ARTERIAL PRESSURE MONITORING ANISH

ARTERIAL PRESSURE MONITORINGDr ANISH JOSHI : 

1 ARTERIAL PRESSURE MONITORINGDr ANISH JOSHI

Slide 2: 

2 Physiology of Arterial Pressure Monitoring

SBP & DBP different with different methods.Flow Vs Pressure : 

3 SBP & DBP different with different methods.Flow Vs Pressure SBP depends on SV Velocity of LV ejection LVEDV SVR Distensibility of large vessels Blood viscosity DBP depends on: Length of cardiac cycle. SVR Blood viscosity, Arterial distensibility

Slide 4: 

4 MAP = CO × SVR MAP mean perfusion pressure throughout the cardiac cycle Forms the basis of Autoregulation MAP = DBP + (SBP - DBP)/3 or MAP = [SBP + (DBP x 2)]/3. Same with any method!

Factors Affecting MAP : 

5 Factors Affecting MAP

NIBP METHODS : 

6 NIBP METHODS PALPATION Auscultation Doppler Probe OSCILLOMETRY Arterial Tonometry

Length & width : 

7 Length & width

Cuff size ? : 

8 Cuff size ?

Importance of cuff position : 

9 Importance of cuff position

Oscillometry : 

10 Oscillometry Unreliable during arrhythmias Cannot be used in bypass

Doppler : 

11 Doppler

Tonometry : 

12 Tonometry

NIBP : 

13 NIBP

Slide 14: 

14

INVASVE ARTERIAL BP MONITORING : 

15 INVASVE ARTERIAL BP MONITORING

INDICATIONS : 

16 INDICATIONS Failure of indirect arterial blood pressure measurement Continous monitoring: Hypotension Major surgeries including bypass Critically ill patients IABP Frequent sampling. Inotrope administration. Supplementary diagnostic information from the arterial waveform   Determination of volume responsiveness from systolic pressure or pulse pressure variation

RELATIVE CONTRAINDICATIONS : 

17 RELATIVE CONTRAINDICATIONS Coagulopathy/haemorraghic disorders Patients on anticoagulants/thrombolytics Positive ALLENS test. Local infection. Severe atherosclerosis. Peripheral vascular disease

ADVANTAGES : 

18 ADVANTAGES Continuous & accurate measurement Response to therapy evident immediately. Subtle change in pressure is evident early.

DISADVANTAGES : 

19 DISADVANTAGES Expensive equipment & disposables. Trained personnel needed. Cx.

PRINCIPLE : 

20 PRINCIPLE

LOCATION : 

21 LOCATION Radial. Ulnar Femoral. Dorsalis pedis. Brachial Axillary

CATHETERS : 

22 CATHETERS 20/22 G Arteriofix. 29/20 G Insyte. 5 Fr/ 6Fr Introducer sheath. Single lumen CVC catheter IABP catheter.

Slide 23: 

23

Slide 24: 

24

Components of arterial waveform : 

25 Components of arterial waveform Anacrotic notch. Dicrotic notch. Peak systolic pressure. Diastolic pressure. Pulse pressure.

As we go towards the periphery… : 

26 As we go towards the periphery… Delay in pressure pulse wave occurs, UL & LL BP don’t correlate More smooth curve Systolic portion becomes more peaked, narrower & of greater amplitude so LL> UL SBP

Wave Reflection : 

27 Wave Reflection

Systolic peak : 

28 Systolic peak ↑ ↑ LV pressure generation ↑ reflection of pressure waves Overshoot artifact (Commonest) ↓ Myocardial depression Hypovolemia Vasodilatation, ↓ reflected waves

Mean pressure : 

29 Mean pressure True driving pressure for peripheral blood flow Does not change as we go towards the periphery Calculated by Estimated by AUC Duration of cardiac cycle 5. Electronic preferred over calculated

COMPLICATIONS : 

30 COMPLICATIONS Pain. Blood loss. Haematoma. Ecchymosis. Sepsis. arteriovenous fistula Arterial occlusion. Peripheral embolization Dissection. Pseudoaneurysm. Peripheral neuropathy

RADIAL : 

31 RADIAL ADVANTAGES. Superficial location.Easy to identify and canulate. Collateral circulation. CC can be assessed. Assesible during major surgeries. Patient can be mobilized. DISADVANTAGES. Small size artery. Higher rate of catheter malfunction. Not reliable in vasoconstriction. Considerable augmentation of SBP. Overshoot artifact.

Slide 32: 

32

FEMORAL : 

33 FEMORAL ADVANTAGES. Large vessel. Accurate central pressure. Easy to cannulate. Easy to compress. Large gauge catheter with high frequency response minimizes overshoot artifact. DISADVANTAGES. Restricted mobility. Difficult to cannulate or compress in obese patients. Thrombosis and embolisation. Massive retroperitoneal haematoma.

DORSALIS PEDIS : 

34 DORSALIS PEDIS ADVANTAGES. When UL unavailable Dual circulation DISADVANTAGES Augmented SBP Thrombus formation Small gauge catheter required.

Slide 35: 

35 Changes in systolic,diastolic and mean arterial pressures with age.

Slide 36: 

36

Underdamped & overdamped : 

37 Underdamped & overdamped

Fast flush / Square wave test : 

38 Fast flush / Square wave test Underdamped system The resonant frequency is the inherent frequency of oscillations produced in the system when it is disturbed. Signal distortion is minimal when the resonant frequency of the recording system is five times greater than the major frequency in the arterial pressure waveform. When the frequency of an incoming signal approaches the resonant frequency of the system, the resident oscillations add to the incoming signal and amplify it. Long tubing, stopcocks, Increased vascular resistance

Slide 39: 

39 Overdamped system The damping factor is a measure of the tendency for the system to attenuate the incoming signal. High damping factor Air bubbles Overly compliant tubing Blood clots / Fibrin Catheter kinks Stopcocks / Injection ports No fluid in flush bag / Low flush bag pressure

Complications : 

40 Complications Hematoma/blood loss (Diagnostic also) Thrombosis/Embolisation: Fibrin/Particulate/Air Distal ischemia Retrograde emboli to brain Vascular insufficiency: Large catheter small vessel Radial>Femoral Peripheral vascular disease DM Extended duration Ischaemic necrosis of overlying skin Arterial injury Infection Accidental intraarterial injection of drugs Pseudoaneurysm HIT Bowel perforation AVF

Care : 

41 Care Aseptic precautions Daily inspection & dressing Pressure bag Transducer to be changed every 72 hours Arterial line to be changed/removed after 1 week Joint near the cannulation site: neutral position Prompt removal if signs of ischaemia

Waveforms : 

42 Waveforms

Respiratory variation : 

43 Respiratory variation Inspiration Expiration

Pulse pressure variation : 

44 Pulse pressure variation Normal: 13% Automatically calculated by newer monitors by algorithms but are not available in all

IABP : 

45 IABP

a) AF/Systolic LVF/Pericardial diseaseb) Cardiac tamponade : 

46 a) AF/Systolic LVF/Pericardial diseaseb) Cardiac tamponade Pulsus alternans Pulsus paradoxus Varying amplitude with variable MAP & SV

Slide 47: 

47 Normal AR AS Hypetrophic cardiomyopathy Pulsus parvus & tardus Bisferiens & wide PP Spike & dome pattern

Not everything that counts can be counted. And not everything thatcan be counted counts. Albert Einstein : 

48 Thankyou Not everything that counts can be counted. And not everything thatcan be counted counts. Albert Einstein