1. CVP measurement- III

2. Femoral vein cannulation
ANATOMY
Femoral vein is a direct continuation of the popliteal vein. ↓
Ascends through the thigh, lying at first on the lateral side of femoral artery, then posterior & then medial to it.
Leaves the thigh, passes behind the inguinal ligament to become the External iliac vein.
Join its counterpart from the other leg → forms the IVC (anterior & to the rt of L5 vertebrae).

3. ANATOMY OF FEMORAL VEIN IN FEMORAL TRIANGLE
TECHNIQUE OF FEMORAL VEIN CANNULATION

4. complications Deep vein thrombosis & thrombophlebitis.
Pulmonary embolism.
Sepsis.
Femoral artery puncture .

5. Advantages disadvantages
Relatively simple.
High success rate %.
Remote from the airway & pleura.
Directly compressible.
Extremely high late complication rate.
Unsuitable for long term cannulation.

6. Peripherally inserted central catheters
Alternative to centrally inserted catheters.
Venous access obtained through an antecubital vein- basillic or cephalic vein.
ANATOMY
Basilic vein- ulnar aspect of dorsal venous network of hand. ↓
Joins brachial vein to form axillary vein.
Continues as Subclavian vein.

7. BASILIC VEIN CANNULATION

8. approach Patient’s arm at his/her side.
Antecubital fossa- prepared & draped. ↓
Tourniquet placed proximally.
Venepuncture- proximal to antecubital crease.
Free back flow of venous blood
Tourniquet released & guidewire threaded
(15-20 cms).

9. ↓
Needle withdrawn & guidewire left in place.
Thread sheath-introducer assembly over guidewire.
Remove the guidewire.
Secure the catheter.
Rt basilic vein -52 cms.
Lt basilic vein – 56 cms.

10. complications
Thrombophlebitis.
Limb edema.
Hematoma at the puncture site.
Infection.

11. Advantages disadvantages
Not suitable for long term placement.
Thrombophlebitis.
Passageinto SVC difficult.
Simplicity.
Low complication rate
Safe placement by non-physicians.

12. complications 1. Vascular injury Arterial Venous Hemothorax
Cardiac tamponade
2. Respiratory compromise
Airway compression from hematoma.
Tracheal, laryngeal injury
Pneumothorax
3. Nerve injury
4. Arrhythmias
5. Thromboembolic
Venous thrombosis
Pulmonary embolism
Arterial thrombosis & embolism (air, clot)
Catheter or guidewire embolism

13. Complications contd…. 6. Infectious Insertion site infection
Catheter infection
Bloodstream infection
Endocarditis

14. Complication
Comment
1. Infection rate
Femoral – proximity to groin
and genital region
Subclavian – away from mouth,
tracheostomy
Infection at site of insertion –
absolute C/I
2. Thrombosis & embolisation
Femoral vein> subclavian vein>
IJV.
IJV cannulation - Carotid artery
puncture → artherosclerotic
embolus to brain.( deadliest
complication )
3. Vein stenosis
Catheter infection, mechanical stress

15. Complication Comment 4. Bleeding
Arterial puncture- femoral vein> IJV> subclavian
Subclavian arterial puncture - hemothorax.
IJV cannulation- airway obstruction.
5. Pneumothorax
subclavian vein > IJV.

16. Cvp waveform
CVP waveform consists of-
Five phasic events
Three peaks ( a, c, v )
Two decents ( x, y )

17. NORMAL CVP WAVEFORM Waveform component Phase of cardiac cycle
Mechanical event
a wave
End diastole
Atrial contraction
c wave
Early systole
Isovolumetric contraction, tricuspid motion towards rt. atrium
v wave
Late systole
Systolic filling of the atrium
h wave
Mid to late diastole
Diastolic plateau
x decent
Mid systole
Atrial relaxation, descent of the base, systolic collapse
y decent
Early diastole
Early ventricular filling, diastolic collapse

18. Abnormal cvp waveforms
Condition
characteristics
Atrial fibrillation
Loss of a wave
Prominent c wave
Atrioventricular dissociation
Cannon a wave
Tricuspid regurgitation
Tall systolic c-v wave
Loss of x decent
Tricuspid stenosis
Tall a wave
Attenuation of y decent
Right ventricular ischemia
Tall a & v waves
Steep x & y decent
Pericardial constriction
Cardiac tamponade
Dominant x decent
Attenuated y decent

19. Atrial fibrillation-
Absence of a wave, prominent c wave, preserved v wave & y decent.
Isorhythmic A-V dissociation-
Early systolic cannon wave.
Ventricular pacing-
Systolic cannon waves
( left panel).

20. Tricuspid regurgitation-
Tall systolic c-v wave.
Loss of x decent.
Tricuspid stenosis-
Tall a wave.
Attenuation of y decent.

21. Clinical interpretation of cvp
CVP reading
Other features that may be present
Diagnosis to consider
Treatment
Low
Rapid pulse Blood pressure normal or low Low urine output Poor capillary refill
Hypovolaemia
Give fluid challenges* until CVP rises and does not fall back again. If CVP rises and stays up but urine output or blood pressure does not improve consider inotropes
Low or normal or high
Rapid pulse Signs of infection Pyrexia Vasodilation/constriction
Sepsis
Ensure adequate circulating volume (as above) and consider inotropes or vasoconstrictors
Normal
Rapid pulse Low urine output Poor capillary refill
Treat as above. Venoconstriction may cause CVP to be normal. Give fluid challenges* and observe effect as above.

22. Clinical interpretation of cvp
CVP reading
Other features that may be present
Diagnosis to consider
Treatment
High
Unilateral breath sounds Assymetrical chest movement Resonant chest with tracheal deviation Rapid pulse
Tension pneumothorax
Thoracocentesis then intercostal drain
Breathlessness Third heart sound Pink frothy sputum Oedema Tender liver
Heart failure
Oxygen, diuretics, sit up, consider inotropes
Very High
Rapid pulse Muffled heart sounds
Pericardial tamponade
Pericardiocentesis and drainage

23. Unreliable cvp readings
Problem
Effect on CVP
Pulmonary embolus High intrathoracic pressure
High pulmonary vascular resistance - left sided pressure and function may be normal. A higher than normal CVP may be needed to ensure adequate return of blood to the left side of the heart.
Left heart failure
Resulting rise in pulmonary venous pressure and right sided heart strain. Initially CVP may be normal but will increase with significant failure.
Constrictive pericardial disease
Paradoxical rise in CVP on inspiration and fall on expiration (opposite of normal in a spontaneously breathing patient). The absolute level will be higher due to impeded filling of the heart

24. Unreliable cvp readings
Problem
Effect on CVP
Blocked cotton wool at top of manometer
Fluid will not move in the tube to give a correct reading
Complete heart block
'Cannon waves' on CVP reading the reading will have a strong pulsatile element when the atrium contracts against a closed tricuspid valve sending the pressure wave back into the SVC
Tricuspid stenosis/regurgitation
Mean CVP will be higher 

25. summary
CVP is the pressure measured at the junction of right atrium & SVC.
Most sophisticated method of CVP measurement is caliberated transducer.
Most preferred route is IJV or subclavian vein.
The possibility of pneumothorax remains upto 24 hrs, so patient should be watched for it.
Strict aseptic precautions should be taken care of.
CVP catheters are used for fluid administeration , especially in ICU’s.
Femoral route , if possible should be avoided.

26. references
Miller’s Anesthesia. 7th edition. Cardiovascular monitoring.
Monitoring in Anaesthesia and Critical Care Medicine. 5th edition.
Mcleod’s Clinical Examination. 11th edition.
Central Venous Catheters.2nd edition.
Update in Anaesthesia. Central Venous Access and Monitoring. Dr. Graham Hocking, Issue 12 (2000) Article 13.
Procedures, Techniques, And Minimally Invasive Monitoring in Intensive Care Medicine. 4th edition.

27. PULMONARY ARTERY CATHETER
Swanz ganz catheter.
Provides measurements of hemodynamic variables.
PAC can be placed from any central venous cannulation routes , but right IJV route is the preferred route.
PAC catheter- 7-9 fr. Circumference, 110 cm in length, marked at 10 cm interval, 4 internal lumens.

28. THANK YOU