Comparison of different techniques for prehospital cervical spine immobilization: Biomechanical measurements with a wireless motion capture system.

BACKGROUND: Various rescue techniques are used for the prehospital transport of trauma patients. This study compares different techniques in terms of immobilization of the cervical spine and the rescue time. METHODS: A wireless motion capture system (Xsens Technologies, Enschede, The Netherlands) was used to record motion in three-dimensional space and the rescue time in a standardized environment. Immobilization was performed by applying different techniques through different teams of trained paramedics and physicians. All tests were performed on the set course, starting with the test person lying on the floor and ending with the test person lying on an ambulance cot ready to be loaded into an ambulance. Six different settings for rescue techniques were examined: rescue sheet with/without rigid cervical collar (P1S1, P1S0), vacuum mattress and scoop stretcher with/without rigid cervical collar (P2S1, P2S0), and long spinal board with/without rigid cervical collar (P3S1, P3S0). Four time intervals were defined: the time interval in which the rigid cervical collar is applied (T0), the time interval in which the test person is positioned on rescue sheet, vacuum mattress and scoop stretcher, or long spinal board (T1), the time interval in which the test person is carried to the ambulance cot (T2), and the time interval in which the ambulance cot is rolled to the ambulance (T3). An ANOVA was performed to compare the different techniques. RESULTS: During the simulated extrication procedures, a rigid cervical collar provided biomechanical stability at all angles with hardly any loss of time (mean angle ranges during T1: axial rotation P1S0 vs P1S1 p<0.0001, P2S0 vs P2S1 p<0.0001, P3S0 vs P3S1 p<0.0001; lateral bending P1S0 vs P1S1 p = 0.0263, P2S0 vs P2S1 p<0.0001, P3S0 vs P3S1 p<0.0001; flexion/extension P1S0 vs P1S1 p = 0.0023, P2S0 vs P2S1 p<0.0001). Of the three techniques examined, the scoop stretcher and vacuum mattress were best for reducing lateral bending in the frontal plane (mean angle ranges during T1: P2S1 vs P3S1 p = 0.0333; P2S0 vs P3S0 p = 0.0123) as well as flexion and extension in the sagittal plane (mean angle ranges during T2: P1S1 vs P2S1 p<0.0001; P1S0 vs P2S0 p<0.0001). On the other hand, the rescue sheet was clearly superior in terms of time (total duration P1S0 vs P2S0 p<0.001, P1S1 vs P2S1 p<0.001, P1S0 vs P3S0 p<0.001, P1S1 vs P3S1 p<0.001) but was always associated with significantly larger angular ranges of the cervical spine during the procedure. Therefore, the choice of technique depends on various factors such as the rescue time, the available personnel, as well as the severity of the suspected instability.

Covid19 vaccination-associated portal vein thrombosis-An interdisciplinary clinical challenge.

Despite one of the largest vaccination campaigns in human history, the COVID-19 pandemic has not been yet defeated. More than 10 billion doses of COVID-19 vaccine have been administered worldwide. AstraZeneca's Vaxzevria (ChAdOx1 nCoV-19 / AZD1222) was approved as the first viral vector-based vaccine in the EU on 29 January 2021. Thromboembolic events are a rare complication of vaccination with ChAdOx1 nCoV-19 in the context of, now known as vaccine-induced immune thrombotic thrombocytopenia (VITT), with an incidence of 1.5-3 in 100,000 vaccinations. VITT is clinically as well as pathophysiologically comparable to heparin-induced thrombocytopenia. Illustrated by a fulminant patient case, a multidisciplinary step-by-step guideline was developed for the recognition, diagnosis, and management of patients with severe acute portosplanchic venous thrombosis with mesenteric ischemia due to vaccine-induced immunogenic thrombotic thrombocytopenia.

Impact of bedside percutaneous dilational and open surgical tracheostomy on intracranial pressure, pulmonary gas exchange, and hemodynamics in neurocritical care patients.

Aim was to compare the impact of bedside percutaneous dilational tracheostomy (PDT) and open surgical technique (ST) on intracranial pressure (ICP), pulmonary gas exchange and hemodynamics.We retrospectively analyzed data of 92 neurocritical care patients with invasive ICP monitoring during either PDT (43 patients) or ST (49 patients).Peak ICP levels were higher during PDT (22 [17-38] mm Hg vs 19 [13-27] mm Hg, P = .029). Mean oxygen saturation (SpO2) and end-tidal carbon dioxide partial pressure (etCO2) did not differ. Episodes with relevant desaturation (SpO2 < 90%) or hypercapnia (etCO2 > 50 mm Hg) occurred rarely (5/49 during ST vs 3/43 during PDT for SpO2 < 90%; 2/49 during ST vs 5/43 during PDT for hypercapnia). Drops in mean arterial pressure (MAP) below 60 mm Hg were seen more often during PDT (8/43 vs 2/49, P = .026). Mean infusion rate of norepinephrine did not differ (0.52 mg/h during ST vs 0.45 mg/h during PDT). No fatal complications were observed.Tracheostomy can be performed as ST and PDT safely in neurocritical care patients. The impact on ICP, pulmonary gas exchange and hemodynamics remains within an unproblematic range.

Incidence of Arterial Hypotension in Patients Receiving Peroral or Continuous Intra-arterial Nimodipine After Aneurysmal or Perimesencephalic Subarachnoid Hemorrhage.

BACKGROUND: Oral nimodipine is used for prophylaxis and treatment of delayed cerebral ischemia in patients with aneurysmal or perimesencephalic subarachnoid hemorrhage (SAH). In cases of serious refractory cerebral vasospasm, a continuous intra-arterial (IA) infusion of nimodipine (CIAN) may be required to avoid cerebral ischemia. Nimodipine can cause arterial hypotension requiring either a dosage reduction or its discontinuation. Aim of the present study was to examine the effect of different nimodipine formulations on arterial blood pressure in aneurysmal or perimesencephalic SAH patients and to measure the plasma levels after both, peroral administration as tablet or solution and IA infusion. METHODS: In a prospective setting, over a 1-year observation period, data on the course of arterial blood pressure and nimodipine dosage were collected for 38 patients undergoing treatment for aneurysmal or perimesencephalic SAH in an intensive care unit. In addition, plasma concentrations of nimodipine were measured by liquid chromatography-tandem mass spectrometry. RESULTS: The intended full dose of 60 mg of nimodipine given orally every 4 h could only be administered on 57.2% of the examined days. Ninety-seven episodes of relevant arterial hypotension probably caused by the administration of nimodipine were observed within the first 14 days of treatment. Drops in blood pressure occurred about three times as often after administration of nimodipine as oral solution than as tablet. However, there were no differences in nimodipine plasma levels between the two formulations. In patients suffering from higher-grade SAH, arterial hypotension and consequent dosage reduction or discontinuation of nimodipine were more frequent than in patients with lower-grade SAH. Plasma concentrations of nimodipine during CIAN did not exceed those achieved by oral administration. CONCLUSIONS: Dosage reduction or discontinuation of oral nimodipine is often necessary in patients with higher-grade SAH. Oral nimodipine solutions cause drops in blood pressure more frequently than tablets. Intra-arterial infusion rates of less than 1 mg/h result in venous plasma concentrations of nimodipine similar to those observed after oral application of 60 mg every 4 h.

Silent cerebral events as a result of left atrial catheter ablation do not cause neuropsychological sequelae--a MRI-controlled multicenter study.

PURPOSE: Recently, diffusion-weighted magnetic resonance imaging (DW-MRI) revealed silent cerebral events (SCEs) as an acute complication of pulmonary vein isolation (PVI). We investigated whether SCEs following PVI are associated with neuropsychological deficits observed during patients' follow-up examinations. METHODS: After PVI, 52 patients were eligible for follow-up. PVI was performed using a variety of ablation technologies (duty-cycled phased radiofrequency (RF) multipolar ablation with the Pulmonary Vein Ablation Catheter® (PVAC) in 24 patients, cooled-tip RF ablation in 23 patients, and cryoballoon ablation in five patients). Fluid-attenuated inversion recovery (FLAIR)- and DW-MRI studies were performed 1 day before PVI and 1 day and 1 month afterward to detect pre-existing cerebral lesions or post-ablation SCEs. At the same times, eight neuropsychological tests were administered. We evaluated changes in patients' neuropsychological capabilities and compared changes in patients with SCEs to those without SCEs. RESULTS: FLAIR-MRI revealed pre-existing cerebral lesions in 42 patients (81 %), and DW-MRI demonstrated new SCEs in 25 patients (48 %) (17 treated with phased RF (PVAC) (71 %), six treated with irrigated RF (26 %), and two treated with cryoablation (40 %)). Neuropsychological test results showed no significant impairment (in median z scores) 1 day and 1 month after the ablation procedure. There was no difference in neuropsychological capabilities between patients with SCEs and those without SCEs except in one subtest (part of the verbal working memory test). CONCLUSIONS: The incidence of pre-existing cerebral lesions and post-ablation SCEs was high. The frequency of SCEs depends on the ablation technology used. Neither PVI nor post-ablation SCEs have any effect on neuropsychological capabilities.

Lone atrial fibrillation as a positive predictor of left atrial volume reduction following ablation of atrial fibrillation.

AIMS: We investigated predictors of left atrial volume reduction (LAVR) in patients with atrial fibrillation (AF) undergoing AF ablation. METHODS AND RESULTS: Sixty patients with AF underwent pulmonary vein isolation (PVI) using a pulmonary vein ablation catheter (PVAC). All patients underwent cardiac imaging by computed tomography or magnetic resonance imaging to determine LAV 1 day before and 140 ± 9.5 days after PVI. Clinical follow-up and 72 h electrocardiogram Holter monitoring were performed 1, 3, and 6 months after ablation, and every 6 months thereafter. Significant LAVR (n = 60, 89.3 ± 3.9 vs. 79.5 ± 3.6 mL, P < 0.0001) was shown for the study group as a whole, caused particularly by the subgroup of patients with ablation success (n = 45, 85.2 ± 4.6 vs. 72.5 ± 3.7 mL, P < 0.0001). In addition, significant LAVR was shown for patients with lone AF (n = 25, 88.8 ± 6.8 vs. 72.7 ± 5.3 mL, P < 0.0001), but not for patients with AF and concomitant arterial hypertension (n = 32, 89 ± 4.8 vs. 86.7 ± 5 mL, P = 0.3), coronary artery disease (n = 12, 91.6 ± 7.8 vs. 89.1 ± 7.8 mL, P = 0.26), or left ventricular hypertrophy (n = 10, 86.3 ± 5.5 vs. 83.1 ± 5.3 mL, P = 0.27). Multivariate analysis revealed absence of arterial hypertension, lone AF, ablation success, and initial LA enlargement as independent predictors for significant LAVR following ablation (each P < 0.05). CONCLUSION: Based on the subgroup of patients with lone AF, PVI leads to a significant LAVR 4 months after the procedure, especially in patients with clinical success in terms of AF freedom. Comorbidities such as arterial hypertension may prevent this reverse atrial remodelling, despite AF freedom. Clinical implications need to be further elucidated.

Predictive value of left atrial volume measured by non-invasive cardiac imaging in the treatment of paroxysmal atrial fibrillation.

PURPOSE: We investigate the role of left atrial volume (LAV) as a predictor of outcome following pulmonary vein isolation (PVI) in patients with exclusive paroxysmal atrial fibrillation (AF). METHODS: PVI was performed in 213 patients (80 females, aged 60 ± 10 years) with paroxysmal AF using either the pulmonary vein ablation catheter (PVAC, n = 78) or conventional single-tip ablation (n = 135). LAV was assessed by multi-detector computed tomography (n = 39) or cardiac magnetic resonance imaging (n = 174) prior to ablation. LA diameter (LAD) and LA area were determined by echocardiography. Patients were followed up for 12 months clinically and with 72-h Holter ECG. RESULTS: The mean LAV was 85 ± 28 ml (range, 22-189 ml). Mean LAD and mean LA area were 43 ± 6 mm and 23 ± 6 cm². After a follow-up period of 18 ± 5 months, 202 patients were analyzed. AF recurrence was documented in 50 (23%) patients. Univariate analysis showed age (59 ± 11 vs. 65 ± 6 years, p = 0.049), LA area (23 ± 5 vs. 27 ± 6 cm², p = 0.03), and LAV (80 ± 27 vs. 96 ± 28 ml, p = 0.04) to be significantly associated with the outcome. Multivariate analysis revealed that none of these parameters were statistically significant (hazards ratio LAV, 0.52-1.12, p = 0.058; LA area, 0.63-1.14, p = 0.069; and age, 0.90-1.09, p = 0.41). In the case of AF recurrence, patients with LAV >95 ml showed a significantly higher probability for the occurrence of persistent AF (24% vs. 8%, p = 0.02). CONCLUSIONS: The assessment of LA size should not be incorporated as a main factor with regard to predicted ablation success in patients with paroxysmal AF being considered for PVI, as PVI may be successful even with considerable LA enlargement. Ablation should be performed promptly in patients with LAV ≤ 95 ml to prevent further LA dilatation, as patients with LAV >95 ml have an increased probability to develop persistent AF in the case of ablation failure.

Evaluation of pulmonary vein stenosis after pulmonary vein isolation using a novel circular mapping and ablation catheter (PVAC).

BACKGROUND: Pulmonary vein stenosis (PVST) is a well-known complication of pulmonary vein isolation (PVI). Specific anatomically designed ablation catheters for antral PVI have not been evaluated with regard to the incidence of PVST. We investigated the incidence, severity, and characteristics of PVST after PVI with the Pulmonary Vein Ablation Catheter (PVAC) and phased radiofrequency technology. METHODS AND RESULTS: A total of 100 patients (55 men) underwent PVI for atrial fibrillation using the PVAC. PVI was guided by selective angiography of each pulmonary vein (PV) in 70 (70%) patients and by reconstructed 3D atriography (ATG) in 30 (30%) patients. Gadolinium-enhanced MRI or multidetector CT was performed in all patients before treatment and 93±78 days after PVI. PVST was classified as follows: insignificant (<25%), mild (25%-50%), moderate (50%-75%), or severe (>75%). A total of 410 PVs were analyzed. Cardiac imaging demonstrated a detectable narrowing of the PV diameter in 23 (23%) patients and in 28 (7%) PVs. In detail, insignificant PVST was observed in 12 (2.9%) PVs, mild PVST in 15 (3.7%), and moderate PVST in 1 (0.2%). No instances of severe PVST were observed. The use of 3D-ATG was associated with a lower incidence of PVST (0.8% [95% CI, 0.0%-2.2%] versus 5.4% [95% CI, 2.7%-8.1%], P=0.027). CONCLUSIONS: To our knowledge, this study is the first to report the incidence of PVST using the PVAC. In this regard, the PVAC seems to be safe if used in an experienced center. In addition, the use of 3D-ATG may decrease the risk of PVST.