Clinical review: Respiratory failure in HIV-infected patients--a changing picture

Study on Respiratory Function and Hemodynamics of AIDS Patients with Respiratory Failure

Objective

We performed a comparative analysis of respiratory function and hemodynamics among patients with Acquired Immunodeficiency Syndrome (AIDS)-associated respiratory failure and those with non-AIDS-associated respiratory failure.

Methods

Data were collected from critically ill patients diagnosed with Acquired Immunodeficiency Syndrome who were admitted to the Intensive Care Unit (ICU) of Beijing Ditan Hospital, affiliated with Capital Medical University, between January 1, 2019, and December 31, 2019. We simultaneously gathered data from non-AIDS patients admitted to the ICU of Beijing Liangxiang Hospital within the same timeframe. A comparative study was performed to analyze clinical data from these two patient groups, encompassing parameters related to respiratory mechanics and hemodynamic indicators.

Results

A total of 12 patients diagnosed with Acquired Immunodeficiency Syndrome (AIDS) and experiencing respiratory failure, along with 23 patients with respiratory failure independent of AIDS, were included in our study. Subsequently, a comparative analysis of clinical information was conducted between the two patient cohorts. Our findings demonstrate non-statistically significant differences between the two patient groups when assessing various indicators, encompassing peak airway pressure, plateau pressure, mean pressure, compliance, oxygenation index, and arterial partial pressure of carbon dioxide (P>0.05). Additionally, the comparison of multiple indicators encompassing mean arterial pressure, central venous pressure, cardiac output index, intrathoracic blood volume index, global end-diastolic volume index, extravascular lung water content, and pulmonary vascular permeability index revealed no statistically significant differences between the two patient groups (P>0.05). Ultimately, the Galileo respiratory system was utilized to assess the pressure-volume (P-V) curve of the experimental cohort, revealing a consistent and seamless trajectory devoid of noticeable points of inflection.

Conclusion

No statistically significant differences were found in the respiratory function and hemodynamic profiles between patients diagnosed with AIDS presenting respiratory failure and those experiencing respiratory failure unrelated to AIDS. Additionally, the pressure-volume curve of individuals diagnosed with AIDS presenting respiratory failure displayed a seamless and uninterrupted trajectory devoid of discernible points of inflection. Hence, there might be constraints when utilizing P-V curve-based adjustments for positive end-expiratory pressure (PEEP) during mechanical ventilation in individuals diagnosed with AIDS presenting respiratory failure.

Mortality in patients with acquired human immunodeficiency virus infection hospitalized in an intensive care unit during the period 2017-2019

Identify risk factors associated with mortality in HIV patients admitted to an ICU in the city of Bogotá. Retrospective cohort study of patients treated in an ICU during the years 2017–2019. The analysis included descriptive statistics, association tests, and a logistic regression model. A predictive model of mortality at the time of admission to the ICU was developed. 110 HIV patients were identified. Association was found between a Charlson index ≥ 6 and mortality (OR = 2.3, 95% CI 1.0–5.1) and an increase in mortality in the first 21 days of ICU stay (OR = 2.2, 95% CI 1.0–4.9). In the logistic regression analysis, the absence of highly active antiretroviral therapy (HAART) upon admission to the ICU (OR = 2.5 95% CI 1.0–6.1) and the first 21 days of ICU stay (OR = 2.3 95% CI 1.0–5.4) were associated with an increase in mortality. The predictive mortality model established that mortality was higher in patients admitted to the ICU without having previously received HAART than in those who did receive therapy at the time of admission to the ICU. In patients with HIV admitted to the ICU, the absence of HAART will negatively impact mortality during their hospital stay.

In-hospital Mortality and Causes of Death in People Diagnosed With HIV in a General Hospital in Shenyang, China: A Cross-Sectional Study

Background: Acquired immune deficiency syndrome (AIDS), caused by human immunodeficiency virus (HIV) infection, is a serious public health issue. This study investigated the correlated factors and possible changing trend of in-hospital death in patients diagnosed with HIV in the past decade in our hospital.

Methods: We retrospectively collected data of firstly hospitalized patients with HIV in the Department of Infectious Disease in the First Affiliated Hospital of China Medical University from January 1, 2010 to December 31, 2019, and compared various factors that correlated with in-hospital death, including age, sex, opportunistic infections, and antiretroviral therapy (ART) status. Cox regression analysis was used to identify the risk factors for death.

Results: In total, 711 patients were recruited for this study, and 62 patients died in the hospital. The in-hospital mortality rate was 8.72%. Tuberculosis (TB), malignancies, and thrombocytopenia were associated with mortality. Antiviral treatment before admission was found to be a protective factor. There was a declining trend in in-hospital mortality from 19.2% in 2010 to 6.3% in 2019 (linear-by-linear association test, p < 0.001), partly due to intensified medical care strategy.

Conclusions: Till date, AIDS-defining illnesses remain the major cause of hospital admission and in-hospital mortality. TB and malignancies were correlated risk factors for in-hospital mortality. ART before admission was found to be beneficial, and considering the decreasing rate of in-hospital mortality, the implementation of intensified medical care strategy requires further effort.

Extra Corporeal Membrane Oxygenation in the Treatment of Human Immunodeficiency Virus-Related P. jirovecii Pneumonia

Despite the undeniable complexity one may encounter while managing critically ill patients with human immunodeficiency virus infection (HIV), intensive care unit-related mortality has declined in recent years, not only because of more efficacious antiretroviral therapy (ART) but also due to the advances in critical support. However, the use of extracorporeal membrane oxygenation (ECMO) in these patients remains controversial. We report four cases of HIV-infected patients with Pneumocystis jirovecii pneumonia (PJP) and acute respiratory distress syndrome (ARDS) treated with ECMO support and discuss its indications and possible role in the prevention of barotrauma and ventilator- induced lung injury (VILI). The eventually favorable clinical course of the patients that we present suggests that although immune status is an important aspect in the decision to initiate ECMO support, this technology can provide real benefit in some patients with severe HIV-related refractory ARDS.

Host-Based Diagnostics for Acute Respiratory Infections

PURPOSE

The inappropriate use of antimicrobials, especially in acute respiratory infections (ARIs), is largely driven by difficulty distinguishing bacterial, viral, and noninfectious etiologies of illness. A new frontier in infectious disease diagnostics looks to the host response for disease classification. This article examines how host response-based diagnostics for ARIs are being used in clinical practice, as well as new developments in the research pipeline.

METHODS

A limited search was conducted of the relevant literature, with emphasis placed on literature published in the last 5 years (2014-2019).

FINDINGS

Advances are being made in all areas of host response-based diagnostics for ARIs. Specifically, there has been significant progress made in single protein biomarkers, as well as in various "omics" fields (including proteomics, metabolomics, and transcriptomics) and wearable technologies. There are many potential applications of a host response-based approach; a few key examples include the ability to discriminate bacterial and viral disease, presymptomatic diagnosis of infection, and pathogen-specific host response diagnostics, including modeling disease progression.

IMPLICATIONS

As biomarker measurement technologies continue to improve, host response-based diagnostics will increasingly be translated to clinically available platforms that can generate a holistic characterization of an individual's health. This knowledge, in the hands of both patient and provider, can improve care for the individual patient and help fight rising rates of antibiotic resistance.

Treating bacterial pneumonia in people living with HIV

Introduction: Bacterial pneumonia remains an important cause of morbidity and mortality in people living with HIV (PLWH) in the antiretroviral therapy (ART) era. In addition to being immunocompromised, as reflected by low CD4 cell counts and elevated HIV viral loads, PLWH often have other behaviors associated with an increased risk of pneumonia including smoking and injected drug use. As PLWH are aging, comorbid conditions such as chronic obstructive pulmonary disease (COPD), cancers, and cardiovascular, renal and liver diseases are emerging as additional risk factors for pneumonia. Pathogens are often similar to those in HIV-uninfected individuals; however, PLWH are at risk for unusual and/or multi-drug resistant organisms causing bacterial pneumonia based, in part, on their CD4 cell counts and other exposures. Areas covered: In this review, we focus on the recognition and management of bacterial community-acquired pneumonia (CAP) in PLWH. Along with antimicrobial treatment, we discuss prevention strategies such as vaccination and smoking cessation. Expert opinion: Early initiation of ART after HIV infection can decrease the risk of pneumonia. Improved efforts at vaccination, smoking cessation, and reduction of other substance use are urgently needed in PLWH to decrease the risk for bacterial pneumonia. As PLWH are aging, comorbidities are additional risk factors for bacterial CAP.

What determines do-not-resuscitate status in critically ill HIV-infected patients admitted to ICU?

PURPOSE

To identify factors associated with do-not-resuscitate (DNR) status in critically ill patients infected with human immunodeficiency virus (HIV) admitted to the Intensive Care Unit (ICU) in the era of combination antiretroviral therapy (cART).

MATERIALS AND METHODS

Retrospective cohort study of first-time admissions of HIV-infected patients to ICUs in Edmonton, Alberta, from 2002 to 2014. Multivariable logistic regression analysis was performed to identify factors associated with DNR status.

RESULTS

There were 282 HIV-infected patients with first-time ICU admissions, with an incidence rate of 6.6 per 1000 ICU admissions. Sixty-seven (24%) patients had a DNR designation and support was withdrawn in 37 (13%). In multivariable analysis, APACHE II score (OR 1.13; 95% CI, 1.08-1.19, p < 0.001), coronary artery disease (OR 5.70; 95% CI, 1.18-27.76, p = 0.031), prior opportunistic infection (OR 2.59; 95% CI, 1.20-5.57, p = 0.015) and duration of HIV infection (OR 1.07 per year; 95% CI, 1.01-1.14, p = 0.025) were independently associated with DNR status. Ethnicity, HIV risk factors, CD4 count and viral load were not associated with DNR status.

CONCLUSIONS

One in four patients had a DNR designation. Illness acuity, selected comorbidity, previous opportunistic infection and HIV duration were associated with DNR designation.

Species, Risk Factors, and Antimicrobial Susceptibility Profiles of Bacterial Isolates from HIV-Infected Patients Suspected to Have Pneumonia in Mekelle Zone, Tigray, Northern Ethiopia

Background

Pneumonia is a condition, where bacterial infections are implicated as the most common causes of morbidity and mortality in humans. The actual burden of HIV-infected patients with pneumonia is not well documented in Mekelle region of Ethiopia. This study estimated the prevalence of bacterial pneumonia in HIV patients, antimicrobial susceptibility patterns of pathogens implicated in pneumonia, and associated risk factors in Mekelle zone, Tigray, Northern Ethiopia, during August-December 2016.

Methods

Sputum specimens were collected from 252 HIV seropositive individuals with suspected pneumonia. Data on sociodemographics and risk factors were also collected using a structured questionnaire. Blood, Chocolate, and Mac Conkey agar plates (Oxoid, Hampshire, UK) were used to grow the isolates. The isolated colonies were identified based on Gram stain, colony morphology, pigmentation, hemolysis, and biochemical tests. The antimicrobial susceptibility test was performed using the modified Kirby-Bauer disc diffusion method. The analysis was performed using SPSS version 22 and p-value < 0.05 with corresponding 95% confidence interval (CI) was considered statistically significant.

Results

Out of the 252 samples, 110 (43.7%) were positive for various bacterial species. The predominant bacterial species were Klebsiella pneumoniae (n=26, 23.6 %) followed by Streptococcus pneumoniae (n=17, 15.5 %), Escherichia coli (n=16, 14.5%), Klebsiella spp. (n=15, 13.6%), Staphylococcus aureus (n=9, 8.2%), Enterobacter spp. (n=7, 6.3%), Pseudomonas aeruginosa (4, n=3.6%), Proteus spp. (n=4, 3.6%), Citrobacter freundii (n=7, 6.3%), Streptococcus pyogenes (3, 2.7%), and Haemophilus influenzae (n=2, 1.8%). Young age (18-29), recent CD4⁺ count less than 350 cells/mL, alcohol consumption, and HIV WHO stage II showed significant association with the occurrence of bacterial pneumonia. Resistance to penicillin, co-trimoxazole, and tetracycline was observed in 81.8%, 39.8%, and 24.5% of the isolates, respectively.

Conclusions

The problem of pneumonia among HIV patients was significant in the study area. The high prevalence of drug-resistant bacteria isolated from the patient's samples possesses a health risk in immunocompromised HIV patients. There is a need to strengthen and expand culture and susceptibility procedures for the administration of appropriate therapy to improve patients management and care which may aid in decreasing the mortality.

The use of extracorporeal membrane oxygenation in HIV-positive patients with severe respiratory failure: a retrospective observational case series

The objective is to describe the outcomes of patients with human immunodeficiency virus (HIV) infection who received extracorporeal membrane oxygenation (ECMO) for severe respiratory failure (SRF). The design and setting was a single centre retrospective observational case series, from January 2012 to June 2017, at a tertiary university hospital and regional referral centre for ECMO in the United Kingdom. The participants were all patients referred with SRF and HIV infection. The main outcome measure was patient 90-day survival. Twenty-four patients were referred, of whom nine received ECMO. Six out of nine (67%) of patients were alive at 90 days. Median duration of ECMO was 18 days. There were no identified differences between survivors and non-survivors. ECMO can be used successfully in selected patients with HIV and SRF, including those with poor HIV control and high illness severity. HIV status alone should not exclude patients from treatment with extracorporeal therapy.

Predictors of 6-month health utility outcomes in survivors of acute respiratory distress syndrome

BACKGROUND

With improving short-term mortality in acute respiratory distress syndrome (ARDS), understanding and improving quality of life (QOL) outcomes in ARDS survivors is a clinical and research priority. We sought to identify variables associated with QOL, as measured by the EQ-5D health utility score, after ARDS using contemporary data science methods.

METHODS

Analysis of prospectively acquired baseline variables and 6-month EQ-5D health utility scores for adults with ARDS enrolled in the ARDS Network Long-Term Outcomes Study (ALTOS). Penalised regression identified predictors of health utility, with results validated using 10-fold cross-validation.

RESULTS

Among 616 ARDS survivors, several predictors were associated with 6-month EQ-5D utility scores, including two lifestyle factors. Specifically, older age, female sex, Hispanic/Latino ethnicity, current smoking and higher body mass index were associated with lower EQ-5D utilities, while living at home without assistance at baseline and AIDS were associated with higher EQ-5D utilities in ARDS survivors. No acute illness variables were associated with EQ-5D utility.

CONCLUSIONS

Acute illness variables do not appear to be associated with postdischarge QOL among ARDS survivors. Functional independence and lifestyle factors, such as obesity and tobacco smoking, were associated with worse QOL. Future analyses of postdischarge health utility among ARDS survivors should incorporate measures of demographics and functional independence at baseline.

TRIAL REGISTRATION NUMBERS

NCT00719446 (ALTOS), NCT00434993 (ALTA), NCT00609180 (EDEN/OMEGA), and NCT00883948 (EDEN); Post-results.

Six-month survival of critically ill patients with HIV-related disease and tuberculosis: a retrospective study

BACKGROUND

Tuberculosis is one of the leading causes of death from infectious diseases worldwide, mainly after the human immunodeficiency virus (HIV) epidemics. Patient with HIV-related illness are more likely to present with severe TB due to immunosuppression. Very few studies have explored HIV/TB co-infection in critically ill patients. The goal of this study was to analyze factors associated with long-term mortality in critically ill patient with HIV-related disease coinfected with TB.

METHODS

We conducted a retrospective study in an infectious disease reference center in Brazil that included all patient with HIV-related illness admitted to the ICU with laboratory-confirmed tuberculosis from March 2007 until June 2012. Clinical and laboratory variables were analyzed based on six-month survival.

RESULTS

Forty-four patients with HIV-related illness with a confirmed diagnosis of tuberculosis were analyzed. The six-month mortality was 52 % (23 patients). The main causes of admission were respiratory failure (41 %), severe sepsis/septic shock (32 %) and coma/torpor (14 %). The median time between HIV diagnosis and ICU admission was 5 (1-60) months, and 41 % of patients received their HIV infection diagnosis ≤ 30 days before admission. The median CD4 count was 72 (IQR: 23-136) cells/mm(3). The clinical presentation was pulmonary tuberculosis in 22 patients (50 %) and disseminated TB in 20 patients (45.5 %). No aspect of TB diagnosis or treatment was different between survivors and nonsurvivors. Neurological dysfunction was more prevalent among nonsurvivors (43 % vs. 14 %, p = 0.04). The nadir CD4 cell count lower than 50 cells/mm(3) was independently associated with Six-month mortality (hazard ratio 4.58 [1.64-12.74], p < 0.01), while HIV diagnosis less than three months after positive serology was protective (hazard ratio 0.27, CI 95 % [0.10-0.72], p = 0.01).

CONCLUSION

The Six-month mortality of HIV critically ill patients with TB coinfection is high and strongly associated with the nadir CD4 cell count less than 50 cels/mm(3).

Characteristics and Outcome of Patients With AIDS in Dutch ICUs Between 1997 and 2014

OBJECTIVE

Knowledge on characteristics and outcome of ICU patients with AIDS is highly limited. We aimed to determine the main reasons for admission and outcome in ICU patients with AIDS and trends over time therein.

DESIGN

A retrospective study within the Dutch National Intensive Care Evaluation registry.

SETTING

Dutch ICUs.

PATIENTS

We used data collected between 1997 and 2014. Characteristics of patients with AIDS were compared with ICU patients without AIDS, matched for age, sex, admission type, and admission year. Joinpoint regression analysis was applied to study trends over time.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We included 1,127 patients with AIDS and 4,479 matched controls. The main admission diagnoses of patients with AIDS were respiratory infection (28.6%) and sepsis (16.9%), which were less common in controls (7.7% and 7.5%, respectively; both p < 0.0001). Patients with AIDS had increased severity of illness and in-hospital mortality (28.2% vs 17.8%; p < 0.0001) compared with controls, which was associated with a higher rate of infections at admission in patients with AIDS (58.4% vs 25.5%). Over time, the proportion of patients with AIDS admitted with an infection decreased (75% in 1999 to 56% in 2013). Mortality declined in patients with AIDS (39% in 1999 to 16% in 2013), both in patients with or without an infection. Mortality also declined in matched controls without AIDS, but to a lesser extent.

CONCLUSION

Infections are still the main reason for ICU admission in patients with AIDS, but their prevalence is declining. Outcome of patients with AIDS continued to improve during a time of widespread availability of combination antiretroviral therapy, and mortality is reaching levels similar to ICU patients without AIDS.

Invasive diagnostic strategies in immunosuppressed patients with acute respiratory distress syndrome

Immunosuppression predisposes the host to development of pulmonary infections, which can lead to respiratory failure and the development of acute respiratory distress syndrome (ARDS). There are multiple mechanisms by which a host can be immunosuppressed and each is associated with specific infectious pathogens. Early invasive diagnostic modalities such as fiber-optic bronchoscopy with bronchoalveolar lavage, transbronchial biopsy, and open lung biopsy are complementary to serologic and noninvasive studies and assist in rapidly establishing an accurate diagnosis, which allows initiation of appropriate therapy and may improve outcomes with relative safety.