HIV INFECTION AND ANAESTHESIA

DR. RAJESH CHOUDHURI PGT, DEPT OF

ANAESTHESIOLOGY AGMC & GBP HOSPITAL

INTRODUCTION• 1981- AIDS was first described in the United States.• 1984-The cause of AIDS was elucidated..a retrovirus,named

HIV type 1 & 2.• More than 50 million people worldwide are infected with HIV

and more than 26 million deaths worldwide.• Mechanism of disease transmission –hetero and homo sexual

intercourse, intravenous drug use, vertical transmission from pregnant mother to child and blood transfusion.

• HAART-Recent treatment modalities have been effective in halting HIV replication.

SIGNS AND SYMOTOMS• 2-3 weeks after inoculation –acute seroconversion illness.• Flue like illness….fever, fatigue, headache, night sweats,

pharyngitis, myalgia and arthralgias.• Generalized lymphadenopathy.• Weight loss and failure to thrive.• HIV positive individual is considered to have AIDS if one of the

AIDS –defining diagnoses is present.• 3 different stages

–Primary HIV infection–Asymptomatic HIV infection–AIDS

CLINICAL CONTINUUM• HIV infection is a disease that encompasses a continuum of clinical signs from

acute infection → clinical latency→ clinical progression → AIDS with associated opportunistic infections → death.

• (A) CARDIAC MANIFESTATIONS: • 50 % of patients→abnormal echocardiographic findings.• 25% of patients→pericardial effusion.• 1 % of patients→pulmonary hypertension.• Left ventricular dilation and cardiac dysfunction may be seen.• Premature atherosclerosis and cardiac dysfunction leading to heart failure, MI due

to protease inhibitors used in HAART.• Myocarditis • Multifocal abdominal aortic aneurysm , aortic arch, aortic dissection

• (B)CENTRAL AND PERIPHERAL NERVOUS SYSTEM MANIFESTATIONS:• AIDS dementia , infectious and neoplastic involvement.• FOCAL CEREBRAL DISEASES: cerebral toxoplasmosis, primary CNS

lymphoma, progressive multifocal leukoencephalopathy.• MENINGITIS: caused by cryptococcus neoformans, HIV nd TB .• ↑ICP –due to intracranial masses or oppportunistic infections.• 35% of patients→polyneuropathy and myopathy.

• (C) ENDOCRINE MANIFESTATIONS:• Adrenal insufficiency-the most serious endocrine complication.• Protease inhibitor therapy→glucose intolerance, disorders of lipid

metabolism and fat redistribution.

• (D)PULMONARY MANIFESTATION:• Typically caused by opportunistic infections.• Cavitary lung disease: caused by pyogenic bacterial lung

abscess, pulm TB, Fungal infection and Nocardia infection.• Kaposi’s sarcoma and lymphoma.• Tracheobronchial obstruction and compression of great

vessels due to adenopathy.• Hemoptysis caused by endobronchial kaposi’s sarcoma.• Pneumocystis carinii pneumonia.• (E) RENAL MANIFESTATION:• Secondary to HIV infection, viral hepatitis, HAART.• Toxic acute tubular necrosis and nephrolithiasis ..due to

protease inhibitor therapy.• Nephrotic syndrome.

DIAGNOSIS• Usually there are no unique signs or symptoms• High index of suspicion- high risk behaviors, unusual infections and

symptoms .• Laboratory testing• Screening tests: ELISA• Confirmatory tests: Western Blot analysis RT-PCR• Most sensitive and specific test: nucleic acid testing of HIV RNA• For assessing the degree of HIV progression: CD4+ cell count.• Determination of viral genotype and phenotype, HIV sensitivity and

resistance to existing HAART.

• (F) HEMATOLOGIC MANIFESTATIONS:• Anaemia- most common.• Lymphocytosis-within 2 weeks of initial HIV infection.• Bone marrow involvement→leukopenia, lymphopenia,

thrombocytopenia.

TREATMENT-HAART

Class of Antiretroviral Drug

Drug Names Anaesthetic spesific drud-HAART interaction

Nucleoside or nucleotide reverse transcriptase

inhibitors (NRTIs)

zidovudine, didanosine , zalcitabine , lamivudine , tenofovir , and stavudine Abacavir, emtricitabine

Potentially changes drug clearance and effects of opiates: methadone.

Nonnucleoside reverse transcriptase inhibitors

(NNRTIs)

Efavirenze, etravirine, nevirapine, and delavirdine

Prolongs half –life of;Sedatives: midazolamOpiates: fentanyl, methadone

Protease inhibitors (PIs) Amprenavir, indinavir, lopinavir, nelfinavir, ritonavir, saquinavir

Prolongs half-life of-antiarrhythmics, sedatives, opiates, local anesthetics

Integrase inhibitors Raltegravir none

Fusion entry inhibitors Enfuvirtide Changes drug clearance and effects of midazolam

HAART THERAPY

• When to start?• Rapidly diminishing CD4+ count.• CD4+ count already < 200 cells/mm3• HIV patients with AIDS defining conditions.• Newer recommendation: HAART be instituted when CD4+ cell

count approach 500 cells/mm3• Aim of therapy: To achieve an undetectable viral load by 24 weeks of therapy

and to improve and extend the length and quality of life.

Therapy- Adverse effects of HAART• Four major groups

-Mitochondrial dysfunction: lactic acidosis, hepatic toxicity, pancreatitis, peripheral neuropathy

– Metabolic abnormalities: fat maldistribution and change in body habitus, dyslipidemia, hyperglycemia and insulin resistance, bone disorders (e.g. osteopenia, osteoporosis and osteonecrosis)

– Bone marrow suppression: anemia, neutropenia and thrombocytopenia

– Allergic reactions: skin rashes and hypersensitivity responses

THERAPY- HAART AND ANESTHETICS

• Due to viral drug resistance it is recommended that HAART be continued throughout the perioperative period if at all possible

• Anesthetic agents can induce pharmacodynamic changes that influence the efficacy and toxicity of HAART agents

• HAART can affect the absorption, distribution, metabolism and elimination of anesthetic agents• PI’s and NNRTI’s are the most commonly implicated HAART agents

associated with drug interactions• Halothane or methoxyflurane with HAART can cause hepatic or

renal dysfunction• Propofol and NRTIs taken together may promote mitochondrial

dysfunction and lactic acidosis

PREVENTION- PROTECTING YOURSELF

• Adopt universal infection control precautions for ALL patients–Especially if practicing in areas of high HIV prevalence –20% of anesthesiologists had at least one needle stick injury in the

past 3 months–High prevalence area; risk acquiring HIV- 4.5% during a 30yr career

• Post-Exposure Prophylaxis- what to do in advance!• Anesthesiologists can acquire HIV during their work via:

–sharp injuries (risk of HIV transmission 0.3%),–contamination of broken skin with the patients’ body fluids (risk of

HIV transmission <0.1%), and–splashing HIV containing body fluid in the eyes, nose or mouth (risk

of HIV transmission 0.1%)

Koplan et al., 2001. MMWR. Vol. 50; RR-11Parthasarathy et al., 2007. Ind J Anaesth. 51;91

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POST-EXPOSURE PROPHYLAXIS• Clean wound with soap and water; mucosal

exposures rinse with water• Report the exposure to the appropriate

department (e.g., infection control, occupational health)

• Start the HIV PEP regimen as soon as possible (within 2 hrs)

• Treat for 4 weeks• If source is tested and found to be HIV

negative discontinue PEP

POST-EXPOSURE PROPHYLAXIS• Recommendations for HIV PEP include a basic

4-week regimen of 2 drugs –Zidovudine (Retrovir™) and lamivudine (Epivir™) (Combivir™ - contains both

zidovudine and lamivudine),–Lamivudine (Epivir™) and stavudine (Zerit™), OR–Didanosine (Videx™) and stavudine (Zerit™)

• An expanded regimen that includes the addition of a 3rd drug for HIV exposures that pose an increased risk for transmission

–Indinavir (Crixivan™), Nelfinavir (Viracept™), Efavirenz (Sustiva™), or Abacavir (Ziagen™)

Anaesthetic management of HIV patients

• PREOPERATIVE: -review current treatment strategies with special consideration to HAART-

Drug interactions. -regardless of whether receiving HAART and has an undetectable viral

load , patients with HIV/AIDS should always be considered a potential source of infection.

-essential investigations: CBC, Basic metabolic panel including RFT, LFT and coagulation studies, chest X-Ray , ECG, Echocardiography or stress test.

-thorough history taking, review of systems , and physical examinations . - HAART has no protective effect in reducing perioperative risks.

Anaesthetic management of HIV patients

• INTRAOPERATIVE:• No anaesthetic technique is superior or inferior.• Succinylcholine could be hazardous in cytomegalovious or HIV

infection itself….due to spinal cord involvement, neuropathy or myopathy.

• Invasive hemodynamic monitoring in patients with severe autonomic dysfunion.

• Steroid supplimentation may decrease hemodynamic instability.

• LSCS decreases the incidence of vertical transmission of HIV from mother to child.

Anaesthetic management of HIV patients

• POSTOPERATIVE: • No significant increase in perioperative complications( wound

healing, wound dehiscence,hospital stay, follow up visits etc) compared with similar cohorts who are not HIV positive.

• 1 year mortality is higher in HIV/AIDS patients.• Higher incidence of postoperative pneumonia.• CD4+ count < 50 cells/mm3 and viral loads> 30,000

copies/ml→ worst outcome in terms of post operative mortality.