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Biomedical subjects

S Tuononen

Publications and source records attributed to S Tuononen.

18 recordsLinked to original sources
PubMed1978

Intraoperative changes in coronary resistance during aortic valve replacement.

Coronary vascular resistance was investigated in 10 patients undergoing aortic valve replacement using continuous constant-pressure coronary perfusion at 32 degrees C. After coronary flow was initiated, resistance was low but increased steadily until it reached a certain resting level. The plateau was attained faster after a short period of anoxia than after a longer period. The initial postischemic resistance was dependent on the duration preceding anoxia, being of the same magnitude after short and moderate periods of anoxia but significantly higher after a long period. This resistance difference between the groups lasted for the whole perfusion. The total coronary resistance and flow reached a plateau in 30 minutes, while resistance increased threefold but flow decreased to half of the initial postanoxia flow. Our results indicate the importance of initiating coronary perfusion soon after aortic cross-clamping to avoid increase in the initial vascular resistance and subsequent inadequate myocardial flow.

Adult↗
PubMed1978

[Blood sugar level in surgical patients].

Serum glucose levels of six different patient groups were investigated preoperatively, during operation, postoperatively and in the first postoperative days: Group A, 10 cholecystectomy patients with 5% glucose infusion 2000 ml/day at a constant infusion rate; group B, 10 cholecystectomy patients with 10% constant rate glucose infusion; group C, 20 cholecystectomy or hernia patients with saline infusion; group D, 34 patients with 5% free rate glucose infusion 2000 ml/day; group E, 15 atrial septal defect patients with 5% constant rate glucose infusion 1500 ml/day and group f, 14 valvular surgery patients with 5% constant rate glucose infusion. Serum glucose increased in all groups during the study, most in the group B and least in the group C. There were no significant differences between the groups A and D, so constant or "free" infusion rate are the same from this viewpoint. The differences between the saline group (C) and all other groups was per- and postoperatively and in the postoperative day significant (p less than 0.001). There were no significant differences between the open heart surgery groups (E and F) and general surgery groups (A and D).

Blood Glucose↗
PubMed1978

Myocardial reactive hyperemia caused by initial myocardial anoxia during aortic valve replacement.

Reactive hyperemic response of individual coronary arteries and of the whole heart to anoxia during coronary cannulation was investigated in 10 patients undergoing aortic valve replacement. Reactive hyperemic response in man is identical to that reported in experimental investigations. The duration of hyperemic response was dependent on the length of the preceding period of anoxia; the longer the period of anoxia, the more prolonged was the hyperemic response. No significant collateral circulation between the coronary arteries could be demonstrated during prolonged anoxia of an individual coronary artery. Blood flow debt was almost always overpaid, but the repayment percentage decreased with the lengthening of the anoxic period, being 460 percent after a short period of anoxia (less than or equal to 2 minutes), 230 percent after an anoxic period of moderate length (3 to 5 minutes), and only 160 percent after a long period of anoxia (greater than or equal to 7 minutes). The total mean repayment of blood flow debt of the whole heart was 195 percent.

Adult↗
PubMed1978

Total pancreatectomy for acute hemorrhagic pancreatitis. A case report.

A patient with acute hemorrhagic pancreatitis treated successfully with total pancreatectomy is reported. Total pancreatectomy is rarely indicated in acute hemorrhagic pancreatitis as suggested by only one surviving patient in the literature so far. Though near total pancreatectomy remains the best surgical treatment in patients with acute hemorrhagic pancreatitis dying from the disease because of failure of nonoperative treatment, total pancreatectomy may be considered as an alternative if circumstances so indicate.

Acute Disease↗
PubMed1978

Effect of initial myocardial anoxia on coronary flow during aortic valve replacement.

Flow to the right and left coronary arteries was recorded continuously during aortic valve replacement using continous constant-pressure coronary perfusion at 32 degrees C in 13 patients. The initially high coronary flow decreased gradually until a certain level, the so-called resting flow level, was reached and stabilized there as long as perfusion temperature remained unchanged. At 32 degrees C, resting flow was about 50% of the peak hyperaemic flow. The length of preceding anoxia had a significant effect on the duration of reactive hyperaemic response. After a short anoxic period, resting flow level was reached in about 3 min, after moderate period in 15 min and after long anoxia in 35 min, respectively.

Adolescent↗
PubMed1977

Intra-operative ascending aortic flowmetry.

Intra-operative flowmetry was carried out before and after cardiopulmonary bypass in 34 patients who underwent aortic root surgery. Most of the patients had either aortic or combined aortic and mitral valve replacement. Flowmetry performed before and after the procedure proved to be a very useful diagnostic tool, particularly in evaluating the immediate postoperative haemodynamic performance of the replaced aortic valve and the completeness of the correction.

Adolescent↗
PubMed1977

Myocardial protection by continuous coronary perfusion during aortic valve replacement.

The coronary perfusion system used at Oulu University Central Hospital is described and the importance of physiological coronary perfusion stressed. Our method of protecting the myocardium from ischemic injury during aortic valve replacement included the following: phasic constant-pressure coronary perfusion, maintenance of coronary perfusion pressure larger than or equal to 80 mmHg, maintenance of the heart in a beating, empty, oxygenated state, and the use of the largest possible coronary canula. Under these circumstances, autoregulation of the coronary vascular bed was maintained. When small coronary cannulae were used a significant pressure drop occured across the tubing system, especially at high flow rates. Flow measurements recorded by an on-line electromagnetic flowmeter proved reliable.

Adolescent↗
PubMed1977

Renal blood flow and intrarenal oxygen tension in haemorrhagic hypotension.

The changes occurring in renal cortical and medullary tissue oxygen tensions and in renal total blood flow (RBF) were studied during haemorrhagic hypotension in six dogs. The flow was measured with an electromagnetic flowmeter, and tissue oxygen tension with IBC (Ineternational Biophysics Corporation, USA) oxygen electrodes. Haemorrhagic hypotension led to a considerable decrease in cortical tissue oxygen tension. The decrease in the medullary tissue oxygen tension was smaller, while the renal total flow decreased considerably during haemorrhage. The role of perfusion pressure alone in the redistribution of renal blood flow during haemorrhagic hypotension is discussed.

Animals↗
PubMed1977

Effects of open-heart surgery on carbohydrate and lipid metabolism.

The concentrations of blood glucose, serum insulin, free fatty acids, and triglycerides were examined preoperatively, during anesthesia, during extracorporeal circulation, and during the following 3 postoperative days in 29 patients. The patients were divided into three groups according to the duration of extracorporeal circulation and the use of hypothermia: short perfusion group (SPG, bypass time shorter than 60 minutes, 15 patients), long perfusion group in normothermia (LPGN, bypass time longer than 60 minutes, 8 patients), and long perfusion group in hypothermia (LPGH, temperature during bypass below 33 degrees C., 6 patients). In all three groups, the concentrations of free fatty acids and blood glucose rose significantly because of anesthesia (p less than 0.001). After cardiopulmonary bypass, the concentrations of free fatty acids diminished significantly. The blood glucose remained at high level until the second postoperative day and was significantly higher in the LPG than in the SPG (p less than 0.05). The serum insulin level remained low during anesthesia and extracorporeal circulation in the SPG and LPGH but rose during the postoperative period; the maximal values were recorded on the first postoperative day. There were no significant differences between the groups with regard to serum insulin during the study. These changes and their metabolic background are discussed.

Blood Glucose↗
PubMed1977

Intraoperative hemodynamic evaluation of the Björk-Shiley tilting disc aortic valve.

Intraoperative cardiac output and aortic and left ventricular pressures were measured simultaneously in 15 consecutive patients before and after aortic valve replacement (AVR) with the Björk-Shiley tilting disc valve. The predominant lesion in these patients was aortic stenosis. The following hemodynamic indices were calculated: aortic valve area (AVA), determined by Gorlin's formula, effective orifice area, and effective area index. Their applicability as hemodynamic criteria of the immediate hemodynamic performance of the replaced valve is discussed. By every criterion, AVR greatly improved the hemodynamic performance. The effective area index seemed more suitable than the other indices for the intraoperative hemodynamic evaluation of the replaced aortic valve.

Adult↗
PubMed1977

Intraoperative determination of the aortic valve area (Gorlin) by flowmetry.

The aortic area (Torlin) for diseased stenotic aortic valves was calculated in 10 patients using two different methods; data obtained in preoperative cardiac catheterization and by intraoperative flowmetric and aortic and left ventricular pressure-recording measurements, and their mutual correlation was tested. The correlation between the aortic valve areas obtained by these methods was very good (r = 0.992), confirming the valve and reliability of the intraoperative flowmetric and pressure recording measurements in clinical work.

Aortic Valve↗
PubMed1977

Plasma renin activity, renal artery blood flow and cortical tissue oxygen tensionin haemorrhagic hypotension.

The changes occurring in plasma renin activity (PRA), tissue oxygen tension of the renal cortex and the change in renal total blood flow were studied during haemorrhagic hypotension in six dogs. The flow was measured with an electromagnetic flowmeter, the plasma renin activity was determined by radioimmunoassay and tissue oxygen tension with IBC oxygen electrodes. Haemorrhagic hypotension led to a significan increase in PRA. The fall in renal total blood flow and cortical tissue oxygen tension were significant after all three epizodes of bleeding (each of 10 ml/kg. Metabolic acidosis increased after every bleed. The correlation between PRA, renal blood flow and cortical tissue oxygen tension is evaluated in the discussion.

Acidosis, Renal Tubular↗
PubMed1977

Management of injuries of the large intestine.

Blunt trauma accounted for 1/3 of the 32 patients operated upon for injuries of the large intestine and penetrating wounds for 2/3. Most of the blunt injuries (9/10) were caused by traffic accidents, and more than half of the penetrating ones (12/22) were stab wounds. The transverse colon was most commonly affected, followed by the ascending, descending and sigmoid colon, rectum and mesentery. Perforation of the small intestine was the most frequent associated intra-abdominal injury, occurring in 11 patients (34%). Most patients (22/32) underwent simple suture, 6 patients suture with proximal colostomy, 3 primary resection and one exteriorization, combined in all cases with broad-spectrum antibiotic coverage and drainage of the abdominal cavity. Injuries to the right and transverse colon were managed mainly with simple suture, and those to the left colon and rectum with suture and proximal colostomy. 50% of the patients had complications, most frequently wound infection and intra-abdominal abscess. The patients with simple suture had fewer complications than the others. In the absence of complicating factors injuries to the colon are best managed with simple suture, whereas in the presence of complicating factors and in injuries of the rectum, suture or resection with proximal colostomy, especially in cases of severe tissue destruction, remains the treatment of choice.

Accidents↗
PubMed1976

Spigelian hernia.

Six consecutive patients with Spigelian hernia treated operatively over a period of ten years are reported. There were no complications, no deaths, and no recurrence in this series. Recognition of this rather rare lesion may be difficult, but it is important because of its quite high predisposition to incarceration and strangulation. The main pathological and clinical features are discussed, and the literature briefly reviewed.

Adult↗
PubMed1976

The effect of furosemide on renal blood flow and renal tissue oxygen tension in dogs.

The effect of furosemide (2 mg/kg i.v.) on blood flowin the renal artery and the tissue oxygen tension of the renal cortex and medulla was investigated in six dogs. The flow was measured with an electromagnetic flowmeter and the tissue oxygen tension with IBC tissue oxygen electrodes. The flow in the renal artery increased significantly (p less than 0.05) 5-15 minutes after furosemide administration. 40 minutes after the injection the flow had returned to its initial level. The tissue oxygen tension of both the cortex and the medulla showed significant elevation following furosemide administration. The maximum increase of tissue oxygen tension was recorded 10-20 minutes after the injection. The oxygen tension values exceeded the initial level by 22% in the cortex and by 48% (p less than 0.001) in the medulla. Simultaneously, with the changes in oxygen tension, urine output increase considerably and urine osmolality declined. Application of these renal effects of furosemide in clinical work, particularly in cardiopulmonary bypass surgery, is discussed.

Animals↗
PubMed1975

Recurrent wound sinuses after cholecystectomy for salmonella paratyphi.

Several cases in which Salmonella, spread by the haematogenous route, produced localised inflammation have previously been described in the literature. The infecting of an operation wound through direct contamination by Salmonella has earlier been reported only once, in connection with appendectomy. The present case report describes a case in which recurrent sinuses infected by Salmonella were formed in the operative wound.

Bile↗
PubMedDate not supplied

The effect of furosemide on renal function in open heart surgery.

The effect of furosemide on renal function in patients undergoing open heart surgery was investigated, using creatinine clearance, urine flow, sodium and potassium excretion as the parameters. The effect of furosemide (2 mg/kg i.v.) on blood flow in arteria renalis and the tissue oxygen tension of the renal cortex and medulla were also investigated experimentally in six dogs. The flow was measured with an electromagnetic flowmeter and the tissue oxygen tension with IBC tissue oxygen electrodes. Prolongation of the perfusion time to more than 60 minutes resulted in a decline of creatinine clearance to appr. 50% of the initial level. Prophylactic furosemide given prior to the perfusion brought down the creatinine clearance to 64% of the initial level. Furosemide, administered either prophylactically just before the cardiopulmonary bypass or after urine flow had declined below 0.5 ml/kg/h, had no effect on the potassium balance in the long perfusion group (over 60 minutes), though it clearly increased the negative potassium balance in the short perfusion group (below 60 minutes). In an experimental work on dogs, furosemide was found to elevate the tissue oxygen tension in the renal cortex and and medulla, and slightly to increase the blood flow in arteria renalis.

Acute Kidney Injury↗