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Biomedical subjects

K Verkkala

Publications and source records attributed to K Verkkala.

At least 19 recordsLinked to original sources
PubMed2000

A comparison of remifentanil and alfentanil for use with propofol in patients undergoing minimally invasive coronary artery bypass surgery.

UNLABELLED: Most patients undergoing minimally invasive direct coronary artery bypass surgery can be awakened and tracheally extubated in the operating room. We have compared two techniques of total IV anesthesia in this patient population: 30 patients (aged 44 to 74 yr; 24 male) premedicated with temazepam were randomly assigned to receive either remifentanil-propofol or alfentanil-propofol. Anesthesia was induced with remifentanil 2 microg/kg or with alfentanil 40 microg/kg, with propofol, and maintained with remifentanil at 0.25 or 0.5 microg x kg(-1) x min(-1) or alfentanil at 0.5 or 1 microg x kg(-1) x min(-1). The stable maintenance infusion rate of propofol was adjusted for age. Times to awakening and tracheal extubation were recorded. Postoperatively, IV morphine provided by patient-controlled analgesia was used for 48 h. Times to awakening and tracheal extubation (mean +/- SD) were shorter (P < 0. 01) in patients receiving remifentanil, and interpatient variations in times to awakening and tracheal extubation smaller (awakening 25 +/- 7 vs 74 +/- 32 min, and extubation 27 +/- 7 vs 77 +/- 32 min). Analysis of variance revealed that postoperative consumption of morphine was dependent on both the intraoperative opioid and the time elapsed after surgery (P < 0.05): patient-controlled analgesia morphine use during the first 3 h after awakening was more in patients receiving remifentanil (P < 0.01). IMPLICATIONS: Recovery of patients undergoing Minimally Invasive Direct Coronary Artery Bypass Surgery is significantly shorter and more predictable after total IV anesthesia with remifentanil-propofol than with alfentanil-propofol, which may be important if the goal is that patients will be awakened and tracheally extubated in the operating room.

Aged↗
PubMed1999

Ventricular Arrhythmia Suppression by Magnesium Treatment after Coronary Artery Bypass Surgery.

Ventricular arrhythmias occur frequently shortly after coronary artery bypass grafting (CABG), and their occurrence coincides with the postoperative decline in serum magnesium (Mg) levels. To examine if this decline causes ventricular arrhythmias and if their appearance could be reduced by intravenous Mg administration, 140 consecutive CABG patients were randomized to receive 70 mmol of Mg sulphate (N = 69) or placebo (N = 71) over two days. Serum Mg concentration fell to 0.77 mmol/l in the control group but rose to 1.09 mmol/l in the Mg group (p < 0.001). On 48 h Holter, the number of ventricular premature complexes (VPC) on the third postoperative day was reduced in the Mg group (4 +/- 5 vs 12 +/- 21 VPCs/h; p < 0.05) and the incidence of complex ventricular arrhythmias (Lown grade 2-5) was significantly diminished (19% vs 41% of the patients; p < 0.05). In multivariate analysis, high risk ventricular arrhythmias (repetitive polymorphic ventricular complexes, couplets, R-on-T complexes or operative tachycardia) were independently predicted by high number of bypassed vessels (p = 0.01), poor NYHA functional class (p = 0.06), preoperative diuretic use (p = 0.07), and low postoperative Mg levels (p = 0.08). In conclusion, correction of the postoperative decline in serum Mg concentration decreases the occurrence of early VPCs and complex ventricular arrhythmias. Patients with extensive underlying coronary artery disease and prior diuretic therapy appear to benefit greatest from Mg treatment.http://link.springer-ny.com/link/service/journals/00547/bibs/8n3p165.html

Journal Article↗
PubMed1999

Donor lung pretreatment with prostaglandin E(1) does not improve lung graft preservation.

Prostaglandin E(1) (PGE(1)) is widely used to improve early graft function after lung transplantation, but some studies have questioned its benefits. Therefore we evaluated the effect of donor pretreatment with PGE(1) in our porcine model of single lung transplantation. Donors received PGE(1) or placebo intravenously before flushing the pulmonary artery with modified Euro-Collins solution. After cold storage, the excised left lung was transplanted. Ischemic time was 4 h. We used our right side heart bypass model to measure standardized pulmonary vascular resistance and to study blood flow distribution between recipient's native and transplanted lung. Systemic and pulmonary hemodynamics and gas exchange were also measured. After transplantation, pulmonary vascular resistance was significantly higher in the transplanted lung, which received only one fourth of the total pulmonary blood flow. PGE(1) pretreatment did not improve pulmonary hemodynamic parameters, or gas exchange.

Alprostadil↗
PubMed1998

Minimally invasive coronary artery bypass grafting using the right gastroepiploic artery.

BACKGROUND: Anastomosis of the left internal thoracic artery to the left anterior descending artery without sternotomy and without cardiopulmonary bypass is a standard approach in minimally invasive coronary artery bypass grafting. To expand the indications for minimally invasive coronary artery bypass grafting from one-vessel disease to two-vessel disease, we began to perform anastomosis of the right gastroepiploic artery (RGEA) to the right coronary artery (RCA). METHODS: From February to November 1996, an RGEA graft was used in 25 of the 100 patients who underwent minimally invasive coronary artery bypass grafting at our clinic. Eleven of the patients had only RCA disease and 14 had both RCA and left anterior descending artery disease. One of the operations was a redo coronary artery bypass grafting. The RGEA was anastomosed to the RCA through a laparotomy incision and the left internal thoracic artery was anastomosed to the left anterior descending artery through a left anterior thoracotomy. In 5 patients, the RGEA was lengthened by venous grafting. RESULTS: All patients underwent angiography after operation; 82.6% of the RGEA grafts and all the left internal thoracic artery grafts were functioning well. In three of the four nonvisualized RGEA grafts, the percentage of proximal stenosis of the RCA seen on postoperative angiography was not critical (40%, 50%, and 50%, respectively), allowing significant competitive flow through the native bypassed RCA. The patency of all the RGEA grafts without competitive flow was 95%, with a 95% confidence interval of 75.1% to 99.9%. CONCLUSIONS: The indications for minimally invasive coronary artery bypass grafting could be extended to primary operations in patients with left anterior descending artery and RCA lesions by using both the left internal thoracic artery and the RGEA.

Adult↗
PubMed1998

The conventionally ventilated operating theatre and air contamination control during cardiac surgery--bacteriological and particulate matter control garment options for low level contamination.

OBJECTIVE: The purpose of the study was to compare the usefulness of a conventional bacteriological technique with that of particle counting under lower air contamination and better aseptic conditions achieved with special staff garments and covering for the patient. Contamination levels were estimated with continuous on line air particle counting measurement, volumetric intermittent short period aerobic bacteriological cultures and wound surface contact cultures. METHODS: In a series of 66 consecutive coronary artery bypass operations performed by the same team and in the same theatre using different types of patient and staff clothing, the impact of a reduced bacteriological and particulate contamination were assessed. The volumetric air contamination of particles > or =5 microm and bacteria-carrying particles were monitored 30 cm above the sternal wound. The bacterial contamination and bacterial wound infections in the sternal and leg wounds were assessed as well. RESULTS: With the alternative garment and textile system, the air counts fell from 25 colony-forming units (CFU)/m3 to 7 CFU/m3 (P < 0.0038). The contamination of the sternal wound was reduced by 46% and that of the leg wound by >90%. In order to give continuous contamination feedback during the whole operation to the theatre staff, particle counts > or =5 microm were monitored and visualized. Air particle counts decreased rapidly from 850 particles/m3 and stabilized to approximately 50 particles/m3 when the alternative clothing system was used (P < 0.001). Low particle counts > or =5 microm should offer the possibility to indirectly estimate air bacteria carrying particle counts during the entire operation. Less than 20% of the total count in this size group carries bacteria. The low air contamination was achieved even in an ordinary ventilated theatre when individual team members used clean air suits in combination with impermeable patient drapes. When air particle level < or =50 particles/m3 is reached, the bacterial air contamination is in the order of that of orthopaedic hip operations. The staff must during the entire operation adjust their activity to air asepsis. CONCLUSIONS: The use of clean air suits and impermeable patient clothing results in a low exogenous contamination of air and wound. Continuous air particle monitoring is a good intraoperative method to monitor the air contamination longitudinally in an operating theatre.

Air Microbiology↗
PubMed1998

Effects of a new calcium sensitizer, levosimendan, on haemodynamics, coronary blood flow and myocardial substrate utilization early after coronary artery bypass grafting.

AIMS: The aim of the study was to evaluate the effects on systemic and coronary haemodynamics and myocardial substrate utilization of a new calcium sensitizer, levosimendan, after coronary artery bypass grafting. METHODS AND RESULTS: Twenty-three low-risk patients were included in this randomized and double-blind study. They received placebo (n = 8), 8 (n = 8) or 24 (n = 7) micrograms.kg-1 of levosimendan after coronary artery bypass operation. Systemic and coronary sinus haemodynamics with thermodilution and myocardial substrate utilization were measured. The heart rate increased 11 beats.min-1 after the higher dose (P < 0.05). Cardiac output increased by 0.7 and 1.61.min-1 (P < 0.05 for both) after 8 and 24 micrograms.kg-1 of levosimendan, respectively. Systemic and pulmonary vascular resistance decreased significantly after both doses. Coronary sinus blood flow increased by 28 and 42 ml/(P = 0.054 for the combined effect) after the lower and higher dose, respectively. Myocardial oxygen consumption or substrate extractions did not change statistically significantly. CONCLUSION: Despite improved cardiac performance, levosimendan did not increase myocardial oxygen consumption or change myocardial substrate utilization. Thus levosimendan has the potential to treat low cardiac output states after cardiopulmonary bypass surgery.

Adult↗
PubMed1997

Surgical treatment of acute myocardial ischaemia related to coronary angioplasty with special reference to use of perfusion balloon catheter and long-term outcome.

Twenty of 569 consecutive patients (3.5%) undergoing percutaneous transluminal coronary angioplasty required emergency coronary artery bypass grafting for acute closure of the dilated vessel. In seven patients an intracoronary autoperfusion balloon catheter was inserted to ensure antegrade blood flow across the injured zone of the coronary artery. The time needed for completion of the bypass grafts ranged from 100 to 399 minutes (mean 180 minutes). An average of 1.9 coronary artery bypasses was inserted. In total, 11 of the 20 patients (55%) developed new Q waves and had elevated CK-MB levels. However, the myocardial infarction rate was only 14% in those with a perfusion balloon catheter as against 77% in those without one. The insertion of a ball-out catheter permitted greater utilization of the internal mammary artery as a bypass graft. Angiographic follow-up was conducted after a mean of 28 months (19 patients). The patency rate of the bypass grafts placed in the emergency setting was relatively good (91%). Thallium tomography revealed a scar of variable size in all 17 patients studied and a reversible exercise perfusion defect requiring coronary reangioplasty in three patients. In conclusion, the insertion of a perfusion balloon catheter after abrupt coronary occlusion during coronary angioplasty solved the problems of acute myocardial ischemia and markedly lowered the definite myocardial infarction rate. This technique ensures favourable haemodynamic conditions for emergency myocardial revascularization.

Angioplasty, Balloon, Coronary↗
PubMed1997

Heart transplantation in Finland 1985-1995.

BACKGROUND AND AIMS: Since improved immunosuppression in the 1980's, heart transplantation is a well established procedure to treat patients with end-stage heart failure. The first heart transplantation in Finland was performed in 1985. Since then the activity has gradually increased to a level of about 25 annual transplants. The aim of this report is to sum up the clinical experience during the first 11 years. MATERIALS AND METHODS: From February 1985 till the end of 1995, 190 heart transplantations were performed in our institution. There were 176 males and 14 females ranging from 15 to 62 (mean 42.2) years of age. End-stage preoperative cardiac disease was dilating cardiomyopathy in 108 cases, coronary artery disease in 65 cases, valvular disease in 12 cases and congenital heart disease in five cases. RESULTS: The 30-day hospital mortality was 29 out of 190 (15.2%). The actuarial survival was 77% at one year, 75% at two years and 73% at 10 years. The most common causes of death were rejection (11 cases), graft failure (11 cases), abdominal complications (six cases) and cytomegalovirus (CMV) infection (four cases). A total of 87 rejection episodes occurred in 53 patients consisting 28 per cent of patients. 44 rejections occurred within three months post transplantation. Significant infections were noted in 198 instances in 97 patients. These were of bacterial origin in 92, viral in 48, fungal in 12 and protozoal in 10 cases, and 36 such infections which responded to antibiotics favourably but in which the microbe remained unidentified. 138 infections (i.e. 80%) occurred within 6 months post transplantation. In viral infections cytomegalovirus (CMV) predominated (29 out of 48). The CMV infection was significantly milder in patients who were seropositive preoperatively than in preoperatively seronegative patients with seropositive donors. CMV infection was associated with increased risk of post-transplant coronary artery disease. Three years after transplantation some restoration of sympathetic nervous response was observed at orthostatic test in heart rate and blood pressure. CONCLUSIONS: It can be concluded that 1) if a patient survives the three immediate postoperative months, his prognosis is good for the forthcoming years, 2) clinically significant rejections occur in less than one third of the patients, 3) cytomegalovirus is the most harmful agent post transplantation and a risk factor for post-transplant coronary artery disease and that 4) some restoration of sympathetic nervous control of the heart occurs within three years after transplantation.

Adult↗
PubMed1997

En bloc heart and lung transplantation in Finland 1988-1996.

UNLABELLED: The purpose of the study was to review the first clinical experience in combined heart-lung transplantation in our institution. MATERIAL: From June 1988 to December 1996 15 en bloc heart and lung transplantations were performed. There were nine men and six women, aged 17-61 (mean 42.3) years. The indications for operation were primary pulmonary hypertension with right heart failure in five, Eisenmenger's syndrome in five, pulmonary embolism and right heart failure in three and emphysema with right heart failure in two cases. RESULTS: The hospital (30 day) mortality was four patients (26.6%). The causes of mortality were graft failure in two cases, infection and bleeding after transbronchial biopsy in one case and sepsis and aspergillosis in one case. Postoperative complications included eight cytomegalovirus (CMV), two Pneumocystis Carinii, five bacterial and five fungal (one Aspergillus and four Candida) infections. Rejection episodes (of the lungs) occurred in four patients (in 27%). During the follow-up to four years two patients developed diabetes mellitus (insulin therapy), one patient renal failure (dialysis), two patients tracheal stricture (laser resection), one patient fracture of the spine and one patient epilepsy. One patient died from prolonged CMV infection and chronic rejection eight months postoperatively. Four patients underwent bronchial artery revascularization (two with the internal thoracic artery and two with a vein graft). This was followed by improved airway healing and resistance towards infections. After a follow-up to four years 10 patients out of 15 (66.7%) were living an active life. CONCLUSION: Combined heart-lung transplantation offers a good mid-term outcome for patients with end-stage cardiopulmonary disease. The results compare favourably with the corresponding international statistics.

Adult↗
PubMed1997

St. Jude versus CarboMedics: follow-up after prosthetic valve replacement.

BACKGROUND: The purpose of the present study was to evaluate the immediate and long-term outcome of patients with two types of mechanical bileaflet heart valves operated on in the same institution by the same group of surgeons. METHODS: A comparative analysis was made in 229 consecutive patients receiving either the St. Jude Medical (SJM) or CarboMedics (CMS) bileaflet mechanical valve in 1990-1991. There were no differences in the preoperative demographics between the two groups. At operations simultaneous coronary bypass operation was performed in 40 patients out of 134 (30%) in the SJM group and 95 (44%) in the CMS group (p=0.026). Sixteen patients in the SJM group underwent replacement of the ascending aorta with a composite graft and none in the CMS group. RESULTS: There was no difference in hospital mortality between the SJM (6.7%) and CMS (6.3%) groups or in other immediate postoperative complications. The patients were followed up to 32 months. There were more patients in the NYHA class I and II in the CMS group (88%) than in the SJM group (69%), p<0.002. Three were 11 thromboembolic events (0.051% per patient year) in the SJM group and one thromboembolic event (0.008% per patient year) in the CMS group. There were no other differences between the groups in long-term survival, rate of bleeding, infective endocarditis or perivalvular leakage. CONCLUSIONS: With the exception of a little more favourable exercise tolerance and fewer thromboembolic events in the CMS group there were no other differences in the outcome of patients with these two types of bileaflet mechanical valves.

Adult↗
PubMed1996

Abnormal in vivo response to sodium nitroprusside after porcine single lung transplantation.

The chronic increase of pulmonary vascular resistance after lung transplantation is only partly due to an active increase in baseline vasomotor tone, but the nature of the acute pulmonary hypertension after ischemia and reperfusion is not known. We studied the effects of sodium nitroprusside on pulmonary hemodynamics during reperfusion in porcine left lung allotransplants. In twelve pigs (weight: 18 to 24 kg) pulmonary arteries of the native and the transplanted lung were cannulated for right-heart bypass. The total blood flow was 2 L/min. Flow distribution between the lungs was measured at equal mean pulmonary artery pressure, and pulmonary vascular resistance at equal and constant flow-i.e., 1 L/min to each lung. After baseline measurements sodium nitroprusside (1, 3, and 9 microg/kg/min) was administered to six animals (SNP group). The control group (n=6) received an equal amount of the vehicle. After 30 min of discontinuation of the drug infusion, the schedule was repeated. In the transplanted lung, pulmonary vascular resistance decreased in all animals during the first hour of reperfusion. During the second drug infusion pulmonary vascular resistance was significantly lower in the SNP group compared with the control group only at the highest infusion rate of the drug (9 microg/kg/min), which also induced a 44% decrease in systemic vascular resistance. Arterial oxygen tension remained comparable in the two groups throughout the study. Our data suggest that other factors besides active vasoconstriction may contribute to the acute increase of pulmonary vascular resistance after lung transplantation.

Animals↗
PubMed1996

Angiographic 5-year follow-up study of right gastroepiploic artery grafts.

BACKGROUND: The right gastroepiploic artery (RGEA) has been used from 1987 in coronary artery bypass grafting in several clinical studies. However, the published 1- to 5-year patency rates have been dependent on the selection of patients for angiography. METHODS: In our study, the RGEA was used from March 1987 to May 1990 for coronary artery bypass grafting in 31 consecutive patients, 25 male and 6 female. All but 1 patient had triple-vessel disease, and the mean number of distal anastomoses was 3.9 (range, 2 to 5). Internal thoracic artery grafts were used concomitantly in all patients. RESULTS: One early and two late deaths occurred. All but 1 of the 28 surviving patients underwent clinical and angiographic follow-up examinations 3 months and 5 years after the operation. The 5-year patency of RGEA grafts was 82.1%, with a 95% confidence interval of 63.1% to 93.9%. In 4 of the 5 nonvisualized cases, the recipient coronary artery showed proximal stenosis of up to 70%, allowing substantial competitive flow. The 5-year patency of the RGEA graft was near that of the left internal thoracic artery, at 90.3%, and the right internal thoracic artery, at 94.4%; and superior to the 66.7% patency of venous grafts. CONCLUSIONS: At 5-year follow-up, angiography of RGEA grafts showed good function and a smooth lumen, especially if the proximal stenosis was more than 70%.

Abdominal Muscles↗
PubMed1996

Thromboxane receptor blockade does not attenuate pulmonary pressor response in porcine single lung transplantation.

BACKGROUND: The ischemia-reperfusion lung injury is characterized by increased pulmonary vascular resistance, edema, and subsequent deterioration of oxygenation. Other models of acute lung injury suggest that thromboxane A2 may contribute to the pulmonary hypertension after transplantation. METHODS: We studied the effects of the selective thromboxane A2 receptor antagonist SQ 30741 on pulmonary hemodynamics and gas exchange in porcine single lung transplantation using extracorporeal circulation (right heart bypass) with separate cannulations of the right and left pulmonary arteries. Pulmonary vascular resistance was measured at equal and constant flow to each lung. Flow distribution between the lungs was registered at equal pulmonary artery pressures. Twelve pigs (weight 17 to 23 kg) were studied. At the onset of reperfusion a bolus dose of the drug (5 mg/kg) was injected into both pulmonary arteries followed by an infusion (5 mg/kg/hr) for 1 hour (SQ group, n = 6). The control group (n = 6) received an equal amount of vehicle. The systemic and pulmonary hemodynamics and blood gas values were registered during 2 hours of reperfusion. RESULTS: The pulmonary vascular resistance of the transplanted lung was significantly higher compared with the native lung (p < 0.001). Administration of SQ 30741 failed to ameliorate the pulmonary pressor response of the graft in comparison with the control group. No difference was found in the systemic arterial oxygen tension between the two groups. CONCLUSIONS: Thromboxane does not seem to be among the principal mediators in the pulmonary hypertension after transplantation.

Animals↗
PubMed1996

Value of high-resolution computed tomography in routine evaluation of lung transplantation recipients during development of bronchiolitis obliterans syndrome.

BACKGROUND: Chronic rejection is a major long-term complication after lung transplantation. The purpose of our study was to evaluate the role of repeated high-resolution computed tomographic examinations in monitoring the development of bronchiolitis obliterans syndrome after lung transplantation. METHODS: A total of 126 high-resolution computed tomographic examination in 13 lung transplant recipients was analyzed. During a mean follow-up period of 23 months, bronchiolitis obliterans syndrome developed in eight of the patients. A scoring system from 0 to 10 based on the number of chronic changes on high-resolution computed tomography was developed, and the score of each patient was compared with decline in the forced expiratory volume in 1 second and maximal forced expiratory flow rate of 50% of the forced vital capacity. RESULTS: The score of chronic changes, measured at 1 year after transplantation, correlated inversely with the values of forced expiratory volume in 1 second and maximal forced expiratory flow rate at 50% of the forced vital capacity (p < 0.05). Stage I bronchiolitis obliterans syndrome was associated with scores of 4 to 6 (mean 5.0), stage 2 with scores of 6 to 9 (mean 7.0), and stage 3 with scores of 6 to 9 (mean 7.7). The sensitivity of high-resolution computed tomography was 93% and its specificity was 92% when five chronic changes were used as a cutoff level. CONCLUSIONS: The progress of chronic changes on high-resolution computed tomography occurs concurrently with the development of bronchiolitis obliterans syndrome. High-resolution computed tomography may provide additional morphologic information for noninvasive evaluation of chronic lung rejection.

Adult↗