Reduced cardiovascular responsiveness to exercise-induced sympathoadrenergic stimulation in patients with cirrhosis

Cardiovascular responsiveness to sympathoadrenergic activation obtained by muscle exercise in the supine position was evaluated in 22 patients with cirrhosis (11 alcoholic, 11 postnecrotic/cryptogenic; 14 with ascites) and 10 controls of comparable age. Plasma norepinephrine, heart rate, diastolic arterial pressure and cardiac function, as evaluated by systolic time intervals, were monitored. At rest, cirrhotics had higher norepinephrine (154 +/- 19 S.E.M. ng/l) and heart rate (79 +/- 2 beats per min) than controls (71 +/- 3 ng/l, p less than 0.01; 67 +/- 2 beats per min, p less than 0.001), whereas diastolic arterial pressure was similar. Among systolic time intervals, electromechanical systole, pre-ejection period, electromechanical delay and pre-ejection period to left ventricular ejection time ratios were prolonged (p less than 0.05 or less). Exercise led to significant increases in plasma norepinephrine, heart rate and diastolic arterial pressure in both controls and patients. In the latter, however, whereas the increase in norepinephrine was greater (p less than 0.001), those in heart rate and diastolic arterial pressure were less (p less than 0.005). As expected, most systolic time intervals shortened, but the decrease in pre-ejection period (p less than 0.05), isometric contraction time (p less than 0.02) and pre-ejection period to left ventricular ejection time ratio (p = 0.06) was less in patients than in controls. Direct correlations between exercise-induced changes in norepinephrine and both diastolic arterial pressure (r = 0.81; p less than 0.005) and heart rate (r = 0.85; p less than 0.002) were observed in controls, while inverse correlations (r = -0.67, p less than 0.001 and r = -0.44; p less than 0.05) were found in cirrhotics. These results suggest that cardiovascular reactivity to the sympathetic drive is impaired in cirrhotics. The impairment of cardiac contractility may be due to altered electromechanical coupling.     

Acid base disorders in patients with COVID-19

Purpose

Acid–base derangement has been poorly described in patients with coronavirus disease 2019 (COVID-19). Considering the high prevalence of pneumonia and kidneys injury in COVID-19, frequent acid–base alterations are expected in patients admitted with SARS-Cov-2 infection. The study aimed to assess the prevalence of acid–base disorders in symptomatic patients with a diagnosis of COVID-19.

Methods

The retrospective study enrolled COVID-19 patients hospitalized at the University Hospital of Modena from 4 March to 20 June 2020. Baseline arterial blood gas (ABG) analysis was collected in 211 patients. In subjects with multiple ABG analysis, we selected only the first measurement. A pH of less than 7.37 was categorized as acidemia and a pH of more than 7.43 was categorized as alkalemia.

Results

ABG analyses revealed a low arterial partial pressure of oxygen (PO₂, 70.2?±?25.1 mmHg), oxygen saturation (SO₂, 92%) and a mild reduction of PO₂/FiO₂ ratio (231?±?129). Acid–base alterations were found in 79.7% of the patient. Metabolic alkalosis (33.6%) was the main alteration followed by respiratory alkalosis (30.3%), combined alkalosis (9.4%), respiratory acidosis (3.3%), metabolic acidosis (2.8%) and other compensated acid–base disturbances (3.6%). All six patients with metabolic acidosis died at the end of the follow-up.

Conclusion

Variations of pH occurred in the majority (79.7%) of patients admitted with COVID-19. The patients experienced all the type of acid–base disorders, notably metabolic and respiratory alkalosis were the most common alterations in this group of patients.

     

Determination of fecal fat concentration by near infrared spectrometry for the screening of pancreatic steatorrhea

Summary Conclusions Near infrared reflectance analysis (NIRA) is a useful test for diagnosing fat malabsorption. Three-day stool collection and determination of fecal fat output are recommended. The measurement of fat concentration on spot samples may be of some use only in screening malabsorption of pancreatic origin; moreover, it does not discriminate between steatorrhea resulting from pancreatic insufficiency and that caused by gastrointestinal disorders. Background NIRA has been proposed as an accurate method for the determination of fecal fat excretion. The aim of this study was to ascertain whether utilization of this technique to measure fat concentration in spot samples of feces is useful in screening for malabsorption. Methods Twenty-five patients with chronic pancreatic disease and 95 with other digestive disorders were studied. In all patients, fecal fat assay with NIRA was performed on three different samples from each daily stool collection for 3 d. In 14 patients with pancreatic disease and 21 with gastrointestinal disorders, a colorimetric assay for fecal fat was performed for comparison. Results When mean 3-d or daily fat fecal output were considered, a strict linear relationship was found between NIRA and the colorimetric method (r=0.97 and 0.94, respectively). Using fat concentration, the two tests correlated less well (r=0.74). Fat concentration was significantly higher in pancreatic than in nonpancreatic steatorrhea, even though values overlapped widely, and thus discrimination was not possible. The diagnostic efficiency of fat concentration for pancreatic and nonpancreatic steatorrhea was 72 and 61%, respectively.     

Non-invasive diagnosis of acute ischemic bowel disease detected as hepatic portal venous gas during intra-aortic balloon percutaneous counterpulsation.

The authors report a very unusual case of non-invasive diagnosis of acute ischemic bowel disease detected as hepatic portal venous gas during intra-aortic balloon percutaneous counterpulsation. A 64-year-old man with acute ST-elevation myocardial infarction complicated by cardiogenic shock was treated with percutaneous angioplasty and intra-aortic balloon percutaneous counterpulsation. The post-procedural period was complicated by severe abdominal pain. Abdominal computed tomography revealed hepatic portal venous gas. Multiple kidney and splenic ischemic areas were also identified. Colonoscopy showed signs referring to acute ischemic colitis. Computed tomography detection of hepatic portal venous gas has permitted the non-invasive diagnosis of bowel necrosis.     

Renal function impairment induced by change in posture in patients with cirrhosis and ascites.

The assumption of upright posture by patients with liver cirrhosis leads to striking activation of adrenergic and renin-angiotensin systems. The tilting-induced modifications in renal function of eight healthy controls and 14 untreated patients with liver cirrhosis and ascites were related to plasma concentrations of noradrenaline, renin activity and aldosterone. All patients had preserved renal blood perfusion. All parameters were evaluated during bed rest for two hours and in the sitting posture for one hour. Basal plasma renin activity (0.1 greater than p greater than 0.05), aldosterone and noradrenaline concentrations (p less than or equal to 0.01) were raised in cirrhotics. The renal function tests (creatinine clearance, filtered sodium, tubular rejection fraction, urinary sodium excretion) were significantly reduced in cirrhosis. Under basal conditions, in cirrhotic patients tubular rejection fraction and urinary sodium excretion were inversely related to both noradrenaline and aldosterone concentrations. After tilting, the noradrenaline and aldosterone integrated outputs (sigma delta) were significantly greater in cirrhosis. All renal function tests significantly decreased in cirrhotics, whereas creatinine clearance only significantly decreased in controls. Patient's tubular rejection fraction of sodium and sodium excretion were related to sigma delta aldosteronaemia (r = -0.72; p less than 0.01), but no longer to sigma delta plasma noradrenaline.     

Contrast-enhanced MRI and PET-CT in the evaluation of patients with suspected local recurrence of rectal carcinoma

Purpose

This study aimed to evaluate the role of contrastenhanced magnetic resonance imaging (MRI) and positron emission tomography-computed tomography (PET-CT) in the assessment of local recurrence of rectal cancer.

Materials and methods

Among 200 patients scheduled for CT follow-up, 60 (48 low risk; 12 high risk) were selected due to CT findings suspicious for or suggestive of local recurrence. Patients underwent contrast-enhanced MRI and PET-CT within 2 weeks. Biopsy was considered the gold standard in 39 cases and follow-up at 6 and 12 months in the remaining 21.

Results

Local recurrence was confirmed by histology in 15 cases (7 low risk; 8 high risk) and was excluded in 21 cases by long-term follow-up and in 24 by histology. Sensitivity, specificity, positive and negative predictive value and accuracy were 86.7%, 68.9%, 48.1%, 93.9% and 73.3% for contrast-enhanced MRI and 93.3%, 68.9%, 50%, 96.9% and 75% for PET-CT.

Conclusions

Contrast-enhanced MRI and PET-CT can help in the detection of local recurrence of rectal cancer, even though their roles in early detection remains debatable, as the value of these techniques in current surveillance protocols is still to be defined.     

Rhodococcus equi Pneumonia in Kidney Transplant Recipient Affected by Acute Intermittent Porphyria: A Case Report

Rhodococcus equi is a gram-positive coccobacillus responsible for severe infections in patients with weakened immune systems. R equi generally causes pnumonia that may evolve into fatal systemic infection if left untreated. Here, we present a case of a 67-year-old woman affected by acute intermittent porphyria (AIP) who developed R equi pneumonia 7 months after kidney transplantation. Although clinical features at presentation were nonspecific, lung computed tomography showed right perihilar consolidation with a mass-like appearance causing bronchial obstruction. Appropriate antibiotic including intravenous meropenem and oral azithromycin that was then switched to oral levofloxacin and oral azithromycin along with reduction of immunosuppressive therapy resolved pneumonia without provoking an acute attack of porphyria. AIP limited the choice of antibiotics for the treatment of R equi infection because some potentially porphyrinogenic antibacterial agents were avoided. Based on this experience, azithromycin and meropenem can be safely administered for the treatment of R Equi infection in patients with AIP.     

3-Tesla MRI for the evaluation of myocardial viability: a comparative study with 1.5-Tesla MRI

PURPOSE: We compared 3-Tesla (3-T) and 1.5-Tesla (1.5-T) cardiac magnetic resonance imaging (MRI) for the assessment of myocardial viability in nearly identical experimental conditions. MATERIALS AND METHODS: Thirty-five patients (mean age 63+/-11; 94.2% men) submitted to primary coronary angioplasty underwent both 3-T and 1.5-T cardiac MRI, which was considered the gold standard. Comparison was performed on the basis of the same viability imaging protocol, which included resting cine-MR [balanced fast-field echo (B-FFE) sequence] followed by contrast-enhanced MR to evaluate perfusion and delayed enhancement (DE). We then performed functional index measurements and visual estimation of kinesis, perfusion and DE referring to a 5-point scale. Image quality was assessed on the basis of signal to noise ratio (SNR) and contrast to noise ratio (CNR). RESULTS: We found nonsignificant differences between the two scanners (P=NS) in measuring the functional and viability parameters. Myocardial SNR was significantly higher with 3-T MRI compared with 1.5-T MRI (61.3% gain). Even though a loss of CNR was recorded in B-FFE and in first-pass perfusion sequences (12.4% and 23.7%, respectively), on DE images, we quantified the increase of SNR and CNR of infarction of 387.8% and 330%, respectively. CONCLUSIONS: We found that 3-T MRI showed high concordance with 1.5-T MRI in the evaluation of functional and viability parameters and provided better evidence of damaged myocardium.     

Activation of coagulation during hemodialysis: effect of blood lines alone and whole extracorporeal circuit

Activation of coagulation during hemodialysis (HD) is a relevant clinical problem, especially when patients at risk of bleeding are treated. However, little is known about the relative contribution of the various components of the circuit to the thrombotic process. Thus, an experimental model was developed that is aimed at evaluating biochemical markers of coagulation activation at different times and sites throughout the HD circuit. A HD blood-tubing set with integrated arterial and venous chambers (cartridge-line set) was used, which was added with the following sampling points: at the beginning of the arterial line (P1), before the blood pump (P2), after the blood pump (P3), and at the end of the venous line (P4). A bypass system allowed us to circulate the blood only into the blood lines for the first 20 min of the extracorporeal circulation. The extracorporeal circuit was rinsed with 1.7 L of heparinized saline (2,500 IU/L) that was completely discarded before patient connection. A continuous administration of unfractionated heparin (500-800 IU/h) without a starting bolus was adopted as a low heparin extracorporeal treatment. Samples were collected before the start of the extracorporeal circulation from the fistula needle (T0P0), after 5 (T1), 10 (T2), and 20 min (T3) from P1, P2, P3, and P4. After 20 min, the blood was returned to the patient using only saline and HD was then started, circulating the blood through the dialyzer. Further samples were obtained from P1 and P4 after 5 (T4) and 210 min (T5). Plasma levels of coagulation activation markers-thrombin-antithrombin complex (TAT) and prothrombin fragment 1 + 2 (F1 + 2)-were evaluated in all the samples in 12 stable HD patients. In each patient, the activated partial thromboplastin time (APTT) was measured at T0P0 and T1-T5 from P1. No significant changes were found at any time as far as F1 + 2 is concerned. However, TAT levels increased over time only after the start of HD, suggesting that the latter test could be more useful in order to detect coagulation activation during HD. The same experiments performed with nonheparin-primed extracorporeal circuit showed similar results. The blood lines used did not significantly activate coagulation during the first 20 min, whereas only 5 min of blood circulation throughout the whole circuit increased TAT values, which still remained lower than previous reports, even after 210 min of treatment.