Local blood flow, monitoring

Apart from echocardiography, another promising clinical application of synthetic microbubbles is the ultrasonic monitoring of local blood flow in the abdomen (analogous to the earlier use of gas microbubbles to monitor myocardial perfusion (ref. 443)). Such refined ultrasonic blood flow measurements, utilizing injected... 

Cerebral blood flow (CBF) was monitored in the cerebral cortex of the ischemic hemisphere corresponding to the supply territory of the middle cerebral artery by laser-doppler flowmetry (DRT4, Moor Instruments, Devon, UK). To this aim, a rectangular bent laser-doppler probe was glued onto the parietal bone (2 mm posterior and 5 mm lateral from bregma) and local CBF was continuously measured from 20 min before the onset of ischemia until 10 min after reperfusion, keeping the animal under isoflurane anaesthesia. Flow values were collected every 5 min before MCAo and after reperfusion whereas data were collected at 10 min intervals during occlusion. 

LIDOCAINE BETA-BLOCKERS 1. Risk of bradycardia (occasionally severe), l BP and heart failure with intravenous lidocaine 2. Risk of lidocaine toxicity due to T plasma concentrations of lidocaine, particularly with propranolol and nadolol 3. t plasma concentrations of propranolol and possibly some other beta-blockers 1. Additive negative inotropic and chronotropic effects 2. Uncertain, but possibly a combination of beta-blocker-induced 1 hepatic blood flow (due to 1 cardiac output) and inhibition of metabolism of lidocaine 3. Attributed to inhibition of metabolism by lidocaine 1. Monitor PR, BP and ECG closely watch for development of heart failure when intravenous lidocaine is administered to patients on beta-blockers 2. Watch for lidocaine toxicity 3. Be aware. Regional anaesthetics should be used cautiously in patients with bradycardia. Beta-blockers could cause dangerous hypertension due to stimulation of alpha-receptors if adrenaline is used with local anaesthetic... 

Generally, priapism reverses spontaneously, while penile blood flow and other signs being monitored, but in urgent cases, local phenylephrine injections or even surgery may be indicated... 

Figure 17 shows the use of DOCT to monitor PDT-induced changes in (microvascular tumor blood flow), illustrating the ability to detect and quantify the tissue-dependent effects of different photosensitizers with different tissue localization and, hence, mechanisms of action. Technical developments have enabled this imaging method to be implemented endoscopically and, recently, also interstitially. 

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