1. Precath Preparation
Dr Fuad Farooq

2. Preparation of the Patient
• Elective cardiac cath should be deferred if
the patient is not prepared physiologically
and physically

3. Consent
• Detailed discussion with the patient and family
• Should be obtained by the operator or his or her
assistant
– Should outline the indication of procedure
– Explain in simple terms which procedure to take place and for
what reason each step of the procedure will occur
– Explain the risk for routine cardiac cath
• Major- stroke, myocardial infarction, kidney failure, death
• Minor- vascular injury, allergic reaction, bleeding, hematoma,
infection
• Possible need of emergency CABG
– Explain any portion of the study used for research
– Provide necessary information and explanation

4. History
• Including
– Reason of cardiac cath
– Precious allergies to dye, sea food
– Asthma, allergic rhinitis
– Medications esp. ASA, Clop, Metformin,
anticoagulants
– History of kidney disease
– In female, if child bearing age, ask especially
for pregnancy

5. Examination
• Thorough general physical examination
should be done
• All peripheral pulses should be palpated
and documented
• Look for arterial bruit and document it as a
baseline for future reference
• Perform Allen’s test if radial approach
• Auscultate chest
• Look for murmurs

6. Metabolic Profile
• Renal function e.g. BUN, creatinin
• Electrolytes e.g., Na, K
• CBC
• Coagulation profile
• Any abnormality in the lab should be
addressed before proceeding to LHC

7. • Precath orders preferably written on
preceding night
– If patient on long acting insulin dose should
be reduced to half
– NPO at least 8 hours before procedure
– Shave both groins for femoral access and
mostly right wrist for radial approach
• Avoid laceration or abrasions
– Apply Foley’s catheter or external/sheath
catheter in male

8. Choice of Dye
• Now a days mostly nonionic low osmolal dye is
used
– Causes less nausea and emesis, LV dysfunction,
bradycardia and hypotension
– Useful in cases of suspected LM stenosis, severe LV
dysfunction, and severe aortic stenosis
– In patients with renal insufficiency and reported
allergy to contrast dye
– More thrombogenic than ionic dye so used with
caution- use 5 IU of heparin per cubic centimeter of
contrast

9. Contrast Media Reaction
• Incidence 5%
• 10-12% patients has history of asthma
• 15% patients has the history of previous reaction
to the contrast media
• Three types
– Cutaneous and mucosal manifestations (angioedema,
flushing, laryngeal edema, pruritis, urticaria)
– Smooth muscle and minor anaphylatoid reaction
(bronchospasm, GI spasm, uterine contraction)
– Cardiovascular and major anaphylactoid reaction
(arrhythmia, hypotension, vasodilatation)

10. • More risk with the ionic contrast media than non-ionic
contrast media
• Any patient reported previous allergy to the contrast
media or history of atopy or prior anaphylactoid reaction
should be premedicated with
– Steroid ( prednisolone 40mg PO Q6H or I.V hydrocortisone
100mg once at least 6 hours before the procedure
– Diphenhydramine ( Benadryl 50mg I.V once )
– H2 blocker ( Clemestine 1mg I.V once)
• If history of life threatening dye allergy, it is prudent to
admister 1ml of dye and watch for few minutes before
proceeding
Contrast Media Reaction..

11. Contrast Induced Acute Kidney
Injury
• High risk patients are
– Patients with diabetes
– Patients with renal insufficiency (Cr >1.5)
– Patients who are dehydrated due to any reason
• Prevented by
– I/V hydration with 0.9% saline ( LV function should be taken into
consideration for selection of rate of infusion)
• Dose: 1ml/kg at least 2 hours before procedure and ideally Upto 6-
12 hours before procedure and continue Upto 6-12 hours post
procedure
– Alkalinization of urine prevent free radical injury to the kidney
• Dose: 3 ml/kg for one hour before procedure and continued as
1ml/kg/hr for 6 hours post procedure

12. Contrast Induced Acute Kidney
Injury
– Acetylcysteine- has antioxidant and vasodilator
properties
• Must be accompanied by I/V hydration and use of low or iso-
osmolal contrast agent
• Risk reduction Upto 50%
• Dose: 1.2 gm P.O twice a day starting day before the
procedure and continue for two days post procedure (I/V
admistration if in emergent procedure and orally cannot be
given-150mg/kg prior procedure and 50mg/kg post
procedure over 4 hours)
– Using low osmolal or iso-osmolal nonionic contrast
media (use in lower dose)
– Avoid closely spaced studies (<48 hours apart)
– Avoid NSAID’s

13. Diabetes Mellitus
• Patient with diabetes on insulin therapy, overnight fast
with normal dose of insulin can cause hypoglycemia
– Dose if insulin should be half
– Patient on NPH insulin has increase risk of protamine reaction
• Patient on Metformin, withheld it 48 hours before
procedure because of risk of lactic acidosis especially in
patients with renal insufficiency
– may resume after 48 hours only when renal function are found to
be normal
– Hydrate the patient before during and after the procedure ( i.v
saline @ 1ml/kg/hr)

14. Patient Education
• Patient should be warned that they might
feel hot sensation for few seconds when
contrast is injected, some patients may
feel nausea
• Patient should specially instructed to
cough when they hear anyone in the cath
lab say “cough” – this will accelerates
resolution of dye induced bradycardia

15. Equipment
• Before performing cath it is very essential
that the monitoring equipment is fully
functional
• Continues ECG recording, heart rate,
rhythm, ST segment an automated BP
and pulse oximetry are essential
• Resuscitation equipment should be tested
and ready – defib and intubation trolley
should be next to the patient