A realist review of the effective implementation of the ICU Liberation Bundle in the paediatric intensive care unit setting.

OBJECTIVE: The objective of this study was to produce an evidence base of what works, for whom, and in what context when implementing the ICU Liberation Bundle into the paediatric intensive care unit (PICU). REVIEW METHOD USED: This is a realist review (a review that considers what works, for whom, and in what context) of contemporary international literature. DATA SOURCES: Data were collected via electronic searches of CINAHL, PubMed, EMBASE and MEDLINE, Google Scholar, and Web of Science for articles published before October 2020. REVIEW METHOD: An initial scoping search identified the underpinning theory of the implementation of the ICU Liberation Bundle (a multifactor intervention aimed at improving patient outcomes) which was mapped onto the Consolidated Framework for Implementation Research (CFIR). We identified 547 unique citations; 12 full-text papers were included that reported eight studies. Data were extracted and mapped to the CFIR domains. RESULTS: Data mapped to all CFIR domains. Characteristics of individuals included involvement of key stakeholders, champions, and parents and understanding of staff attitudes and perceptions of the intervention, and all bedside staff members were involved and given training. Within the inner setting, understanding of unit culture, ensuring effective support systems in place, knowledge of the baseline, and leadership support, and buy-in were important. Culture of family-centred care and alignment of the intervention to national guidelines related to the outer setting. Intervention characteristics included the number and timings of interventions, de-escalation rounding checklists, the use of age-appropriate and validated assessment tools, and local policies for the bundle. The process included set training program, senior unit/hospital team consultation on all processes, continual audit adherence to the bundle and feedback, and celebration of successes. CONCLUSIONS: This novel realist review of the literature identified that successful implementation of the ICU Liberation Bundle into PICU settings involves the following: (i) a thorough understanding of the PICU context, including baseline metrics, resources, and staff attitudes; (ii) using contextual information to adapt the intervention elements to ensure fit; and (iii) both clinical effectiveness and implementation outcomes must be measured. Registration of review: PROSPERO 2020 CRD42020211944.

Paediatric intensive care follow-up provision in the United Kingdom and Republic of Ireland.

The objective of this study was to examine the characteristic, content, and role of Paediatric Intensive Care Units (PICUs) in the provision of follow-up for children and their families' post-intensive care discharge in the United Kingdom (UK) and Republic of Ireland (RoI). The study followed a descriptive self-reported, web-based survey design. "In-hospital PICU follow-up" was defined as follow-up delivered by the PICU team following PICU discharge but before hospital discharge and "post-discharge PICU follow-up" was defined as follow-up delivered by the PICU team following hospital discharge. The survey was administered to all 28 PICUs in the UK and RoI. Paediatric intensive care medical directors or delegated individuals participated. Data were collected between September 2017 and January 2018 with a response rate of 79% (n = 22/28). Twelve units provided either in-hospital and/or post-discharge PICU follow-up. Ten (45%) PICUs reported providing in-hospital follow-up, with half (n = 5) using an eligibility criteria for in-hospital follow-up, which related to disease groups. The most frequently reported form of in-hospital PICU follow-up consisted of face-to-face patient consultation (n = 8) by a PICU doctor (n = 5) and/or nurse (n = 4). The time at which initial contact was made was usually not predetermined (n = 4) and the assessment of care needs included are tracheostomy care (n = 4), respiratory care (n = 4), and sedative medication weaning plan (n = 5). Four PICUs reported to provide post-discharge follow-up. This involved telephone (n = 2), follow-up clinic consultations (n = 1) or home visits (n = 1), provided predominantly by PICU doctors (n = 2), with their activity directed by patient needs (n = 3). Despite increasing evidence to suggest PICU survivors and their families experience negative sequalae post-PICU discharge, less than half of PICUs surveyed provide in-hospital follow-up and only a minority provide post-discharge follow-up. There is variation in the delivery, content, and format of in-hospital and post-discharge PICU follow-up in the UK and RoI.

Cytotoxic T-lymphocyte escape does not always explain the transient control of simian immunodeficiency virus SIVmac239 viremia in adenovirus-boosted and DNA-primed Mamu-A*01-positive rhesus macaques.

Adenovirus 5 (Ad5) vectors show promise as human immunodeficiency virus vaccine candidates. Indian rhesus macaques vaccinated with Ad5-gag controlled simian-human immunodeficiency virus SHIV89.6P viral replication in the absence of Env immunogens that might elicit humoral immunity. Here we immunized 15 macaques using either a homologous Ad5-gag/Ad5-gag (Ad5/Ad5) or a heterologous DNA-gag/Ad5-gag (DNA/Ad5) prime-boost regimen and challenged them with a high dose of simian immunodeficiency virus SIVmac239. Macaques vaccinated with the DNA/Ad5 regimen experienced a brief viral load nadir of less than 10,000 viral copies per ml blood plasma that was not seen in Mamu-A*01-negative DNA/Ad5 vaccinees, Mamu-A*01-positive Ad5/Ad5 vaccinees, or vaccine-naive controls. Interestingly, most of these animals were not durably protected from disease progression when challenged with SIVmac239. To investigate the reasons underlying this short-lived vaccine effect, we investigated breadth of the T-cell response, immunogenetic background, and viral escape from CD8+ lymphocytes that recognize immunodominant T-cell epitopes. We show that these animals do not mount unusually broad cellular immune response, nor do they express unusual major histocompatibility complex class I alleles. Viral recrudescence occurred in four of the five Mamu-A*01-positive vaccinated macaques. However, only a single animal in this group demonstrated viral escape in the immunodominant Gag181-189 CM9 response. These results suggest that viral "breakthrough" in vaccinated animals and viral escape are not inextricably linked and underscore the need for additional research into the mechanisms of vaccine failure.

A dominant role for CD8+-T-lymphocyte selection in simian immunodeficiency virus sequence variation.

CD8(+) T lymphocytes (CD8-TL) select viral escape variants in both human immunodeficiency virus and simian immunodeficiency virus (SIV) infections. The frequency of CD8-TL viral escape as well as the contribution of escape to overall virus diversification has not been assessed. We quantified CD8-TL selection in SIV infections by sequencing viral genomes from 35 SIVmac239-infected animals at the time of euthanasia. Here we show that positive selection for sequences encoding 46 known CD8-TL epitopes is comparable to the positive selection observed for the variable loops of env. We also found that >60% of viral variation outside of the viral envelope occurs within recognized CD8-TL epitopes. Therefore, we conclude that CD8-TL selection is the dominant cause of SIV diversification outside of the envelope.

Identification of seventeen new simian immunodeficiency virus-derived CD8+ T cell epitopes restricted by the high frequency molecule, Mamu-A*02, and potential escape from CTL recognition.

MHC class I-restricted CD8+ T cells play an important role in controlling HIV and SIV replication. In SIV-infected Indian rhesus macaques (Macaca mulatta), comprehensive CD8+ T cell epitope identification has only been undertaken for two alleles, Mamu-A*01 and Mamu-B*17. As a result, these two molecules account for virtually all known MHC class I-restricted SIV-derived CD8+ T cell epitopes. SIV pathogenesis research and vaccine testing have intensified the demand for epitopes restricted by additional MHC class I alleles due to the shortage of Mamu-A*01+ animals. Mamu-A*02 is a high frequency allele present in over 20% of macaques. In this study, we characterized the peptide binding of Mamu-A*02 using a panel of single amino acid substitution analogues and a library of 497 unrelated peptides. Of 230 SIVmac239 peptides that fit the Mamu-A*02 peptide-binding motif, 75 peptides bound Mamu-A*02 with IC50 values of < or = 500 nM. We assessed the antigenicity of these 75 peptides using an IFN-gamma ELISPOT assay with freshly isolated PBMC from eight Mamu-A*02+ SIV-infected macaques and identified 17 new epitopes for Mamu-A*02. The synthesis of five Mamu-A*02 tetramers demonstrated the discrepancy between tetramer binding and IFN-gamma secretion by SIV-specific CD8+ T cells during chronic SIV infection. Bulk sequencing determined that 2 of the 17 epitopes accumulated amino acid replacements in SIV-infected macaques by the chronic phase of infection, suggestive of CD8+ T cell escape in vivo. This work enhances the use of the SIV-infected macaque model for HIV and increases our understanding of the breadth of CD8+ T cell responses in SIV infection.

Extraepitopic compensatory substitutions partially restore fitness to simian immunodeficiency virus variants that escape from an immunodominant cytotoxic-T-lymphocyte response.

Selection for escape mutant immunodeficiency viruses by cytotoxic T lymphocytes (CTL) has been well characterized and may be associated with disease progression. CTL epitopes accrue escape mutations at different rates in vivo. Interestingly, certain high-frequency CTL do not select for escape until the chronic phase of infection. Here we show that mutations conferring escape from immunodominant CTL directed against an epitope in the viral Gag protein are strongly associated with extraepitopic mutations in gag in vivo. The extraepitopic mutations partially restore in vitro replicative fitness of viruses bearing the escape mutations. Constraints on epitope sequences may therefore play a role in determining the rate of escape from CTL responses in vivo.

Reversion of CTL escape-variant immunodeficiency viruses in vivo.

Engendering cytotoxic T-lymphocyte (CTL) responses is likely to be an important goal of HIV vaccines. However, CTLs select for viral variants that escape immune detection. Maintenance of such escape variants in human populations could pose an obstacle to HIV vaccine development. We first observed that escape mutations in a heterogeneous simian immunodeficiency virus (SIV) isolate were lost upon passage to new animals. We therefore infected macaques with a cloned SIV bearing escape mutations in three immunodominant CTL epitopes, and followed viral evolution after infection. Here we show that each mutant epitope sequence continued to evolve in vivo, often re-establishing the original, CTL-susceptible sequence. We conclude that escape from CTL responses may exact a cost to viral fitness. In the absence of selective pressure upon transmission to new hosts, these original escape mutations can be lost. This suggests that some HIV CTL epitopes will be maintained in human populations.

Neonatal procedural pain: a survey of nursing staff.

This study explored aspects of neonatal procedural pain and its assessment and management by nursing staff working in neonatal units. Twenty-one neonatal nursing staff from three units were surveyed. They were all grade D or above and had between one and 15 years' experience with neonates. A self-completion questionnaire was used to investigate attitudes to neonatal pain, pain assessment approaches and pharmacological and non-pharmacological methods used. Staff underestimated the pain caused by procedures. Pain assessment tools were used by 48 per cent of respondents and pharmacological methods of pain management were rarely used. Non-nutritive sucking was used by 66 per cent of respondents but other methods of non-pharmacological management were under-utilised. The use of pain protocols may be beneficial in increasing administration of analgesia and use of non-pharmacological methods of relief for procedure-related pain. Education is also required about analgesics and their use in neonates.

Major histocompatibility complex class I alleles associated with slow simian immunodeficiency virus disease progression bind epitopes recognized by dominant acute-phase cytotoxic-T-lymphocyte responses.

Certain major histocompatibility complex class I (MHC-I) alleles are associated with delayed disease progression in individuals infected with human immunodeficiency virus (HIV) and in macaques infected with simian immunodeficiency virus (SIV). However, little is known about the influence of these MHC alleles on acute-phase cellular immune responses. Here we follow 51 animals infected with SIV(mac)239 and demonstrate a dramatic association between Mamu-A*01 and -B*17 expression and slowed disease progression. We show that the dominant acute-phase cytotoxic T lymphocyte (CTL) responses in animals expressing these alleles are largely directed against two epitopes restricted by Mamu-A*01 and one epitope restricted by Mamu-B*17. One Mamu-A*01-restricted response (Tat(28-35)SL8) and the Mamu-B*17-restricted response (Nef(165-173)IW9) typically select for viral escape variants in early SIV(mac)239 infection. Interestingly, animals expressing Mamu-A*1 and -B*17 have less variation in the Tat(28-35)SL8 epitope during chronic infection than animals that express only Mamu-A*01. Our results show that MHC-I alleles that are associated with slow progression to AIDS bind epitopes recognized by dominant CTL responses during acute infection and underscore the importance of understanding CTL responses during primary HIV infection.

Escape in one of two cytotoxic T-lymphocyte epitopes bound by a high-frequency major histocompatibility complex class I molecule, Mamu-A*02: a paradigm for virus evolution and persistence?

It is now accepted that an effective vaccine against AIDS must include effective cytotoxic-T-lymphocyte (CTL) responses. The simian immunodeficiency virus (SIV)-infected rhesus macaque is the best available animal model for AIDS, but analysis of macaque CTL responses has hitherto focused mainly on epitopes bound by a single major histocompatibility complex (MHC) class I molecule, Mamu-A*01. The availability of Mamu-A*01-positive macaques for vaccine studies is therefore severely limited. Furthermore, it is becoming clear that different CTL responses are able to control immunodeficiency virus replication with varying success, making it a priority to identify and analyze CTL responses restricted by common MHC class I molecules other than Mamu-A*01. Here we describe two novel epitopes derived from SIV, one from Gag (Gag(71-79) GY9), and one from the Nef protein (Nef(159-167) YY9). Both epitopes are bound by the common macaque MHC class I molecule, Mamu-A*02. The sequences of these two eptiopes are consistent with the molecule's peptide-binding motif, which we have defined by elution of natural ligands from Mamu-A*02. Strikingly, we found evidence for the selection of escape variant viruses by CTL specific for Nef(159-167) YY9 in 6 of 6 Mamu-A*02-positive animals. In contrast, viral sequences encoding the Gag(71-79) GY9 epitope remained intact in each animal. This situation is reminiscent of Mamu-A*01-restricted CTL that recognize Tat(28-35) SL8, which reproducibly selects for escape variants during acute infection, and Gag(181-189) CM9, which does not. Differential selection by CTL may therefore be a paradigm of immunodeficiency virus infection.

New antifungal agents.

Treatment of fungal infections is an area of increasing concern. This is because of the complexity of underlying illness in affected patients as well as the limited number of antifungal agents available for use. Current strategies focus on prevention of these infections in patients at high risk; however, this has the potential to lead to the emergence of clinically resistant pathogens and superinfections in these patient populations. Future efforts need to focus on earlier diagnosis and more targeted prophylaxis strategies to limit unnecessary use of these potentially toxic pharmaceuticals. Of equal importance is the development of new therapeutic options that provide viable alternatives for practitioners as well as optimal administration of currently available agents. Recent work in this area has yielded a handful of new agents that provide the first step in improving efficacy in these severely immunosuppressed patients, but outcomes still remain suboptimal for many patients suffering from severe fungal infections and/or serious underlying diseases. Clinical antifungal drug resistance must be controlled by improving a series of antifungal therapeutic strategies.

Acute phase cytotoxic T lymphocyte escape is a hallmark of simian immunodeficiency virus infection.

Cytotoxic T-lymphocyte (CTL) responses peak coincident with the decline in acute HIV viremia. Despite two reports of CTL-resistant HIV variants emerging during acute infection, the contribution of acute CTL escape to HIV pathogenesis remains unclear. Difficulties inherent in studying acute HIV infection can be overcome by modeling virus-host interactions in SIV-infected rhesus macaques. We sequenced 21 complete simian immunodeficiency virus (SIV)mac239 genomes at four weeks post-infection to determine the extent of acute CTL escape. Here we show that viruses from 19 of 21 macaques escaped from CTLs during acute infection and that these escape-selecting CTLs were responsive to lower concentrations of peptide than other SIV-specific CTLs. Interestingly, CTLs that require low peptide concentrations for stimulation (high 'functional avidity') are particularly effective at controlling other viral infections. Our results suggest that acute viral escape from CTLs is a hallmark of SIV infection and that CTLs with high functional avidity can rapidly select for escape variants.