Non-invasive neurally adjusted ventilatory assist in rabbits with acute lung injury

OBJECTIVE: Neurally adjusted ventilatory assist uses the electrical activity of the diaphragm (EAdi)-a pneumatically-independent signal-to control the timing and pressure of the ventilation delivered, and should not be affected by leaks. The aim of this study was to evaluate whether NAVA can deliver assist in synchrony and proportionally to EAdi after extubation, with a leaky non-invasive interface. DESIGN AND SETTING: Prospective, controlled experimental study in an animal laboratory. ANIMALS: Ten rabbits, anesthetized, mechanically ventilated. INTERVENTIONS: Following lung injury, the following was performed in sequential order: (1) NAVA delivered via oral endotracheal tube with PEEP; (2) same as (1) without PEEP; (3) non-invasive NAVA at unchanged NAVA level and no PEEP via a single nasal prong; (4) no assist; (5) non-invasive NAVA at progressively increasing NAVA levels. MEASUREMENTS AND RESULTS: EAdi, esophageal pressure, blood gases and hemodynamics were measured during each condition. For the same NAVA level, the mean delivered pressure above PEEP increased from 3.9[Symbol: see text]+/-[Symbol: see text]1.4[Symbol: see text]cmH(2)O (intubated) to 7.5[Symbol: see text]+/-[Symbol: see text]3.8[Symbol: see text]cmH(2)O (non-invasive) (p[Symbol: see text]<[Symbol: see text]0.05) because of increased EAdi. No changes were observed in PaO(2) and PaCO(2). Increasing the NAVA level fourfold during non-invasive NAVA restored EAdi and esophageal pressure swings to pre-extubation levels. Triggering (106[Symbol: see text]+/-[Symbol: see text]20[Symbol: see text]ms) and cycling-off delays (40[Symbol: see text]+/-[Symbol: see text]21[Symbol: see text]ms) during intubation were minimal and not worsened by the leak (95[Symbol: see text]+/-[Symbol: see text]13[Symbol: see text]ms and 33[Symbol: see text]+/-[Symbol: see text]9[Symbol: see text]ms, respectively). CONCLUSION: NAVA can be effective in delivering non-invasive ventilation even when the interface with the patient is excessively leaky, and can unload the respiratory muscles while maintaining synchrony with the subject's demand.

Stenting of common iliac vein obstructions combined with regional thrombolysis and thrombectomy in acute deep vein thrombosis

OBJECTIVES: To evaluate the efficacy of stent placement after infrainguinal loco-regional thrombolysis and iliac thrombectomy (surgical TT) of acute deep vein thrombosis (DVT) in patients with May-Thurner-Syndrome. MATERIAL AND METHODS: We retrospectively analysed a group of 11 patients (9 women) (mean age 34 years, range 16-64 years) with surgical TT and additional intra-operative stenting due to compression of the common iliac vein. Patients underwent venography to demonstrate outflow patency after surgical TT, and to identify any obstruction at the level of the left-sided common iliac vein ("Beckenvenen-Sporn"). Obstruction at the level of arterial crossing was treated using Wallstents placed via an introducer sheath from the inguinal access site. Stents were fully deployed using balloons adjusted to the size of vein. Patients were treated with oral anticoagulants for 6 months, and followed using duplex ultrasonography. RESULTS: Technical success defined as complete vein patency and normal valve function was documented in all 11 patients. One patient needed early stent extension due to residual stenosis. At 6 months follow-up one patient (9%) had an asymptomatic occlusion of the stented common iliac vein. In all 11/11 (100%) patients the femoral segment was found to be patent, and in 1/11 (9%) there was mild reflux with few clinical symptoms of post-thrombotic syndrome. The calculated cumulative primary patency rate for venous iliac stents was 82%, and assisted patency rate was 91%, which remained unchanged over a mean follow-up of 22 months. CONCLUSION: Combining surgical TT and stenting of common iliac vein obstructions in DVT is safe, effective, and results in a acceptable venous patency.

Resuspension of the aortic valve in acute type A dissection: long-term results

BACKGROUND AND AIM OF THE STUDY: Preservation of the aortic valve during the repair of acute type A aortic dissection (AADA) is a viable option to prevent lifelong oral anticoagulation. The study aim was to assess aortic valve function following resuspension and supracoronary ascending aortic grafting. METHODS: Among a collective of 210 consecutive patients undergoing surgery for AADA, 140 (66.7%) with resuspension of the aortic valve and supracoronary ascending graft were analyzed. Of these patients, 83 (59.3%) had a complete follow up (mean 61.2 +/- 40.8 months), with 65 of the subgroup (78.3%) being followed by computed tomography scanning and echocardiography. RESULTS: Reoperation due to severe aortic valve regurgitation was required in seven patients (10.8%). The perioperative characteristics were similar in these patients; notably, no significant difference was evident with regards to the aortic annulus diameter and the severity of regurgitation at the time of surgery. The left ventricular mass index was significantly higher in patients requiring reoperation due to aortic valve regurgitation (219.3 +/- 146.6 versus 123.9 +/- 146.6 g/m2; p <0.05). None of the patients died as a result of reoperation. CONCLUSION: The long-term functional results following resuspension of the aortic valve in AADA were very good. A close echocardiographic follow up was necessary, as reoperation of the aortic valve was required in more than 10% of the collective, with an average follow up of five years. Reoperation was mainly related to secondary dilatation of the aortic root.

Thrombolysis in patients with acute stroke caused by cervical artery dissection: analysis of 9 patients and review of the literature

BACKGROUND: Results of recently published studies suggest that intravenous thrombolysis (IVT) and local intra-arterial thrombolysis (LIT) are feasible procedures in acute stroke after cervical artery dissection (CAD). OBJECTIVES: To describe 9 patients with acute stroke caused by CAD who were treated by LIT (n = 7) or IVT (n = 2) and to review the literature. METHODS: Retrospective analysis of clinical and neuroradiological findings; literature review from 1980 to present. MAIN OUTCOME MEASURE: Modified Rankin Scale (mRS) score. RESULTS: Of 7 patients treated with LIT, 3 had good outcomes (mRS score of 0-2) and 4 had bad outcomes (mRS score of 3-6) at 3 months. The 2 patients who had received IVT recovered to mRS scores of 0 and 3. Twenty-one patients were identified in the literature. Overall (N = 30), in the IVT group (n = 19), the outcome was good in 8 patients (42%) and bad in 11 (58%); in the LIT group (n = 11), 6 patients (55%) had a good outcome and 5 (45%) had a bad outcome. Overall, 47% (14/30) of the patients (IVT and LIT groups) had a good outcome. Total mortality was 13% (4/30). There were no secondary complications due to extension of wall hematoma or angiography. One symptomatic hemorrhage occurred. CONCLUSIONS: Thrombolysis is feasible in acute stroke caused by CAD. Local complications from extension of wall hematoma did not occur. Further prospective studies are needed to determine the safety and efficacy of thrombolysis in the special circumstance of acute stroke caused by CAD.

Effect of oral melatonin on the procoagulant response to acute psychosocial stress in healthy men: a randomized placebo-controlled study

Acute mental stress is a potent trigger of acute coronary syndromes. Catecholamine-induced hypercoagulability with acute stress contributes to thrombus growth after coronary plaque rupture. Melatonin may diminish catecholamine activity. We hypothesized that melatonin mitigates the acute procoagulant stress response and that this effect is accompanied by a decrease in the stress-induced catecholamine surge. Forty-five healthy young men received a single oral dose of either 3 mg melatonin (n = 24) or placebo medication (n = 21). One hour thereafter, they underwent a standardized short-term psychosocial stressor. Plasma levels of clotting factor VII activity (FVII:C), FVIII:C, fibrinogen, D-dimer, and catecholamines were measured at rest, immediately after stress, and 20 min and 60 min post-stress. The integrated change in D-dimer levels from rest to 60 min post-stress differed between medication groups controlling for demographic and metabolic factors (P = 0.047, eta(p)(2) = 0.195). Compared with the melatonin group, the placebo group showed a greater increase in absolute D-dimer levels from rest to immediately post-stress (P = 0.13; eta(p)(2) = 0.060) and significant recovery of D-dimer levels from immediately post-stress to 60 min thereafter (P = 0.007; eta(p)(2) = 0.174). Stress-induced changes in FVII:C, FVIII:C, fibrinogen, and catecholamines did not significantly differ between groups. Oral melatonin attenuated the stress-induced elevation in the sensitive coagulation activation marker D-dimer without affecting catecholamine activity. The finding provides preliminary support for a protective effect of melatonin in reducing the atherothrombotic risk with acute mental stress.

Effect of oral calcium loading on intact PTH and calcitriol in idiopathic renal calcium stone formers and healthy controls

The calciuric response after an oral calcium load (1000 mg elemental calcium together with a standard breakfast) was studied in 13 healthy male controls and 21 recurrent idiopathic renal calcium stone formers, 12 with hypercalciuria (UCa x V > 7.50 mmol/24 h) and nine with normocalciuria. In controls, serum 1,25(OH)2 vitamin D3 (calcitriol) remained unchanged 6 h after oral calcium load (50.6 +/- 5.1 versus 50.9 +/- 5.0 pg/ml), whereas it tended to increase in hypercalciuric (from 53.6 +/- 3.2 to 60.6 +/- 5.4 pg/ml, P = 0.182) and fell in normocalciuric stone formers (from 45.9 +/- 2.6 to 38.1 +/- 3.3 pg/ml, P = 0.011). The total amount of urinary calcium excreted after OCL was 2.50 +/- 0.20 mmol in controls, 2.27 +/- 0.27 mmol in normocalciuric and 3.62 +/- 0.32 mmol in hypercalciuric stone formers (P = 0.005 versus controls and normocalciuric stone formers respectively); it positively correlated with serum calcitriol 6 h after calcium load (r = 0.392, P = 0.024). Maximum increase in urinary calcium excretion rate, delta Ca-Emax, was inversely related to intact PTH levels in the first 4 h after calcium load, i.e. more pronounced PTH suppression predicted a steeper increase in urinary calcium excretion rate. Twenty-four-hour urine calcium excretion rate was inversely related to the ratio of delta calcitriol/deltaPTHmax after calcium load (r = -0.653, P = 0.0001), indicating that an abnormally up-regulated synthesis of calcitriol and consecutive relative PTH suppression induce hypercalciuria.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of an oral glucose load on sodium and water excretion after rapid intravenous infusion of 0.9% (w/v) saline

Previous studies have suggested that oral or intravenous glucose enhances salt and water retention following a saline load. To test this, we studied the effects of an oral glucose load on urinary sodium and water excretion and serum biochemistry in response to a 2l intravenous infusion of 0.9% saline in normal subjects.

The adherence to initial processes of care in elderly patients with acute venous thromboembolism.

BACKGROUND We aimed to assess whether elderly patients with acute venous thromboembolism (VTE) receive recommended initial processes of care and to identify predictors of process adherence. METHODS We prospectively studied in- and outpatients aged ≥65 years with acute symptomatic VTE in a multicenter cohort study from nine Swiss university- and non-university hospitals between September 2009 and March 2011. We systematically assessed whether initial processes of care, which are recommended by the 2008 American College of Chest Physicians guidelines, were performed in each patient. We used multivariable logistic models to identify patient factors independently associated with process adherence. RESULTS Our cohort comprised 950 patients (mean age 76 years). Of these, 86% (645/750) received parenteral anticoagulation for ≥5 days, 54% (405/750) had oral anticoagulation started on the first treatment day, and 37% (274/750) had an international normalized ratio (INR) ≥2 for ≥24 hours before parenteral anticoagulation was discontinued. Overall, 35% (53/153) of patients with cancer received low-molecular-weight heparin monotherapy and 72% (304/423) of patients with symptomatic deep vein thrombosis were prescribed compression stockings. In multivariate analyses, symptomatic pulmonary embolism, hospital-acquired VTE, and concomitant antiplatelet therapy were associated with a significantly lower anticoagulation-related process adherence. CONCLUSIONS Adherence to several recommended processes of care was suboptimal in elderly patients with VTE. Quality of care interventions should particularly focus on processes with low adherence, such as the prescription of continued low-molecular-weight heparin therapy in patients with cancer and the achievement of an INR ≥2 for ≥24 hours before parenteral anticoagulants are stopped.