Low tidal volume ventilation is associated with reduced mortality in HIV-infected patients with acute lung injury

Changes in short-term (in-ICU and in-hospital) mortality following intensive care unit admission in adults living with HIV: 2000-2019

OBJECTIVE

Limited data suggest intensive care unit (ICU) outcomes have improved in people with HIV (PWH). We describe trends in in-ICU/in-hospital mortality among PWH following admission to ICU in a single UK-based HIV referral centre, from 1 January 2000 to 31 December 2019.

METHODS

Modelling of associations between ICU admission and calendar year of admission was done using logistic regression with adjustment for age, sex, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, CD4 + T-cell count and diagnosis of HIV at/within the past 3 months.

RESULTS

Among 221 PWH (71% male, median [interquartile range (IQR)] age 45 years [38-53]) admitted to ICU, median [IQR] APACHE II score and CD4 + T-cell count were 19 [14-25] and 122 cells/μl [30-297], respectively; HIV-1 viral load was ≤50 copies/ml in 46%. The most common ICU admission diagnosis was lower respiratory tract infection (30%). In-ICU and in-hospital, mortality were 29 and 38.5%, respectively. The odds of in-ICU mortality decreased over the 20-year period by 11% per year [odds ratio (OR): 0.89 (95% confidence interval (CI): 0.84-0.94)] with in-hospital mortality decreasing by 14% per year [0.86 (0.82-0.91)]. After adjusting for patient demographics and clinical factors, both estimates were attenuated, however, the odds of in-hospital mortality continued to decline over time [in-ICU mortality: adjusted OR: 0.97 (0.90-1.05); in-hospital mortality: 0.90 (0.84-0.97)].

CONCLUSION

Short-term mortality of critically ill PWH admitted to ICU has continued to decline in the ART era. This may result from changing indications for ICU admission, advances in critical care and improvements in HIV-related immune status.

Critically Ill Patients With HIV: 40 Years Later

The development of combination antiretroviral therapies (cARTs) in the mid-1990s has dramatically modified the clinical presentation of critically ill, HIV-infected patients. Most cART-treated patients aging with controlled HIV replication are currently admitted to the ICU for non-AIDS-related events, mostly bacterial pneumonia and exacerbation of comorbidities, variably affected by chronic HIV infection (COPD, cardiovascular diseases, or solid neoplasms). Today, Pneumocystis jirovecii pneumonia, cerebral toxoplasmosis, TB, and other severe opportunistic infections only occur in patients with unknown viral status, limited access to cART, viral resistance, or compliance issues. Acute respiratory failure, neurological disorders, and sepsis remain the main conditions that lead HIV-infected patients to the ICU, although admissions for liver diseases or acute kidney injury are increasing. Case fatality dropped substantially over the past decades, reaching figures of HIV-uninfected critically ill patients with similar demographic characteristics, comorbidities, and level of organ dysfunctions. Several other facets of critical care management have evolved in this population, including diagnostic procedures, cART management at the acute phase of critical illness, and ethical considerations. The goal of this narrative review was to depict the current evidence and emerging challenges for the management of critically ill, HIV-infected patients, almost 40 years following the onset of the AIDS epidemic.

HIV-related Pneumocystis jirovecii pneumonia managed with caspofungin and veno-venous extracorporeal membrane oxygenation rescue therapy

Patients with pneumocystis pneumonia have a risk of progressing to acute respiratory failure necessitating admission to intensive care. The case described is of a patient with a newly diagnosed HIV infection presenting with pneumocystis pneumonia. Despite initiating the appropriate pharmacological treatment the patient’s clinical condition deteriorated, and required both rescue pharmacological therapy with echinocandins as well as respiratory support with extracorporeal membrane oxygenation therapy. The patient recovered well on ventilator and circulatory support despite a long weaning process complicated by sequelae common to pneumocystis pneumonia. Following initialisation of antiretroviral therapy and step-down from an intensive care setting, the patient required further prolonged hospital stay for rehabilitation and mental health support before being discharged. This case reviews the novel pharmacological therapies and respiratory support strategies used in cases of pneumocystis pneumonia, including the clinical and psychological sequelae that may follow.

Extracorporeal membrane oxygenation in an HIV-positive man with severe acute respiratory distress syndrome secondary to pneumocystis and cytomegalovirus pneumonia

The management of critically ill human immunodeficiency virus (HIV)-positive patients is challenging; however, intensive care unit-related mortality has declined significantly in recent years. There are 10 case reports in the literature of extracorporeal membrane oxygenation (ECMO) use in HIV-positive patients, of whom seven survived to hospital discharge. We describe a 33-year-old Brazilian man who presented with Pneumocystis jirovecii pneumonia and severe hypoxic respiratory failure. He developed refractory acute respiratory distress syndrome (ARDS) and was commenced on veno-venous ECMO. He was successfully decannulated following 21 days of ECMO and survived to hospital discharge. Despite poor evidence surrounding the use of ECMO in immunocompromised patients, it is evident that ECMO could represent an important rescue therapy in HIV-positive patients with refractory ARDS.

Provision of critical care services to HIV-infected children in an era of advanced intensive care and availability of combined antiretroviral therapy

Intensive care facilities are always in demand in the public sector and there is constant competition for beds. Appropriate allocation of children to these resources is based on the ethical principles of distributive justice and beneficence that is determined on the presumed short-term outcome of the acute illness, long-term outcome of the underlying chronic disease and the overall demand for these facilities. At the onset of the HIV epidemic in South Africa, HIV-infected children were refused admission to the paediatric intensive care unit (PICU) on the basis of poor ICU outcomes and the lack of provision of combined antiretroviral therapy (cART) for survivors. The recent significant improvement in outcome in these patients through early recognition and treatment of HIV-related opportunistic infections, the provision of advanced organ support and the routine availability of cART suggests that the previous policy requires review. Ethical principles, the Paediatric Index of Mortality Score for each request, the quality and disability-adjusted life years and cost-effectiveness of care are all important considerations in deciding which patients should be allowed access to these limited and expensive resources. With the improved long-term outcome in HIV-infected children on cART, admission of these cases to a PICU should now be based on the prognosis of the acute illness, as with any other chronic disease such as asthma or diabetes. Withholding and withdrawing advanced life support should accord with standard protocols applied to any condition for which a child is admitted to the PICU.

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

Respiratory failure in HIV-infected patients is a relatively common presentation to ICU. The debate on ICU treatment of HIV-infected patients goes on despite an overall decline in mortality amongst these patients since the AIDS epidemic. Many intensive care physicians feel that ICU treatment of critically ill HIV patients is likely to be futile. This is mainly due to the unfavourable outcome of HIV patients with Pneumocystis jirovecii pneumonia who need mechanical ventilation. However, the changing spectrum of respiratory illness in HIV-infected patients and improved outcome from critical illness remain under-recognised. Also, the awareness of certain factors that can affect their outcome remains low. As there are important ethical and practical implications for intensive care clinicians while making decisions to provide ICU support to HIV-infected patients, a review of literature was undertaken. It is notable that the respiratory illnesses that are not directly related to underlying HIV disease are now commonly encountered in the highly active antiretroviral therapy (HAART) era. The overall incidence of P. jirovecii as a cause of respiratory failure has declined since the AIDS epidemic and sepsis including bacterial pneumonia has emerged as a frequent cause of hospital and ICU admission amongst HIV patients. The improved overall outcome of HIV patients needing ICU admission is related to advancement in general ICU care, including adoption of improved ventilation strategies. An awareness of respiratory illnesses in HIV-infected patients along with an appropriate diagnostic and treatment strategy may obviate the need for invasive ventilation and improve outcome further. HIV-infected patients presenting with respiratory failure will benefit from early admission to critical care for treatment and support. There is evidence to suggest that continuing or starting HAART in critically ill HIV patients is beneficial and hence should be considered after multidisciplinary discussion. As a very high percentage (up to 40%) of HIV patients are not known to be HIV infected at the time of ICU admission, the clinicians should keep a low threshold for requesting HIV testing for patients with recurrent pneumonia.

Management of persons infected with human immunodeficiency virus requiring admission to the intensive care unit

Rates of admission to the intensive care unit (ICU) for persons infected with human immunodeficiency virus (HIV) remain relatively unchanged in the modern era despite advances in antiretroviral therapy (ART) and improvements in ICU survival. Critical care may be required for patients with HIV because of severe opportunistic infections or malignancy, antiretroviral drug toxicity, or critical illness seemingly unrelated to HIV, and each of these scenarios may present different management challenges. In this article, the epidemiology of HIV-related ICU admission is reviewed and key management issues are discussed.

Pneumocystis pneumonia associated with human immunodeficiency virus

Pneumocystis pneumonia (PCP) is caused by the yeastlike fungus Pneumocystis. Despite the widespread availability of specific anti-Pneumocystis prophylaxis and of combination antiretroviral therapy (ART), PCP remains a common AIDS-defining presentation. PCP is increasingly recognized among persons living in Africa. Pneumocystis cannot be cultured and bronchoalveolar lavage is the gold standard diagnostic test to diagnose PCP. Use of adjunctive biomarkers for diagnosis requires further evaluation. Trimethoprim-sulfamethoxazole remains the preferred first-line treatment regimen. In the era of ART, mortality from PCP is approximately 10% to 12%. The optimal time to start ART in a patient with PCP remains uncertain.

Should highly active antiretroviral therapy be prescribed in critically ill HIV-infected patients during the ICU stay? A retrospective cohort study

Background

The impact of highly active antiretroviral therapy (HAART) in HIV-infected patients admitted to the intensive care unit (ICU) remains controversial. We evaluate impact of HAART prescription in HIV-infected patients admitted to the ICU of Tourcoing Hospital from January 2000 to December 2009.

Results

There were 91 admissions concerning 85 HIV-infected patients. Reasons for ICU admission were an AIDS-related diagnosis in 46 cases (51%). Fifty two patients (57%) were on HAART at the time of ICU admission, leading to 21 immunovirologic successes (23%). During the ICU stay, HAART was continued in 29 patients (32%), and started in 3 patients (3%). Only one patient experienced an adverse event related to HAART. Mortality rate in ICU and 6 months after ICU admission were respectively 19% and 27%. Kaplan-Meier estimates of the cumulative unajusted survival probability over 6 months were higher in patients treated with HAART during the ICU stay (Log rank: p = 0.04). No benefit of HAART in ICU was seen in the adjusted survival proportion at 6 months or during ICU stay. Prescription of HAART during ICU was associated with a trend to lower incidence of new AIDS-related events at 6 months (respectively 17% and 34% with and without HAART, p = 0.07), and with higher incidence of antiretroviral resistance after ICU stay (respectively 25% and 7% with and without HAART, p = 0.02).

Conclusions

Our results suggest a lower death rate over 6 months in critically ill HIV-infected patients taking HAART during ICU stay. The optimal time to prescribe HAART in critically ill patients needs to be better defined.

The impact of comorbid [corrected] conditions on critical illness

OBJECTIVE

To review the current knowledge of common comorbidities in the intensive care unit, including diabetes mellitus, chronic obstructive pulmonary disease, cancer, end-stage renal disease, end-stage liver disease, HIV infection, and obesity, with specific attention to epidemiology, contribution to diseases and outcomes, and the impact on treatments in these patients.

DATA SOURCE

Review of the relevant medical literature for specific common comorbidities in the critically ill.

RESULTS

Critically ill patients are admitted to the intensive care unit for various reasons, and often the admission diagnosis is accompanied by a chronic comorbidity. Chronic comorbid conditions commonly seen in critically ill patients may influence the decision to provide intensive care unit care, decisions regarding types and intensity of intensive care unit treatment options, and outcomes. The presence of comorbid conditions may predispose patients to specific complications or forms of organ dysfunction. The impact of specific comorbidities varies among critically ill medical, surgical, and other populations, and outcomes associated with certain comorbidities have changed over time. Specifically, outcomes for patients with cancer and HIV have improved, likely related to advances in therapy. Overall, the negative impact of chronic comorbidity on survival in critical illness may be primarily influenced by the degree of organ dysfunction or the cumulative severity of multiple comorbidities.

CONCLUSION

Chronic comorbid conditions are common in critically ill patients. Both the acute illness and the chronic conditions influence prognosis and optimal care delivery for these patients, particularly for adverse outcomes and complications influenced by comorbidities. Further work is needed to fully determine the individual and combined impact of chronic comorbidities on intensive care unit outcomes.

Survival of HIV-infected patients admitted to the intensive care unit in the era of highly active antiretroviral therapy

We retrospectively studied outcomes for HIV-infected patients admitted to the intensive care unit (ICU) between January 1999 and June 2009. Patient demographics, receipt of highly active antiretroviral therapy (HAART), reason for ICU admission and survival to ICU and hospital discharge were recorded. Comparison was made against outcomes for general medical patients contemporaneously admitted to the same ICU. One hundred and ninety-two HIV-infected patients had 222 ICU admissions; 116 patients required mechanical ventilation (MV) and 43 required renal replacement therapy. ICU admission was due to an HIV-associated diagnosis in 113 patients; 37 had Pneumocystis pneumonia. Survival to ICU discharge and hospital discharge for HIV-infected patients was 78% and 70%, respectively, and was 75% and 68% among 2065 general medical patients with 2274 ICU admissions; P = 0.452 and P = 0.458, respectively. HIV infection was newly diagnosed in 42 patients; their ICU and hospital survival was 69% and 57%, respectively. From multivariable analysis, factors associated with ICU survival were patient's age (odds ratio [OR] = 0.74 [95% confidence interval (CI) = 0.53-1.02] per 10-year increase), albumin (OR = 1.05 [1.00-1.09] per 1 g/dL increase), Acute Physiology and Chronic Health Evaluation (APACHE) II score (OR = 0.55 [0.35-0.87] per 10 unit increase), receipt of HAART (OR = 2.44 [1.01-4.94]) and need for MV (OR = 0.14 [0.06-0.36]). In the era of HAART, HIV-infected patients should be offered ICU admission if it is likely to be of benefit.

A prognostic scoring tool for identification of patients at high and low risk of death from HIV-associated Pneumocystis jirovecii pneumonia

A prognostic scoring tool (PST) was created to aid prediction of outcome from HIV-associated Pneumocystis jirovecii pneumonia (PCP) using data obtained from 577 episodes of PCP among 540 patients presenting to a specialist HIV treatment centre in London, UK. It used risk factors identifiable at/soon after hospitalization, previously identified as being associated with mortality: repeat episode of PCP, patient's age, haemoglobin (Hb) and oxygen partial pressure (PaO2) on admission, presence of medical co-morbidity (Comorb) and of pulmonary Kaposi sarcoma (PKS). The derived PST was 25.5+(age in years/10) + 2 (if a repeat episode of PCP) + 3 (if Comorb present) + 4 (if PKS detected) – PaO2 (kPa) – Hb (g/dL), and produced scores that ranged between 0 and 19. Patients were divided into five groups according to their prognostic score: 0-3.9 = group 1 (0% mortality), 4-7.9 = group 2 (3% mortality), 8-10.9 = group 3 (9% mortality), 11-14.9 = group 4 (29% mortality) and ≥15 = group 5 (52% mortality). This PST facilitates rapid identification of patients early in their hospitalization who have mild or severe HIV-associated PCP and who are at high and low risk of in-hospital death from PCP. The PST may aid assessment of severity of illness and in directing treatment strategies, but requires validation in patient cohorts from other healthcare institutions.

Critical illness in HIV-infected patients in the era of combination antiretroviral therapy

As HIV-infected persons on combination antiretroviral therapy (ART) are living longer and rates of opportunistic infections have declined, serious non-AIDS-related diseases account for an increasing proportion of deaths. Consistent with these changes, non-AIDS-related illnesses account for the majority of ICU admissions in more recent studies, in contrast to earlier eras of the AIDS epidemic. Although mortality after ICU admission has improved significantly since the earliest HIV era, it remains substantial. In this article, we discuss the current state of knowledge regarding the impact of ART on incidence, etiology, and outcomes of critical illness among HIV-infected patients. In addition, we consider issues related to administration of ART in the ICU and identify important areas of future research.

Outcomes for critically ill patients with HIV and severe sepsis in the era of highly active antiretroviral therapy

RATIONALE

With the advent of highly active antiretroviral therapy (HAART), sepsis has become a more frequent ICU diagnosis for patients with HIV infections. Yet, little is known about the etiologies of acute infections in critically ill patients with HIV and the factors that affect in-hospital mortality.

METHODS

Cases of patients with HIV requiring intensive care specifically for severe sepsis were identified over 27 months. Demographic information, variables related to acute illness severity, variables related to HIV infection, and all acute infections contributing to ICU stay were recorded.

RESULTS

Of 990 patients admitted to the ICU with severe sepsis, 136 (13.7%) were HIV-infected. There were 194 acute infections among the 125 patients with full data available; 112 of the infections were nosocomial/health care-associated, 55 were AIDS-related, and 27 were community-acquired. Patients with nosocomial/health care-associated and AIDS-related infections had lower CD4 counts and were less likely to be on HAART (P < .05). The inpatient mortality was 42%. In a multivariable logistic regression model, only the APACHE II score (odds ratio, 1.12; 95% confidence interval, 1.02-1.23) was significantly associated with hospital mortality, although any HAART use (odds ratio, 0.53; 95% confidence interval, 0.22-1.33, P = .18) approached statistical significance.

CONCLUSIONS

In this large cohort study, nosocomial/health care-associated infections were common in ICU patients with HIV and severe sepsis. Hospital mortality was associated with acute illness severity, but not clearly associated with variables related to HIV infection. Interventions that aim to prevent or more effectively treat nosocomial infections in critically ill patients with HIV may favorably impact clinical outcomes.

The changing epidemiology of HIV-infected patients in the intensive care unit

With the introduction of highly active antiretroviral therapy (HAART), HIV has become a chronic disease. As HIV-infected patients are aging, they are at increased risk for comorbid diseases. These non-AIDS related diseases account for a growing proportion of intensive care unit (ICU) admissions in HIV-infected patients in recent studies. HIV-infected patients still present to the ICU with HIV-related conditions such as Pneumocystis jirovecii pneumonia (PCP), but these conditions are becoming less common. Respiratory failure remains the most common indication for ICU admission. Immune reconstitution inflammatory response syndrome and toxicities related to HAART may also result in ICU admission. While ICU survival has improved since the earliest era of the HIV epidemic, hospital mortality for HIV-infected patients admitted to the ICU remains around 30%. Risk factors for ICU mortality include poor functional status, weight loss, more than one year between HIV diagnosis and ICU admission, lower serum albumin, higher severity of illness, need for mechanical ventilation, and respiratory failure-particularly if due to PCP and accompanied by pneumothorax. The impact of HAART on ICU outcomes is unclear. HAART administration in the ICU can be challenging due to limited delivery routes, concern for viral resistance and medication toxicities. There are no data to determine the safety or efficacy of HAART initiation in the ICU. Future studies are needed to address the role of age, associated comorbidities and impact of HAART on outcomes of HIV-infected patients admitted to the ICU.

An official ATS workshop report: Emerging issues and current controversies in HIV-associated pulmonary diseases

Pulmonary diseases are major causes of morbidity and death in persons with HIV infection. Millions of people with HIV/AIDS throughout the world are at risk of opportunistic pneumonias such as tuberculosis, bacterial pneumonia, and Pneumocystis pneumonia. However, the availability of combination antiretroviral therapy has turned HIV into a chronic disease, and noninfectious lung diseases such as lung cancer, chronic obstructive pulmonary disease, and pulmonary arterial hypertension are also emerging as important causes of illness. Despite the importance of these diseases and the rapidly evolving understanding of their pathogenesis and epidemiology, few avenues exist for the discussion and dissemination of new clinical and basic insights. In May of 2008, the American Thoracic Society sponsored a 1-day workshop, "Emerging Issues and Current Controversies in HIV-Associated Pulmonary Diseases," which brought together basic and clinical researchers in HIV-associated pulmonary disease. A review of the literature was performed by workshop participants, and the workshop included 18 presentations on diverse topics summarized in this article.

Seasonal variation in mortality of Pneumocystis jirovecii pneumonia in HIV-infected patients

A seasonal variation in the presentation of Pneumocystis jirovecii pneumonia (PCP) has been reported and a previous study from this centre noted a seasonal variation in mortality rates. This study examined seasonal influences (including climatic factors) within-host factors (clinical and laboratory-derived variables), the infectious burden of P. jirovecii in bronchoalveolar lavage (BAL) fluid, the presence of dihydropteroate synthase (DHPS) mutations in P. jirovecii, variations in knowledge and skills of junior medical staff, and mortality in 547 episodes of PCP occurring in 494 HIV-infected patients. The overall mortality rate was 13.5%. There was a seasonal variation in mortality: highest in autumn (21.2%) and lowest in spring (9.7%), P = 0.047. After adjustment was made for prognostic factors previously identified as being associated with mortality (increasing patient age, second/third episode of PCP, low haemoglobin, low PaO(2), presence of medical co-morbidity and pulmonary Kaposi sarcoma), there was no seasonal association with mortality, P = 0.249. The quantity of P. jirovecii DNA in BAL fluid showed no evidence of seasonal variation, P = 0.67; DHPS mutations were identified with equal frequency in each season and the mortality rate for February and August (when junior medical staff arrive in new posts) was 16.7%, only slightly greater than for other months (13.0%).

AIDS Patients in the ICU

At the beginning of the AIDS epidemic, there were higher mortality rates in patients requiring admission to an intensive care unit (ICU) most likely due to acute respiratory failure. Whereas the use of prophylaxis and corticosteroids for Pneumocystisjiroveci pneumonia and highly active antiretroviral therapy has changed this outcome and has improved survival rate. However, respiratory failure has remained the most common indication for an ICU admission. When HIV-infected patients are admitted to the ICU, intensivists need to be knowledgeable about the manifestations of common diseases and the new manifestations related to antiretroviral therapy. Much HIV mortality has been linked directly to late diagnosis and late initiation of appropriate antiviral therapy. This l, the most important cause of ICU admission for AIDS patients. We analyzed the characteristics of P.jiroveci pneumonia, bacterial pneumonia, cytomegalovirus pneumonia, mycobacterial infections, pulmonary invasive fungal infections, Kaposi’s sarcoma, and the immune reconstitution inflammatory syndrome.

Sepsis is a major determinant of outcome in critically ill HIV/AIDS patients

Introduction

New challenges have arisen for the management of critically ill HIV/AIDS patients. Severe sepsis has emerged as a common cause of intensive care unit (ICU) admission for those living with HIV/AIDS. Contrastingly, HIV/AIDS patients have been systematically excluded from sepsis studies, limiting the understanding of the impact of sepsis in this population. We prospectively followed up critically ill HIV/AIDS patients to evaluate the main risk factors for hospital mortality and the impact of severe sepsis on the short- and long-term survival.

Methods

All consecutive HIV-infected patients admitted to the ICU of an infectious diseases research center, from June 2006 to May 2008, were included. Severity of illness, time since AIDS diagnosis, CD4 cell count, antiretroviral treatment, incidence of severe sepsis, and organ dysfunctions were registered. The 28-day, hospital, and 6-month outcomes were obtained for all patients. Cox proportional hazards regression analysis measured the effect of potential factors on 28-day and 6-month mortality.

Results

During the 2-year study period, 88 HIV/AIDS critically ill patients were admitted to the ICU. Seventy percent of patients had opportunist infections, median CD4 count was 75 cells/mm³, and 45% were receiving antiretroviral therapy. Location on a ward before ICU admission, cardiovascular and respiratory dysfunctions on the first day after admission, and the presence of severe sepsis/septic shock were associated with reduced 28-day and 6-month survival on a univariate analysis. After a multivariate analysis, severe sepsis determined the highest hazard ratio (HR) for 28-day (adjusted HR, 3.13; 95% CI, 1.21-8.07) and 6-month (adjusted HR, 3.35; 95% CI, 1.42-7.86) mortality. Severe sepsis occurred in 44 (50%) patients, mainly because of lower respiratory tract infections. The survival of septic and nonseptic patients was significantly different at 28-day and 6-month follow-up times (log-rank and Peto test, P < 0.001).

Conclusions

Severe sepsis has emerged as a major cause of admission and mortality for hospitalized HIV/AIDS patients, significantly affecting short- and longer-term survival of critically ill HIV/AIDS patients.

Human immunodeficiency virus infection and hospital mortality in acute lung injury patients

OBJECTIVE

To evaluate the impact of human immunodeficiency virus infection on hospital mortality in patients with acute lung injury and to evaluate predictors of mortality among acute lung injury patients with human immunodeficiency virus.

DESIGN, SETTING, AND PATIENTS

Retrospective study of human immunodeficiency virus-infected patients enrolled in an ongoing prospective cohort study of acute lung injury patients conducted at 13 intensive care units in four teaching hospitals in Baltimore, Maryland.

MEASUREMENTS AND MAIN RESULTS

Of 520 consecutive acute lung injury patients, 66 (13%) were human immunodeficiency virus-positive. In human immunodeficiency virus-positive vs. human immunodeficiency virus-negative patients, pneumonia was the most common acute lung injury risk factor (43 [65%] vs. 184 [41%]; p=.001), and the median (interquartile range) Acute Physiology and Chronic Health Evaluation II score was modestly higher (27 [22-33] vs. 26 [20-33]; p=.06). There was no difference in crude hospital mortality (44% vs. 46%; p=.78) between human immunodeficiency virus-positive and human immunodeficiency virus-negative acute lung injury patients. After adjustment for potential confounders, human immunodeficiency virus infection was not an independent predictor of hospital mortality (odds ratio, 1.39; 95% confidence interval, 0.69-2.78; p=.35). In the human immunodeficiency virus-infected acute lung injury patients, among 23 relevant measures of intensive care unit and human immunodeficiency virus severity of illness, only the presence of an opportunistic infection before hospital admission was independently associated with hospital mortality (odds ratio, 6.4; 95% confidence interval, 1.27-32.3; p=.025).

CONCLUSIONS

In patients with acute lung injury, human immunodeficiency virus-positive patients had similar hospital mortality as human immunodeficiency virus-negative patients; hence, human immunodeficiency virus status should not influence estimates of short-term prognosis for acute lung injury patients in the intensive care unit. Among human immunodeficiency virus-positive patients with acute lung injury, the presence of a previous opportunistic infection, rather than traditional measures of severity of illness, may be most strongly predictive of hospital mortality.

The Challenges of HIV Disease in the Intensive Care Unit

HIV/AIDS continues to be a significant world health issue. Patterns of referral to intensive care units (ICU) have changed in parallel with advances in treatment. Proven Pneumocystis therapy and the introduction of antiretroviral drugs have increased life expectancy. Lower respiratory tract infection predominates as a reason for ICU admission. Pneumocystis jirovecii, TB, fungi and bacterial infections rank highly as respiratory pathogens and should be considered potentially causative. Neurological pathology and severe sepsis commonly necessitate ICU admission in this population. The timing of highly active antiretroviral therapy (HARRT) remains controversial in critically ill patients. Therapy may be difficult due to associated drug interactions, lack of intravenous drug formulation and known toxic side effects. Improvement in survival may have resulted as much from general improvements in ICU care as from advances in highly active antiretroviral therapy, notably lung protective ventilation strategies and approaches to the early recognition and management of sepsis. HIV infection is now considered a chronic illness and should not be seen as a bar to ICU admission. Many HIV-positive patients present with non-HIV related illness and can be expected to make as good a recovery as non-infected patients.

Clinical efficacy of first- and second-line treatments for HIV-associated Pneumocystis jirovecii pneumonia: a tri-centre cohort study

OBJECTIVES

First-line therapy for Pneumocystis jirovecii pneumonia (PCP) is trimethoprim/sulfamethoxazole. Few data exist to guide the choice of second-line therapy for patients failing or developing toxicity to first-line therapy.

METHODS

A case note review of 1122 patients with 1188 episodes of HIV-associated PCP from three observational cohorts in Copenhagen, London and Milan, between 1989 and 2004, was conducted.

RESULTS

Trimethoprim/sulfamethoxazole (962 PCP episodes, 81%) was the most frequently used first-line therapy, followed by intravenous pentamidine (87 episodes, 7%), clindamycin/primaquine (72 episodes, 6%) and 'other' (atovaquone, dapsone/pyrimethamine, trimetrexate or inhaled pentamidine; 67 episodes, 6%). Rates of unchanged therapy were trimethoprim/sulfamethoxazole = 79%, clindamycin/primaquine = 65% and pentamidine = 60% (P < 0.001). First-line therapy was changed because of failure in 82 (7%) episodes and because of toxicity in 198 (17%) episodes. Three month survival rates were trimethoprim/sulfamethoxazole = 85%, clindamycin/primaquine = 81% and pentamidine = 76% (P = 0.09). After adjustment for possible confounders, pentamidine was associated with a significantly greater risk of death at 3 months [hazard ratio (HR) = 2.0, 95% confidence interval (CI) = 1.2-3.4]. Second-line therapy survival rates differed: trimethoprim/sulfamethoxazole = 85%; clindamycin/primaquine = 87%; and pentamidine = 60% (P = 0.01). Multivariable time-updated Cox regression analysis showed a greater risk of death associated with pentamidine (HR = 3.3, 95% CI = 2.2-5.0), but not for clindamycin/primaquine, when both were compared with trimethoprim/sulfamethoxazole.

CONCLUSIONS

Pentamidine was associated with a greater risk of death when used as first- and second-line therapy for HIV-associated PCP, and was associated with more treatment changes. Clindamycin/primaquine appeared superior to pentamidine as second-line therapy for PCP in patients failing or developing toxicity with trimethoprim/sulfamethoxazole. In patients failing first-line treatment with non-trimethoprim/sulfamethoxazole regimens, second-line therapy should be trimethoprim/sulfamethoxazole.

Predicting mortality from HIV-associated Pneumocystis pneumonia at illness presentation: an observational cohort study

BACKGROUND

Although the use of antiretroviral therapy has led to dramatic declines in AIDS-associated mortality, Pneumocystis pneumonia (PCP) remains a leading cause of death in HIV-infected patients.

OBJECTIVES

To measure mortality, identify predictors of mortality at time of illness presentation and derive a PCP mortality prediction rule that stratifies patients by risk for mortality.

METHODS

An observational cohort study with case note review of all HIV-infected persons with a laboratory diagnosis of PCP at San Francisco General Hospital from 1997 to 2006.

RESULTS

451 patients were diagnosed with PCP on 524 occasions. In-hospital mortality was 10.3%. Multivariate analysis identified five significant predictors of mortality: age (adjusted odds ratio (AOR) per 10-year increase, 1.69; 95% CI 1.08 to 2.65; p = 0.02); recent injection drug use (AOR 2.86; 95% CI 1.28 to 6.42; p = 0.01); total bilirubin >0.6 mg/dl (AOR 2.59; 95% CI 1.19 to 5.62; p = 0.02); serum albumin <3 g/dl (AOR 3.63; 95% CI 1.72-7.66; p = 0.001); and alveolar-arterial oxygen gradient >or=50 mm Hg (AOR 3.02; 95% CI 1.41 to 6.47; p = 0.004). Using these five predictors, a six-point PCP mortality prediction rule was derived that stratifies patients according to increasing risk of mortality: score 0-1, 4%; score 2-3, 12%; score 4-5, 48%.

CONCLUSIONS

The PCP mortality prediction rule stratifies patients by mortality risk at the time of illness presentation and should be validated as a clinical tool.

Etiologies and outcome of acute respiratory failure in HIV-infected patients

Objective

To assess the etiologies and outcome of acute respiratory failure (ARF) in HIV-infected patients over the first decade of combination antiretroviral therapy (ART) use.

Methods

Retrospective study of all HIV-infected patients (n = 147) admitted to a single intensive care unit (ICU) for ARF between 1996 and 2006.

Results

ARF revealed the diagnosis of HIV infection in 43 (29.2%) patients. Causes of ARF were bacterial pneumonia (n = 74), Pneumocystis jirovecii pneumonia (PCP, n = 52), other opportunistic infections (n = 19), and noninfectious pulmonary disease (n = 33); the distribution of causes did not change over the 10-year study period. Two or more causes were identified in 33 patients. The 43 patients on ART more frequently had bacterial pneumonia and less frequently had opportunistic infections (P = 0.02). Noninvasive ventilation was needed in 49 patients and endotracheal intubation in 42. Hospital mortality was 19.7%. Factors independently associated with mortality were mechanical ventilation [odds ratio (OR) = 8.48, P < 0.0001], vasopressor use (OR, 4.48; P = 0.03), time from hospital admission to ICU admission (OR, 1.05 per day; P = 0.01), and number of causes (OR, 3.19; P = 0.02). HIV-related variables (CD4 count, viral load, and ART) were not associated with mortality.

Conclusion

Bacterial pneumonia and PCP remain the leading causes of ARF in HIV-infected patients in the ART era. Hospital survival has improved, and depends on the extent of organ dysfunction rather than on HIV-related characteristics.

Impact of intraoperative lung-protective interventions in patients undergoing lung cancer surgery

Introduction

In lung cancer surgery, large tidal volume and elevated inspiratory pressure are known risk factors of acute lung (ALI). Mechanical ventilation with low tidal volume has been shown to attenuate lung injuries in critically ill patients. In the current study, we assessed the impact of a protective lung ventilation (PLV) protocol in patients undergoing lung cancer resection.

Methods

We performed a secondary analysis of an observational cohort. Demographic, surgical, clinical and outcome data were prospectively collected over a 10-year period. The PLV protocol consisted of small tidal volume, limiting maximal pressure ventilation and adding end-expiratory positive pressure along with recruitment maneuvers. Multivariate analysis with logistic regression was performed and data were compared before and after implementation of the PLV protocol: from 1998 to 2003 (historical group, n = 533) and from 2003 to 2008 (protocol group, n = 558).

Results

Baseline patient characteristics were similar in the two cohorts, except for a higher cardiovascular risk profile in the intervention group. During one-lung ventilation, protocol-managed patients had lower tidal volume (5.3 ± 1.1 vs. 7.1 ± 1.2 ml/kg in historical controls, P = 0.013) and higher dynamic compliance (45 ± 8 vs. 32 ± 7 ml/cmH₂O, P = 0.011). After implementing PLV, there was a decreased incidence of acute lung injury (from 3.7% to 0.9%, P < 0.01) and atelectasis (from 8.8 to 5.0, P = 0.018), fewer admissions to the intensive care unit (from 9.4% vs. 2.5%, P < 0.001) and shorter hospital stay (from 14.5 ± 3.3 vs. 11.8 ± 4.1, P < 0.01). When adjusted for baseline characteristics, implementation of the open-lung protocol was associated with a reduced risk of acute lung injury (adjusted odds ratio of 0.34 with 95% confidence interval of 0.23 to 0.75; P = 0.002).

Conclusions

Implementing an intraoperative PLV protocol in patients undergoing lung cancer resection was associated with improved postoperative respiratory outcomes as evidence by significantly reduced incidences of acute lung injury and atelectasis along with reduced utilization of intensive care unit resources.