Feasibility of self-directed learning in clerkships.

BACKGROUND: Self-directed learning has been well described in preclinical settings. However, studies report conflicting results when self-directed initiatives are implemented in clinical clerkships. AIM: To explore the feasibility of self-directed learning stimulated by clinical encounter-cards (CECs) in clinical clerkships. METHODS: Two focus groups of year-four and year-five students were interviewed about the usefulness of CECs to their learning in clerkships. The CECs were then introduced in two cohorts of 248 year-four and 250 year-five medical students and evaluated on a nine-point scale with regard to usefulness and feasibility. RESULTS: The pilot groups reported that the CECs had positive effects in terms of engaging in diagnostic reasoning, reflection on management plans, and professional identity formation. However, the two large cohorts of students rated the usefulness of the CECs on learning in clerkship low (year-four: mean 2.92, SD 1.54; year-five: mean 2.28, SD 1.06) along with preceptor support (year-four: mean 2.68, SD 1.62; year-five: mean 2.59, SD 1.78, p = 0.34). CONCLUSION: Self-directed CECs can have a positive effect on participation and clinical reasoning but are highly dependent on the context of use. Self-directed learning initiatives that aim to increase participation in communities of practice may not be feasible without major faculty development initiatives.

Increased cardiac BNP expression associated with myocardial ischemia.

Congestive heart failure is accompanied by increased cardiac brain natriuretic peptide (BNP) gene expression with elevated plasma concentrations of BNP and its precursor, proBNP. We investigated if myocardial ischemia in the absence of overt heart failure may be another mechanism for increased myocardial BNP expression. The BNP expression was examined in hypoxic myocardium of patients undergoing coronary bypass grafting surgery, in patients with coronary artery disease and normal left ventricular function undergoing percutaneous transluminal intervention therapy, and in heart failure patients without coronary artery disease. BNP mRNA was quantified by real-time PCR, and plasma BNP and proBNP concentrations were measured with radioimmunoassays. Quantitative analysis of BNP mRNA in atrial and ventricular biopsies from coronary bypass grafting patients revealed close associations of plasma BNP and proBNP concentrations to ventricular, but not atrial, BNP mRNA levels. Plasma BNP and proBNP concentrations were markedly increased in patients with coronary artery disease but without concomitant left ventricular dysfunction. These results are compatible with the notion that myocardial ischemia, even in the absence of left ventricular dysfunction, augments cardiac BNP gene expression and increases plasma BNP and proBNP concentrations. Thus, elevated BNP and proBNP concentrations do not necessarily reflect heart failure but may also result from cardiac ischemia.

Effects of passive tilting on capillary filtration in the lower leg in idiopathic dilated cardiomyopathy and after heart transplantation for the same condition.

Abnormal reflex control of the peripheral microvasculature during orthostasis in congestive heart failure (CHF) and after heart transplantation (HT) may cause failure of microvascular homeostasis and peripheral edema. We explored the effect of passive head-up tilt on lower leg capillary filtration measured by strain-gauge plethysmography in 24 patients with CHF, in 20 patients after HT (12 patients with preserved native right atrium, 8 patients without native right atrium), and in 18 controls. We hypothesized that an impaired peripheral microvascular reflex during orthostasis in CHF and HT might allow increased arterial hydrostatic pressure to increase pressure at the capillary level. To identify an impact of changes in arterial hydrostatic pressure, capillary fluid filtration was expressed per mm Hg arterial hydrostatic pressure (capillary filtration coefficient(arterial pressure) [CFC(AP)]) and was measured (1) during elevated venous pressure alone (50 mm Hg venous stasis in supine position), and (2) during elevated hydrostatic pressure at both the venous and arterial side of the vascular tree (head-up tilt with a vertical distance from the right atrium to the strain-gauge of 68 cm of water [50 mmHg]). Elevated venous pressure alone resulted in the highest CFC(AP) in controls (0.79+/-0.28 ml/min x 100 ml mm Hg x 10(-3)+/-SD) versus those with CHF (0.44+/-0.23, p <0.0001) and those after HT (0.54+/-0.22, p <0.01). However, during head-up tilt, CFC(AP) was similar in all 3 groups, because CFC(AP) decreased in controls (to 0.49+/-0.22, p <0.0001), in contrast to unchanged CFC(AP) in those with CHF (0.43+/-0.24) and in those with HT (0.50+/-0.21). HT patients with complete removal of the native right atrium had higher CFC(AP) (0.62+/-0.17) during head-up tilt than patients with preserved native right atrium (0.36+/-0.16, p <0.005). In conclusion, patients with CHF and those after HT have increased capillary filtration to a lesser degree than controls during elevated venous pressure alone. However, during orthostasis this apparent edema-protective mechanism vanishes, probably because of compromised microvascular reflex control. During daily upright activities, this may be one important factor in the edema pathogenesis. The phenomenon is particularly distinct in HT patients without preserved native right atrium.

Surgical and arteriographic results of bronchial artery revascularization in lung and heart lung transplantation.

BACKGROUND: On the basis of our experience with bronchial artery revascularization (BAR) in lung transplantation since its introduction in Copenhagen in 1992, a description of the surgical anatomy of the bronchial arteries and the results of attempted BAR in these patients will be presented. METHODS: Since June 1992, BAR was performed in 50 en bloc double lung, six single lung, and nine heart-lung transplantations. The location, number, type, and size of each bronchial artery identified and revascularized were recorded. Our choice of conduit for BAR was the internal mammary artery. Routine internal mammary-bronchial arteriography was performed early after the transplantation to evaluate the result of BAR. All arteriograms were carefully studied together with the surgical records. The arteriographic results after attempted BAR were classified as complete, incomplete (bilateral, hemilateral, or poor), or failed. The surgical and arteriographic anatomy of the bronchial arteries has been described, and nomenclature for the as yet unnamed bronchial arteries has been developed. RESULTS: During surgery 128 bronchial arteries were identified in the descending aorta of the 64 donor lung blocs. Internal mammary-bronchial arteriography was performed in 53 patients. BAR was complete in 32, incomplete in 18, and failed in 3. The number of bronchial arteries identified and revascularized in each case increased with experience. The central and intrapulmonary bronchial artery anatomy was described, and different patterns have been identified. CONCLUSIONS: Bronchial artery identification is reliable, but a learning process is involved. BAR is possible with a high success rate. Complete BAR is an obtainable goal in most cases.

Myocardial perfusion scintigraphy as a screening method for significant coronary artery stenosis in cardiac transplant recipients.

BACKGROUND: Several studies have explored the feasibility of using myocardial perfusion imaging to detect allograft vasculopathy after heart transplantation. We undertook the present prospective consecutive study to comparatively evaluate the role of serial myocardial perfusion single-photon emission computed tomography (SPECT) scanning and coronary arteriography (CAG) in detecting coronary artery stenosis suitable for coronary angioplasty in heart transplant recipients. METHODS: Within a 2-week interval during a follow-up period of 5.6 (95% confidence limits 2.1 to 12) years, 255 serial CAGs and myocardial perfusion scintigraphies were performed in 67 patients. Arteriography and scintigraphy were performed once yearly after heart transplantation. We retrospectively analyzed the data. RESULTS: Myocardial scintigraphy showed pathologic reversible defects in 9 out of 67 patients. Four of these patients had significant (>50% and also >70%) focal segmental stenosis in the middle and proximal parts of the coronary arteries (Type A lesions), 1 had diffuse and circumferential narrowing in the distal parts (Type B lesions), whereas CAG showed no lesions in the remaining 4 patients. The patients with significant Type A lesions were revascularized with percutaneous coronary angioplasty. Coronary arteriography showed that 1 patient had extensive Type A and Type B lesions, whereas myocardial perfusion scans detected no. The predictive value of a negative (normal) SPECT was 98% (95% confidence limits 94% to 100%) for the detection of lesions suited for revascularization. CONCLUSIONS: Annual myocardial SPECT seems well suited to screen for significant coronary artery stenosis. A SPECT study without reversible defects virtually excludes lesions suitable for coronary artery revascularization.

Direct bronchial artery revascularization and en bloc double lung transplantation--surgical techniques and early outcome.

BACKGROUND: Lung transplantation including direct bronchial artery revascularization (BAR) has produced promising early results in small clinical series. METHODS: In Copenhagen primary en bloc double lung transplantation with BAR, with the left mammary artery used as conduit, has been performed in 47 patients from 1992 to the end of 1995. After introduction of the bloc into the recipient, the mammary-to-bronchial artery anastomosis is performed as the first anastomosis, allowing perfect exposure and early reperfusion. Internal mammary-bronchial artery arteriography has been performed routinely after operation. RESULTS: Bronchoscopic examination performed in all patients documented normal airway healing in 42, disturbed in two, and complicated in three. Arteriography performed in 42 patients demonstrated complete BAR in 25, incomplete in 15, and failed BAR in 2. Failed BAR was associated with complicated airway healing. The 1- and 2-year survival rate (Kaplan-Meyer) is 83%. Eleven patients have died, only one within 30 days. The total incidence of bronchiolitis obliterans syndrome at 3 years (with Kaplan-Meier technique) is 33%. Successful BAR has also been performed with an adjusted technique in a limited number of heart-lung and single lung transplantations. Our total experience of BAR in any type of lung transplantation includes 65 patients with an arteriographic BAR success rate of 94% (50 of 53 examined patients). CONCLUSIONS: Experience has improved the surgical technique and has made BAR reliable and safe, be it double lung, single lung, or heart-lung transplantation. Early results are good, but only follow-up will show if long-term results after lung transplantation will be improved by BAR. Already today, en bloc double lung transplantation with BAR is a viable alternative to sequential bilateral lung transplantation.

Vascular graft infection: an analysis of sixty-two graft infections in 2411 consecutively implanted synthetic vascular grafts.

Among 2411 consecutive arterial reconstructions performed with synthetic prosthetic material in Denmark during a 4-year period, 62 patients (2.6%) developed graft infection. Graft infection occurred only when the groin had been incised. The incidence of infection and the spread of infection along the graft did not relate to the graft material used (Dacron velour, Dacron woven, polytetrafluoroethylene, and umbilical vein). Retrospective analysis disclosed predisposing or precipitating factors in 50 of the 62 cases; the most important seemed to be unsatisfactory surgical technique. Fifty-three percent of the graft infections occurred within 30 days. Gram-positive cocci were the most common pathogen. The 62 patients had been in the hospital for a mean of 90 days and had undergone an average of 1.4 operations for graft infections. Of the patients, 25.8% died and 30.6% underwent amputations. Vascular graft infection is still one of the major problems in vascular surgery; greater care should be taken to improve antiseptics, improve surgical technique, and establish a rational prophylactic antibiotic regimen. A prophylactic antibiotic regimen of a combination of cephalosporin and ampicillin is recommended.

Surgical repair of a postendocarditis abscess cavity in the heart guided by intraoperative transoesophageal echocardiography.

A case of aortic prosthetic endocarditis is presented that was complicated by the formation of a cavity in the spatium between the aorta and the roof of the left atrium. At the primary operation this cavity had not been detected. During reoperation the surgeon localized the cavity in the cardioplegic heart, guided by transoesophageal echocardiography.

CABG shortly after AMI treated with thrombolysis: an analysis of the surgical group and a comparison with PTCA in the DANAMI study. Danish multicenter randomized study of invasive versus conservative treatment in patients with inducible ischemia after thrombolysis in acute myocardial infarction.

OBJECTIVE: To present surgical results of the DANAMI study comparing conservative and invasive treatment of postinfarction myocardial ischaemia and to compare these with percutaneous transluminal angioplasty (PTCA) which was the alternative invasive treatment in that study. METHODS: A group of 413 patients with verified acute myocardial infarction treated with thrombolysis within 12 h of the onset of symptoms, who demonstrated postinfarction myocardial ischaemia were treated with coronary artery bypass grafting (CABG) or PTCA. Patients with left main lesions, three-vessel disease, two-vessel disease with more than three stenoses and patients with occlusions of a non-infarct related vessel had primary CABG. Patients with 1- and 2-vessel disease with not more than a total of three stenoses had PTCA. In case of failed PTCA patients had secondary CABG. The median distance from AMI to CABG was 45 days. PTCA was performed at a mean of 39 days after the infarction. RESULTS: A total of 147 patients had CABG and 266 had PTCA. The operative mortality for CABG was 1.4%. No PTCA patients died in relation to the procedure, 0.8% developed acute myocardial infarction as a consequence of the procedure, 1.5% had acute CABG and 3.5% elective CABG due to failed PTCA. In spite of more severe coronary artery disease among the CABG patients there was no difference in survival at 2.4 years. The CABG group had significantly fewer episodes of unstable angina, 10.2% versus 25.6% (P = 0.0002). No CABG patients had re-do revascularisation at 2.4 years follow-up versus 15.4% of the PTCA patients. At 3 years 80% of the CABG patients were free of angina compared to the 61% of the PTCA group (P < 0.0001). CONCLUSION: Low morbidity and mortality justifies the deferred elective revascularisation in patients with postinfarction myocardial ischaemia even in patients with silent ischaemia. There is no difference in survival at 2.4 years between CABG and PTCA but CABG offers more lasting results concerning incidence of stable and unstable angina than PTCA, which, however, is a valuable alternative in patients with less severe coronary artery disease.

Intra-aortic balloon counterpulsation in Denmark 1988-1991. Early results and complications.

During the years 1988-1991 6319 patients underwent cardiac surgical procedures in Denmark. In 183 patients (2.9%) with left ventricular failure intra-aortic balloon counterpulsation (IABP) was used. Four percent of the IABP were placed preoperatively, 86% intraoperatively and 10% postoperatively. Severe complications occurred in 16 patients (8.7%) and were mainly vascular due to limb ischemia. The incidence of complications was independent of the duration of balloon pumping. Sixty percent of the patients were weaned from IABP. The 30-day mortality rate was 54%. During the observation period we found a gradual decrease in the use of IABP as well as a reduction in mortality.

Significance and management of early graft failure after coronary artery bypass grafting: feasibility and results of acute angiography and re-re-vascularization.

UNLABELLED: Perioperative ischaemia and infarction after CABG are associated with increased morbidity and mortality. OBJECTIVE: To study causes of perioperative ischaemia and infarction by acute re-angiography and to treat incomplete re-vascularization caused by graft failure or any other cause. METHODS: Between 1990 and 1995, 2003 patients underwent an isolated CABG operation. Myocardial ischaemia was suspected if one or more of the following criteria were present: New changes in the ST-segment in the ECG; a CKMB value greater than 80 U/L; new Q-waves in the ECG; recurrent episodes of, or sustained ventricular tachyarrhythmia; ventricular fibrillation; haemodynamic deterioration and left ventricular failure. Acute coronary angiography was performed in stable patients, while haemodynamically severely compromised patients were rushed to the operating room. RESULTS: A total of 71 (3.5%) patients of all CABGs with suspected graft failure were identified and included in the study. Patients were grouped according to whether they had an acute re-angiography (n = 59; group 1) or an immediate re-operation (n = 12; group 2) performed. In group 1, the acute re-angiography demonstrated graft failure/incomplete re-vascularization in 43 patients (73%). The angiographic findings were: Occluded vein graft(s) in 19 (32%); poor distal run-off to the grafted coronary artery in ten (17%); internal mammary artery stenosis in four (7%); internal mammary artery occlusion in three (5%); vein graft stenoses in three (5%); left mammary artery subclavian artery steal in two (3%); and the wrong coronary artery grafted in one (2%). Based on the angiography findings, 27 patients were re-operated and re-grafted. At the time of re-operation, 18 patients (67%) had evolving infarction documented by ECG or CKMB. Two patients (3%) experienced stroke in immediate relation to the re-angiography. The 30-day mortality was three (7%). In group 2, graft occlusions were found in 11 patients (92%). The 30-day mortality was six (50%). CONCLUSION: An acute re-angiography demonstrated graft failure or incomplete re-vascularization in the majority of patients with myocardial ischaemia early after CABG. Re-operation for re-re-vascularization was performed with low risk. Few patients with circulatory collapse could be saved by an immediate re-operation without preceding angiography.

Early experience of double-lung transplantation with bronchial artery revascularization using mammary artery.

En-bloc double-lung transplantation with tracheal and bronchial revascularization using the left internal mammary artery has been performed in 14 Danish patients. Primary healing of the tracheal anastomosis was observed in 12 patients, in 10 of whom a successful revascularization has been verified by angiography. Two patients have been operated recently and not yet examined by angiography. Mucosal necrosis and subsequent development of bronchial stenosis had to be treated by left-sided pneumonectomy in two patients with failed revascularization. All patients were early survivors (1-14 months). We conclude that bronchial revascularization with the internal mammary artery is possible with an acceptable success rate and is associated with primary healing of the tracheal anastomosis. The impact on long-term results remains to be seen.

[Brachial plexus injuries after catheterization of the internal jugular vein]. / Plexus brachialis laesion efter anlaeggelse af vena jugularis interna kateter.

During a period of 17 months, four cases of lesions to the brachial plexus after cannulation of the internal jugular vein were observed in the Department of Thoracic Surgery in Odense Hospital. Other possible complications are mentioned and a method of catheterization with the fewest possible complications is reviewed. Patients who have been submitted to catheterization of the internal jugular vein should be observed with particular attention to nerve lesions. These symptoms usually regress within a relatively short period.

[Mediastinal infection following open heart surgery]. / Mediastinalinfektion efter åben hjertekirurgi.

A retrospective investigation was undertaken of the mediastinal infections in patients submitted to cardiac surgery. A total of 1,763 patients participated in a period of 11 years from 1978 to 1988. All of the case records were reviewed for the occurrence of infections in the mediastinum and 24 patients (1.4%) were found to have had mediastinitis. Predisposing factors to mediastinal infections are reviewed. In all of the cases, treatment consisted re-thoracotomy with removal of all necrotic and infectious material. This was followed by primary closure over a retrosternal irrigation system which supplied an antibiotic solution for six days. In addition, oral antibiotics were administered on the basis of the findings on culture. The incidence of infection was found to be increased when the left internal mammary artery (LIMA) had been employed and in cases of combined cusp and coronary surgery. In 20 patients (83%), relevant culture findings were found from the mediastinal drain on an average of 2.5 days after the primary operation. These were reencountered in the mediastinum at rethoracotomy which was performed on an average of 15 days after the primary operation. This raises the question of the possibility of earlier intervention. The commonest microorganisms were micrococci and Staphylococcus aureus which together comprized approximately 83%. The antibiotic treatment routinely employed was 1 g meticillin four times daily. Five patients died (21%) and 19 patients were discharged. On follow-up examination, the sternum was stable and the scar healed. When infection in the mediastinum is suspected after cardiac surgery, early diagnosis and active surgical treatment are important. The closed method of irrigation drainage is recommended by the authors.

[Reoperation for angina pectoris]. / Reoperation for angina pectoris.

During the 16-year period from 1974 to 1989, coronary bypass operations were carried out on 938 patients. During the same period, 48 patients (5.1%) were submitted to reoperation on account of recurrent angina pectoris. Patients with early recurrence had more frequently graft-occlusion than patients with late recurrence in whom the main cause was progression of the arteriosclerotic cardiac condition. The actual rethoractomy was carried out without serious complications. The perioperative frequency of complications and the mortality correspond to the frequencies at the first operation. Follow-up control of these patients was undertaken after an average of 34 months (8-100) after reoperation. The results after reoperation as regards freedom from symptoms are not quite as good as the results after the primary operation but approximately 2/3 of the patients will benefit from reoperation.

[Danish experience with physical and occupational rehabilitation after heart transplantation. The heart transplantation group at Rigshospitalet]. / De danske erfaringer med fysisk og arbejdsmaessig rehabilitering efter hjertetransplantation. Hjertetransplantationsgruppen på Rigshospitalet.

Heart transplantations have been carried out for one year (1.9.1990-1.9.1991) in Denmark. Twenty-three out of 27 patients survived at the end of this period. Prior to transplantation, all of the patients were in NYHA groups III or IV. On discharge, all of the patients could manage a 45-60 minutes training programme followed by a stair test (two to six floors up). Prior to transplantation, 17 patients received financial aid in one form or another and one child received special schooling. On an average 165 days (1.9.1991) after transplantation, nine patients were in full or part-time employment, two were students, seven received financial aid and five were still in hospital. A correlation between the duration of financial aid before transplantation and return to work after transplantation was found. In addition, age was found to be of significance. It is concluded that physical status and return to work are satisfactory.

[Heart transplantation]. / Hjertetransplantation.

In carefully selected patients with end-stage heart failure heart transplantation has developed from an experimental procedure to standard therapy during the last 30 years. It is currently accepted as a procedure for prolonging life and also for improving quality of life. According to the Registry of the International Society for Heart and Lung Transplantation the overall one-year actuarial survival is 79% and 10-year survival barely 50%. Nine years after the start of the Heart Transplant Program at Rigshospitalet the overall actuarial survival of 157 consecutive patients is 66%. Due to the limited donor access a decline of heart transplant recipients has been recorded during the late nineties. Mechanical replacement of the heart may develop from technological advances and possibly this therapy may gain a complementary status in heart failure, however the human biological replacement is currently the standard.

[Clinical results after en block double lung transplantation with direct bronchial revascularization. The first three and a half years' experience in Denmark]. / Kliniske resultater efter en bloc dobbeltlungetransplantation med direkte bronkial revaskularisering. De første tre et halvt års erfaring i Danmark.

En-bloc double lung transplantation with tracheal anastomosis and direct revascularization of the bronchial arteries to the left internal mammary artery has been carried out in Denmark since June 1992. Forty-seven patients (32 with alfa-1 antitrypsin deficiency, 11 with chronic obstructive pulmonary disease, two with cystic fibrosis and two with primary pulmonary hypertension), 25 men and 22 women, average age 39 years (17-64 years), have received their first double-lung transplant with bronchial artery revascularization. Arteriography of the internal mammary artery and bronchial arteries was performed in 42 (89%) of the patients from 1-150 days after the operation. Successful bronchial artery revascularization was demonstrated arteriographically in 40 patients, in two patients the arteriography failed to show bronchial artery revascularization. Arteriography was not performed in five patients due to early complications and death. Bronchoscopy showed rapid, uncomplicated airway healing in 42 patients. Mucosal necrosis under the tracheal anastomosis was found in three patients, and severe obstructive endobronchial growth of the fungus Aspergillus fumigatus was diagnosed in the last two patients. The one- and two-year survival is 83% (Kaplan-Meier). Eleven patients are dead, five due to pulmonary causes and six due to extra-pulmonary causes. Pulmonary function became normal in nearly all surviving patients between three to six months after the transplantation. In conclusion, en-bloc double-lung transplantation with bronchial artery vascularization has shown good short-term results, and the one- and two-year survival gives hope that a successful bronchial artery revascularization will improve the long-term survival following lung transplantation.

[Coronary bypass surgery at the Rigshospitalet 1993-1995. Results after 1.000 consecutive operations]. / Koronar bypass-kirurgi på Rigshospitalet 1993-1995. Resultater efter 1.000 konsekutive operationer.

During 1993-95 1000 consecutive patients were admitted for coronary bypass surgery. The total 30-day mortality of 1.9% was 0.9% for elective cases, 0.8% for reoperations and 0.2% for urgent cases. Perioperative myocardial infarction occurred in 44 patients of whom 25% had infarction at the start of the operation. Respiratory insufficiency occurred in 1.4% of the patients, 3.6% developed renal insufficiency and 1.8% had neurological defects postoperatively. Reoperation for bleeding occurred in 6%, and 0.2% developed sternal or mediastinal infection. This study demonstrates that the results of coronary bypass surgery at Rigshospitalet, Copenhagen are fully comparable to similar results in our neighbouring countries. The results can probably be further improved by more intensive treatment of perioperative ischaemia, especially in reoperations and urgent cases.

[Heart transplantation in Denmark. Therapeutic routines and preliminary results]. / Hjertetransplantation i Danmark. Behandlingsrutiner og praeliminaere resultater.

When the criterion of brain-death was introduced in Denmark on 1.7.1990, the possibility for heart transplantation and other interventions was opened. The first heart transplantation was carried out 3.10.1990 and, during the first year, 28 transplantations were carried out on 27 patients. The therapeutic routines in the department are reviewed and the results obtained after the first year are presented. A total of 33 donors who fulfilled the donor criteria were available. Of these, 28 came to Rigshospitalet, two were sent abroad and suitable recipients could not be found for two. The recipient group consisted of four women and 23 men with an average of 46 years. At the time of writing, on an average 169 days after operation (13-330), 23 out of 27 patients survived in good health and with normal cardiac function. Three patients are still in hospital.