The role of intestinal mucosa injury induced by intra-abdominal hypertension in the development of abdominal compartment syndrome and multiple organ dysfunction syndrome

Introduction

Abdominal distension is common in critical illness. There is a growing recognition that intra-abdominal hypertension (IAH) may complicate nonsurgical critical illness as well as after abdominal surgery. However, the pathophysiological basis of the injury to the intestinal mucosal barrier and its influence on the onset of abdominal compartment syndrome (ACS) and multiorgan dysfunction syndrome (MODS) remain unclear. We measured intestinal microcirculatory blood flow (MBF) during periods of raised intra-abdominal pressure (IAP) and examined how this influenced intestinal permeability, systemic endotoxin release, and histopathological changes.

Methods

To test different grades of IAH to the injury of intestinal mucosa, 96 New Zealand white rabbits aged 5 to 6 months were exposed to increased IAP under nitrogen pneumoperitoneum of 15 mmHg or 25 mmHg for 2, 4 or 6 hours. MBF was measured using a laser Doppler probe placed against the jejunal mucosa through a small laparotomy. Fluorescein isothiocyanate (FITC)-conjugated dextran was administered by gavage. Intestinal injury and permeability were measured using assays for serum FITC-dextran and endotoxin, respectively, after each increase in IAP. Structural injury to the intestinal mucosa at different levels of IAH was confirmed by light and transmission electron microscopy.

Results

MBF reduced from baseline by 40% when IAP was 15 mmHg for 2 hours. This doubled to 81% when IAP was 25 mmHg for 6 hours. Each indicator of intestinal injury increased significantly, proportionately with IAP elevation and exposure time. Baseline serum FITC-dextran was 9.30 (± SD 6.00) μg/ml, rising to 46.89 (±13.43) μg/ml after 15 mmHg IAP for 4 hours (P <0.01), and 284.59 (± 45.18) μg/ml after 25 mmHg IAP for 6 hours (P <0.01). Endotoxin levels showed the same pattern. After prolonged exposure to increased IAP, microscopy showed erosion and necrosis of jejunal villi, mitochondria swelling and discontinuous intracellular tight junctions.

Conclusions

Intra-abdominal hypertension can significantly reduce MBF in the intestinal mucosa, increase intestinal permeability, result in endotoxemia, and lead to irreversible damage to the mitochondria and necrosis of the gut mucosa. The dysfunction of the intestinal mucosal barrier may be one of the important initial factors responsible for the onset of ACS and MODS.     

Matching positive end-expiratory pressure to intra-abdominal pressure improves oxygenation in a porcine sick lung model of intra-abdominal hypertension

Introduction

Intra-abdominal hypertension (IAH) causes atelectasis, reduces lung volumes and increases respiratory system elastance. Positive end-expiratory pressure (PEEP) in the setting of IAH and healthy lungs improves lung volumes but not oxygenation. However, critically ill patients with IAH often suffer from acute lung injury (ALI). This study, therefore, examined the respiratory and cardiac effects of positive end-expiratory pressure in an animal model of IAH, with sick lungs.

Methods

Nine pigs were anesthetized and ventilated (48 +/- 6 kg). Lung injury was induced with oleic acid. Three levels of intra-abdominal pressure (baseline, 18, and 22 mmHg) were randomly generated. At each level of intra-abdominal pressure, three levels of PEEP were randomly applied: baseline (5 cmH₂O), moderate (0.5 × intra-abdominal pressure), and high (1.0 × intra-abdominal pressure). We measured end-expiratory lung volumes, arterial oxygen levels, respiratory mechanics, and cardiac output 10 minutes after each new IAP and PEEP setting.

Results

At baseline PEEP, IAH (22 mmHg) decreased oxygen levels (-55%, P <0.001) and end-expiratory lung volumes (-45%, P = 0.007). At IAP of 22 mmHg, moderate and high PEEP increased oxygen levels (+60%, P = 0.04 and +162%, P <0.001) and end-expiratory lung volume (+44%, P = 0.02 and +279%, P <0.001) and high PEEP reduced cardiac output (-30%, P = 0.04). Shunt and dead-space fraction inversely correlated with oxygen levels and end-expiratory lung volumes. In the presence of IAH, lung, chest wall and respiratory system elastance increased. Subsequently, PEEP decreased respiratory system elastance by decreasing chest wall elastance.

Conclusions

In a porcine sick lung model of IAH, PEEP matched to intra-abdominal pressure led to increased lung volumes and oxygenation and decreased chest wall elastance shunt and dead-space fraction. High PEEP decreased cardiac output. The study shows that lung injury influences the effects of IAH and PEEP on oxygenation and respiratory mechanics. Our findings support the application of PEEP in the setting of acute lung injury and IAH.     

Ultrasound examination using contrast agent and elastosonography in the evaluation of single thyroid nodules: Preliminary results

Aim

To evaluate the usefulness of ultrasound (US) using contrast agent and elastosonography in the characterization of thyroid nodules.

Materials and methods

From November 2006 to July 2007, 23 patients with single thyroid nodules underwent B-mode US and power Doppler, US examination using contrast agent, elastosonography and fine needle aspiration cytology (FNAC). Sixteen patients underwent thyroidectomy.

Results

The 23 nodules included 14 benign and 9 malignant lesions. Analysis of time/intensity curves showed that wash-in (8.8 ± 1.3 vs 12.1 ± 2.6 s; p = 0.002, t-test) and peak enhancement (15.3 ± 4.6 vs 22.2 ± 3.9 s; p = 0.001, t-test) occurred significantly earlier in the malignant nodules than in the benign nodules. Wash-out was monophasic in 70% of benign nodules, but in none of the malignant nodules; polyphasic in 30% of benign nodules and in 100% of malignant nodules. Polyphasic wash-out showed a statistically significant association with malignancy (p = 0.0007, χ²). Polyphasic wash-out yielded a sensitivity of 100%, specificity of 71%, positive predictive value (PPV) of 69%, negative predictive value (NPV) of 100% and diagnostic accuracy of 83%. In 78% of the benign nodules (11/14) elastosonographic patterns was 1–2 (elevated elasticity); in 88% of the malignant nodules (8/9) elastosonographic patterns was 3–4 (reduced elasticity). Elastosonography yielded a sensitivity of 88%, specificity of 78%, PPV of 72%, NPV of 91% and diagnostic accuracy of 82%. Elastosonographic patterns 3–4 is associated with malignancy (p = 0.001, χ²).

Conclusion

US using contrast agent and elastosonography can be a useful diagnostic tool in the evaluation of single thyroid nodules, particularly when FNAC result is non-diagnostic or suggests a follicular lesion, and in nodules <1 cm.     

Contrast-enhanced ultrasound findings in soft-tissue lesions: preliminary results

Objectives

There is currently no widely available, minimally invasive first-level examination that allows physicians to identify soft-tissue lesions that are likely to be malignant. The aim of this pilot study was to explore the potential suitability of dynamic contrast-enhanced ultrasound (DCE-US) for this purpose.

Materials and methods

23 patients were referred to the Veneto Oncological Institute for work-up of superficial soft-tissue lesions. Fourteen lesions were examined with CEUS and enhancement kinetics was analyzed. Subsequently, all lesions were surgically removed and subjected to histological analysis.

Results

The 14 lesions included in the study were histologically classified as malignant (n = 7) or benign (n = 7, including 3 schwannomas). A statistically significant difference between benign and malignant lesions was found in terms of mean times to peak enhancement intensity (p = 0.03) but not mean filling times (FT). When schwannomas were analyzed as a separate group, their mean FT was found to be significantly different from that of the other benign lesions (p = 0.001) and from that of the group comprising other benign lesions as well as malignant lesions (p < 0.005).

Conclusions

CEUS with analysis of contrast-enhancement kinetics is a relatively low-cost, minimally invasive imaging technique, which appears to be a potentially effective first-level method for identifying suspicious soft-tissue masses.     

Assessment of cardiovascular physiology using dobutamine stress cardiovascular magnetic resonance reveals impaired contractile reserve in patients with cirrhotic cardiomyopathy

Background

Liver cirrhosis has been shown to affect cardiac performance. However cardiac dysfunction may only be revealed under stress conditions. The value of non-invasive stress tests in diagnosing cirrhotic cardiomyopathy is unclear. We sought to investigate the response to pharmacological stimulation with dobutamine in patients with cirrhosis using cardiovascular magnetic resonance.

Methods

Thirty-six patients and eight controls were scanned using a 1.5 T scanner (Siemens Symphony TIM; Siemens, Erlangen, Germany). Conventional volumetric and feature tracking analysis using dedicated software (CMR42; Circle Cardiovascular Imaging Inc, Calgary, Canada and Diogenes MRI; Tomtec; Germany, respectively) were performed at rest and during low to intermediate dose dobutamine stress.

Results

Whilst volumetry based parameters were similar between patients and controls at rest, patients had a smaller increase in cardiac output during stress (p = 0.015). Ejection fraction increase was impaired in patients during 10 μg/kg/min dobutamine as compared to controls (6.9 % vs. 16.5 %, p = 0.007), but not with 20 μg/kg/min (12.1 % vs. 17.6 %, p = 0.12). This was paralleled by an impaired improvement in circumferential strain with low dose (median increase of 14.4 % vs. 30.9 %, p = 0.03), but not with intermediate dose dobutamine (median increase of 29.4 % vs. 33.9 %, p = 0.54). There was an impaired longitudinal strain increase in patients as compared to controls during low (median increase of 6.6 % vs 28.6 %, p < 0.001) and intermediate dose dobutamine (median increase of 2.6%vs, 12.6 % p = 0.016). Radial strain response to dobutamine was similar in patients and controls (p > 0.05).

Conclusion

Cirrhotic cardiomyopathy is characterized by an impaired cardiac pharmacological response that can be detected with magnetic resonance myocardial stress testing. Deformation analysis parameters may be more sensitive in identifying abnormalities in inotropic response to stress than conventional methods.     

Sonoelastography findings of supraspinatus tendon in rotator cuff tendinopathy without tear: comparison with magnetic resonance images and conventional ultrasonography

Background and purpose

Sonoelastography (SE) is a new technique that can assess differences in tissue stiffness. This study investigated the performance of SE for the differentiation of supraspinatus (SSP) tendon alterations of tendinopathy compared to magnetic resonance imaging (MRI) and conventional ultrasonography (US).

Methods

One hundred and eighteen consecutively registered patients with symptoms and MRI findings of SSP tendinopathy were assessed with US and SE. Coronal images of the SSP tendon were obtained using US and SE. Increased signal intensity on T2-weighted images in the coronal planes were graded according to the extent of the signal changes from ventral to dorsal. SE images were evaluated by reviewers using an experimentally proven color grading system.

Results

Using SE, 7.6 % of the SSP tendons were categorized as grade 0, 30.5 % as grade 1, 19.5 % as grade 2, and 42.4 % as grade 3. Evaluation of the interobserver reliability of the SE findings showed “almost perfect agreement”, with a weighted kappa coefficient of 0.83. By comparing the MRI findings with the SE findings, grades of MRI and SE had a positive correlation (r = 0.829, p = <0.001). Furthermore, grades of US and SE also had a positive correlation (r = 0.723, p = <0.001).

Conclusions

SE is valuable in the detection of the intratendinous and peritendinous alterations of the SSP tendon and has excellent interobserver reliability and excellent correlation with MRI findings and conventional ultrasonography findings.     

Sonography of the optic nerve sheath beyond the hyperacute stage of intracerebral hemorrhage

Purpose

To evaluate the feasibility and utility of serial measuring of the optic nerve sheath diameter beyond the hyperacute and acute stage of intracerebral hemorrhage (ICH).

Methods

Four patients with extensive ICH in the left basal ganglia were followed using ultrasound (US) and cerebral CT scans.

Results

Optic nerve sheath diameter values assessed beyond the acute stage of ICH showed a high correlation (ρ = 0.84, p = 0.0022) with midline shift of the third ventricle seen on CT scans.

Conclusions

Optic nerve sonography can be useful to evaluate patients with extensive ICH beyond the acute stage and help monitoring clinical evolution in these patients, when ICP monitoring is not feasible.     

Fast and fully automatic calibration of frequency offset for balanced steady-state free precession cardiovascular magnetic resonance at 3.0 Tesla

Background

This study proposed a fast and fully automatic calibration system to suppress the dark banding artifacts in balanced steady-state free precession (bSSFP) cardiovascular magnetic resonance (CMR) at 3.0 T.

Methods

Twenty-one healthy volunteers (18 men, 3 women; mean age 24.9 years) participated in this study after providing institutionally approved consent. The optimal frequency was obtained using sweep scans of transition-band low flip-angle bSSFP (bSSFP-L), performed with three conditions: breath-hold plus electrocardiography (ECG) triggering (BH + ECG), breath-hold only (BH), and free breathing (FB). A real-time feedback system was implemented to allow the performing of bSSFP-L calibration scanning and conventional cine bSSFP within one breath-hold. For each scan condition, the optimal phase was estimated using 20-point and 10-point spline fitting.

Results

Linear regression analysis indicated high correlation between the optimal phases obtained using BH and FB and those obtained using BH + ECG (R² = 0.91 to 0.98, n = 21). The optimal phases obtained using 10-point datasets showed high correlation with the 20-point BH + ECG datasets (R² = 0.92 to 0.99, n = 21); although the within-subject coefficient of variation (wsCV) was larger using 10-point fitting. The variation of repeated measurements was largest with FB acquisition and smallest with BH + ECG acquisition. The optimal frequency obtained by offline calculation and by real-time feedback calibration significantly reduced dark-band artifacts in cine bSSFP images (both p < .01).

Conclusions

The proposed real-time feedback calibration method for bSSFP imaging is rapid and fully automatic. This method could greatly reduce dark-band artifacts in bSSFP images and facilitate clinical CMR at 3.0 T.     

Sonoelastography findings of biceps tendinitis and tendinosis

Objective

The purpose of this study was to evaluate sonoelastography (SE) in the assessment of the long head of biceps tendon (LHBT) in patients with symptoms of biceps tendinitis or tendinosis and in patients without biceps lesion. The findings were compared with those obtained at clinical examination, using ultrasonography (US).

Materials and methods

36 shoulders of 34 consecutively registered patients with clinical symptoms and US findings of biceps tendinitis or tendinosis, and 114 shoulders of 98 patients without biceps lesions were assessed with SE. Transverse and longitudinal images of LHBT were obtained using SE. SE images were evaluated by reviewers using an experimentally proven color grading system.

Results

The transverse images of SE showed a mean sensitivity of 69.4 %, a mean specificity of 95.6 % and a mean accuracy of 89.3 %. Good correlation of conventional ultrasound findings was found (p < 0.001, r = 0.763). The longitudinal images of SE showed a mean sensitivity of 94.4 %, a mean specificity of 92.1 % and a mean accuracy of 92.7 %. Good correlation of conventional ultrasound findings was found (p < 0.001, r = 0.585). Inter-observer reliability of SE was in “almost perfect agreement” with a weighted kappa coefficient of 0.84.

Conclusions

SE has potential to be clinically useful in the detection of the intratendinous and peritendinous alterations of LHBT and has excellent accuracy and excellent correlation with conventional ultrasound findings.     

Comparison of cardiovascular magnetic resonance characteristics and clinical consequences in children and adolescents with isolated left ventricular non-compaction with and without late gadolinium enhancement

Background

Although cardiovascular magnetic resonance (CMR) is showing increasingly diagnostic potential in left ventricular non-compaction (LVNC), relatively little research relevant to CMR is conducted in children with LVNC. This study was performed to characterize and compare CMR features and clinical outcomes in children with LVNC with and without late gadolinium enhancement (LGE).

Methods

A cohort of 40 consecutive children (age, 13.7 ± 3.3 years; 29 boys and 11 girls) with isolated LVNC underwent a baseline CMR scan with subsequent clinical follow-up. Short-axis cine images were used to calculate left ventricular (LV) ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), myocardial mass, ratio of non-compacted-to-compacted myocardial thickness (NC/C ratio), and number of non-compacted segments. The LGE images were analyzed to assess visually presence and patterns of LGE. The primary end point was a composite of cardiac death and heart transplantation.

Results

The LGE was present in 10 (25 %) children, and 46 (27 %) segments were involved, including 23 non-compacted segments and 23 normal segments. Compared with LGE- cohort, LGE+ cohort had significantly lower LVEF (23.8 ± 10.7 % vs. 42.9 ± 16.7 %, p < 0.001) and greater LVEDV (169.2 ± 65.1 vs. 118.2 ± 48.9 mL/m², p = 0.010), LVESV (131.3 ± 55.5 vs. 73.3 ± 46.7 mL/m², p = 0.002), and sphericity indices (0.75 ± 0.19 vs. 0.60 ± 0.20, p = 0.045). There were no differences in terms of number and distribution of non-compacted segments, NC/C ratio, and myocardial mass index between LGE+ and LGE- cohort. In the LGE+ cohort, adverse events occurred in 6 patients compared to 2 events in the LGE- cohort. Kaplan-Meier analysis showed a significant difference in outcome between LGE+ and LGE- cohort for cardiac death and heart transplantation (p = 0.011).

Conclusions

The LGE was present in up to one-fourth of children with LVNC, and the LGE+ children exhibited a more maladaptive LV remodeling and a higher incidence of cardiovascular death and heart transplantation.     

Continuous positive airway pressure titration in infants with severe upper airway obstruction or bronchopulmonary dysplasia

Abstracta

Introduction

Noninvasive continuous positive airway pressure (CPAP) is recognized as an effective treatment for severe airway obstruction in young children. The aim of the present study was to compare a clinical setting with a physiological setting of noninvasive CPAP in infants with nocturnal alveolar hypoventilation due to severe upper airway obstruction (UAO) or bronchopulmonary dysplasia (BPD).

Methods

The breathing pattern and respiratory muscle output of all consecutive infants due to start CPAP in our noninvasive ventilation unit were retrospectively analysed. CPAP set on clinical noninvasive parameters (clinical CPAP) was compared to CPAP set on the normalization or the maximal reduction of the oesophageal pressure (Poes) and transdiaphragmatic pressure (Pdi) swings (physiological CPAP). Expiratory gastric pressure (Pgas) swing was measured.

Results

The data of 12 infants (mean age 10 ± 8 mo) with UAO (n = 7) or BPD (n = 5) were gathered. The mean clinical CPAP (8 ± 2 cmH₂O) was associated with a significant decrease in Poes and Pdi swings. Indeed, Poes swing decreased from 31 ± 15 cmH₂O during spontaneous breathing to 21 ± 10 cmH₂O during CPAP (P < 0.05). The mean physiological CPAP level was 2 ± 2 cmH₂O higher than the mean clinical CPAP level and was associated with a significantly greater improvement in all indices of respiratory effort (Poes swing 11 ± 5 cm H₂O; P < 0.05 compared to clinical CPAP). Expiratory abdominal activity was present during the clinical CPAP and decreased during physiological CPAP.

Conclusions

A physiological setting of noninvasive CPAP, based on the recording of Poes and Pgas, is superior to a clinical setting, based on clinical noninvasive parameters. Expiratory abdominal activity was present during spontaneous breathing and decreased in the physiological CPAP setting.     

Technical feasibility of real-time elastography to assess the peri-oral region in patients affected by systemic sclerosis

Purpose

To evaluate the technical feasibility of real-time elastography (RTE) to assess the stiffness of the skin of the peri-oral region in patients affected by systemic sclerosis (SSc).

Methods

Six female patients affected by SSc (median age = 52 years) presenting with microstomia and six healthy controls matched for age and sex underwent RTE evaluation of the peri-oral region. Two operators with different experience evaluated the stiffness of the peri-oral region placing the probe in four different positions: parasagittal left (PL), parasagittal right (PR), upper axial (UA), lower axial (LA). Color map was converted into a semi-quantitative scale in which blue = 1, green = 2 and red = 3. Thus, each subject had a variable score ranging from 4 (four positions × value = 1) and 12 (four positions × value = 3). Mann–Whitney U and k statistics were used.

Results

RTE demonstrated that the skin of the peri-oral region of patients affected by SSc was stiffer than that of controls, both overall (6;4–6 [median; 25–75th percentile] vs. 11;9–11, p < 0.001) and for each probe position (PL = 1;1–2 vs. 2;2-3, PR = 1;1–2 vs. 2;2–3, UA = 1;1–2 vs. 2;2–3; LA = 1;1–1 vs. 3;3–3, p ≤ 0.011 for all). Interobserver reproducibility was excellent both overall and for each probe position (k = 1).

Conclusion

RTE is a feasible modality to assess peri-oral region skin stiffness with excellent interobserver reproducibility. Further studies on a larger cohort of patients including more clinical data and measures are warranted to confirm our initial results.     

Pulmonary artery to aorta ratio for the detection of pulmonary hypertension: cardiovascular magnetic resonance and invasive hemodynamics in heart failure with preserved ejection fraction

Background

Previous work indicates that dilatation of the pulmonary artery (PA) itself or in relation to the ascending aorta (PA:Ao ratio) predicts pulmonary hypertension (PH). Whether these results also apply for heart failure with preserved ejection fraction (HFpEF) is unknown.In the present study we evaluated the diagnostic and prognostic power of PA diameter and PA:Ao ratio on top of right ventricular (RV) size, function, and septomarginal trabeculation (SMT) thickness by cardiovascular magnetic resonance (CMR) in HFpEF.

Methods and Results

159 consecutive HFpEF patients were prospectively enrolled. Of these, 111 underwent CMR and invasive hemodynamic evaluation.By invasive assessment 64 % of patients suffered from moderate/severe PH (mean pulmonary artery pressure (mPAP) ≥30 mmHg). Significant differences between groups with and without moderate/severe PH were observed with respect to PA diameter (30.9 ± 5.1 mm versus 26 ± 5.1 mm, p < 0.001), PA:Ao ratio (0.93 ± 0.16 versus 0.78 ± 0.14, p < 0.001), and SMT diameter (4.6 ± 1.5 mm versus 3.8 ± 1.2 mm; p = 0.008). The strongest correlation with mPAP was found for PA:Ao ratio (r = 0.421, p < 0.001). By ROC analysis the best cut-off for the detection of moderate/severe PH was found for a PA:Ao ratio of 0.83.Patients were followed for 22.0 ± 14.9 months. By Kaplan Meier analysis event-free survival was significantly worse in patients with a PA:Ao ratio ≥0.83 (log rank, p = 0.004). By multivariable Cox-regression analysis PA:Ao ratio was independently associated with event-free survival (p = 0.003).

Conclusion

PA:Ao ratio is an easily measureable noninvasive indicator for the presence and severity of PH in HFpEF, and it is related with outcome.     

Effects of intra-abdominal sepsis on atherosclerosis in mice

Introduction

Sepsis and other infections are associated with late cardiovascular events. Although persistent inflammation is implicated, a causal relationship has not been established. We tested whether sepsis causes vascular inflammation and accelerates atherosclerosis.

Methods

We performed prospective, randomized animal studies at a university research laboratory involving adult male ApoE-deficient (ApoE^−/−) and young C57B/L6 wild-type (WT) mice. In the primary study conducted to determine whether sepsis accelerates atherosclerosis, we fed ApoE^−/− mice (N = 46) an atherogenic diet for 4 months and then performed cecal ligation and puncture (CLP), followed by antibiotic therapy and fluid resuscitation or a sham operation. We followed mice for up to an additional 5 months and assessed atheroma in the descending aorta and root of the aorta. We also exposed 32 young WT mice to CLP or sham operation and followed them for 5 days to determine the effects of sepsis on vascular inflammation.

Results

ApoE^−/− mice that underwent CLP had reduced activity during the first 14 days (38% reduction compared to sham; P < 0.001) and sustained weight loss compared to the sham-operated mice (−6% versus +9% change in weight after CLP or sham surgery to 5 months; P < 0.001). Despite their weight loss, CLP mice had increased atheroma (46% by 3 months and 41% increase in aortic surface area by 5 months; P = 0.03 and P = 0.004, respectively) with increased macrophage infiltration into atheroma as assessed by immunofluorescence microscopy (0.52 relative fluorescence units (rfu) versus 0.97 rfu; P = 0.04). At 5 months, peritoneal cultures were negative; however, CLP mice had elevated serum levels of interleukin 6 (IL-6) and IL-10 (each at P < 0.05). WT mice that underwent CLP had increased expression of intercellular adhesion molecule 1 in the aortic lumen versus sham at 24 hours (P = 0.01) that persisted at 120 hours (P = 0.006). Inflammatory and adhesion genes (tumor necrosis factor α, chemokine (C-C motif) ligand 2 and vascular cell adhesion molecule 1) and the adhesion assay, a functional measure of endothelial activation, were elevated at 72 hours and 120 hours in mice that underwent CLP versus sham-operations (all at P <0.05).

Conclusions

Using a combination of existing murine models for atherosclerosis and sepsis, we found that CLP, a model of intra-abdominal sepsis, accelerates atheroma development. Accelerated atheroma burden was associated with prolonged systemic, endothelial and intimal inflammation and was not explained by ongoing infection. These findings support observations in humans and demonstrate the feasibility of a long-term follow-up murine model of sepsis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0469-1) contains supplementary material, which is available to authorized users.     

Lung protection during non-invasive synchronized assist versus volume control in rabbits

Introduction

Experimental work provides insight into potential lung protective strategies. The objective of this study was to evaluate markers of ventilator-induced lung injury after two different ventilation approaches: (1) a “conventional” lung-protective strategy (volume control (VC) with low tidal volume, positive end-expiratory pressure (PEEP) and paralysis), (2) a physiological approach with spontaneous breathing, permitting synchrony, variability and a liberated airway. For this, we used non-invasive Neurally Adjusted Ventilatory Assist (NIV-NAVA), with the hypothesis that liberation of upper airways and the ventilator’s integration with lung protective reflexes would be equally lung protective.

Methods

In this controlled and randomized in vivo laboratory study, 25 adult White New Zealand rabbits were studied, including five non-ventilated control animals. The twenty animals with aspiration-induced lung injury were randomized to ventilation with either VC (6 mL/kg, PEEP 5 cm H2O, and paralysis) or NIV-NAVA for six hours (PEEP = zero because of leaks). Markers of lung function, lung injury, vital signs and ventilator parameters were assessed.

Results

At the end of six hours of ventilation (n = 20), there were no significant differences between VC and NIV-NAVA for vital signs, PaO2/FiO2 ratio, lung wet-to-dry ratio and broncho-alveolar Interleukin 8 (Il-8). Plasma IL-8 was higher in VC (P <0.05). Lung injury score was lower for NIV-NAVA (P = 0.03). Dynamic lung compliance recovered after six hours in NIV-NAVA but not in VC (P <0.05). During VC, peak pressures increased from 9.2 ± 2.4 cm H2O (hour 1) to 12.3 ± 12.3 cm H2O (hour 6) (P <0.05). During NIV-NAVA, the tracheal end-expiratory pressure was similar to the end-expiratory pressure during VC. Two animals regurgitated during NIV-NAVA, without clinical consequences, and survived the protocol.

Conclusions

In experimental acute lung injury, NIV-NAVA is as lung-protective as VC 6 ml/kg with PEEP.

Electronic supplementary material

The online version of this article (doi:10.1186/cc13706) contains supplementary material, which is available to authorized users.     

Impact of motion correction on reproducibility and spatial variability of quantitative myocardial T2 mapping

Background

To evaluate and quantify the impact of a novel image-based motion correction technique in myocardial T₂ mapping in terms of measurement reproducibility and spatial variability.

Methods

Twelve healthy adult subjects were imaged using breath-hold (BH), free breathing (FB), and free breathing with respiratory navigator gating (FB + NAV) myocardial T₂ mapping sequences. Fifty patients referred for clinical CMR were imaged using the FB + NAV sequence. All sequences used a T₂ prepared (T₂prep) steady-state free precession acquisition. In-plane myocardial motion was corrected using an adaptive registration of varying contrast-weighted images for improved tissue characterization (ARCTIC). DICE similarity coefficient (DSC) and myocardial boundary errors (MBE) were measured to quantify the motion estimation accuracy in healthy subjects. T₂ mapping reproducibility and spatial variability were evaluated in healthy subjects using 5 repetitions of the FB + NAV sequence with either 4 or 20 T₂prep echo times (TE). Subjective T₂ map quality was assessed in patients by an experienced reader using a 4-point scale (1-non diagnostic, 4-excellent).

Results

ARCTIC led to increased DSC in BH data (0.85 ± 0.08 vs. 0.90 ± 0.02, p = 0.007), FB data (0.78 ± 0.13 vs. 0.90 ± 0.21, p < 0.001), and FB + NAV data (0.86 ± 0.05 vs. 0.90 ± 0.02, p = 0.002), and reduced MBE in BH data (0.90 ± 0.40 vs. 0.64 ± 0.19 mm, p = 0.005), FB data (1.21 ± 0.65 vs. 0.63 ± 0.10 mm, p < 0.001), and FB + NAV data (0.81 ± 0.21 vs. 0.63 ± 0.08 mm, p < 0.001). Improved reproducibility (4TE: 5.3 ± 2.5 ms vs. 4.0 ± 1.5 ms, p = 0.016; 20TE: 3.9 ± 2.3 ms vs. 2.2 ± 0.5 ms, p = 0.002), reduced spatial variability (4TE: 12.8 ± 3.5 ms vs. 10.3 ± 2.5 ms, p < 0.001; 20TE: 9.7 ± 3.5 ms vs. 7.5 ± 1.4 ms) and improved subjective score of T₂ map quality (3.43 ± 0.79 vs. 3.69 ± 0.55, p < 0.001) were obtained using ARCTIC.

Conclusions

The ARCTIC technique substantially reduces spatial mis-alignment among T₂-weighted images and improves the reproducibility and spatial variability of in-vivo T₂ mapping.     

Transrectal ultrasound in patients with hematospermia

Introduction

To illustrate the lesions detected with transrectal ultrasound (TRUS) in patients with hematospermia.

Material and methods

This study included 74 male patients (25–73 years old) affected by hematospermia. Clinical history was obtained and all patients underwent rectal examination as well as TRUS examination in both axial and coronal planes to evaluate the prostate, ejaculatory ducts and seminal vesicles. Biopsy was performed in 10 patients.

Results

Abnormalities were detected in 59 patients. Calculi (n = 20) were seen within the prostate, seminal vesicles and along the course of the ejaculatory ducts. Chronic prostatitis (n = 14) appeared as hyperechoic and hypoechoic areas within the prostate with capsule thickening suggesting seminal vesiculitis (n = 8). Granulomatous prostatitis (n = 3) appeared as hyperechoic and calcified areas scattered within the prostate and the seminal vesicles. Hypoechoic focal lesions and heterogeneous texture were seen in prostate cancer (n = 5). Utricular cysts (n = 3) appeared as small midline lesions, and Mullerian duct cysts (n = 8) appeared as larger midline cysts protruding above the prostate. Ejaculatory duct cysts (n = 4) appeared as thick walled cystic lesions along the course of the ejaculatory duct. Seminal vesicle cysts were detected in 2 patients.

Conclusion

Our conclusion is that TRUS is a safe, non-invasive technique which can be used to detect lesions of the prostate, seminal vesicles and the ejaculatory ducts in patients with hematospermia.     

Nonalcoholic fatty liver disease (NAFLD) in nonobese patients with diabetes: Prevalence and relationships with hemodynamic alterations detected with Doppler sonography

Aim

To evaluate the prevalence, severity, and hemodynamic features of nonalcoholic fatty liver disease (NAFLD) in nonobese diabetics.

Methods

We studied 100 consecutive nonobese (body mass index [BMI] < 30) patients with type 1 (n = 17) or type 2 (n = 83) diabetes and no known causes of liver disease. Steatosis was diagnosed and graded with ultrasonography. Digital sonographic images of the liver and right kidney were analyzed with dedicated software (HDI-Lab), and the liver/kidney ratio of grey-scale intensity was calculated as an index of the severity of the steatosis. Severity scores ranging from 0 (none) to 5 (severe) were compared with sonographic and Doppler findings (right liver size, portal vein diameter and flow velocity, hepatic and splenic arterial pulsatility indices, hepatic-vein flow profile and A- and S-wave velocities).

Results

The prevalence of steatosis was 24% in type I and 80% in type II diabetes (grade 1 in 17%, grade 2 in 34%, grade 3 in 33%, grade 4 in 9%, grade 5 in 7%). In patients with steatosis (especially those with grades 4–5 disease), hepatic volume was increased (p < 0.005). Portal vein diameter was increased in grade 5 steatosis. The hepatic artery pulsatility index was significantly increased, particularly in grades 4 and 5 (p < 0.0001); portal and A-wave velocities were significantly reduced in grades 3–5 (p < 0.001); and the hepatic vein flow profile was altered in 27% (biphasic: 20%, flat: 7%) patients with steatosis, although there was no correlation with severity.

Conclusions

NAFLD is very frequent in nonobese diabetics with type 2 but not type 1 disease, and it is associated with hepatomegaly and liver hemodynamic alterations only when it is severe.     

Cognitive processing of cluster headache patients: evidence from event-related potentials

Background

The peripheral and central origins of pain in cluster headache (CH) have been a matter of much debate. The development and application of functional imaging techniques have provided more evidence supporting the hypothesis that CH is not a disorder exclusively peripheral in origin, and in fact central regions might be more important. Event-related potentials confer advantages in the functional evaluation of the cortex, but few studies thus far have employed this method in cluster headache.

Methods

Seventeen cluster patients (15 males; mean age = 35.4 years) and 15 age-matched healthy participants (13 males; mean age = 34.6 years) were recruited. A visual oddball paradigm was employed to analyze target processing using event-related potentials. We investigated the P3/P3d components in the experiment.

Results

P3/P3d amplitudes were decreased in CH patients (P3, 3.82 μV; P3d, 5.8 μV) compared with controls (P3, 7.28 μV; P3d, 8.95 μV), F(1,30) = 4.919, p < 0.05, η2 = 0.141 for P3 and F(1,30) = 8.514, p < 0.05, η2 = 0.221 for P3d, respectively). Moreover, the amplitudes of P3/P3d were no significantl difference in the side of pain as compared to contralateral one (p > 0.05).

Conclusions

These results provide evidence of dysfunction in the cognitive processing of CH patients, which may also contribute to the pathophysiology of CH.     

Influence of phase correction of late gadolinium enhancement images on scar signal quantification in patients with ischemic and non-ischemic cardiomyopathy

Background

Myocardial fibrosis imaging using late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) has been validated as a quantitative predictive marker for response to medical, surgical, and device therapy. To date, all such studies have examined conventional, non-phase corrected magnitude images.  However, contemporary practice has rapdily adopted phase-corrected image reconstruction. We sought to investigate the existence of any systematic bias between threshold-based scar quantification performed on conventional magnitude inversion recovery (MIR) and matched phase sensitive inversion recovery (PSIR) images.

Methods

In 80 patients with confirmed ischemic (N = 40), or non-ischemic (n = 40) myocardial fibrosis, and also in a healthy control cohort (N = 40) without fibrosis, myocardial late enhancement was quantified using a Signal Threshold Versus Reference Myocardium technique (STRM) at ≥2, ≥3, and ≥5 SD threshold, and also using the Full Width at Half Maximal (FWHM) technique. This was performed on both MIR and PSIR images and values compared using linear regression and Bland-Altman analyses.

Results

Linear regression analysis demonstrated excellent correlation for scar volumes between MIR and PSIR images at all three STRM signal thresholds for the ischemic (N = 40, r = 0.96, 0.95, 0.88 at 2, 3, and 5 SD, p < 0.0001 for all regressions), and non ischemic (N = 40, r = 0.86, 0.89, 0.90 at 2, 3, and 5 SD, p < 0.0001 for all regressions) cohorts. FWHM analysis demonstrated good correlation in the ischemic population (N = 40, r = 0.83, p < 0.0001). Bland-Altman analysis demonstrated a systematic bias with MIR images showing higher values than PSIR for ischemic (3.3 %, 3.9 % and 4.9 % at 2, 3, and 5 SD, respectively), and non-ischemic (9.7 %, 7.4 % and 4.1 % at ≥2, ≥3, and ≥5 SD thresholds, respectively) cohorts. Background myocardial signal measured in the control population demonstrated a similar bias of 4.4 %, 2.6 % and 0.7 % of the LV volume at 2, 3 and 5 SD thresholds, respectively. The bias observed using FWHM analysis was −6.9 %.

Conclusions

Scar quantification using phase corrected (PSIR) images achieves values highly correlated to those obtained on non-corrected (MIR) images. However, a systematic bias exists that appears exaggerated in non-ischemic cohorts. Such bias should be considered when comparing or translating knowledge between MIR- and PSIR-based imaging.