Read by QxMD icon Read

Ventilation-perfusion mismatch

Nobuaki Hamazaki, Takashi Masuda, Kentaro Kamiya, Ryota Matsuzawa, Kohei Nozaki, Emi Maekawa, Chiharu Noda, Minako Yamaoka-Tojo, Junya Ako
BACKGROUND AND OBJECTIVE: Respiratory muscle weakness causes fatigue in these muscles during exercise and thereby increases dead-space ventilation ratio with decreased tidal volume. However, it remains unclear whether respiratory muscle weakness aggravates ventilation-perfusion mismatch through the increased dead-space ventilation ratio. In ventilation-perfusion mismatch during exercise, minute ventilation versus carbon dioxide production (VE/VCO2 ) slope > 34 is an indicator of poor prognosis in patients with chronic heart failure (CHF)...
November 14, 2018: Respirology: Official Journal of the Asian Pacific Society of Respirology
Nathan Marzlin, Sara Dunbar, Michael Cinquegrani
INTRODUCTION: Platypnea-orthodeoxia syndrome is a rare clinical syndrome defined by worsening deoxygenation and dyspnea when changing to an upright sitting or standing position. It is seen in 3 different clinical scenarios: intracardiac shunts, pulmonary arteriovenous shunts, and ventilation/perfusion mismatch in the lungs. CASE: An 82-year-old woman with a history of nonischemic cardiomyopathy with reduced ejection fraction was admitted with dyspnea and hypoxemia...
October 2018: WMJ: Official Publication of the State Medical Society of Wisconsin
Andrew W Bowman, Brittany K Albers, Manoj K Jain
Despite the increasing use of computed tomography pulmonary angiography to evaluate for pulmonary embolism (PE), ventilation/perfusion (V/Q) scintigraphy is still a fairly common examination. A rare finding on V/Q scintigraphy is whole-lung mismatched perfusion defect. Although this finding can occur with PE, it has an important, limited differential diagnosis. In this pictorial essay, we describe different causes of acquired whole-lung mismatched perfusion defect.
October 2018: Indian Journal of Nuclear Medicine: IJNM: the Official Journal of the Society of Nuclear Medicine, India
Julien Dupont, Didier Serteyn, Charlotte Sandersen
Horses are susceptible to developing large areas of pulmonary atelectasis during recumbency and anesthesia. The subsequent pulmonary shunt is responsible for significant impairment of oxygenation. Since ventilation perfusion mismatch persists into the post-operative period, hypoxemia remains an important concern in the recovery stall. This case report describes the diagnosis and supportive therapy of persistent hypoxemia in a 914 kg draft horse after isoflurane anesthesia. It highlights how challenging it can be to deal with hypoxemia after disconnection from the anesthesia machine and how life-threatening it can become if refractory to treatment...
2018: Frontiers in Veterinary Science
Morgan Hepburn-Brown, Jai Darvall, Gary Hammerschlag
An acute Pulmonary Embolism (aPE) is characterised by occlusion of one or more pulmonary arteries. Physiological disturbance may be minimal, but often cardiac output decreases as the right ventricle attempts to overcome increased afterload. Additionally, ventilation-perfusion mismatches can develop in affected vascular beds, reducing systemic oxygenation. Incidence is reported at 50-75 per 100,000 in Australia and New Zealand, with 30- day mortality rates ranging from 0.5% to over 20%. Incidence is likely to increase with the aging population, increased survival of patients with co-morbidities that are considered risk factors and improving sensitivity of imaging techniques...
October 15, 2018: Internal Medicine Journal
Vijay Kumar Mishra, Souvik Chaudhuri, Rajesh Kumar Singh, Ajay Kumar Singh
Unilateral pulmonary artery agenesis (UPAA) is a rare condition where the patient may remain asymptomatic for a long period till adulthood. Presentation may be in the form of dyspnea, cough, hemoptysis, decreased exercise tolerance, and recurrent respiratory tract infections. Ventilation-perfusion mismatch and excessive blood flow to the normal lung may eventually lead to unilateral acute respiratory distress syndrome (ARDS). We present a case of a 40-year-old gentleman with nonresolving pneumonia who was diagnosed to have unilateral ARDS due to UPAA...
July 2018: Anesthesia, Essays and Researches
Robert Ruemmler, Alexander Ziebart, Christian Moellmann, Andreas Garcia-Bardon, Jens Kamuf, Frances Kuropka, Bastian Duenges, Erik Kristoffer Hartmann
BACKGROUND: The effects of different ventilation strategies during CPR on patient outcomes and lung physiology are still poorly understood. This study compares positive pressure ventilation (IPPV) to passive oxygenation (CPAP) and a novel ultra-low tidal volume ventilation (ULTVV) regimen in an experimental ventricular fibrillation animal model. STUDY DESIGN: Prospective randomized controlled trial. ANIMALS: 30 male German landrace pigs (16-20 weeks)...
November 2018: Resuscitation
Sethuraman Swaminathan, Arpit Agarwal, Juan C Infante, Eliot Rosenkranz
Tetralogy of Fallot with absent pulmonary valve syndrome is a rare form of congenital heart disease. Among the different variations with this rare anomaly is nonconfluent pulmonary artery branches with anomalous origin of the left pulmonary artery from the ductus arteriosus. The authors present one such case which was diagnosed prenatally to have tetralogy of Fallot with absent pulmonary valve and identified postnatally to have nonconfluent pulmonary artery branches in addition. We discuss the conundrum of respiratory management in this patient pre- and postoperatively due to a unique ventilation perfusion mismatch problem, which varies between the two lungs...
August 27, 2018: World Journal for Pediatric & Congenital Heart Surgery
Henrik Reinius, Joao Batista Borges, Joakim Engström, Oskar Ahlgren, Fredrik Lennmyr, Anders Larsson, Filip Fredén
BACKGROUND: One-lung ventilation (OLV) with induced capnothorax carries the risk of severely impaired ventilation and circulation. Optimal PEEP may mitigate the physiological perturbations during these conditions. METHODS: Right-sided OLV with capnothorax (16 cm H2 O) on the left side was initiated in eight anesthetized, muscle-relaxed piglets. A recruitment maneuver and a decremental PEEP titration from PEEP 20 cm H2 O to zero end-expiratory pressure (ZEEP) was performed...
August 21, 2018: Acta Anaesthesiologica Scandinavica
Sam Orde, Michel Slama, Nicola Stanley, Stephen Huang, Anthony Mclean
BACKGROUND: Transthoracic 3D cardiac analysis is enticing in its potential simplicity and wealth of data available. It has been suggested to be accurate vs magnetic resonance imaging in relatively stable patients, but feasibility and agreement with conventional echocardiographic assessment of stroke volume (SV) have not been thoroughly assessed in critically ill patients, who are traditionally harder to image. The objectives of this study were to compare 3D transthoracic volumetric analysis vs Doppler assessment of SV (which is suggested to be accurate in the critically ill) and Simpson's biplane assessment in a cohort typical of the intensive care unit (ICU), where accurate assessment is important: mechanically ventilated patients with a significant ventilation/perfusion (V/Q) mismatch...
August 19, 2018: Critical Care: the Official Journal of the Critical Care Forum
Alastair J E Moore, Jason Wachsmann, Murthy R Chamarthy, Lloyd Panjikaran, Yuki Tanabe, Prabhakar Rajiah
Imaging plays an important role in the evaluation and management of acute pulmonary embolism (PE). Computed tomography (CT) pulmonary angiography (CTPA) is the current standard of care and provides accurate diagnosis with rapid turnaround time. CT also provides information on other potential causes of acute chest pain. With dual-energy CT, lung perfusion abnormalities can also be detected and quantified. Chest radiograph has limited utility, occasionally showing findings of PE or infarction, but is useful in evaluating other potential causes of chest pain...
June 2018: Cardiovascular Diagnosis and Therapy
Ebru Biricik, Feride Karacaer, Yasemin Güneş, Nebile Dağlıoğlu, Pınar Efeoğlu, Murat Ilgınel, Alper Avcı, Dilek Özcengiz
OBJECTIVE: To determine the blood sevoflurane and desflurane concentrations during one-lung ventilation (OLV). DESIGN: Randomized, single-blind study. SETTING: Single university hospital. PARTICIPANTS: The study comprised 24 patients, 35 to 70 years old who were scheduled for either a major abdominal surgery or thoracotomy. INTERVENTIONS: The patients were divided into the following 4 groups: sevoflurane two-lung ventilation (TLV), sevoflurane OLV, desflurane TLV, and desflurane OLV...
June 1, 2018: Journal of Cardiothoracic and Vascular Anesthesia
D Chemla, E Berthelot, P Assayag, P Attal, P Hervé
The right ventricle (RV) plays a key role in the maintenance of an adequate cardiac output whatever the demand, and thus contributes to the optimization of the ventilation/perfusion ratio. The RV has a thin wall and it buffers the physiological increases in systemic venous return without causing a deleterious rise in right atrial pressure (RAP). The RV is coupled to the pulmonary circulation which is a low pressure, low resistance, high compliance system. In the healthy subject at rest, the contribution of the RV to right heart systolic function is surpassed by the contribution of both left ventricular contraction and the respiratory pump...
June 23, 2018: Revue des Maladies Respiratoires
Carl Schümichen, Matthias Schmidt, Thomas Krause
The S1 guideline for lung scintigraphy has been updated and extended in order to emphasize the advantages oft the method in detecting acute pulmonary embolism (PE) in the periphery oft the lung (subsegmental PE), in underlying subacute and chronic pulmonary disorders, as well as in detecting chronic LE (CTEPH). Method of choice is ventilation / perfusion (V/P) SPECT or V/P SPECT/CT with even higher specificity. Because of its high sensitivity, a threshold (V/P mismatch in at least one segment or two subsegments) is introduced to avoid overtreatment...
June 2018: Nuklearmedizin. Nuclear Medicine
Zsolt Szabó, Tamás Tanczos, Gábor Lebak, Zsolt Molnár, József Furák
General anaesthesia has been the most commonly used method for almost all types of thoracic surgery. Recently, there has been a growing interest in non-intubated anaesthetic techniques. The rationale being, to prevent complications related to general anaesthesia and positive pressure ventilation such as barotrauma or ventilation-perfusion mismatch. We present a case with severely impaired forced expiration volume (26%), carbon monoxide diffusing capacity (26%) and VO2 max (13.9 mL/kg/min). According to current guidelines, this patient was suitable to undergo one-lung ventilation only with high risk of morbidity and mortality...
April 2018: Journal of Thoracic Disease
Matthieu Masy, Jessica Giordano, Grégory Petyt, Claude Hossein-Foucher, Alain Duhamel, Maeva Kyheng, Pascal De Groote, Marie Fertin, Nicolas Lamblin, Jean-François Bervar, Jacques Remy, Martine Remy-Jardin
OBJECTIVES: To evaluate the concordance between DECT perfusion and ventilation/perfusion (V/Q) scintigraphy in diagnosing chronic thromboembolic pulmonary hypertension (CTEPH). METHODS: Eighty patients underwent V/Q scintigraphy and DECT perfusion on a 2nd- and 3rd-generation dual-source CT system. The imaging criteria for diagnosing CTEPH relied on at least one segmental triangular perfusion defect on DECT perfusion studies and V/Q mismatch on scintigraphy examinations...
December 2018: European Radiology
Amy Mallorie, Kenneth Chan, Stefanos Ioannidis, Matthew Stubbs, Shaunak Navalkissoor, Thomas Wagner
OBJECTIVES: The risk of recurrent venous thromboembolic disease and the management of patients with isolated subsegmental pulmonary embolism (SSPE) remain unclear. We sought to assess the long-term clinical outcome of patients with isolated SSPE demonstrated by isolated subsegmental mismatch found on ventilation/perfusion (V/Q) scans. PATIENTS AND METHODS: We performed a retrospective observational study of 1300 consecutive patients with suspected pulmonary embolism who underwent index V/Q single-photon emission computed tomography between 2012 and 2013...
July 2018: Nuclear Medicine Communications
Danielle L Kirkman, Bryce J Muth, Joseph M Stock, Raymond R Townsend, David G Edwards
Background Reductions in exercise capacity associated with exercise intolerance augment cardiovascular disease risk and predict mortality in chronic kidney disease. This study utilized cardiopulmonary exercise testing to (a) investigate mechanisms of exercise intolerance; (b) unmask subclinical abnormalities that may precede cardiovascular disease in chronic kidney disease. Design The design of this study was cross-sectional. Methods Cardiopulmonary exercise testing was carried out in 31 Stage 3-4 chronic kidney disease patients (60 ± 11 years; estimated glomerular filtration rate 43 ± 13 ml/min/1...
January 1, 2018: European Journal of Preventive Cardiology
A M Al-Sharydah, A H Al-Abdulwahhab, H A Abu AlOla
INTRODUCTION: In patients with a hypercoagulable state, such as patients with pulmonary embolism and/or Budd-Chiari syndrome, the complications from multiple gene mutations are more numerous than those from a single mutation. The authors present a woman with no major prior medical history who presented with pulmonary embolism and Budd-Chiari syndrome; this enigmatic co-occurrence has never been solely reported without underlying aetiology in a patient without prior medical conditions...
2018: International Journal of Surgery Case Reports
Taisuke Nakade, Hitoshi Adachi, Makoto Murata, Shigeru Oshima
PURPOSE: Cardiopulmonary exercise testing (CPX) is used to evaluate functional capacity and assess prognosis in cardiac patients. Ventilatory efficiency (VE/VCO2 ) reflects ventilation-perfusion mismatch; the minimum VE/VCO2 value (minVE/VCO2 ) is representative of pulmonary arterial blood flow in individuals without pulmonary disease. Usually, minVE/VCO2 has a strong relationship with the peak oxygen uptake (VO2 ), but dissociation can occur. Therefore, we investigated the relationship between minVE/VCO2 and predicted peak VO2 (peak VO2 %) and evaluated the parameters associated with a discrepancy between these two parameters...
May 14, 2018: European Journal of Applied Physiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"