Body Weight and Steroidal Implants Impact Animal Growth Performance, Sera Metabolites, and Pulmonary Arterial Pressure in Feedlot Cattle

The study objective was to evaluate steer growth performance, sera metabolite responses, carcass characteristics, and pulmonary arterial pressure as affected by body weight at time of implantation and steroidal implant administration. Crossbred steers (n = 20) were used in a 2 × 2 factorial arrangement of treatments in a completely randomized design experiment, Factors included: body weight: light (L), or heavy (H) and implant: Non-implanted (NoIMP), or Implanted (IMP) with steer serving as the experimental unit for all analyses. Initial weights for L and H steers were 398 ± 27.6 and 547 ± 25.2 kg, respectively. Implanted steers received a terminal implant (200 mg trenbolone acetate and 20 mg estradiol-17β;Revalor-200;Merck Animal Health, Madison, NJ) on d 0. Cattle within treatments were group housed in common pens (n = 5 steers/pen). Bodyweight, blood samples, and pulmonary arterial pressure were collected on d 0, 14, 35, 70 and 104. Cattle were fed a common diet once daily to provide ad libitum access to feed. The finishing diet contained (DM basis) 13.3% CP, 2.13 Mcal/kg NEm, and 1.45 Mcal/kg NEg. Growth performance (body weight and ADG) and carcass traits were analyzed using the MIXED procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC). Sera metabolites were analyzed as repeated measures over time, with day as the repeated measure. For all analyses, α level < 0.05 determined significance. Heavy steers consumed 2.2 kg more per head of DM daily than L cattle and IMP steers consumed 1.0 kg more DM daily than NoIMP steers. Cumulative ADG did not differ between the L and H steers (1.41 vs. 1.52 ± 0.060 kg;P = 0.20). Implanting increased (P < 0.01) ADG by 39% (1.22 vs. 1.70 ± 0.060 kg). No differences (P > 0.05) in ADG were observed in NoIMP vs. IMP cattle beyond d 70 (1.21 vs. 1.01 ± 0.16 kg;P = 0.38). Sera urea-N concentrations were decreased (P < 0.01) in L cattle subjected to IMP during the study and tended to increase over time for the other treatments. Ribfat, HCW, LM, marbling score, calculated YG, and estimated EBF were greater (P ≤ 0.05) in H compared to L. Steers from IMP had heavier HCW (P < 0.01) but decreased marbling scores (P = 0.05) compared to NoIMP. Mean pulmonary arterial pressure was greater (P < 0.01) for H compared to L steers which may predispose heavier cattle to right-sided heart failure. The steroid implant had no effect on pulmonary arterial pressure (P > 0.49). The study reaffirms the effects of implanting on animal growth performance and carcass characteristics in cattle. In addition, elevated BW leads to increased pulmonary arterial pressures which may increase the risk of right-sided heart failure.

Ambulatory pulmonary artery pressure monitoring in advanced heart failure patients

Heart failure (HF) is an emerging epidemic associate with significant morbidity, mortality, and health care expenditure. Although there were major advances in pharmacologic and device based therapies for the management of HF, mortality of this condition remains high. Accurate monitoring of HF patients for exacerbations is very important to reduce recurrent hospitalizations and its associated complications. With the failure of clinical signs, tele-monitoring, and laboratory bio-markers to function as early markers of HF exacerbations, more sophisticated techniques were sought to accurately predict the circulatory status in HF patients in order to execute timely pharmacological intervention to reduce frequent hospitalizations. CardioMEMSTM (St. Jude Medical, Inc., Saint Paul, Minnesota) is an implantable, wireless pulmonary arterial pressure (PAP) monitoring system which transmits the patient’s continuous PAPs to the treating health care provider in the ambulatory setting. PAP-guided medical therapy modification has been shown to significantly reduce HF-related hospitalization and overall mortality. In advanced stages of HF, wireless access to hemodynamic information correlated with earlier left ventricular assist device implantation and shorter time to heart transplantation.

Qualitative estimation of pulmonary artery systolic pressure:could right heart catheterization be replaced by transthoracic Doppler echocardiography?

Background Transthoracic Doppler echocardiography is recommended for screening the presence of pulmonary hypertension(PH).However,the accuracy of pulmonary artery systolic pressure(PASP) estimated by Doppler echocardiographic is still unknown.Methods We conducted a retrospective study on 102 patients with idiopathic pulmonary arterial hypertension who underwent Doppler echocar-diography within 72 hours before right heart catheterization. During this time,all patients were stable without any specific drug therapy.Results There was moderate correlation between Doppler echocardiographic and right heart catheteriza- tion measurements of PASP(r =0.642,P【0.001).Using Bland-Altman analytic methods,the bias for the echocardio-graphic estimates of PASP was 6.65 mm Hg with 95%limits of agreement ranging from -47.62 to 34.30 mm Hg.There were 58.8%cases with absolute differences over 10 mm Hg between the two methods.Overestimation and underestimation of PASP by Doppler echocardiography occurred in 15.7% (16/102) and 43.1%(44),respectively.The magnitude of pressure underestimation and overestimation was insignificant (24.52±12.15 vs.25.69±16.09,P=0.765),while the corresponding diagnostic categories of severity that each subject would fall into for each technique are not in good agreement. The diagnostic categories of 16 overestimated patients were in accordance.During 44 underestimated patients,20.5%of patients had their pressure underestimated within one diagnostic category(minor error);4.5%of the underestimates were with two diagnostic categories(major error).Conclusions Transthoracic Doppler echocardiography may frequently be inaccurate in estimating PASP and could not replace the right heart catheterization.

Impact of Tricuspid Regurgitation Severity on Accuracy of Echocardiographic Estimation of Systolic Pulmonary Artery Pressure in Patients With Pulmonary Arterial Hypertension

Objective:This study aims to investigate the impact of tricuspid regurgitation(TR)severity on the accuracy of echocardiographic estimation of systolic pulmonary arterial pressure(sPAP)in patients with pulmonary arterial hypertension(PAH).Methods:Patients who were diagnosed with PAH and had a right heart catheterization(RHC)and echocardiography examination were selected retrospectively from May 2018 to December 2021.sPAP measured by RHC is used as the gold standard.A difference in sPAP of less than 10 mmHg between echocardiographic estimation by peak TR velocity and RHC measurement was defined as accurate,with a difference≥10 mmHg considered inaccurate.The factors affecting the accuracy of echocardiographic sPAP estimation were analyzed by univariate and multivariate analysis.Results:A total of 138 patients aged(45.57±15.97)years with PAH were enrolled.sPAP measured by echocardiography and RHC were(80.83±23.46)and(81.62±30.05)mmHg,respectively.The values of the 2 methods were highly correlated(r=0.809,P<0.01)and Bland-Altman plots showed good consistency.The accuracy rate of sPAP estimation by echocardiography was 42.03%(58/138).In the 57.97%(80/138)of patients where echocardiography was inaccurate,sPAP was overestimated in 28.26%(39/138)and underestimated in 29.71%(41/138).Univariate analysis showed that there was a statistically significant difference between the accurate and inaccurate groups in World Health Organization-Function Class,N-terminal pro-B-type natriuretic peptide,severity of TR,tricuspid annular plane systolic excursion(TAPSE),sPAP-RHC,mean pulmonary artery pressure,pulmonary vascular resistance(P<0.05).Multivariate logistic regression analyses identified the TR severity(odds ratio=2.292,95%confidence interval:1.126–4.667,P=0.022)and TAPSE(odds ratio=0.733,95%confidence interval:0.621–0.865,P<0.001)as independent predictors for the accuracy of echocardiographic sPAP estimation.Conclusion:Higher TR severity and lower TAPSE values reduce the accuracy of sPAP estimated by echocardiography.Therefore,TR severity and right heart function should be considered when echocardiography is used to estimate sPAP by the TR velocity.

Correlation analysis between lung ultrasound scores and pulmonary arterial systolic pressure in patients with acute heart failure admitted to the emergency intensive care unit

Background:No convenient,inexpensive,and non-invasive screening tools exist to identify pulmonary hypertension(PH)-left heart disease(LHD)patients during the early stages of the disease course.This study investigated whether different methods of lung ultrasound(LUS)could be used for the initial investigation of PH-LHD.Methods:This was a single-center prospective observational study which was performed in the Zigong Fourth People’s Hospital.We consecutively enrolled patients with heart failure(HF)admitted to the emergency intensive care unit from January 2018 to May 2020.Transthoracic echocardiography and LUS were performed within 24 h before discharge.We used the Spearman coefficient for correlation analysis between ultrasound scores and pulmonary arterial systolic pressure(PASP).Bland-Altman plots were generated to inspect possible bias,and receiver operating characteristic(ROC)curves were calculated to assess the relationship between ultrasound scores and an intermediate and high echocardiographic probability of PH-LHD.Results:Seventy-one patients were enrolled in this study,with an overall median age of 79(interquartile range:71.5–84.0)years.Among the 71 patients,36(50.7%)cases were male,and 26(36.6%)had an intermediate and high echocardiographic probability of PH.All four LUS scores in patients with an intermediate and high probability of PH were significantly higher than in patients with a low probability of PH(P<0.05).The correlation coefficient(r)between different LUS scoring methods and PASP was moderate for the 6-zone(r=0.455,P<0.001),8-zone(r=0.385,P=0.001),12-zone(r=0.587,P<0.001),and 28-zone(r=0.535,P<0.001)methods.In Bland-Altman plots,each of the four LUS scoring methods had a good agreement with PASP(P<0.001).The 8-zone and 12-zone methods showed moderately accurate discriminative values in differentiating patients with an intermediate and high echocardiographic probability of PH(P<0.05).

Prediction of pulmonary arterial wedge pressure from arterial pressure or pulse oximetry plethysmographic waveform

Objective To assess the possibility of using arterial pressure waveform or pulse oximetry plethysmographic waveform variation to estimate the pulmonary arterial wedge pressure (PAWP) Methods Fourteen American Society of Anesthesiologists grade Ⅰ-Ⅱ patients aged 33-69 years and weighing 62 0±9 5 kg scheduled for elective abdominal tumor surgery were studied Their hemoglobin exceeded 120 g/L and hematocrit exceeded 35% Pre operative acute hypervolemic hemodilution was applied immediately after general anesthestic induction and tracheal intubation PAWP, systolic pressure variation (SPV), delta down (dDown), SPV plet , dDown plet and other hemodynamic parameters were measured and recorded when total fluid volume (crystalloid and colloid) infused reached 10 ml/kg and 20 ml/kg and again at the end of the operation Central venous pressure was maintained at 10-12 mm Hg during operation Systolic blood pressure at the end of Valsalva maneuver (airway pressure was kept at 22 mm Hg) and the systolic pressure before the Valsalva manoeuvre during apnea were used to calculate arterial pressure ratio (APR) Results APR, SPV, dDown, SPV plet and dDown plet all correlated well with PAWP ( r =0 717, -0 695, -0 680, -0 522 and -0 624 respectively, P <0 01) There was a closer linear correlation between APR and PAWP than between the other parameters The regression equation was PAWP (mm Hg)=0 207×APR (%)-0 382 Conclusion During positive pressure mechanical ventilation, APR, SPV, dDown, SPV plet and dDown plet can be used to estimate PAWP effectively

Effects of extrinsic positive end-expiratory pressure on cardiopulmonary function in patients with chronic obstructive pulmonary disease

Objective To choose one optimal extrinsic positive end-expiratory pressure (PEEPe) for ventilated patients with chronic obstructive pulmonary disease (COPD) and to compare two methods for choosing the optimal level of PEEPe.Methods Ten ventilated patients with COPD were included in the study. First, static intrinsic positive end-expiratory pressure (PEEPi,st) was measured when PEEPe was zero, and the PEEPi,st was called PEEPi,stz. PEEPe at 0%, 40%, 50%, 60%, 70%, 80%, 90% and 100% of PEEPi,stz, respectively, were applied randomly. Respiratory mechanics, hemodynamics, and oxygen dynamics were recorded 30 minutes after the level of PEEPe was changed.Results When PEEPe was not higher than 80% of PEEPi,stz, no measurement changed significantly. When PEEPe was increased to 90% and 100% of PEEPi,stz, PEEPi,st, peak inspiratory pressure, plateau pressure, pulmonary capillary wedge pressure and central venous pressure increased significantly, P<0.01. Cardiac output and left ventricular work index decreased significantly, P<0.01. Oxygen delivery decreased significantly, P<0.05. When PEEPe was increased to 100% of PEEPi,stz, the right ventricular work index decreased significantly, P<0.05.Conclusion Eighty percent of PEEPi,stz was the upper limit of PEEPe. The results of the two methods used to set the level of PEEPe were identical.

Effects of extrinsic positive end-expiratory pressure on work of breathing in patients with chronic obstructive pulmonary disease

Objective To investigate the effects of extrinsic positive end-expiratory pressure (PEEPe) on work of breathing in patients with chronic obstructive pulmonary disease (COPD) and their corresponding mechanism.Methods Ten ventilated patients with COPD were included in the study. A Bicore CP-100 pulmonary monitor (Bicore Monitoring System, USA) was used for monitoring respiratory mechanics. First, dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn) was measured when PEEPe was zero, which was called PEEPi,dynz. Then the PEEPe was set randomly at 0%, 40%, 60%, 80% and 100% of PEEPi,dynz respectively. Pulmonary mechanics and other parameters (heart rate, blood pressure and blood gas analysis) were measured 30 minutes after the level of PEEPe was changed.Results Work of breathing patient (WOBp), pressure time product, difference of esophageal pressure and PEEPi,dyn decreased significantly when PEEPe was applied, and continued decreasing as PEEPe was increased. Work of breathing ventilator increased significantly when PEEPe was increased to 80% and 100% of PEEPi,dynz. Significantly positive linear correlation was found between the changes in WOBp and in PEEPi,dyn.Conclusions WOBp decreases gradually as PEEPe is increased. WOBp decreases by narrowing the difference between the alveolus pressure and the central airway pressure at the end of expiration when PEEPe is applied.

Functional changes of the heart and lung in perioperative period of orthotopic liver transplantation

Objective: To investigate the variation of functions of the heart and lung during orthotopic liver transplan- tation (OLT). Methods: Pulmonary artery cannula and right radial artery cannula were indewelled before anaesthesia and the parameters of hemodynamics in different pe- riods were monitored. Analysis of variance was used to reveal the variation among the groups. T hypothe- sis test in paired data was used to compare the preop- erative parameters with those in each period during operation and after operation respectively, and to compare the parameters immediately after operation with those in each period after operation respective- ly. Results: During the operation, heart rate increased, but blood pressure decreased significantly at the be- ginning of no-liver period, increased again in a short period and then increased progressively 12 h after op- eration. Pulmonary artery pressure (PAP) increased from before the no-liver period to 60 h after opera- tion. Pulmonary wedge pressure changed in accord- ance with the variation of PAP. Cardiac output was maintained at a high-output level from before opera- tion to 60 h after operation. Systemic vascular resist- ance (SVR) was within the normal limits before op- eration, whereas pulmonary vascular resistance (PVR) was lower than normal. In the no-liver peri- od during the operation, SVR decreased significant- ly. Both SVR and PVR increased progressively and returned to normal postoperatively. Conclusions: The patients undergoing OLT have a high cardiac output and Iow resistance obstacle be- fore and during the operation, and will recover grad- ually after operation. Monitoring hemodynamics during the peri-operative period is of significance in the prevention and treatment of pneumonedema and cardiac functional insufficiency.

Diagnosis and treatment of heart failure with preserved left ventricular ejection fraction

Nearly six million people in United States have heart failure.Fifty percent of these people have normal left ventricular(LV)systolic heart function but abnormal diastolic function due to increased LV myocardial stiffness.Most commonly,these patients are elderly women with hypertension,ischemic heart disease,atrial fibrillation,obesity,diabetes mellitus,renal disease,or obstructive lung disease.The annual mortality rate of these patients is 8%-12%per year.The diagnosis is based on the history,physical examination,laboratory data,echocardiography,and,when necessary,by cardiac catheterization.Patients with obesity,hypertension,atrial fibrillation,and volume overload require weight reduction,an exercise program,aggressive control of blood pressure and heart rate,and diuretics.Miniature devices inserted into patients for pulmonary artery pressure monitoring provide early warning of increased pulmonary pressure and congestion.If significant coronary heart disease is present,coronary revascularization should be considered.

Prognostic implications of elevated pulmonary artery systolic pressure on 6-month mortality in elderly patients with acute myocardial infarction

Background:Pulmonary artery systolic pressure(PASP)has often been evaluated as an indicator of heart failure,but the relationship between PASP and the prognosis of elderly patients with acute myocardial infarction(AMI)is not well understood.Methods:The medical data of 3460 hospitalized elderly patients diagnosed with AMI between January 2013 and June 2018 were reviewed.PASP was calculated usingtransthoracic color Doppler ultrasonography.Patients were grouped accordingtotheir admission PASP results as follows:Group A,PASP≤30 mmHg;Group B,30 mmHg<PASP≤50 mmHg;and Group C,PASP≥51 mmHg.The primary endpoint was all-cause death 6 months following AMI.Multiple Cox regression analysis was used to identify independent risk factors for 6-month mortality in elderly patients with AMI.Results:PASP was associated with age,Killip classification,AMI site,and decreased ejection fraction in elderly patients.After adjusting for clinical and echocardiographic parameters in the Cox model,PASP was found to be significantly related to all-cause mortality.In receiver operating characteristic analysis,a PASP of>34 mmHg had a sensitivity of 62.3%and specificity of 65.7%for predicting 6-month all-cause death after AMI.Conclusion:PASP at admission is a useful marker for predicting short-term mortality in elderly patients with AMI.This finding could be used to help identify high-risk patients and make appropriate clinical decisions.

Study on the changes in pulmonary artery pressure in elderly Chronic kindney disease patients without end-stage renal disease

Objective To prospectively investigate the characteristics and correlative influential factors for the changes in pulmonary artery hypertension(PAH)in chronic kidney disease(CKD)patients without end-stage renal disease.Methods Complete clinical and laboratory data of133 outpatients without ESRD(CKD stage 2,3 and 4)

Effects of thrombolytic drugs and a selective endothelin-1 receptor antagonist on acute pulmonary thromboembolism in dogs

Background It has been shown that neurohumoral factors other than mechanical obstruction are involved in the pathophysiology of acute pulmonary thromboembolism （APTE）. The aim of this study was to investigate the effects of thrombolytic drugs, a selective endothelin-1 receptor （ET-1 R） antagonist alone or their combination on APTE in a canine model. Methods Twenty dogs were randomly assigned to five groups： sham, model, urokinase （UK）, BQ123, and combination （UK plus BQ123）. The dogs in the sham group underwent sham surgery. APTE was induced in the other four groups by intravenous injection of autologous blood clots. Dogs in the UK, BQ123 and combination groups received UK, BQ123 （a selective ET-1R antagonist）, or UK plus BQ123, respectively. The dogs in the model group were given saline. Mean pulmonary artery pressure （mPAP）, serum concentrations of ET-1, thromboxane （TXB2）, and tumor necrosis factor （TNF）-α were determined at different time points following the induction of APTE. Results UK and BQ123 alone markedly decreased mPAP in APTE. By comparison, the reduction was more significant in the combination group. Compared with the sham group （（-0.90±0.61） mmHg）, mPAP increased by （7.44±1.04）, （3.42±1.12） and （1.14±0.55） mmHg in the model group, UK alone and BQ123 alone groups, respectively, and decreased by （2.24±0.67） mmHg in the combination group （P 〈0.01）. Serum ET-1 concentrations in the BQ123 and combination groups were （52.95±8.53） and （74.42±10.27） pg/ml, respectively, and were significantly lower than those in the model and UK groups （（84.56±7.44） and （97.66±8.31） pg/ml respectively; P 〈0.01）. Serum TNF-α concentrations were significantly lower in the BQ123 group than in the model, UK and combination groups （P 〈0.05）. Conclusions Our results indicate that the selective ET-1R antagonist BQ123 not only reduces the increase of mPAP and serum ET-1 level, but also inhibits the production of TNF-α, and attenuates the local inflammatory response induced by APTE. Selective ET-1R antagonists may be beneficial to the treatment of APTE, particularly when used in combination with a thrombolytic agent.

Distribution of ventilation and hemodynamic effects of different ventilatory patterns

OBJECTIVE: To compare the influence of cardiac-pulmonary function on clinical acute respiratory failure patients using Proportional assist ventilation (PAV), Pressure support ventilation (PSV) and intermittent positive pressure ventilation (IPPV). Here, we also describe some our experience with the clinical use of PAV. METHODS: Using the IPPV mode in ten acute respiratory failure patients, calculate Elastance (Ers) and Resistance (Rrs), then change to PSV, set inspiratory positive airway pressure (IPAP) according to IPPV, so that tidal volume (V(T)) is the same as that of IPPV. We then changed the mode into PAV and set the assist ratio according to PSV, so that V(T) and Ppeak were the same as that of PSV. Then we observed the changes of respiratory mechanics, blood gas levels and hemodynamics during ventilation. RESULTS: Compared with PSV and IPPV, peak pressure (Ppeak) of PAV was markedly lower while V(T) was similar; work of breathing of patient (WOBp), and work of breathing of ventilation (WOBv) were also lower; center vein pressure (CVP) and pulmonary capillary wedge pressure (PCWP) of PAV were markedly lower than that of IPPV while V(T) were similar. Compared with PSV, V(T), mean blood pressure (mBP) and cardiac output (CO) of PAV were higher. Mean pulmonary artery pressure (mPAP) and WOBp of PAV were lower while Ppeak was similar; the differences in WOBp were notable. CONCLUSIONS: For clinical acute respiratory failure patients, compared with PSV and IPPV, PAV has lower airway pressure, less WOBp and less influence on hemodynamics.

Long-term outcome of correction of tetralogy of Fallot in 56 adult patients

Background Although most patients with tetralogy of Fallot undergo radical repair during infancy and childhood,patients that remain undiagnosed and untreated until adulthood can still be treated.This study aimed to evaluate longterm outcomes of adult patients with tetralogy of Fallot who were treated surgically,and to determine the predictors of postoperative pulmonary regurgitation.Methods Fifty-six adult patients underwent complete surgical repair.Forty-three patients （76.8%） required a transannular patch.Systolic,diastolic,and mean pressure in the main pulmonary artery were measured after repair.Results The early mortality rate was 3.6%.The 16-year survival rate was （84.4±11.5）%.Late echocardiography revealed 41 patients with transannular patch who had pulmonary regurgitation,consisting of mild pulmonary regurgitation in 28 patients,moderate in eight,and severe regurgitation in five patients.In addition,there was right ventricular outflow tract stenosis in nine patients,moderate/severe tricuspid valve regurgitation in seven,and residual ventricular septal defect in five.Logistic regression analysis demonstrated that the mean pulmonary pressure measured just after repair predicted late pulmonary regurgitation.Conclusions The long-term survival of surgically treated adult patients with tetralogy of Fallot is acceptable.The mean pressure 〉20 mmHg in the main pulmonary artery measured right after surgical repair may be a feasible reference to time the reconstruction of the pulmonary valve.