PubMed Health⌕ Search

Biomedical subjects

K Saatvedt

Publications and source records attributed to K Saatvedt.

At least 19 recordsLinked to original sources

[Placebo effect in research related to surgery and technical procedures].

BACKGROUND: Development of new technology has led to the introduction of many new high-tech surgical treatment modalities. It has been claimed that the use of high-tech medicine is a potent inductor of placebo effect; in fact, many new treatment modalities have been established before they have been evaluated in placebo-controlled trials. However, there are several ways to minimize the confounding effects of placebo in surgical trials. MATERIAL AND METHODS: This is a review based on a thoroughly performed search on Medline of Norwegian and English language publications published up until August 2000. RESULTS: Several studies have demonstrated that surgical treatment induces significant placebo effect. To minimize the confounding effects of placebo in trials evaluating new surgical modalities, it is important to use adequate blinding, neutral patient information, objective end-points, and correction for estimated placebo effects. The use of placebo surgery has been a source of lively controversy; many consider it ethically unacceptable.

Clinical Trials as Topic↗

Is there a relationship between cognitive dysfunction and systemic inflammatory response after cardiopulmonary bypass?

BACKGROUND: The systemic inflammatory reaction (SIR) is assumed to be one of the factors that causes cerebral dysfunction after cardiopulmonary bypass (CPB). The aim of the present study was to evaluate the relationship between the SIR and postoperative cognitive performance at 5 days and 3 months. METHODS: One hundred patients undergoing coronary artery bypass grafting were studied. Inflammatory markers and markers of coagulation and fibrinolysis were determined at several time points during and after the operation. Correlation analysis between maximum levels of the different markers and early and late performance was performed. RESULTS: No overall association was found between the maximum levels of the inflammatory markers and early and late function. CONCLUSIONS: Notwithstanding limitations of statistical power established markers of systemic inflammatory reaction showed no relationship with outcome at 5-day or 3-month follow-up in this subset of patients.

Aged↗

Cardiac enzymes after transmyocardial laser treatment with CO2 laser.

OBJECTIVES: The aim of the present study was to examine postoperative serum levels of cardiac enzymes after transmyocardial laser treatment (TML) and to evaluate any associations between this release, postoperative cardiac events and change in ejection fraction after 3 months' follow-up. DESIGN: Forty-nine patients with angina pectoris Canadian Cardiovascular Society Angina Score Class III & IV refractory to medical therapy and untreatable by coronary artery bypass or percutaneous transluminal angioplasty treated with CO2 laser were included. Inclusion criteria were age less than 75 years, left ventricular ejection fraction greater than or equal to 30% and myocardial regions with reversible ischemia. Serum levels of aspartate aminotranspherase (ASAT), alanine aminotranspherase (ALAT) and MB-isoenzymes of creatine kinase (CK-MB) were followed during the first 72 h after surgery. Ejection fractions were estimated by multiple-gated acquisition ventriculography at inclusion and 3 months postoperatively. RESULTS: A significant increase in serum markers of myocardial necrosis was observed 8 h after surgery. A subsequent increase from 8 to 24 h after surgery was associated with the presence of postoperative cardiac adverse events. An inverse correlation was found between peak level of cardiac enzymes and change in ejection fraction from baseline to 3 months' follow-up. CONCLUSIONS: TML with CO2 laser is followed by a significant increase in serum levels of cardiac enzymes after 8 h. Further significant increases are associated with cardiac adverse events postoperatively. Peak enzyme values are inversely correlated with change in ejection fraction from baseline to 3 months' follow-up.

Angina Pectoris↗

Mechanical bridge to recovery in fulminant myocarditis.

A patient with acute fulminant lymphocytic myocarditis and cardiogenic shock was successfully treated by mechanical off loading of the left ventricle. A nonpulsatile left-heart bypass was undertaken with an implantable centrifugal blood pump. Careful weaning resulted in device removal on the seventh day. Left and right ventricular function is sustained at 7 months. Widespread application of this method depends on the availability of an inexpensive user friendly blood pump, appropriate weaning protocols and emerging strategies to promote sustainable myocardial recovery.

Adult↗

Perioperative cardiac function and predictors for adverse events after transmyocardial laser treatment.

BACKGROUND: Previous studies have reported that mortality and morbidity after transmyocardial laser treatment (TML) mainly occur perioperatively. The present study was designed to evaluate left-ventricular function and identify risk factors for cardiac-related adverse events in this phase. METHODS: Forty-nine patients were studied. The inclusion criteria were angina pectoris Canadian Cardiovascular Society Angina Score (CCSAS) class III and IV refractory to medical therapy and untreatable by coronary artery bypass graft or percutaneous transluminal coronary angioplasty, age less than 75 years, left ventricular ejection fraction greater than or equal to 30%, and myocardial regions with reversible ischemia. Hemodynamic data and cardiac adverse events were registered. The follow-up time was 30 days. RESULTS: A transient decrease in mean cardiac index (CI) was observed, reaching its minimum immediately after end of the surgical procedure (1.8+/-0.4, p<0.01 vs. baseline). Two patients (4%) died during the postoperative period (30 days). Seventeen patients (35%) experienced adverse cardiac-related events, where CCSAS class IV, unprotected left main stem stenosis, and diabetes mellitus were identified as risk factors in a multivariate analysis. CONCLUSIONS: A transient impairment of left ventricular function was observed after TML. The morbidity and mortality after TML were almost exclusively cardiac-related, identifying CCSAS class IV, unprotected left main stem stenosis, and diabetes as risk factors.

Aged↗

Is there a relationship between serum S-100beta protein and neuropsychologic dysfunction after cardiopulmonary bypass?

OBJECTIVES: Over the past decade, the glial protein S-100beta has been used to detect cerebral injury in a number of clinical settings including cardiac surgery. Previous investigations suggest that S-100beta is capable of identifying patients with cerebral dysfunction after cardiopulmonary bypass. Whether detection of elevated levels S-100beta reflects long-term cognitive impairment remains to be shown. The present study evaluated whether perioperative release of S-100beta after coronary artery operations with cardiopulmonary bypass could predict early or late neuropsychologic impairment. METHODS: A total of 100 patients undergoing elective coronary bypass without a previous history of neurologic events were prospectively studied. To exclude noncerebral sources of S-100beta, we did not use cardiotomy suction or retransfusion of shed mediastinal blood. Serial perioperative measurements of S-100beta were performed with the use of a new sensitive immunoluminometric assay up to 8 hours after the operation. Patients underwent cognitive testing on a battery of 11 tests before the operation, before discharge from the hospital, and 3 months later. RESULTS: No significant correlation was found between S-100beta release and neuropsychologic measures either 5 days or 3 months after the operation. CONCLUSION: Despite using a sensitive immunoluminometric assay of S-100beta, we found no evidence to support the suggestion that early release of S-100beta may reflect long-term neurologic injury capable of producing cognitive impairment.

Anesthesia, General↗

Transmyocardial revascularization with CO2 laser in patients with refractory angina pectoris. Clinical results from the Norwegian randomized trial.

OBJECTIVES: The purpose of the study was to evaluate clinical effects, exercise performance and effect on maximal oxygen consumption (MVO2) of transmyocardial revascularization with CO2-laser (TMR) in patients with refractory angina pectoris. BACKGROUND: Transmyocardial laser revascularization is a new method to treat patients with refractory angina pectoris not eligible for conventional revascularization. Few randomized studies comparing TMR with conventional treatment have been published. METHODS: One hundred patients with refractory angina not eligible for conventional revascularization were block-randomized in a 1:1 ratio to receive continued optimal medical treatment (MT) or TMR in addition to MT. The patients were evaluated at baseline and at three and 12 months with end points to symptoms, exercise capacity and MVO2. RESULTS: Transmyocardial laser revascularization resulted in significant relief in angina symptoms after three and 12 months compared to baseline. Time to chest pain during exercise increased from baseline by 78 s after three months (p = NS) and 66 s (p < 0.01) after 12 months in the TMR group, whereas total exercise time and MVO2 were unchanged. No significant changes were observed in the MT group. Perioperative mortality was 4%. One year mortality was 12% in the TMR group and 8% in the MT group (p = NS.) CONCLUSIONS: Transmyocardial laser revascularization was performed with low perioperative mortality and caused significant symptomatic improvement, but no improvement in exercise capacity.

Adult↗

[Transmyocardial laser treatment--a new treatment modality in pronounced angina pectoris?].

Transmyocardial laser treatment is currently being evaluated as a treatment modality for patients with severe coronary artery disease unsuitable for conventional revascularization with percutaneous transluminal coronary angioplasty or coronary artery bypass grafting. The original hypothesis was that laser-made channels could contribute to myocardial perfusion by conducting blood from the left ventricular cavity into the ischemic myocardium. Results from clinical trials suggest that transmyocardial laser treatment leads to a significant decrease in physician-assessed angina scores and improvement of quality of life. There are, however, conflicting data regarding the effect of myocardial perfusion, and the mechanisms responsible for the observed clinical effect remain unclear. It has been suggested that the angina relief is caused by destruction of myocardial peripheral nerve-endings and improved perfusion through induction of angiogenesis and collateral recruitment. A review of transmyocardial laser treatment with emphasis on experimental and clinical results, based on a thoroughly performed search on Medline of English language publications up until May 1999, is presented.

Angina Pectoris↗

Is atrial fibrillation caused by extracorporeal circulation?

BACKGROUND: Atrial fibrillation is the most common rhythm disturbance encountered after open heart operations, with a reported incidence up to 40%. Despite its high incidence and clinical relevance its etiology remains obscure. It has been hypothesized that atrial fibrillation might be related to extracorporeal circulation. We performed a retrospective study (January 1, 1997 to December 31, 1997) comparing the incidence of atrial fibrillation in 3 groups of patients revascularized with and without extracorporeal circulation. METHODS: The first group comprised patients with coronary artery disease operated on with standard revascularization technique with cardiopulmonary bypass (n = 685). The second group included patients who had minimally invasive coronary artery bypass grafting without the use of extracorporeal circulation (n = 19). Patients in the third group had off-pump transmyocardial laser revascularization (n = 19). RESULTS: There was no significant difference in the incidence of atrial fibrillation in the group that had conventional coronary artery bypass and the group that had minimally invasive coronary artery bypass without cardiopulmonary bypass. The incidence of atrial fibrillation was significantly lower in the transmyocardial laser group compared with the other two groups. CONCLUSIONS: The present study found that postoperative atrial fibrillation is not caused solely by extracorporeal circulation, but patients who had transmyocardial laser revascularization had a significantly lower incidence of atrial fibrillation.

Aged↗

Thyroid function during and after cardiopulmonary bypass in children.

BACKGROUND: The aim of the study was to elucidate the changes in thyroid function during and after cardiopulmonary bypass (CPB) in children. METHODS: Triiodothronine (T3), thyroxine (T4), free thyroxine (FT4) and thyroid-stimulating hormone (TSH) were determined preoperatively, at specific times throughout CPB, and serially up to 48 h postoperatively, in 10 children (median age 35, range 23-68 months) undergoing elective surgery for congenital heart disease. RESULTS: T3 decreased from 2.01 +/- 0.08 preoperatively to 0.94 +/- 0.10 nmol/l 24 h postoperatively (P < 0.05). T4 levels followed a pattern similar to changes in T3. FT4 increased from 17.4 +/- 0.7 preoperatively to 30.0 +/- 0.4 pmol/l after 30 min of CPB (P < 0.05). TSH decreased from 2.44 +/- 0.43 preoperatively to 0.93 +/- 0.21 24 h postoperatively (P < 0.05). CONCLUSION: T3, T4 and TSH are significantly depressed after open heart surgery in children.

Cardiopulmonary Bypass↗

Carpentier-Edwards bioprosthesis. Experiences of 17 years with analysis of risk factors of early mortality.

Isolated aortic (AVR, N = 71), mitral (MVR, N = 103), tricuspid (TVR, N = 3), pulmonary (PVR, N = 8), combined AVR + MVR (N = 4), or combined MVR + TVR (N = 2) valve replacement with a Carpentier-Edwards porcine bioprosthesis was performed in 191 patients between 1979 and 1986. Mean age was 56.9 +/- 17 (range 5-80) years in the total cohort. The operative mortality rates were 5.6% and 8.7%, respectively, for AVR and MVR. Mean observation time was 8 +/- 4.2 (0-16.7) years (total = 1.467 patient-years). Follow-up was 100% complete with respect to mortality. There were 78 late deaths (44%). Actuarial survival rates at 5 and 10 years were 73.2 +/- 5.2 and 52.1 +/- 6.6 for AVR and 76.7 +/- 4.2 and 61.6 +/- 4.8 for MVR. Coronary artery disease, concomitant coronary artery bypass grafting and emergency operation were significant risk factors of early mortality (p < 0.05). Postoperatively, sepsis and multiorgan failure were associated with early mortality (p < 0.05). The 10-year actuarial freedom from structural deterioration for AVR was 89 +/- 4.6 and 76.4 +/- 4.3 for MVR. It is concluded that structural valve failure is the most important factor that adversely affects the performance of Carpentier-Edwards bioprosthesis.

Adolescent↗

Retrograde internal mammary artery as coronary bypass. A prospective study with postoperative angiographic evaluation.

Although the internal mammary artery (IMA) as a coronary graft offers better long-term patency than the saphenous vein, a factor limiting its use has been the length of the artery's pedicle. In an attempt to overcome this limitation, we evaluated the use of retrograde right IMA in a prospective study. In ten patients scheduled for routine coronary artery bypass surgery, bilateral IMA grafting was used, the left IMA in routine fashion, but the right IMA dissected from the level of the first rib, cut there and placed as an inverted graft. Three months postoperatively the patients were clinically evaluated with stress exercise test (n = 10) and coronary angiography (n = 9). No patient had recurrence of angina. Angiography revealed patency of the retrograde right IMA graft in six of nine patients. On the basis of these data we do not recommend routine use of retrograde IMA.

Aged↗

[Video-assisted heart surgery--an alternative in the future?].

Percutaneous angioplasty has been the procedure of choice for one- or two-vessel coronary artery disease because it is less invasive than open heart surgery. Video-assisted coronary artery bypass surgery, using the internal mammary artery, may be an alternative method which is also less invasive than conventional open heart surgery. A technique of video-assisted coronary bypass surgery is described. A limited incision is performed in the 4. intercostal space. The left anterior descending artery is pictured and inspected. A 30 degrees thoracoscope is introduced through a separate incision lateral to the thoracotomy. The dissection is performed and the cauterising instrument introduced through the thoracotomy. The anastomotic procedure is performed while the heart is beating and without extracorporeal circulation. The heart rate may be slowed down by administering a betablocking agent. The patient is extubated in the early postoperative period and mobilized in the same way as after conventional coronary artery bypass surgery.

Coronary Artery Bypass↗

[Mitral valve plasty. A 12-year material].

46 patients underwent mitral valve repair at the Regional Hospital in Trondheim/St. Elisabeth Heart Clinic, during the period 1983-95. There were 20 female patients. The valve pathology was ischemic in 40%, rheumatic in 10% and other or unknown in 50%. The surgical technique included commissurotomy (n = 9), ring annuloplasty (n = 18), resection of posterior leaflet (n = 12), Kay annuloplasty (n = 10), shortening of chordae (n = 3) and other techniques (n = 2). Postoperative complications included wound infection (n = 1), pneumonia (n = 1), mediastinitis (n = 1), pleural effusion (n = 5), renal failure (n = 1) and multi-organ failure (n = 1). One patient required re-exploration for postoperative bleeding. Three (6.5%) patients died within 30 days of surgery due to low cardiac output (n = 2) and multi-organ failure (n = 1). Nine patients (21%) died later. At follow up, within one year of surgery, marked functional improvement was registered, with only one patient in NYHA class III and none in class IV.

Adult↗

Release of interleukin 6 and activation of complement during and after paediatric cardiopulmonary bypass. Effect of autotransfusion of shed mediastinal blood and ultrafiltration.

Interleukin-6 (IL-6) and the complement activation products C3bc and terminal complement complex (TCC) were measured in three groups of children undergoing open heart surgery. One group was treated with intraoperative extracorporeal ultrafiltration and postoperative autotransfusion of shed mediastinal blood, one group was subjected to autotransfusion only and in one group none of these procedures were performed. No differences between the groups were observed concerning the degree of complement activation. Peak and total accumulated level of IL-6 was significantly higher in the group subjected to ultrafiltration and autotransfusion compared to the group treated conventionally with no interventions. IL-6 may be a sensitive marker of maneuvres increasing the inflammatory load during and after open heart surgery in children.

Biomarkers↗

Release of soluble tumour necrosis factor alpha receptors during and after paediatric cardiopulmonary bypass. Correlation with haemodynamic and clinical variables.

The release of cytokines during cardiopulmonary bypass (CPB) may contribute to haemodynamic alternations encountered after open heart surgery. Regulatory mechanisms exist and include soluble cytokine receptors. We have measured blood levels of tumour necrosis factor (TNF) and its soluble receptor (TNFsr) during and after open heart surgery in children. Correlation analysis to haemodynamic and clinical variables was performed. Using immunoassays the authors registered a significant increase in plasma levels of TNFsr with peak levels 2 h post-operatively at a level of 1702 +/- 170 pg/ml. The concentration of TNFsr remained significantly elevated until 48 h postoperatively but TNF was not significantly elevated. An inverse correlation existed between peak TNFsr and mean arterial pressure (rho = -0.827, P < 0.05), between TNFsr and cardiac index (rho = -0.8, P < 0.05), between TNFsr and left ventricular stroke work index (rho = -0.983, P < 0.01), between TNFsr and weight (rho = -0.85, P < 0.05) and between TNFsr and body surface area (rho = -0.867, P < 0.05). The authors demonstrate that the smallest children experienced the highest TNFsr concentration post-operatively. Furthermore cardiac performance, expressed as cardiac index and left ventricular stroke work index, correlated inversely to peak TNFsr level post-operatively.

Cardiopulmonary Bypass↗