New sensitive measuring technique can save lives following cardiac surgery
Staff in intensive care units have up until now used indirect methods to determine whether a bypass operation has been successful. A new sensitive technique known as microdialysis can quickly show whether the surgically inserted blood vessels are remaining open following cardiac surgery, as a thesis from Sahlgrenska Academy shows.
Approximately 50,000 bypass operations to improve blood flow to the patient´s heart are performed in Sweden annually. After a bypass operation, a patient can usually resume a normal life relatively quickly, but the first few hours after the operation are critical. All recovering patients are therefore monitored in the ICU until heart function has normalised. This includes taking regular blood samples for analysis of substances given off by the heart muscle.A doctoral thesis from Sahlgrenska Academy describes a new, advanced technique for obtaining better information about heart function. The technique is known as microdialysis and involves the insertion of a thin catheter in the heart muscle during the operation. The catheter is allowed to remain in the heart for 24 hours and is then removed through the patient´s skin.
Measurements can be made faster using the catheter because the microdialysate does not need to be sent to a laboratory but can be analysed within minutes at the patient´s bedside. Another advantage is that the substances can be measured directly at the heart muscle. The information obtained is thus more precise. Microdialysis can confirm that the surgically inserted blood vessels are open and functioning after cardiac surgery. The technique can also provide information about how the heart uses blood sugar as fuel during and after cardiac surgery.
Microdialysis has previously been used in other parts of the body and organs, but the technique has up until now not been able to be used clinically in heart muscle because of the heart´s movements.
Thesis for the degree of Doctor of Medicine at Sahlgrenska Academy, Institute of Medicine, Department of Acute and Cardiovascular Medicine.
Title: Myocardial metabolism and ischemia assessed by microdialysis: Clinical and experimental studies in cardiac surgery
