Category Archives: Cardiac Surgery : Part 2

Closing Capacity and Gas Exchange in Chronic Heart Failure: CC and Gas Exchange

Closing Capacity and Gas Exchange in Chronic Heart Failure: CC and Gas ExchangeThere also was no significant difference in CC between CHF patients and control subjects, indicating that in our CHF patients there was “no premature airway closure.” In fact, in CHF patients the CC was actually smaller than that in control subjects, although not significantly. This may reflect the fact that pulmonary fibrosis and/or vascular engorgement- may render the peripheral airways more resistant to collapse. In line with the findings of Collins et al, however, in most of our patients (13 of 20) the CC exceeded the FRC (ie, during tidal breathing there was cyclic opening and closing of peripheral airways with a concurrent maldistribution of ventilation and a risk of mechanical injury to the peripheral airways). As a result of this maldistribution of ventilation, Pa02 decreased and P(A-a)O2 increased (Table 4). review

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Closing Capacity and Gas Exchange in Chronic Heart Failure: Lung Volumes

In line with the results of most previous re-ports,’’ our patients exhibited a reduction in TLC and FRC but normal FEV1/FVC ratio. In contrast, Yap et al found a significant reduction in TLC but not in FRC. Their patients, however, were studied just after a period of acute decompensation, which may be associated with the presence of FL and dynamic hyperinflation with the patient in the sitting position. Hart et al found no reduction of either TLC or FRC in 10 CHF patients; half of their patients, however, had CHF due to coronary artery disease. In the present study, only 30% of the patients (6 of 20) had a history of coronary artery disease. cfp-for-you.com

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Closing Capacity and Gas Exchange in Chronic Heart Failure: Research

Closing Capacity and Gas Exchange in Chronic Heart Failure: ResearchResting ventilation and P01 were higher in CHF patients than in control subjects (Table 4), with the increase of minute ventilation (Ve) resulting from increased respiratory frequency (fR). While the tidal volume (VT)/inspiratory time (Ti) ratio was significantly higher in CHF patients (reflecting the higher P01), Tl/total breathing cycle time (Ttot) ratio was the same in CHF patients and control subjects. The P01/Plmax ratio (percentage) was, on average, more than twice as large in CHF patients as in control subjects, reflecting in part the increased P0.1 and in part the decreased Plmax. As a result of the increased VE, the PaC02 was lower in CHF patients than in control subjects.

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Closing Capacity and Gas Exchange in Chronic Heart Failure: Results

Table 1 provides the anthropometric characteristics and baseline respiratory data for control subjects and CHF patients. In the control subjects, all baseline respiratory data were within normal limits; the MRC and Borg scores were zero, while the CHF patients exhibited slightly higher levels of MRC and Borg dyspnea scores.
In CHF patients, the FEV1/FVC ratio was within normal limits, while TLC and its subdivisions were reduced. This is also shown in Figure 1, where, for comparative purposes, volumes are expressed as the percentage of the predicted TLC. There were no significant differences in lung function between nonsmokers and ex-smokers in both CHF patients and control subjects, except for RV (percent predicted), which in control subjects was significantly (p < 0.05) lower in nonsmokers than in ex-smokers (Table 2). further

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Closing Capacity and Gas Exchange in Chronic Heart Failure: Statistical Analysis

Closing Capacity and Gas Exchange in Chronic Heart Failure: Statistical AnalysisBreathing pattern and mouth occlusion pressure 100 ms after onset of inspiratory effort (P0.1), maximal inspiratory pressure (Plmax), CV, CC, and alveolar plateau slope (AN2) were measured (VMAX 229; SensorMedics), as previously described. The Pimax was measured at RV according to American Thoracic Society/ERS criteria with predicted values obtained from Black and Hyatt.
The CV and AN2 were measured in triplicate by a single-breath N2 test with the mean taken as the final value. The CV was expressed in liters or as the percentage of VC measured during the single-breath exhalation. By adding RV to CV, the CC (in liters) was obtained and was also expressed as the percentage of total lung capacity (TLC) [ie, CC/TLC ratio]. Predicted CV/VC and CC/TLC ratios were obtained from Buist and Ross. From these predicted ratios, the predicted values of CV and CC (in liters) were computed using predicted values of VC and TLC, respectively. other
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Closing Capacity and Gas Exchange in Chronic Heart Failure: Experimental Protocol

Within 1 month prior to entering our study, Weber class was determined by cardiopulmonary exercise testing: Weber class B, 7 patients; Weber class C, 10 patients; and Weber class D, 3 patients. Heart failure was defined as symptomatic left ventricular dysfunction, with a left ejection fraction of < 0.45 documented by bidimensional echocardiography. Patients were excluded if they had primary pulmonary, neurologic, or myopathic disease. The echocardiographic ejection fraction and systolic pulmonary artery pressure (sPAP) were measured within the 2 weeks preceding entry into our study. The mean ejection fraction was 23% (range, 9 to 34%) [Table 1]. Twenty healthy subjects (control subjects) who were matched for sex and age were also studied with the same protocol as for the CHF patients. All control subjects were nonsmokers, but nine patients were ex-smokers (Table 1). The study was approved by the local ethics committee, and informed consent was obtained from each subject. add comment
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Closing Capacity and Gas Exchange in Chronic Heart Failure

Closing Capacity and Gas Exchange in Chronic Heart FailureCollins et al reported that the ratio of closing volume (CV) to vital capacity (VC) was increased in patients with chronic heart failure (CHF), and suggested that pulmonary congestion and edema promote peripheral airway closure. This is in line with the study by Hughes and Rosenzweig, who showed that in isolated perfused dog lungs the volume of trapped gas increased with increased lung water and was greater in the more dependent parts of the lung in which interstitial pulmonary edema was most prominent on histologic examination. They postulated that enhanced air trapping was caused by premature peripheral airway closure due to the presence of cuffs of edema fluid in the loose connective tissue around the extraalveolar peripheral airways before there was any significant change in alveolar wall thickness. An increase in the CV/VC ratio, however, can be due to an increase in CV and/or a decrease in VC. read

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Early Sepsis Treatment With Immunoglobulins After Cardiac Surgery in Score-identified High-risk Patients – Conclusion

Selection of Ig Preparations and Ig Serum Levels
The IgG preparation was chosen for its high antibody titers against Gram-positive bacterial toxins and its effectiveness against these pathogens in experimental animals, given the preponderance of these microorganisms as infective agents after heart surgery. The IgGMA preparation was selected for its reported antibody titer, particularly including IgM, against endotoxic determinants of the core polysaccharide, since endotoxemia is known to occur in the early postoperative course after extracorporeal circulation.
Our study confirms the ability of supplemental Ig administration to significantly increase serum IgG levels in patients with sepsis. The data from our IgG therapy group favor the assumption of an association between higher posttreatment IgG levels and a beneficial outcome and thus the concept of a deficient immunoprotein synthesis and/or abnormal IgG consumption in patients with severe infections. These clinical results are consistent with a decreased Ig production in culture of Ig synthesizing and secreting cells from patients after cardiac surgery. A surprising yet unexplained finding in the IgGMA group was the tendency toward higher IgM levels in the nonresponders. buy birth control

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Early Sepsis Treatment With Immunoglobulins After Cardiac Surgery in Score-identified High-risk Patients – Patient Groups Comparability

Early Sepsis Treatment With Immunoglobulins After Cardiac Surgery in Score-identified High-risk Patients - Patient Groups ComparabilityThese conclusions can be drawn from the present study despite a potential limitation due to its nonrandomized design. Thus, according to Makuch and Simon, “if the historical-control and the experimen-tal-treatment patients are similar with regard to measured factors that are thought to be of prognostic importance, then one has a reasonable basis for employing significance tests to compare their response rates.” Given the necessity to know whether the patient groups being studied were indeed comparable (thus, at equal risk of having the outcome being assessed), every effort has been made to quantitatively assess the present study groups’ comparability.
First, demographic data and operation characteristics were similar in control and treatment groups (Table 1). The incidence of risk and high-risk patients was nearly constant, arguing against a relevant imbalance in the patients’ population characteristics. buy asthma inhalers

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Early Sepsis Treatment With Immunoglobulins After Cardiac Surgery in Score-identified High-risk Patients – Discussion

Identification of Risk Patients
A major problem of postoperative care is the early identification of patients at risk of developing sepsis and multiple organ failure. By comparing different parameters on the first postoperative day in patients after cardiac surgery (plasma elastase and neopterin, hemodynamic data, scoring systems), we have found the best predictive value for several scoring systems (work in preparation). Among these, the APACHE II score was selected for its best practicability (routine bedside availability within 5 to 10 min using a microcomputer-based program). It is applicable for imminent sepsis risk stratification, discriminating on the first postoperative day between the large population of low-risk patients (score < 19) with mostly uneventful course and the small groups of patients at risk (19 to 23) and high risk ( < 24) who have an at least tenfold higher postsurgical mortality (Fig la). This approach yields several advantages: (1) early and standardized use of supplemental treatment; (2) specific use of therapy in the small percentage of risk patients (Table 1) and thus cost-effectiveness; (3) early physicians’ awareness of a patient’s risk (leading, for instance, to increased antibiotic therapy [Table 1]); and (4) clear-cut prospective identification of the target treatment groups, avoiding the problem of treating a large population although therapy is likely to be efficacious only in a minority who are not a priori identifiable (note recent controversy; over monoclonal endotoxin antibodies in sepsis with Gram-negative bacteremia). buy claritin online

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