Care of the patient with a tracheostomy.

Patients with tracheostomies may not be commonly admitted to orthopaedic units. Since this is an infrequently seen therapy in this population, and because the potential complications carry very high risks, orthopaedic nurses may be unfamiliar or uncomfortable with the nursing care needs of these patients. This article reviews the indications for tracheostomy tube insertion and the resulting physiologic changes that occur. Nursing assessment and tracheostomy care is described along with detailed information on potential complications and the associated nursing interventions.

Prehospital correlates of sleep in patients hospitalized with cardiac disease.

The purpose of this study was to examine relationships among selected endogenous factors and sleep patterns during hospitalization in patients with cardiac disease. Participants included 33 male and female patients with myocardial infarction and unstable angina. Wrist actigraph recordings and a computerized sleep algorithm demonstrated that the participants slept for a mean of 424.55 min (SD = 114.52), had a mean sleep efficiency of 77.30% (SD = 15.80), and experienced from 5 to 32 awakenings each night (M = 13.94, SD = 6.29). The mean duration of nighttime awakenings was 9.24 min (SD = 5.60). Self-reports of sleep efficiency, sleep supplementation, and sleep disturbance, using the Verran and Snyder-Halpern (1990) sleep scale, were better than normative data reported for hospitalized patients. The combination of age, gender, New York Heart Association Functional Classification scores (NYHA Criteria Committee, 1964), and prehospitalization sleep loss explained 29% of the variance in objectively measured sleep efficiency and 46% of the variance in duration of nighttime awakenings. These findings suggest the importance of prehospitalization variable as predictors of sleep patterns in hospitalized cardiac patients and provide baseline data for future study.

[The peripheral circulation: ECG-gated magnetic resonance angiography]. / Circolo periferico: angiografia con Risonanza Magnetica con sincronizzazione con ECG.

This work was aimed at comparing magnetic resonance angiography (MRA) with and without ECG gating in the study of peripheral vessels. Ten volunteers, mean age 27.8 years, were examined with MRA of the femoral, popliteal and tibial segments. MRA was performed with a 1.5-T superconductive magnet, a transmit head coil and the TOF 2D technique. In all cases MRA was performed without cardiac gating and with different times of trigger delay (0, 20, 40, 70 and 200 ms). When comparing the different acquisitions, the number of vessels and the signal-to-noise (S/N) ratio were calculated. In the femoral segment, MRA without cardiac gating showed a mean of 7.7 vessels with 2.79 S/N ratio; MRA with 0 ms of trigger delay showed a mean of 13.1 vessels with 1.51 S/N ratio; MRA with 20 ms trigger delay showed a mean of 13.1 vessels with 1.52 S/N ratio; MRA with 40 ms trigger delay showed a mean of 13.2 vessels with 1.52 S/N ratio; MRA with 70 ms trigger delay showed a mean of 13.5 vessels with 1.50 S/N ratio; finally, MRA with 200 ms trigger delay showed a mean of 13.4 vessels with 1.50 S/N ratio. In the popliteal segment, the corresponding values were 6.4 vessels and 2.51 S/N ratio, 11.4 vessels with 1.54 S/N ratio, 11.3 vessels and 1.54 S/N ratio, 11.6 vessels and 1.52 S/N ratio, 11.8 vessels and 1.52 S/N ratio and, finally, 11.9 vessels and 1.52 S/N ratio. In the tibial segment, the corresponding values were 8.5 vessels and 1.84 S/N ratio, 14.4 vessels and 1.14 S/N ratio, 14.5 vessels and 1.17 S/N ratio, 14.5 vessels and 1.14 S/N ratio, 14.3 vessels and 1.17 S/N ratio and, finally, 14.5 vessels and 1.19 S/N ratio. To conclude, MRA with cardiac gating better visualized peripheral vessels whatever the trigger delay.

[Isoflurane in angiography with magnetic resonance]. / Isoflurane nell'angiografia con Risonanza Magnetica.

The authors investigated if the use of vasodilating drugs could increase Magnetic Resonance angiography (MRA) capabilities in demonstrating intracranial vessels. Twenty patients (mean age: 10 years) were examined with MRA: a vasodilating drug (isoflurane) was administered to 10 of them and 10 matched-pair subjects were selected as controls and submitted to MRA without receiving any drug known to increase cerebral blood flow. MRA was performed with a 1.5-T superconductive magnet; FISP 3D sequences were used in all cases. A multiple choice card was used by a reader reporting the following diagnostic information for the different segments of the intracranial vessels: 1) hyperintense and homogeneous vessel with high signal-to-noise (S/N) ratio; 2) hyperintense and heterogeneous vessel with high S/N ratio; 3) hyperintense vessel with low S/N ratio; 4) poor vessels depiction. Small vessels (ophthalmic arteries, A3, M3, M4, anterior communicating arteries and P2 segments) were better demonstrated with isoflurane than with conventional MRA. The results were compared with the Mann-Withney test: isoflurane MRA allowed good vessel depiction in 127 cases, versus 83 of conventional MRA; the difference was statistically significant. To conclude, the use of vasodilating drugs represents a new research field in MRA of the intracranial vessels.

The role of magnetic resonance angiography in the diagnosis of subclavian steal.

PURPOSE: To compare magnetic resonance angiography (MRA) with digital angiography for diagnosis of subclavian steal syndrome. METHODS: A comparison study between MRA and digital contrast arteriography was carried out in 10 patients with suspected subclavian steal syndrome. Two of these patients were studied by MRA before and after percutaneous transluminal angioplasty (PTA). MRA was obtained on a 1.5 tesla superconductive magnet with linear head coil using a fast low angle shot (FLASH 2D) sequence in the axial plane as well as a fast imaging with steady state precession (FISP 3D) with velocity compensation gradient echo sequence in the coronal plane. The coronal images were used as source data for the construction of projection images with the use of a maximum-intensity pixel algorithm. The images were rotated from -45 degrees to 45 degrees in 15 degrees steps. RESULTS: All 10 patients had evidence of proximal subclavian artery obstruction and flow reversal in the ipsilateral vertebral artery. On MRA, consistent visualization of the affected vertebral artery in the FLASH 2D sequences and nonvisualization in the FISP 3D sequences was interpreted as an indirect sign of subclavian steal. The subclavian artery obstruction could not be assessed due to field size limits of MRA. CONCLUSION: MRA allows determination of flow reversal in the diagnosis of subclavian steal.

[Artifacts in magnetic resonance angiography]. / Artefatti in angiografia a Risonanza Magnetica.

UNLABELLED: This study was aimed at assessing and classifying the incidence of Magnetic Resonance Angiography (MRA) artifacts using the 2D and 3D time-of-flight (TOF) technique. MATERIALS AND METHODS: from 300 MRA examinations performed January 1991 through April 1993, we selected the first 10 examinations for each vascular region which exhibited an artifact. Many kinds of artifacts were considered, i.e., hardware, sequence, magnetic susceptibility, patient and maximum intensity projection (MIP) artifacts. A superconductive 1.5-T magnet (Magnetom, Siemens) was used, with 2D and 3D TOF acquisitions. RESULTS: the quantitative analysis of artifact frequency showed that in the intracranial vessels (2D and 3D TOF sequences) the most common artifacts are saturation (30%) and magnetic susceptibility (30%) artifacts. As for neck vessels (3D TOF sequences), turbulence (40%) and lack of inclusion (30%) artifacts are the most common ones. In thoracic vessels (2D TOF sequences), MIP (50%) and ghost (30%) artifacts are the most common ones, while in the abdominal aorta (2D TOF sequences) magnetic susceptibility (20%), voluntary movement (20%), peristalsis (20%) and MIP (20%) artifacts occurred most frequently. Saturation (30%) and respiratory movement (30%) artifacts were the most common ones in the study of the renal arteries (3D TOF sequences), while MIP artifacts prevailed (40%) in the inferior vena cava (2D TOF sequences). Finally, MIP (40%) and patient movement (30%) artifacts were the most frequent ones in the study of the lower limbs (2 TOF sequences). CONCLUSIONS: in 2D and 3D TOF studies, being familiar with artifacts and their physical principles helps avoid image misinterpretation so that, if no technical means can prevent an artifact from occurring, at least it will not become a diagnostic pitfall.

[Aneurysm of the abdominal aorta. Angiography with magnetic resonance versus color Doppler ultrasonography]. / Aneurismi dell'aorta addominale. Angiografia con risonanza magnetica versus eco color Doppler.

This prospective study was aimed at comparing the diagnostic accuracy of Magnetic Resonance Angiography (MRA) with that of color-Doppler ultrasonography (color-Doppler US) in the detection and assessment of abdominal aortic aneurysms. Twenty patients with abdominal aortic aneurysms underwent MRA, color-Doppler US, digital subtraction angiography (DSA) and Computed Tomography (CT) on three consecutive days. Fourteen patients underwent surgical repair of the aneurysm. MRA and color-Doppler findings were compared with DSA, surgical and pathologic findings, which were considered as the gold standard. In the 6 patients who refused surgery, CT and DSA were considered the gold standard. MRA always correctly assessed the size and site of the aneurysm, the involvement of the renal and common iliac arteries, the retroarotic course of the left renal vein, the thrombotic component and calcifications. Color-Doppler US always correctly assessed the size and site of the aneurysm, the thrombotic component and calcifications and the involvement of the iliac arteries. In one case color-Doppler US failed to demonstrate the involvement of the renal arteries and the retroaortic course of the left renal vein. Our preliminary results suggest MRA as the best non-invasive technique to study abdominal aortic aneurysms.

Magnetic resonance angiography of the left renal vein.

The authors evaluated magnetic resonance angiography (MRA) as a possible diagnostic method to image the left renal vein. Twenty-five patients with abdominal aortic aneurysm underwent both plain and contrast-enhanced CT, as well as two-dimensional (2D) sequential time of flight (TOF) MRA. MRA images were evaluated on the basis of the results of CT, taken as the "gold standard" for vessel demonstration. MRA was performed with a 1.5 T superconductive magnet (Magnetom), fast imaging with steady-state free precession (FISP) 2D sequence (TR 40 ms, TE 10 ms, FA 18 degrees). Images were acquired in breath-hold on the coronal and sagittal plane and reconstructed according to maximum intensity projection (MIP) and targeted-MIP techniques. MRA images acquired on the sagittal plane correctly showed the retroaortic course on the left renal v. in six cases. On the coronal plane, targeted-MIP reconstructions for the course of the left renal v. correctly detected its outlet at the level of the inferior vena cava in five cases and of the left iliac v. in one case. MRA appears to be a promising noninvasive vascular imaging technique capable of correctly detecting the course and the outlet of the left renal v. We particularly noticed that the left renal v. can be imaged in a few seconds by using only one scout view with 2D sequential TOF technique on the sagittal plane at the level of the abdominal aorta.

[Peripheral pulmonary neoplasms: combined imaging (computerized tomography, ultrasonography, magnetic resonance) in the evaluation of chest wall involvement]. / Neoplasie polmonari periferiche: imaging integrato (tomografia computerizzata, ecografia, risonanza magnetica) nella valutazione del coinvolgimento parietale.

Chest wall involvement by a peripheral lung neoplasm, found in 4-8% of the cases, makes a difference in both staging and surgical approach. In the evaluation of the regional extent of the tumor, the radiologist must give the surgeon as much information as possible about relationships between lung neoplasm and chest wall structures, to correctly evaluate stage-T2 cancers and differentiate them from stage-T3 cancers. The authors report the results of a study made to assess the value of Computed Tomography (CT), ultrasonography (US) and Magnetic Resonance Imaging (MRI) to define chest wall invasion by a peripheral bronchogenic carcinoma. To this purpose 25 patients with primary peripheral lung neoplasm were studied with CT, US and MRI and the results were compared with surgical findings by means of TNM classification. Overall sensitivity and specificity were 68% and 74% for CT, 74% and 72% for US and 88% and 86% for MRI, respectively. CT, which still plays the major role in staging lung cancer, seems to get the worst results because of its impossibility to differentiate the cancers adjoining the chest wall from those showing signs of initial invasion. In these cases the use of the other imaging techniques (US, MRI) depends on their availability and on the specific experience of the radiologist.

[Hydronephrosis and peripelvic cysts. A new echographic sign for the differential diagnosis]. / Idronefrosi e cisti peripieliche. Un nuovo segno ecografico per la diagnosi differenziale.

The differential diagnosis of peripelvic cysts and hydronephrosis by means of US sometimes presents some problems; in fact, the use of urography to solve a diagnostic doubt is not uncommon. This study was aimed at demonstrating that another US sign, which we have called the "convexity" sign, can be useful in allowing peripelvic cysts to be distinguished from hydronephrosis. Thus, cysts exhibit convex walls and curved outline, whereas in hydronephrosis the walls of the dilated calices are linear. The latter feature is present in all degrees of hydronephrosis, except in severe cases. Forty-nine adult patients, a total of 98 kidneys, were examined with US and urography; 69 kidneys were found to be pathologic: 48 presented with cysts, and 21 with hydronephrosis. In addition to the new sign, the classic signs of peripelvic cysts were also considered, that is the separate areas and the non-visualization of the ureter. The sensitivity of the new sign was 97% and its specificity was 95%. The sensitivity and the specificity of the classic signs were 97% and 95%, respectively for the separated areas, and 100% and 91% for the non-visualization of the ureter. The cumulative sensitivity of the 3 signs was 99%, and their specificity 96%. Our results show how the integrated analysis of the considered signs (especially those with high specificity) is useful for the differential diagnosis, and therefore to avoid the indiscriminate use of urography.