However, these conditions are rarely encountered early after adult cardiac surgery. Another argument against the usefulness of SvO 2 measurements is that considerable regional differences in venous oxygen saturation may exist, and hence SvO 2 may not detect hypoperfusion of vital organs such as the splanchnic system.
To reduce this risk SvO 2 is assessed together with other clinical and laboratory data. If SvO 2 and diuresis are acceptable and there is no significant acidosis, we have found that the risk of clinically important hypoperfusion of the splanchnic system or kidneys is small.
In the present series, where low cardiac outputs were accepted and inotropes were rarely used, there was no case of renal failure requiring dialysis and no case of intestinal ischemia requiring surgery. The widespread use of fiberoptic catheters for continuous monitoring of SvO 2 seems to have been restrained by doubt regarding the cost-effectiveness of these catheters [1 , 2]. The insertion of the catheter only takes a few minutes and as it is done during rewarming of the patient it does not prolong the operation.
Due to the prognostic value of SvO 2 measurements and its specificity with respect to cardiorespiratory problems, Swan Ganz catheters can be reserved for high risk patients.
Consequently, intermittent SvO 2 measurements by this method can contribute to cost containment in perioperative care. The overall results from the present study with a mortality of 0. Furthermore, as there is data suggesting that routine use of Swan Ganz catheters lead to increased use of vasoactive infusions and prolonged ICU stay [3 , 4] , a change towards simplified strategies for postoperative monitoring may be desirable also with respect to clinical outcome.
Prospective randomized studies comparing simplified routine monitoring such as surgical PA catheters or central venous catheters with routine use of Swan Ganz catheters are warranted. The authors are grateful to Ingemar Vanhanen and Inger Huljebrant for assistance with collection of data.
Google Scholar. Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide.
Sign In or Create an Account. Sign In. Advanced Search. Search Menu. Article Navigation. Close mobile search navigation Article Navigation. Volume Article Contents Abstract. Oxford Academic. Revision received:. Select Format Select format. Permissions Icon Permissions. Abstract Objective : It has been argued that the poor correlation between cardiac output and mixed venous oxygen saturation SvO 2 reduces the value of SvO 2.
Mixed venous oxygen saturation , Cardiac output , Postoperative care , Cardiac surgery , Coronary surgery , Monitoring , Prognosis , Risk stratification. Open in new tab Download slide. Con: perioperative continuous monitoring of mixed venous oxygen saturation should not be routine in high-risk cardiac surgery. Google Scholar Crossref. Search ADS. Pro: perioperative continuous monitoring of mixed venous oxygen saturation should be routine during high-risk cardiac surgery.
Effect of pulmonary artery catheterization on outcome in patients undergoing coronary artery surgery. Glutamate and high-dose glucose-insulin-potassium GIK in the treatment of severe cardiac failure after cardiac operations. Dopamine and high-dose insulin infusion glucose-insulin-potassium after a cardiac operation. Metabolic and hemodynamic effects of intravenous glutamate infusion early after coronary operations.
Clinical significance of perioperative Q-wave myocardial infarction: the Emory Angioplasty versus Surgery Trial. Are electrocardiographic Q-wave criteria reliable for diagnosis of perioperative myocardial infarction after coronary surgery?
Acute renal failure after coronary surgery — a study of incidence and risk factors in consecutive patients. Dissociation of mixed venous oxygen saturation and cardiac index during opioid induction.
Continuous monitoring of mixed venous oxygen saturation for detecting alterations in cardiac output after discontinuation of cardiopulmonary bypass. Mixed venous oxygen saturation as a predictor of cardiac output in the postoperative cardiac surgical patient.
The value of mixed venous oxygen saturation as a therapeutic indicator in the treatment of advanced congestive heart failure.
For some individuals, a cardiac output that falls below the normal range may be adequte, whereas for others, a normal or elevated cardiac output value may be too low. An SvO2 in the normal range, along with a normal lactate, suggests that the cardiac output is adequate.
SVO2 can be very helpful when attempting to determine whether a change in therapy is beneficial. Measuring SvO2 before and after a change can assist in determining whether the therapy made the patient better or worse. SvO2 can also be useful when evaluating changes to ventilator therapy, especially in unstable patients. Changes may be made to the ventilator to increase the oxygen content of the blood, which is important to the total oxygen delivery cardiac ouptut X oxygen content.
Tissue oxygen need is met when the amount of oxygen being delivered to the tissues is sufficient to meet the amount of oxygen being consumed VO2. When the oxygen delivery falls below oxygen consumption needs, lactic acidosis develops. Critical Care Trauma Centre. SvO2 mixed venous oxygen saturation or ScvO2 central venous oxygen saturation What is it? What does it tell us? What are the normal values? How do I use this information clinically?
If the amount of oxygen being received by the tissues falls below the amount of oxygen required because of an increased need, or decreased supply , the body attempts to compensate as follows: First Compensation: Cardiac Output increases The cardiac output is increased in an effort to increase the amount of oxygen being delivered to the tissues as shown below.
If this is not sufficient to meet tissue energy needs; Third - Anaerobic Metabolism Increases. If the tissues fail to receive an adequate supply of oxygen, anaerobic metabolism becomes the only mechanism to produce tissue ATP. Anaerobic metabolism is inefficient, producing a large amount of metabolic waste e.
It also produces a relatively poor supply of ATP. Prolonged anaerobic metabolism leads to energy depletion and metabolic acidosis. Why Measure SvO 2? If SvO 2 decreases, it indicates that the tissues are extracting a higher percentage of oxygen from the blood than normal. In otherwords, a decreased SvO 2 indicates that the cardiac output is not high enough to meet tissue oxygen needs. Thus, SvO 2 can indicate whether an individual's cardiac output is high enough to meet their needs.
A rise in SvO 2 demonstrates a decrease in oxygen extraction, and usually indiates that the cardiac output is meeting the tissue oxygen need. A return of the SvO 2 to normal, in the presence of a normal or improving lactate, suggests patient improvement. However, a rise in SvO 2 in the presence of a rising lactate is inappropriate - the patient who has resorted to anaerobic metaolism third compensation should have evidence of a high cardiac output and increased extraction.
This is an ominous finding, suggesting that the tissues are unable to extract. Critical Care Compendium. Chris Nickson. His one great achievement is being the father of two amazing children.
Leave a Reply Cancel reply. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. In case of sale of your personal information, you may opt out by using the link Do not sell my personal information.
Cookies Policy. Close Privacy Overview This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website.
We also use third-party cookies that help us analyze and understand how you use this website.
0コメント