HIV and AIDS

OVERVIEW

• HIV = retrovirus infection -> infection of T-helper lymphocytes (CD4+) and progressively destroys them -> immunosuppression
• 40 million patients in the world
• 2 types: HIV 1 and HIV 2 (West Africa)
• modes of transmission: sexual intercourse, mother to child (pregnancy, labour and breast feeding), contaminated blood and needles
• AIDS = HIV with an AIDS defining illness
• can be thought of as a multi-system disorder
• respiratory failure is the commonest reason for admission to ICU
• with the new era of HAART (highly active antiretroviral therapy) -> ICU admissions for PCP are declining
• common procedures requiring anaesthesia = lymph node biopsy, splenectomy, partial colectomy, CVL’s, gastrostomy tubes and diagnostic procedures.

CLINICAL FEATURES

Risk Factors

• promiscuity
• other STI’s
• IVDU
• hemophiliacs
• Haitian and central/west African people

CDC Classification of HIV

• I – acute seroconversion illness
• II – asymptomatic infection
• III – persistent generalised lymphadenopathy
• IV – symptomatic HIV infection

Manifestations by system:

• RESP – PCP, aspergillosis, herpetic infections, candidiasis, CMV, Tb, normal bacterial pneumonia’s, nocardia, lymphoma, Kaposi sarcoma
•  CVS – endocarditis, CCF, brainstem involvement -> arrhythmias, myocarditis -> DCM from cryptococcus, coxsackievirus B, CMV, aspergillus
•  GI – diarrhoea, vomiting, LOA, dysphagia -> fluid assess and check electrolytes
•  CNS – toxoplasmosis, cryptococcus, candida, mycobacterium, treponema, aspergillus, encephalitis, aseptic meningitis, HSV, multifocal leukoencephalopathy, lymphoma, polyneuropathy, HIV dementia
•  HAEM – anaemia, thrombocytopaenia, leucopenia
•  ENDO – CMV adrenalitis, exogenous corticosteroid administration -> adrenal suppression
• OBSTETRICS – with no intervention there is a transmission rate of 30% during pregnancy and 20% through breast milk -> with antiretroviral and C/S the transmission rate can be decreased to 2%
• PAIN – numerous aetiologies, HSV, arthralgia, peripheral neuropathy, drug-related pain

PROGRESSION OF ILLNESS

INVESTIGATIONS

• HIV RNA Reverse Transcription and amplification by PCR (primary HIV infection diagnosis)
• CD4 count
• anti-HIV IgG antibodies
• enzyme linked immunosorbent assay
• as indicated on clinical grounds

MANAGEMENT

Outpatient Management

• in the last 10 years our perceptions of HIV and AIDS has changed from fatal disease -> manageable chronic illness with the introduction of HAART (highly active antiretroviral therapy)

Antiretrovirals

• usually use 3 agents

1. nucleoside reverse transcriptase inhibitors (NRTI’s – zidovudine)
2. nucleotide reverse transcriptase inhibitors (RTI’s – tenofovir)
2. non-nucleoside reverse transcriptase inhibitors (NNRTI’s – nevirapine)
3. protease inhibitors (PI’s – saquinavir)
4. others: enfuvirtide

•  aims = achieve an undetectable viral load -> improve duration and QOL

ICU Management

• HIV patients can present to ICU because of many reasons
• mortality rates from ICU admission is dramatically improving

Immune Reconstitution Syndromes

• HAART inhibits viral replication
  -> increase in population of memory and naïve T cells
  -> enhancement of lymphoproliferative responses
  -> increased IL-2
  -> reduction of some plasma proteins

• immune reconstitution syndrome = SIRS like illness with no organism found (granuloma in lung or fever, lymphadenopathy) that develops 2-8 weeks after starting HAART
• treatment: stop HAART -> reintroduction +/- steroids

Toxic effects of HAART

• PI’s -> pancreatitis, insulin resistance, hyperlipidaemia
• NRTI’s -> lactic acidosis by disruption of mitochondrial DNA replication
• abacavir -> hypersensitivity and subsequent anaphylaxis if re-challenged

Respiratory Failure

• can be caused by anything!

Diffuse Pulmonary Infiltrates:

Pneumocystis jiroveci (PCP):

• normally pneumocystis carinii (protozoa)
• now is classified as a fungus that only infects humans
• PCP with respiratory failure is a common reason with high mortality, however latest data shows that this decreasing with HAART
• CXR: ALI, pneumatoceles -> pneumothorax
•  diagnosis: sputum PCR induced by inhalation of hypertonic saline or BAL
•  treatment:
  -> trimethoprim-sulfamethoxazole or pentamidine
  -> steroids are typically given to attenuate lung injury caused by inflammatory response to killed organisms
•  prognosis: with HAART long term survival is considerably longer

Hepatitis C

• + HIV is associated with higher mortality
• with the introduction of HAART the prevalence of HCV associated cirrhosis increased by 4
• cellular immunity from HIV infections leads to accelerated HCV reproduction
• HCV also accelerates the progression of HIV disease
• consult widely if dealing with these disorders!

Central Nervous System Pathology

Meningitis/Encephalitis

• cryptococcal meningitis -> amphotericin B then PO fluconazole
• toxoplasma encephalitis -> sulfadiazine or clindamycin or pyrimethamine

Lesions that cause mass effect

• toxoplasmosis
• primary CNS lymphoma
• tuberculoma
• brain abscess (strep, staph, salmonella, aspergillus, norcardia, cryptococcus, listeria)

Perioperative Management

PREVENTION OF TRANSMISSION

• prevention of needle stick injuries (0.3% risk of transmission)
• prevention of mucocutaneous transmission (0.03% risk)
• vigilance
• universal precautions
• gloves
• HME’s
• appropriate decontamination

MANAGEMENT OF INJURY

• first aid
• post-exposure prophylaxis within 2 hours
• documentation (AIMS and Events Form)
• ID and occupational health follow up

AIDS defining illnesses that present to ICU

• pneumocystis jiroveci pneumonitis
• oesophageal candidiasis
• cryptococcal meningitis
• toxoplasma encephalitis
• CMV disease (retinal, oesophagus, bile ducts or colon)
• cryptosporidiosis
• mycobacterium avium complex
• Kaposi sarcoma (angioproliferative tumour)
• Lymphoma
• Cervical and anal neoplasms
• HIV related neurological disease (encephalopathy, myelopathy, peripheral neuropathy)

References and Links

LITFL

• CCC — Pneumocystis pneumonia (PJP or PCP)
• Clinical Cases – Humongous HIV Extravaganza

Journal articles

• Akgün KM, Huang L, Morris A, Justice AC, Pisani M, Crothers K. Critical illness in HIV-infected patients in the era of combination antiretroviral therapy. Proc Am Thorac Soc. 2011 Jun;8(3):301-7. doi: 10.1513/pats.201009-060WR. Review. PubMed PMID: 21653532; PubMed Central PMCID: PMC3132789.
• Akgün KM, Miller RF. Critical Care in Human Immunodeficiency Virus-Infected Patients. Seminars in respiratory and critical care medicine. 37(2):303-17. 2016. [pubmed]
• Huang L, Quartin A, Jones D, Havlir DV. Intensive care of patients with HIV infection. N Engl J Med. 2006 Jul 13;355(2):173-81. Review. PubMed PMID: 16837681. [Free Fulltext]
• Sarkar P, Rasheed HF. Clinical review: Respiratory failure in HIV-infected patients–a changing picture. Critical care (London, England). 17(3):228. 2013. [pubmed]