Anesthesia in HIV-infected children

Surgical implications of HIV infection

According to the joint United Nations Programme on HIV/AIDS (UNAIDS), 37.7 million adults and children worldwide were estimated to be living with HIV or acquired immune deficiency syndrome (AIDS) at the end of 2020 [UNAIDS. (2022). http://www.unaids.org . Accessed 30 May 2022]. Most reside in low- and middle-income countries, with approximately 67% in sub-Saharan Africa (SSA). At the end of 2020, the total number of children less than 15 years of age living with HIV infection was 2.6 million, of whom 2.3 million (88%) were living in SSA. Aggressive interventions have reduced the annual number of incident (new) HIV infections among children to around 150,000 [UNAIDS. (2022). http://www.unaids.org . Accessed 30 May 2022]. However, paediatric HIV infection remains a pandemic affecting children predominantly in SSA but is also seen in Asia and sporadically elsewhere particularly in areas of civil strife such as is currently the case in Ukraine [War in Ukraine. (2022). https://www.unaids.org/en/War-Ukraine-special . Accessed Apr 2022]. New HIV infections among children declined by more than half (54%) from 2010 to 2020, due mainly to the increased provision of antiretroviral therapy to pregnant and breastfeeding women living with HIV [UNAIDS. (2022). http://www.unaids.org . Accessed 30 May 2022]. These programmes include early identification of HIV infection in pregnant or breastfeeding women through routine HIV testing, provision of antiretroviral therapy (ART) to all HIV-infected women who are pregnant or breastfeeding, provision of antiretroviral prophylaxis to their newborn infants during the first 6-12 weeks of life, delivery by elective Caesarean section when indicated, promotion of exclusive breastfeeding, early infancy screening for HIV infection, and initiation of ART in infants with HIV infection. HIV-infected children may require surgery either as an emergency to deal with a life-threatening incidental condition unrelated to HIV infection or for a complication of the disease such as tuberculosis or an aggressive soft tissue infection like necrotising fasciitis. Non-emergency surgical procedures may be required to assist in the diagnosis of an HIV-related condition or to correct a routine surgical problem electively. Surgical conditions associated with HIV infection are described under categories of soft tissue or organ-specific infections requiring drainage or debridement; gastrointestinal tract disease and complications; infections in the perineal area; malignancies and HIV-associated vasculitis. Although surgical outcomes are less favourable in HIV-infected children, pre-operative treatment of coinfections, administration of cotrimoxazole prophylaxis, nutritional support and antiretroviral therapy, together with peri-operative antibiotic prophylaxis have resulted in excellent short-term outcomes [World Health Organization. Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection: Recommendations for a public health approach, June 201 http://www.apps.who.int/iris/bitstream/10665/85321/1/9789241505727_eng.pdf?ua=1 ; World Health Organization Guideline on when to start antiretroviral therapy and on pre-exposure prophylaxis for HIV, September 2015. http://www.apps.who.int/iris/bitstream/10665/186275/1/9789241509565_eng.pdf?ua=1;Eley et al. in BMC Infect Dis 2:3, 2002;Karpelowsky et al. in Pediatr Surg Int 28:1007-1014, 2012;].

Interactions of the protease inhibitor, ritonavir, with common anesthesia drugs

The protease inhibitor, ritonavir, is a strong inhibitor of CYP 3A. The drug is used for management of the human immunovirus and is currently part of an oral antiviral drug combination (nirmatrelvir-ritonavir) for the early treatment of SARS-2 COVID-19-positive patients aged 12 years and over who have recognized comorbidities. The CYP 3A enzyme system is responsible for clearance of numerous drugs used in anesthesia (e.g., alfentanil, fentanyl, methadone, rocuronium, bupivacaine, midazolam, ketamine). Ritonavir will have an impact on drug clearances that are dependent on ritonavir concentration, anesthesia drug intrinsic hepatic clearance, metabolic pathways, concentration-response relationship, and route of administration. Drugs with a steep concentration-response relationship (ketamine, midazolam, rocuronium) are mostly affected because small changes in concentration have major changes in effect response. An increase in midazolam concentration is observed after oral administration because CYP 3A in the gastrointestinal wall is inhibited, causing a large increase in relative bioavailability. Fentanyl infusion may be associated with a modest increase in plasma concentration and effect, but the large between subject variability of pharmacokinetic and pharmacodynamic concentration changes suggests it will have little impact on an individual patient, especially when used with adverse effect monitoring. It has been proposed that drugs that have no or only a small metabolic pathway involving the CYP 3A enzyme be used during anesthesia, for example, propofol, atracurium, remifentanil, and the volatile agents. That anesthesia approach denies children of drugs with considerable value. It is better that the inhibitory changes in clearance of these drugs are understood so that rational drug choices can be made to tailor drug use to the individual patient. Altered drug dose, anticipation of duration of effect, timing of administration, use of reversal agents and perioperative monitoring would better behoove children undergoing anesthesia.

Surgical implications of human immunodeficiency virus infections

Pediatric HIV (human immunodeficiency virus) is a pandemic predominantly in sub-Saharan Africa. Approximately 2.2 million children aged less than 15 years are infected with HIV, representing almost 95% of the total number of children globally infected with HIV. Therefore, increasing numbers of HIVi or -exposed but uninfected children can be expected to require a surgical procedure to assist in the diagnosis of an HIV/acquired immune deficiency syndrome-related complication, to address a life-threatening complication of the disease, or for routine surgery encountered in HIV-unexposed children. HIVi children may present with both conditions unique to HIV infection and surgical conditions routine in pediatric surgical practice. HIV exposure confers an increased risk of complications and mortality for all children after surgery, whether they are HIV infected or not. This risk of complications is higher in the HIVi group of patients. These findings seem to be independent of whether patients undergo an elective or emergency procedure, but the risk of an adverse outcome is higher for a major procedure. Surgical implications of HIV infection are comprehensively reviewed in this article.

Anaesthetic considerations of the HIV-infected patients

PURPOSE OF REVIEW

Human immunodeficiency virus (HIV) infection is one of the major global health problems. Because the advances in treatment of HIV infection increase the patient's survival, anaesthesiologists may care for these patients during their practice. This article highlights HIV infection and anaesthetic implications.

RECENT FINDINGS

HIV infection is a spectrum of disease varying from asymptomatic to multiple organ involvement. Safe anaesthetic management in HIV-infected patients includes understanding basic knowledge of HIV infection, organ involvement, pharmacology and adverse reactions of antiretroviral agents. There are no specific anaesthetic agents and techniques for HIV-infected patients. Issues on central neural blockade and immunological aspects on HIV infection were discussed. Infection control to prevent transmission of infections to and from HIV-infected patients must be strictly conducted.

SUMMARY

Anaesthesia in HIV-infected patients should be individualized and depend on the status of the patient.

Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 February 2008 and 31 January 2009 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.