cryobiopsy from visualised intraluminal tumour lesions may decrease the rate of diagnostic failure and shorten the time to diagnosis https://bit.ly/3NkyJ98.

Hyperoxemia post thoracic surgery - Does it matter?

Introduction: Post-operative oxygen therapy is used to prevent hypoxemia and surgical site infection. However, with improvements of anesthesia techniques, post-operative hypoxemia incidence is declining and the benefits of oxygen on surgical site infection have been questioned. Moreover, hyperoxemia might have adverse effects on the pulmonary and cardiovascular systems. We hypothesized hyperoxemia post thoracic surgery is associated with post-operative pulmonary and cardiovascular complications. Methods: Consecutive lung resection patients were included in this post-hoc analysis. Post-operative pulmonary and cardiovascular complications were prospectively assessed during the first 30 post-operative days, or hospital stay. Arterial blood gases were analyzed at 1, 6 and 12 h after surgery. Hyperoxemia was defined as arterial partial pressure of oxygen (PaO2)>100 mmHg. Patients with hyperoxemia duration in at least two adjacent time points were considered as hyperoxemic. Student t-test, Mann-Whitney U test and two-tailed Fisher exact test were used for group comparison. P values < 0.05 were considered statistically significant. Results: Three hundred sixty-three consecutive patients were included in this post-hoc analysis. Two hundred five patients (57%), were considered hyperoxemic and included in the hyperoxemia group. Patients in the hyperoxemia group had significantly higher PaO2 at 1, 6 and 12 h after surgery (p < 0.05). Otherwise, there was no significant difference in age, sex, comorbidities, pulmonary function tests parameters, lung surgery procedure, incidence of post-operative pulmonary and cardiovascular complications, intensive care unit and hospital length of stay and 30-day mortality. Conclusion: Hyperoxemia after lung resection surgery is common and not associated with post-operative complications or 30-day mortality.

The risk of post-operative pulmonary complications in lung resection candidates with normal forced expiratory volume in 1 s and diffusing capacity of the lung for carbon monoxide: a prospective multicentre study.

Introduction: According to the guidelines for preoperative assessment of lung resection candidates, patients with normal forced expiratory volume in 1 s (FEV1) and diffusing capacity of the lung for carbon monoxide (D LCO) are at low risk for post-operative pulmonary complications (PPC). However, PPC affect hospital length of stay and related healthcare costs. We aimed to assess risk of PPC for lung resection candidates with normal FEV1 and D LCO (>80% predicted) and identify factors associated with PPC. Methods: 398 patients were prospectively studied at two centres between 2017 and 2021. PPC were recorded from the first 30 post-operative days. Subgroups of patients with and without PPC were compared and factors with significant difference were analysed by uni- and multivariate logistic regression. Results: 188 subjects had normal FEV1 and D LCO. Of these, 17 patients (9%) developed PPC. Patients with PPC had significantly lower pressure of end-tidal carbon dioxide (P ETCO2 ) at rest (27.7 versus 29.9; p=0.033) and higher ventilatory efficiency (V'E/V'CO2 ) slope (31.1 versus 28; p=0.016) compared to those without PPC. Multivariate models showed association between resting P ETCO2 (OR 0.872; p=0.035) and V'E/V'CO2 slope (OR 1.116; p=0.03) and PPC. In both models, thoracotomy was strongly associated with PPC (OR 6.419; p=0.005 and OR 5.884; p=0.007, respectively). Peak oxygen consumption failed to predict PPC (p=0.917). Conclusions: Resting P ETCO2 adds incremental information for risk prediction of PPC in patients with normal FEV1 and D LCO. We propose resting P ETCO2 be an additional parameter to FEV1 and D LCO for preoperative risk stratification.

Prediction of Postoperative Complications: Ventilatory Efficiency and Rest End-tidal Carbon Dioxide.

BACKGROUND: Cardiopulmonary exercise testing parameters including ventilatory efficiency (VE/VCO2 slope) are used for risk assessment of lung resection candidates. However, many patients are unable or unwilling to undergo exercise. VE/VCO2 slope is closely related to the partial pressure of end-tidal carbon dioxide (PETCO2). We hypothesized PETCO2 at rest predicts postoperative pulmonary complications. METHODS: Consecutive lung resection candidates were included in this prospective multicenter study. Postoperative respiratory complications were assessed from the first 30 postoperative days or from the hospital stay. Student t test or Mann-Whitney U test was used for comparison. Multivariate stepwise logistic regression analysis was used to analyze association with the development of postoperative pulmonary complications. The De Long test was used to compare area under the curve (AUC). Data are summarized as median (interquartile range). RESULTS: Three hundred fifty-three patients were analyzed, of which 59 (17%) developed postoperative pulmonary complications. PETCO2 at rest was significantly lower (27 [24-30] vs 29 [26-32] mm Hg; P < .01) and VE/VCO2 slope during exercise significantly higher (35 [30-40] vs 29 [25-33]; P < .01) in patients who developed postoperative pulmonary complications. Both rest PETCO2 with odds ratio 0.90 (95% confidence interval [CI] 0.83-0.97); P = .01 and VE/VCO2 slope with odds ratio 1.10 (95% CI 1.05-1.16); P < .01 were independently associated with postoperative pulmonary complications by multivariate stepwise logistic regression analysis. There was no significant difference between AUC of both models (rest PETCO2: AUC = 0.79 (95% CI 0.74-0.85); VE/VCO2 slope: AUC = 0.81 (95% CI 0.75-0.86); P = .48). CONCLUSIONS: PETCO2 at rest has similar prognostic utility as VE/VCO2 slope, suggesting rest PETCO2 may be used for postoperative pulmonary complications prediction in lung resection candidates.

Ventilatory efficiency is superior to peak oxygen uptake for prediction of lung resection cardiovascular complications.

INTRODUCTION: Ventilatory efficiency (VE/VCO2 slope) has been shown superior to peak oxygen consumption (VO2) for prediction of post-operative pulmonary complications in patients undergoing thoracotomy. VE/VCO2 slope is determined by ventilatory drive and ventilation/perfusion mismatch whereas VO2 is related to cardiac output and arteriovenous oxygen difference. We hypothesized pre-operative VO2 predicts post-operative cardiovascular complications in patients undergoing lung resection. METHODS: Lung resection candidates from a published study were evaluated by post-hoc analysis. All of the patients underwent preoperative cardiopulmonary exercise testing. Post-operative cardiovascular complications were assessed during the first 30 post-operative days or hospital stay. One-way analysis of variance or the Kruskal-Wallis test, and multivariate logistic regression were used for statistical analysis and data summarized as median (IQR). RESULTS: Of 353 subjects, 30 (9%) developed pulmonary complications only (excluded from further analysis), while 78 subjects (22%) developed cardiovascular complications and were divided into two groups for analysis: cardiovascular only (n = 49) and cardiovascular with pulmonary complications (n = 29). Compared to patients without complications (n = 245), peak VO2 was significantly lower in the cardiovascular with pulmonary complications group [19.9 ml/kg/min (16.5-25) vs. 16.3 ml/kg/min (15-20.3); P<0.01] but not in the cardiovascular only complications group [19.9 ml/kg/min (16.5-25) vs 19.0 ml/kg/min (16-23.1); P = 0.18]. In contrast, VE/VCO2 slope was significantly higher in both cardiovascular only [29 (25-33) vs. 31 (27-37); P = 0.05] and cardiovascular with pulmonary complication groups [29 (25-33) vs. 37 (34-42); P<0.01)]. Logistic regression analysis showed VE/VCO2 slope [OR = 1.06; 95%CI (1.01-1.11); P = 0.01; AUC = 0.74], but not peak VO2 to be independently associated with post-operative cardiovascular complications. CONCLUSION: VE/VCO2 slope is superior to peak VO2 for prediction of post-operative cardiovascular complications in lung resection candidates.

Extracorporeal Membrane Oxygenation Use in Thoracic Surgery.

This narrative review is focused on the application of extracorporeal membrane oxygenation (ECMO) in thoracic surgery, exclusive of lung transplantation. Although the use of ECMO in this indication is still rare, it allows surgery to be performed in patients where conventional ventilation is not feasible-especially in single lung patients, sleeve lobectomy or pneumonectomy and tracheal or carinal reconstructions. Comparisons with other techniques, various ECMO configurations, the management of anticoagulation, anesthesia, hypoxemia during surgery and the use of ECMO in case of postoperative respiratory failure are reviewed and supported by two cases of perioperative ECMO use, and an overview of published case series.

Cerebral air embolism complicating transbronchial lung biopsy: A case report.

BACKGROUND: In this case report we describe an extremely rare case of cerebral air embolism following transbronchial lung biopsy (TBLB). Only a few cases of this rare complication were described previously. Every bronchologist should recognize this severe adverse event. Prompt recognition of this complication is mandatory in order to initiate supportive measures and consider hyperbaric oxygen therapy. CASE SUMMARY: In this case report we describe an extremely rare case of cerebral air embolism following TBLB. Only a few cases of this rare complication were described previously. Our patient had an incidental finding of lung tumour and pulmonary emphysema. Cerebral air embolism developed during bronchoscopy procedure, immediately after the third trans-bronchial lung biopsy sample and caused cerebral ischaemia of the right hemisphere and severe left-sided hemiplegia. Despite timely initiation of hyperbaric oxygen therapy hemiplegia didn´t resolve and the patient died several weeks later. Cerebral air embolism is an extremely rare complication of TBLB. This condition should be considered in case the patient remains unresponsive or presents with acute neurological symptoms in the post-intervention period since early recognition, diagnosis and hyperbaric oxygen therapy initiation are key factors determining the patient´s outcome. CONCLUSION: Within this report, we conclude that air/gas embolism is an extremely rare complication after TBLB, which should be considered in case the patient remains unresponsive or presents with acute neurological symptoms in the post-intervention period after bronchoscopy. The current gold standard for diagnosis is computed tomography scan of the head. After recognition of this complication we suggest immediate hyperbaric oxygen therapy, if available.

Poor ventilatory efficiency during exercise may predict prolonged air leak after pulmonary lobectomy.

Poor ventilatory efficiency, defined as the increase in minute ventilation relative to carbon dioxide production during exercise (VE/VCO2 slope), may be associated with dynamic hyperinflation and thereby promote the development of prolonged air leak (PAL) after lung resection. Consecutive lung lobectomy candidates (n = 96) were recruited for this prospective two-centre study. All subjects underwent pulmonary function tests and cardiopulmonary exercise testing prior to surgery. PAL was defined as the presence of air leaks from the chest tube on the 5th postoperative day and developed in 28 (29%) subjects. Subjects with PAL were not different in terms of age, sex, American Society of Anesthesiologists class, type of surgery (thoracotomy/video-assisted thoracoscopic surgery) and site of surgery (right/left lung; upper/lower lobes). Subjects with PAL had more frequent pleural adhesions (50% vs 21%; P = 0.006) and steeper VE/VCO2 slope (35 ± 7 vs 30 ± 5; P = 0.001). Stepwise logistic regression showed that only the presence of pleural adhesions [odds ratio (OR) 3.9, 95% confidence interval (CI) 1.4-10.9; P = 0.008] and VE/VCO2 slope (OR 1.1, 95% CI 1.0-1.2; P = 0.003) were independently associated with PAL (AUC 0.74, 95% CI 0.62-0.86). We conclude that a high VE/VCO2 slope during exercise may be helpful in identifying patients at greater risk for the development of PAL after lung lobectomy. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov identifier: NCT03498352.

Pulmonary Limitations in Heart Failure.

The heart and lungs are intimately linked. Hence, impaired function of one organ may lead to changes in the other. Accordingly, heart failure is associated with airway obstruction, loss of lung volume, impaired gas exchange, and abnormal ventilatory control. Cardiopulmonary exercise testing is an excellent tool for evaluation of gas exchange and ventilatory control. Indeed, many parameters routinely measured during cardiopulmonary exercise testing, including the level of minute ventilation per unit of carbon dioxide production and the presence of exercise oscillatory ventilation, have been found to be strongly associated with prognosis in patients with heart failure.

Cardiopulmonary exercise testing for identification of patients with hyperventilation syndrome.

INTRODUCTION: Measurement of ventilatory efficiency, defined as minute ventilation per unit carbon dioxide production (VE/VCO2), by cardiopulmonary exercise testing (CPET) has been proposed as a screen for hyperventilation syndrome (HVS). However, increased VE/VCO2 may be associated with other disorders which need to be distinguished from HVS. A more specific marker of HVS by CPET would be clinically useful. We hypothesized ventilatory control during exercise is abnormal in patients with HVS. METHODS: Patients who underwent CPET from years 2015 through 2017 were retrospectively identified and formed the study group. HVS was defined as dyspnea with respiratory alkalosis (pH >7.45) at peak exercise with absence of acute or chronic respiratory, heart or psychiatric disease. Healthy patients were selected as controls. For comparison the Student t-test or Mann-Whitney U test were used. Data are summarized as mean ± SD or median (IQR); p<0.05 was considered significant. RESULTS: Twenty-nine patients with HVS were identified and 29 control subjects were selected. At rest, end-tidal carbon dioxide (PETCO2) was 27 mmHg (25-30) for HVS patients vs. 30 mmHg (28-32); in controls (p = 0.05). At peak exercise PETCO2 was also significantly lower (27 ± 4 mmHg vs. 35 ± 4 mmHg; p<0.01) and VE/VCO2 higher ((38 (35-43) vs. 31 (27-34); p<0.01)) in patients with HVS. In contrast to controls, there were minimal changes of PETCO2 (0.50 ± 5.26 mmHg vs. 6.2 ± 4.6 mmHg; p<0.01) and VE/VCO2 ((0.17 (-4.24-6.02) vs. -6.6 (-11.4-(-2.8)); p<0.01)) during exercise in patients with HVS. The absence of VE/VCO2 and PETCO2 change during exercise was specific for HVS (83% and 93%, respectively). CONCLUSION: Absence of VE/VCO2 and PETCO2 change during exercise may identify patients with HVS.