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Biomedical subjects

L Nuutinen

Publications and source records attributed to L Nuutinen.

At least 37 records · Page 2Linked to original sources
PubMed1986

Plasma vasopressin levels during and after cardiopulmonary bypass in man.

The effect of cardiopulmonary bypass (CPB) using high dose fentanyl anaesthesia on the concentrations of plasma arginine vasopressin (pAVP), serum electrolytes and osmolality was studied in 12 patients by repeated sampling up to 4th postoperative day. These values were also followed in another 20 patients for the first postoperative day. Fentanyl abolished the pAVP response often seen in major operations but not that produced by CBP. The pAVP concentration 4.8 +/- 0.8 pg/ml immediately after sternotomy increased to 27.2 +/- 1.5 pg/ml (P less than 0.001) after 5-10 minutes on CPB. By the 4th postoperative day the pAVP levels had reached normal values. The main reason for the elevated pAVP concentrations seems to be the onset of CPB, which provokes a fall in mean arterial pressure leading to pAVP release.

Adolescent↗
PubMed1984

Stewart-Hamilton and gamma variate methods in computer analysis of dye curves.

The conventional Stewart-Hamilton (SH) principle was compared to the gamma variate function fitting (G) method in on-line computer determination of cardiac output from dye dilution curves on anaesthetized animals (dogs, cats and reindeer), and on an artificial circulation model with known flows. In animal experiments, indicator was injected into the pulmonary artery (n = 674), the coefficient of linear correlation (Rlin) between G and SH was 0.982, and the regression line of G was 1.101 x SH-0.072 l/min. When the right atrium was the site of indicator injection (n = 88), Rlin was 0.982, and the regression line nearly agreed with the line of unity. In the artificial circulation model with the single circulation arrangement (n = 81), Rlin between SH and known flow (Q) was 0.959, and between G and Q it was 0.951; both methods over-estimated the flows, with the over-estimation being greater in the case of G. In the artificial model with recirculation effect (n = 31), Rlin between SH and Q was 0.953, and between G and Q 0.942, G again over-estimating the real flow essentially more than SH. Thus, in most cases the Stewart-Hamilton principle seems to be the more reliable way of analysis of dye dilution curves also in modern computer practice.

Anesthetics↗
PubMed1983

Haemodynamic comparison of dopamine and dobutamine in normovolaemic and hypovolaemic dogs.

The haemodynamic effects of dopamine and dobutamine in doses of 1-106 micrograms/kg/min were compared in dogs, first in the normovolaemic state and then after bleeding (10 ml/kg). In normovolaemia, dopamine caused a dose-dependent rise in systolic, mean and diastolic aortic pressures, while dobutamine caused a rise only in systolic pressure. In hypovolaemia, a rise in all three aortic pressures, was caused by both drugs, but to a lesser extent by dobutamine. Heart rate and cardiac output were similarly increased by both drugs, as was pulmonary artery pressure with high doses, in both states. Renal blood flow and diuresis increased in the middle-dose area. Both inotropic drugs caused an elevation in Paco2 and a drop in Pao2 and O2-saturation in both normovolaemia and hypovolaemia. The results agree with current opinion on the dose-dependent alpha-sympathomimetic action of dopamine and the relatively pure beta-action of dobutamine.

Animals↗
PubMed1979

Liver drug metabolism in patients undergoing open-heart surgery.

The effect of open-heart surgery on the drug metabolism of the liver was investigated in 17 patients by using the rate of antipyrine elimination as an index. A correlation was found between the pre-operative heart size and the antipyrine elimination rate. In patients with a markedly dilated heart, the plasma antipyrine half-life was prolonged and apparent clearance significantly impaired. Immediately postoperatively, antipyrine elimination was impaired in all patients. Later, the drug metabolism improved in patients with atrial septal defect, changed temporarily in patients with aortic valve replacement, and remained unchanged in patients with mitral valve replacement. The results indicate that adaptive changes in drug metabolizing capacity occur in patients undergoing cardiac surgery. The changes are related to the type of lesion corrected, the pre-operative functional capacity of the liver, and the time lapse after surgery.

Adolescent↗
PubMed1979

Are changes in serum immunoglobulin and complement levels following open heart surgery influenced by oxygenator type or postoperative parenteral nutrition?

The serum IgG and IgA concentrations significantly decreased through the seventh day and the serum IgM and complement (C3 and C4) concentrations through the second day after elective open heart surgery for heart valve disease in a series of 16 patients. A significant increase over the preoperative concentration was seen, however, in the serum IgA, IgM, C3 and C4 on day 14 postoperatively. The serum IgG and IgM concentrations declined significantly only in patients perfused by a bubble oxygenator, although the two small series of patients perfused by bubble and membrane oxygenator did not differ significantly from each other. Parenteral nutrition had no effect on postoperative changes in serum immunoglobulin and complement concentrations.

Adolescent↗
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

Catecholamines and free fatty acids in plasma of patients undergoing cardiac operations with hypothermia and bypass.

Plasma concentrations of adrenaline, noradrenaline, and free fatty acids were measured at different stages of cardiac operations in which hypothermia and bypass were used. The rise of adrenaline, noradrenaline, and free fatty acid concentrations in plasma is consistent with the concept that these are important compounds in stress situations such as hypothermia and surgical operations. There is a more marked release of adrenaline and it may be a more specific hormone in response to hypothermia and bypass than is noradrenaline in man.

Cardiac Surgical Procedures↗
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

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↗