scholarly journals Effects of mechanical ventilation with expiratory negative airway pressure on porcine pulmonary and systemic circulation: mechano-physiology and potential application

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Mihoko Hagiwara-Nagasawa ◽  
Ryuichi Kambayashi ◽  
Ai Goto ◽  
Koki Chiba ◽  
Takeshi Wada ◽  
...  

AbstractWe studied the impact of mechanically regulated, expiratory negative airway pressure (ENAP) ventilation on pulmonary and systemic circulation including its mechanisms and potential applications. Microminipigs weighing about 10 kg were anesthetized (n = 5). First, hemodynamic variables were evaluated without and with ENAP to approximately −16 cmH2O. ENAP significantly increased heart rate and cardiac output, but decreased right atrial, pulmonary arterial and pulmonary capillary wedge pressures. Second, the evaluation was repeated following pharmacological adrenergic blockade, modestly blunting ENAP effects. Third, fluvoxamine (10 mg/kg) was intravenously administered to intentionally induce cardiovascular collapse in the presence of adrenergic blockade. ENAP was started when systolic pressure was < 40 mmHg in the animals assigned to ENAP treatment-group. Fluvoxamine induced cardiovascular collapse within 4 out of 5 animals. ENAP increased systolic pressure to > 50 mmHg (n = 2): both animals fully recovered without neurological deficit, whereas without ENAP both animals died of cardiac arrest (n = 2). ENAP may become an innovative treatment for drug-induced cardiovascular collapse.

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Maria Drakopoulou ◽  
Konstantinos Stathogiannis ◽  
Konstantinos Toutouzas ◽  
George Latsios ◽  
Andreas Synetos ◽  
...  

Objective: Severe aortic stenosis leads to increased pulmonary arterial systolic pressure. A controversy still remains regarding the impact of persistent pulmonary hypertension (PHT) on prognosis of patients undergoing transcatheter aortic valve implantation (TAVI). We sought to investigate the impact of persistent PHT on 2-year all-cause mortality of patients with severe aortic stenosis following TAVI. Methods: Patients with severe and symptomatic aortic stenosis (effective orifice area [EOA]≤1 cm 2 ) who were scheduled for TAVI with a self-expanding valve at our institution were prospectively enrolled. Prospectively collected echocardiographic data before and after TAVI were retrospectively analyzed in all patients. Pulmonary artery systolic pressure was estimated as the sum of the right ventricular to the right atrial gradient during systole and the right atrial pressure. PHT following TAVI was classified as absent if <35 mmHg and persistent if ≥35 mmHg. Primary clinical end-point was 2-year all-cause mortality defined according to the criteria proposed by the Valve Academic Research Consortium-2. Results: Hundred and forty patients (mean age: 82±9 years) were included in the study. The primary clinical end point occurred in 17 patients (12%) during a median follow-up period of 2 years. Mean pulmonary artery systolic pressure was reduced in all patients following TAVI (45±9 versus 41±6 mmHg, p<0.01). Mortality rate was higher in patients with persistent PHT compared to patients with normal pulmonary artery systolic pressure following TAVI (26% versus 14 %, p<0.01). Patients that reached the primary clinical end point had a higher post procedural mean systolic pulmonary pressure (43±9 versus 39±6 mmHg, p=0.02). In multivariate regression analysis, persistence of PHT (OR: 2.51, 95% CI: 1.109-7.224, p=0.01) was an independent predictor of long-term mortality. Conclusions: The persistence of pulmonary hypertension after TAVI is associated with long term mortality. Identifying the population that will clearly benefit from TAVI is still need to be validated by larger trials.


1982 ◽  
Vol 96 (1) ◽  
pp. 343-354 ◽  
Author(s):  
WARREN BURGGREN ◽  
KJELL JOHANSEN

The haemodynamics of the anatomically undivided ventricle of the monitor lizard Varanus exanthematicus have been examined by measurements of blood pressure and flow. Central blood POO2, PCOCO2 and pH were also measured. Intracardiac pressure measurements show the ventricle to be functionally divided throughout systole into a high pressure pump (cavum arteriosum: ‘mean’ pressure 89 cm H2O) perfusing the systemic circulation, and a low pressure pump (cavum pulmonale: ‘mean’ pressure 40 cm H2O) perfusing the pulmonary circulation. Hypoxia produced by asphyxia or N2 breathing changed systolic pressures in the ventricular cava, but never resulted in superimposable pressure waveforms which would have indicated a breakdown from ventricular division into two pressure pumps. Diastolic pressures were superimposable in the ventricular cava under all conditions. Analysis of blood POO2 and O2 content revealed the potential for nearly complete separation of left and right atrial blood in the ventricle, but both left-to-right and right-to-left shunts of considerable magnitude could also develop. The varanid heart with its systolic pressure separation allows the development of high blood pressure gradients capable of driving a large cardiac output through the high impedance systemic vascular beds. Concurrently, the low impedance pulmonary circuit is perfused at a much reduced blood pressure, circumventing filtration of plasma into the lungs and impairment of gas exchange. Haemodynamically this situation resembles that present in crocodilians and the homeothermic vertebrates.


2012 ◽  
Vol 302 (12) ◽  
pp. H2583-H2591 ◽  
Author(s):  
Timo Weimar ◽  
Yoshiyuki Watanabe ◽  
Toshinobu Kazui ◽  
Urvi S. Lee ◽  
Marc R. Moon ◽  
...  

Current techniques to describe atrial function are limited by their load dependency and hence do not accurately reflect intrinsic mechanical properties. To assess the impact of atrial fibrillation on atrial function, combined pressure-volume relationships (PVR) measured by conductance catheters were used to evaluate the right (RA) and left (LA) atrium in 12 isoflurane-anesthetized pigs. Biatrial PVR were recorded over a wide range of volumes during transient caval occlusion at baseline sinus rhythm (SR), after onset of rapid atrial pacing (RAP), after 1 h of RAP, after conversion to SR, and after 1 h of recovery. Cardiac output decreased by 16% ( P = 0.008) with onset of RAP. Mean LA and RA pressures increased by 21 and 40% ( P < 0.001), respectively, and remained elevated during the entire recovery period. RA reservoir function increased from 51 to 58% and significantly dropped to 43% after resumption of SR ( P = 0.017). Immediately after RAP, a right shift of LA end-systolic PVR-intercept for end-systolic volume required to generate an atrial end-systolic pressure of 10 mmHg (24.4 ± 4.9 to 28.1 ± 5.2 ml, P = 0.005) indicated impaired contractility compared with baseline. Active LA emptying fraction dropped from 17.6 ± 7.5 to 11.7 ± 3.7% ( P < 0.001), LA stroke volume and ΔP/Δ tmax/P declined by 22% ( P = 0.038 and 0.026, respectively), while there was only a trend to impaired RA systolic function. Stiffness quantified by the ratio of pressure to volume at end-diastole was increased immediately after RAP only in the RA ( P = 0.020), but end-diastolic PVR shifted rightward in both atria ( P = 0.011 LA, P = 0.045 RA). These data suggest that even short periods of RAP have a differential impact on RA and LA function, which was sustained for 1 h after conversion to SR.


2021 ◽  
Vol Volume 13 ◽  
pp. 2087-2099
Author(s):  
Yu-Hsuan Kuo ◽  
Tien-Jen Liu ◽  
Feng-Hsiang Chiu ◽  
Yi Chang ◽  
Chia-Mo Lin ◽  
...  

Author(s):  
Sarah A. Luse

In the mid-nineteenth century Virchow revolutionized pathology by introduction of the concept of “cellular pathology”. Today, a century later, this term has increasing significance in health and disease. We now are in the beginning of a new era in pathology, one which might well be termed “organelle pathology” or “subcellular pathology”. The impact of lysosomal diseases on clinical medicine exemplifies this role of pathology of organelles in elucidation of disease today.Another aspect of cell organelles of prime importance is their pathologic alteration by drugs, toxins, hormones and malnutrition. The sensitivity of cell organelles to minute alterations in their environment offers an accurate evaluation of the site of action of drugs in the study of both function and toxicity. Examples of mitochondrial lesions include the effect of DDD on the adrenal cortex, riboflavin deficiency on liver cells, elevated blood ammonia on the neuron and some 8-aminoquinolines on myocardium.


1996 ◽  
Vol 270 (5) ◽  
pp. R955-R962
Author(s):  
C. D. Mazer ◽  
B. Naser ◽  
K. S. Kamel

We examined the impact of alkali therapy on myocardial contractility in a model of myocardial ischemia in dogs using direct measurements of myocardial contractile function. Myocardial ischemia in the left anterior descending (LAD) artery territory was induced using a perfusion circuit from the internal carotid artery to the LAD artery. Myocardial contractile function was assessed using sonomicrometry for measurement of percent systolic shortening (%SS), preload recruitable stroke work (PRSW) slope, and end-systolic pressure-length relationship (ESPLR) area. Because the blood flow in LAD artery was diminished by approximately 70%, there was a significant decrease in O2 delivery and uptake by the ischemic myocardium. Ischemia led to a significant fall in LAD regional contractile function with %SS decreasing from 15 +/- 2 to 7 +/- 2%, PRSW slope from 82 +/- 10 to 37 +/- 5 mmHg, and ESPLR area from 121 +/- 2 to 48 +/- 14 mmHg.mm (P < 0.05). In six dogs, the intracoronary administration of NaHCO(3) resulted in a significant increase in pH in LAD arterial and venous blood. There was, however, no significant increase in %SS (6 +/- 2), PRSW slope (43 +/- 10 mmHg), or ESPLR area (60 +/- 13 mmHg.mm). Since administration of NaHCO(3) resulted in a significant increase in PCO2 in LAD arterial and venous blood, similar experiments were carried out in five dogs, but with the intracoronary infusion of the amine buffer THAM [tris(hydroxymethyl)aminomethane (Tris) buffer; 2-amino-2-hydroxyl-1,3-propandiol] instead of NaHCO3. Although administration of THAM resulted in a significant increase in pH and a significant decrease in PCO2, in both LAD arterial and venous blood, there was no significant improvement in any of the parameters used to assess myocardial contractile function. In conclusion, administration of alkali (NaHCO3 or THAM) does not enhance the contractile function of the ischemic myocardium.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Matthew G. Hanson ◽  
Barry Chan

Abstract Background Symptomatic pericardial effusion (PCE) presents with non-specific features and are often missed on the initial physical exam, chest X-ray (CXR), and electrocardiogram (ECG). In extreme cases, misdiagnosis can evolve into decompensated cardiac tamponade, a life-threatening obstructive shock. The purpose of this study is to evaluate the impact of point-of-care ultrasound (POCUS) on the diagnosis and therapeutic intervention of clinically significant PCE. Methods In a retrospective chart review, we looked at all patients between 2002 and 2018 at a major Canadian academic hospital who had a pericardiocentesis for clinically significant PCE. We extracted the rate of presenting complaints, physical exam findings, X-ray findings, ECG findings, time-to-diagnosis, and time-to-pericardiocentesis and how these were impacted by POCUS. Results The most common presenting symptom was dyspnea (64%) and the average systolic blood pressure (SBP) was 120 mmHg. 86% of people presenting had an effusion > 1 cm, and 89% were circumferential on departmental echocardiogram (ECHO) with 64% having evidence of right atrial systolic collapse and 58% with early diastolic right ventricular collapse. The average time-to-diagnosis with POCUS was 5.9 h compared to > 12 h with other imaging including departmental ECHO. Those who had the PCE identified by POCUS had an average time-to-pericardiocentesis of 28.1 h compared to > 48 h with other diagnostic modalities. Conclusion POCUS expedites the diagnosis of symptomatic PCE given its non-specific clinical findings which, in turn, may accelerate the time-to-intervention.


BMJ Open ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. e044499
Author(s):  
Fanny Bertelli ◽  
Carey Meredith Suehs ◽  
Jean Pierre Mallet ◽  
Marie Caroline Rotty ◽  
Jean Louis Pepin ◽  
...  

Introduction To date, continuous positive airway pressure (CPAP) remains the cornerstone of obstructive sleep apnoea treatment. CPAP data describing residual sleep-disordered breathing events (ie, the CPAP-measured apnoea–hypopnoea indices (AHI-CPAPflow)) is difficult to interpret because it is an entirely different metric than the polysomnography (PSG) measured AHI gold standard (AHI-PSGgold). Moreover, manufacturer definitions for apnoea and hypopnoea are not only different from those recommended for PSG scoring, but also different between manufacturers. In the context of CPAP initiation and widespread telemedicine at home to facilitate sleep apnoea care, there is a need for concrete evidence that AHI-CPAPflow can be used as a surrogate for AHI-PSGgold. Methods and analysis No published systematic review and meta-analysis (SRMA) has compared the accuracy of AHI-CPAPflow against AHI-PSGgold and the primary objective of this study is therefore to do so using published data. The secondary objectives are to similarly evaluate other sleep disordered breathing indices and to perform subgroup analyses focusing on the inclusion/exclusion of central apnoea patients, body mass index levels, CPAP device brands, pressure titration modes, use of a predetermined and fixed pressure level or not, and the impact of a 4% PSG desaturation criteria versus 3% PSG on accuracy. The Preferred Reporting Items for SRMA protocols statement guided study design. Randomised controlled trials and observational studies of adult patients (≥18 years old) treated by a CPAP device will be included. The CPAP intervention and PSG comparator must be performed synchronously. PSGs must be scored manually and follow the American Academy of Sleep Medicine guidelines (2007 AASM criteria or more recent). To assess the risk of bias in each study, the Quality Assessment of Diagnostic Accuracy Studies 2 tool will be used. Ethics and dissemination This protocol received ethics committee approval on 16 July 2020 (IRB_MTP_2020_07_2020000404) and results will be disseminated via peer-reviewed publications. PROSPERO/Trial registration numbers CRD42020159914/NCT04526366; Pre-results


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 371.1-371
Author(s):  
A. Koltakova ◽  
A. Lila ◽  
L. P. Ananyeva ◽  
A. Fedenko

Background:Pts with cancer may have MD that can be caused by neoplastic/paraneoplastic disease, rheumatic diseases or be induced by anticancer drug treatment. There is no data about MD influence on the QoL of cancer patients. The EORTC QoL questionnaire (QLQ)-C30 is a valid questionnaire designed to assess different aspects (Global health (GH), Functional (FS) and symptoms (SS) scales) that define the QoL of cancer patients [1].Objectives:The objective of the study was to assess the impact of drug induced and other types of MD on the QoL of cancer patients that received anticancer drug treatment by using of EORTC QLQ-C30 v3.0.Methods:The sampling of 123 pts (M/F – 40/83; mean age 54.4±12.8) with breast (32,5%), gastrointestinal (17%), ovary (8%), lung (7%) and other cancer was observed by rheumatologist in the oncology outpatient clinic. All pts received anticancer drug treatment: chemotherapy (104 pts), target therapy (16 pts) checkpoint-inhibitors (14 pts), hormone therapy (13 pts) in different combinations. 102(82.9%) of 123pts had MD include arthritis (12 pts), synovitis (5 pts), arthralgia (66 pts), periarthritis (34 pts), osteodynia (13 pts). There were 58 pts (group 1; M/F – 14/44; mean age 52.5±12.2) with anticancer drug treatment induced MD and 44 pts (group 2; M/F – 16/27; mean age 57.6±13.5) with other type of MD include 26 pts with skeletal metastasis. The were 21 pts (group 3; M/F – 10/11; mean age 52.9±11.1) without MD. All pts fulfilled EORTC QLQ-C30 v3.0 (tab.1).Table 1.The median [Q1;Q3] of results of GH, SS and SS of EORTC QLQ-C30ScaleSubscaleGroup1Group2Group3GH58.3[50;58]58.3[41.7;83.3]50[50;66.7]FS*Physical functioning73.3[60;86.7]73.3[66.7;86.7]86.7[80;93]Role functioning66.7[66.7;100]83.3[50;100]100[83;100]Emotional functioning83.3[66.7;100]75[66.7;91.7]91.6[83.3;100]Social functioning83.3[66.7;100]83.3[50;100]100[83.3;100]SS*Pain33.3[0;50]16.7[0;33.3]0[0;16.7]*There are only the scores that had got a statistical difference between the groups.Kruskal-Wallis H and post-hoc (Dwass-Steel-Critchlow-Fligner (DSCF) pairwise comparisons) tests for data analysis were performed.Results:A Kruskal-Wallis H test has shown a statistically significant difference in physical (χ2(2)=7.54; p=0.023), role (χ2(2)=9.87; p=0.007), emotion (χ2(2)=7.69; p=0.021) functioning and pain (χ2(2)=8.44; p=0.015) scores between the different groups. A post-hoc test with DSCF pairwise comparisons of median has shown a statistically significant difference between 1 and 3 groups (W=3.904; p=0.016) for physical functioning, between 2 and 3 groups (W=3.35; p=0.004) for role functioning, between 2 and 3 groups (W=4.03; p=0.012) for emotional functioning, between 1 and 3 groups (W=-3.97; p=0.014) for pain scale.Conclusion:The study has shown that MD associated with anticancer drug treatment adversely affected the QoL of cancer patients received anticancer drug treatment by reducing a physical functioning and by increasing pain scores. Presence of other types of MD adversely affect the QoL by reducing emotional and role functioning.References:[1]Aaronson NK,et al.The European Organization for Research and Treatment of Cancer QLQ-C30: a quality-of-life instrument for use in international clinical trials in oncology. J Natl Cancer Inst.1993;85(5):365-376. doi:10.1093/jnci/85.5.365Disclosure of Interests:None declared


Author(s):  
Yuji Tominaga ◽  
Masaki Taira ◽  
Takashi Kido ◽  
Tomomitsu Kanaya ◽  
Kanta Araki ◽  
...  

Abstract OBJECTIVES The clinical significance of persistent end-diastolic forward flow (EDFF) after pulmonary valve replacement (PVR) remains unclear in patients with repaired tetralogy of Fallot. This study aimed to identify the characteristics of these patients and the impact of persistent EDFF on outcomes. METHODS Of 46 consecutive patients who underwent PVR for moderate to severe pulmonary regurgitation between 2003 and 2019, 23 (50%) did not show EDFF before PVR [group (−)]. In the remaining 23 patients with EDFF before PVR, EDFF was diminished after PVR in 13 (28%) [group (+, −)] and persisted in 10 (22%) [group (+, +)]. The following variables were compared between these 3 groups: (i) preoperative right ventricular (RV) and right atrial volumes measured by magnetic resonance imaging, haemodynamic parameters measured by cardiac catheterization and the degree of RV myocardial fibrosis measured by RV biopsy obtained at PVR and (ii) the post-PVR course, development of atrial arrhythmia and need for intervention. RESULTS A high RV end-diastolic pressure, a greater right atrial volume index and a greater RV end-systolic volume index before PVR and a high degree of RV fibrosis were significantly associated with persistent EDFF 1 year after PVR. Persistent EDFF was a significant risk factor for postoperative atrial tachyarrhythmia, and catheter ablation and pacemaker implantation were required more frequently in these patients. CONCLUSIONS Persistent EDFF after PVR could predict a worse prognosis, especially an increased risk of arrhythmia. Close follow-up is required in patients with persistent EDFF for early detection of arrhythmia and prompt reintervention if necessary. Clinical trial registration number Institutional review board of Osaka University Hospital, number 16105


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