PERIOPERATIVE MANAGEMENT

OF

ANAPHYLACTIC REACTIONS

PROF. MRIDUL M. PANDITRAO

CONSULTANTDEPARTMENT OF ANESTHESIOLOGY AND

CRITICAL CARERAND MEMORIAL HOSPITAL

FREEPORTGRAND BAHAMA

THE COMMONWEALTH OF BAHAMAS

1. Importance of Diagnosis.2. Goals of Diagnosis 3. Risk factors in patients.4. Suppression of Mediators

Release.5. Tests to be done at the time of

reaction.6. Tests to be done 4-6 weeks

after reaction.7. Documentation & Medico legal

Implications.8. Pre anesthetic testing.

IMPORTANCE OF DIAGNOSIS

1. Epidemiological.

2. Medico legal.

3. To prevent reactions in subsequent anesthetics.

GOALS OF DIAGNOSTIC TESTING

1.Cause of reaction.

2. To pinpoint a specific drug.

3. Which other drug could produce similar reaction.

RISK FACTORS IN PATIENTS

1. Rare in neonates and Geriatrics

2. Rare in Shock states

3.Behavioral changes in mast cells

4. Low levels of Renin Angiotensin systems

5. Relation with h/o Atopy or Allergy

RISK FACTORS IN PATIENTS (CONTD)

6. Female : Male – 4:1 ↑ IgA, IgM, IgG → Polio virus & bovine albumine

Female Sex hormones- Prolactin ↑ses Cell mediated responses

Androgenic hormones- Immunosuppressive

7. Previous exposure- not important

8. β blocked patients – Difficult to treat Needs ↑ doses

SUPPRESSION OF MEDIATOR RELEASE

1. Adenyl cyclase- ↑ cAMP synthesis →↓ mast cell degranulation. Prostaglandins, histamine ( small doses ) & β agonists ↑ adenyl cyclase. Epinephrine acts via β receptors.

2. Corticosteroids act → cytokines →↓ mast cell activity.

3. Phosphodiesterase inhibitors→ ↑cAMP by inhibiting its breakdown.

4. Disodium cromoglycate inhibits Ca influx into cell & prevents initiation of response.

TESTS PERFORMED DURING REACTION

1.Plasma histamine: 0-1ng/ml. Half life is only 10 minutes. Level > 20ng/ml shows histamine involved reaction.

2. Urinary Methyl Histamine : 0-118mcg/24hours sample 10 in 10 patients →↑ plasma histamine. 4 in 10 patients →↑ urinary methyl histamine.

3. Immunoglobulin E levels-↑ indicates reaction. * Drug specific IgE.

4. Complement levels is serum : 55-110ng/ml.

5. Mast Cell Tryptase- 10ng/ml (2-23ng/ml). 25% of Mast Cell protein- degranulation – liberated. Half life- 90 min. 1 hrs, 6 hrs & 24 hrs- sensitive test.

TESTS DONE 4-6 WEEKS AFTER THE REACTION

Time allowed to normalize.

All drugs used should be tested.

Patient to be made aware.

SKIN TESTING

Main stay in our hands as labs are distant.

Skin of back and anterior face of forearm.

h\o anaphylaxis- positive for plasma H, Tryptase, Urinary Methyl H.

Operation Theatre Complex- Resuscitation measures , Drugs, IV fluids, Equipment.

Monitors – pulse, BP, resp, O2 saturation.

Sweating /discomfort.

CONTD.

0.4% phenol in saline- negative - < 2-4mm dia 9% codeine phosphate- positive- > 15mm dia Drug test positive- wheal > 7-8mm dia Each prick test – observed 15 minutes . Next drug- 30 mins after previous. 2 drugs on each forearm/ day. Injection site examined 12-24 hrs- late

reaction. Not useful for colloids & contrast media. Cross sensitivity should also be tested.

2 TYPES OF SKIN TESTING

Intra dermal injection-1 in 100 con of drug used - flare or wheal. If negative- Less dilutions may be tried in strongly suggestive case with caution.

Prick test- drop of undiluted drug placed on forearm- prick with sterile needle through drop.

Moderate to severe reactions-seen & treated. No death on skin testing reported as yet.

RADIO IMMUNO ASSAY

Reflects IgE bound to mast cells.

Antigen ( drug) + patient’s serum – incubated- antigen antibody complex formed.

Complex + radio labeled anti IgE – incubated bound radioactivity assessed.

SKIN TEST+ RIA- CONCLUSIONS

ST more specific than RIA- particular drug.

Drug specific RIA – not available for all drugs.

ST+RIA- preferable. Cross sensitivity – better with RIA. Thio and NMBD.

LEUCOCYTE & BASOPHIL- H - not specific.

MEDICO LEGAL IMPLICATIONS

CLEAR DUTIES1. Diagnose & treat.2. Investigations in immediate, postop 4-6

weeks as per availability.3. Skin testing – 4-6 weeks. All drugs and cross.4. Documentation: all events – intra - post –

late post op on case paper& main hospital records.

5. Communicate results to patients and relatives . Durable card / warning plate- all details.

SUBSEQUENT ANAESTHESIA

• After listening to these tests - All patients- skin test & RIA.

• No predictive value. Not practical.

PRE-ANAESTHETIC TESTING:• Done in patients with positive H/O reaction during

anaesthesia or any treatment.• Possible in elective- but not in emergency.• Testing schedule:

History, previous records – study & document. Skin testing planned – all precautions . All drugs to be

used, cross sensitivity. All testing negative – does not rule out possibility. All

precautions & resuscitative measures -ready.

PREFERENCES

• Premedication- fentanyl, pethidine over morphine.

• Induction- ketamine/ propofol /thiopentone.• Inhalational anaesthesia preferred over TIVA.• Regional anaesthesia- lesser no. of drugs, less

sensitivity to local anaesthetic.• Prefer Starches over Haemacoel. • Preventive measures – corticosteroids,

disodium cromoglycate, β agonists, epinephrine.

EMERGENCY CASES

No time for testing. If previous records available – avoid

those drugs other preferences as per the routine

cases. ketamine / propofol / thiopentone Mivacurium / pancuronium / vecuronium Inhalational better than TIVA. Regional anaesthesia better than

general anaesthesia.

Thank You

FUTURE DEVELOPMENTS

• Rare event so simulated anaphylaxis drill – practical

• Desensitization by exposure to increasing doses still inconclusive.

• More efficient H receptor blockers & other mediator blockers.

• Safer drug designing eliminating anaphylaxis component.

• Methods to measure trigeriness of mast cell.• Measurement of circulating IL-4,5, still distant

possibility.