Outcomes of acute chest syndrome in adult patients with sickle cell disease: predictors of mortality

Lipid and hemolysis parameters predicting acute chest syndrome in adulthood with sickle cell disease

Sickle cell disease (SCD) is a lifelong blood disorder affecting approximately 100,000 people in the United States and is one of the most common monogenic diseases. A serious complication of SCD is acute chest syndrome (ACS). ACS is a condition with a high rate of morbidity and mortality. The aim of the study was to assess hemolysis and lipid parameters in a cohort of confirmed SCD patients to predict ACS development in the following year.Standard lipid were performed (triglycerides, total cholesterol, high-density cholesterol, low-density cholesterol) panel to calculate of non-HDL-C, large buoyant LDL cholesterol (lbLDL-C) and small dense LDL cholesterol (sdLDL-C) with Sampson equation. Hemolysis and hematologic parameters were also evaluated.Among 91 patients included between September 2018 and June 2021, thirty-seven patients had history of ACS and 6 patients developed ACS during following year. In unadjusted logistic regression, total bilirubin was associated with ACS occurrence (RR: 1.2 [1.05-1.51] p = 0.013). Concerning lipid profile, non-HDL-C (RR: 0.87 [0.0.67-0.99] p = 0.04) and sdLDL-C (RR: 0.78 [0.49-0.96] p = 0.03) were associated with ACS occurrence decrease. C-reactive protein was associated with ACS occurrence (RR: 1.27 [1.065-1.85] p = 0.011).Based on these findings, this study demonstrated that several biomarker easily available can be used at steady state to predict ACS in the following year. The validation of these results are required to ensure the reproducibility of the findings.

Multi-center study on mortality in children, and adults with sickle cell anemia-risk factors and causes of death

Sickle cell disease (SCD) is a major public health burden worldwide with increasing morbidity and mortality. The study evaluates the risk factors associated with mortality in SCD patients, between the years 2006 and 2020 at three hospitals in Oman. The analysis includes clinical manifestations, haematological, biochemical, and radiological parameters, use of antibiotics, and blood and exchange transfusions. Our cohort included 123 patients (82 males, 41 females), with a median age of 27 (Interquartile Range 21-35 years). SCD related complications included acute chest syndrome (ACS) in 52.8%, splenic sequestration in 21.1%, right upper quadrant syndrome in 19.5%, more than > 6 VOC/year in 17.9%, and stroke in 13.8%. At the terminal admission, patients had cough, reduced O2 saturation, crepitation and fever in 24.4%, 49.6%, 53.6% and 68.3% respectively. Abnormal chest X-ray and chest CT scan were seen in 57.7%, and 76.4% respectively. Laboratory parameters showed a significant drop in hemoglobin (Hb) and platelet counts from baseline, with a significant rise in WBC, LDH and CRP from baseline (p < 0.05, Wilcoxon Signed Ranks test). All patients received antibiotics, whereas, 95.9% and 93.5% received simple blood transfusions, and exchange transfusions respectively, and 66.6% required non-invasive ventilation. Among the causes of death, ACS is seen in 32 (26%), sepsis in 49 (40%), and miscellaneous in 42 (34%). Sudden death was seen in 32 (26%) of patients. Male gender, with low HbF, rapid drop in Hb and platelet, and increased in WBC, LDH, ferritin, and CRP, correlated significantly with mortality in this cohort.

Acute Chest Syndrome in Sickle Cell Disease

Acute chest syndrome (ACS) is the leading cause of mortality among individuals with sickle cell disease (SCD) accounting for 25% of all deaths. The etiologies and clinical manifestations of ACS are variable among children and adults, with a lack of clear risk stratification guidelines for the practicing clinician. In addition, the management of ACS is based on limited evidence and is currently guided primarily by expert opinion. This manuscript reviews the pathophysiology, risk factors, and current management strategies for ACS through a review of published data on this subject between 1988 and 2022. Blood transfusion is often used as a therapeutic intervention for ACS to increase blood's oxygen-carrying capacity and reduce complications by reducing hemoglobin S (HbS) percentage, based on the very low quality of the evidence about its efficacy. The benefit of RBC transfusion for ACS has been described in case series and observational studies, but randomized studies comparing simple transfusion vs. exchange transfusions for ACS are lacking. In this review, we conclude that the development of clinical and laboratory risk stratification is necessary to further study an optimal management strategy for individuals with ACS to avoid transfusion-related complications while minimizing mortality.

Adherence to hydroxyurea and clinical outcomes among children with sickle cell anemia

OBJECTIVE

Hydroxyurea lowers the incidence of vaso-occlusive pain crises (VOC) and acute chest syndrome (ACS) among children with sickle cell anemia (SCA). Our objective was to assess the relationship between levels of adherence to hydroxyurea and clinical outcomes among children and adolescents with SCA.

METHODS

This retrospective cohort study included Medicaid data (2005-2012) from Florida, Illinois, Louisiana, Michigan, South Carolina, and Texas. The study population consisted of children 1-17 years old with SCA enrolled in Medicaid for 3 years. Among children that initiated hydroxyurea, the medication possession ratio (MPR) was calculated as the proportion of days covered by hydroxyurea. Six months after initiation of hydroxyurea, clinical outcomes were assessed through the end of the study period: numbers of VOC-related inpatient admissions and emergency department visits, and encounters for ACS. Multivariable Poisson models were used to predict outcomes by MPR quartile adjusting for previous healthcare utilization, state, and age.

RESULTS

Hydroxyurea was initiated by 515 children. The median MPR was 0.53 (interquartile range = 0.3-0.8). The annual median number of visits was 0.0 for ACS, 1.3 for VOC-related emergency department, and 1.4 for VOC-related inpatient admissions. For each outcome, the highest quartile of MPR had the lowest predicted count; this difference was significant for ACS visits when compared with the lowest quartile of MPR.

CONCLUSION

This study demonstrated a high level of adherence (>75%) was essential to achieve a lower incidence of common negative clinical outcomes. Further, moderate and severe hydroxyurea nonadherence may be more common than previously appreciated among children, emphasizing the importance of developing and testing innovative strategies to increase adherence.

Characterizing the process of urgent referrals and transfers to a large tertiary care apheresis centre in Ontario: A retrospective database review

BACKGROUND

Therapeutic plasma exchange (TPE) and red blood cell exchange (RBCX) are life-saving apheresis procedures offered in 7 Ontario hospitals. Most referrals are directed by CritiCall Ontario (CritiCall), a 24/7 service funded by the Ontario Ministry of Health and Long-Term Care. We used CritiCall data to examine referral requests, acceptances, and transfers for urgent apheresis to our centre.

METHODS

Retrospective CritiCall referral and transfer data for urgent apheresis between October 2013 and December 2018 were included. Continuous variables were analyzed by linear regression. Categorical variables were analyzed using nonparametric tests.

RESULTS

Eighty-five cases (52 TPE, 33 RBCX) were identified. Median patient age was 52 years (interquartile range [IQR] 32) for TPE, 29 years (IQR 18) for RBCX. Most patients (58%) were female. Total time from referral to arrival at our centre was 243 (IQR 166) minutes. The greatest proportion of this total was from patient acceptance to arrival (169 [IQR 112] minutes). Median distance between referring and accepting centres was 39 (IQR 30) kilometres, with ground transportation used most often. Multiple linear regression examining factors that contribute to total time demonstrated that the number of physicians contacted prior to patient acceptance and inter-hospital distance were independently associated (p = 0.007 and p = 0.048, respectively).

INTERPRETATION

Addressing modifiable factors to reduce time is important given that time to initiate treatment is associated with better outcomes. Quality improvement strategies should be aimed at coordinated provincial resource sharing, pairing referrals with nearest available apheresis centres, and creating efficiency in the interval between patient acceptance and arrival.

[Lung manifestations of sickle-cell disease]

Sickle-cell disease is an autosomal recessive genetic disorder of hemoglobin that causes systemic damage. Hypoxia is the main actor of sickle-cell disease. It initiates acutely the pathogenic cascade leading to tissue damages that in turn induce chronic hypoxia. Lung lesions represent the major risk of morbidity and mortality. Management of sickle-cell disease requires a tight collaboration between hematologists, intensivists and chest physicians. Recurrent episodes of thrombosis and hemolysis characterize the disease. New therapeutic protocols, associating hydroxyurea, transfusion program and stem cell transplantation in severe cases allow a prolonged survival until the fifth decade. However, recurrent pain, crisis, frequent hospital admissions due to infection, anemia or acute chest syndrome and chronic complications leading to organ deficiencies degrade the patients' quality of life. In low-income countries where the majority of sickle-cell patients are living, the disease is still associated with a high mortality in childhood. This paper focuses on acute chest syndrome and chronic lung manifestations.

Acute chest syndrome in adult patients with sickle cell disease: The relationship with the time to onset after hospital admission

Data on acute chest syndrome (ACS) in adult sickle cell disease patients are scarce. In this study, we describe 105 consecutive ACS episodes in 81 adult patients during a 32-month period and compare the characteristics as a function of the time to onset after hospital admission for a vaso-occlusive crisis (VOC), that is early-onset episodes (time to onset ≤24 h, 42%) versus secondary episodes (>24 h, 58%; median [interquartile range] time to onset: 2 [2-3] days). The median age was 27 [22-34] years, 89% of the patients had an S/S or S/β⁰ -thalassaemia genotype; 81% of the patients had a history of ACS (median: 3 [2-5] per patient), only 61% were taking a disease-modifying treatment at the time of the ACS. Fever and chest pain were noted in respectively 54% and 73% of the episodes. Crackles (64%) and bronchial breathing (32%) were the main abnormal auscultatory findings. A positive microbiological test was found for 20% of episodes. Fifty percent of the episodes required a blood transfusion; ICU transfer and mortality rates were respectively 29% and 1%. Secondary and early-onset forms of ACS did not differ significantly. Disease-modifying treatments should be revaluated after each ACS episode because the recurrence rate is high.

[Acute chest syndrome in adult sickle cell patients]

Sickle cell disease is a frequent genetic condition, due to a mutation of the β-globin gene, leading to the production of an abnormal S hemoglobin and characterized by multiple vaso-occlusive events. The acute chest syndrome is a severe complication associated with a significant disability and mortality. It is defined by the association of one or more clinical respiratory manifestations and a new infiltrate on lung imaging. Its pathophysiology is complex and implies vaso-occlusive phenomena (pulmonary vascular thrombosis, fat embolism), infection, and alveolar hypoventilation. S/S or S/β⁰-thalassemia genotype, a history of vaso-occlusive crisis or acute chest syndrome, a low F hemoglobin level (<5%), a high steady-state hemoglobin level (> 10 g/dL), or a high steady-state leukocytosis (>10 G/L) are the main risk factors. Febrile chest pain, dyspnea, sometimes cough with expectorations are its main clinical manifestations, and bi-basal crackles are found at auscultation. Inferior alveolar opacities with or without pleural effusions are identified on chest X-ray or CT-scan. Management of the acute chest syndrome should be prompt and implies, besides the recognition of severity signs, a multimodal analgesia, oxygen supplementation, sometimes a parenteral antibiotic treatment and the frequent use of blood transfusions especially in the most severe cases. Prevention is important and includes a regular monitoring of hospitalized patients and the use of incentive spirometry.

Cortactin loss protects against hemin-induced acute lung injury in sickle cell disease

In patients with sickle cell disease (SCD), acute chest syndrome (ACS) is a common form of acute lung injury and a major cause of morbidity and mortality. The pathophysiology of ACS is complex, and hemin, the prosthetic moiety of hemoglobin, has been implicated in endothelial cell (EC) activation and subsequent acute lung injury (ALI) and ACS in vitro and in animal studies. Here, we examined the role of cortactin (CTTN), a cytoskeletal protein that regulates EC function, in response to hemin-induced ALI and ACS. Cortactin heterozygous (Cttn+/-) mice (n = 8) and their wild-type siblings (n = 8) were irradiated and subsequently received bone marrow cells (BMCs) extruded from the femurs of SCD mice (SS) to generate SS Cttn+/- and SS CttnWT chimeras. Following hemoglobin electrophoretic proof of BMC transplantation, the mice received 35 µmol/kg of hemin. Within 24 h, surviving mice were euthanized, and bronchoalveolar fluid (BAL) and lung samples were analyzed. For in vitro studies, human lung microvascular endothelial cells (HLMVECs) were used to determine hemin-induced changes in gene expression and reactive oxygen species (ROS) generation in cortactin deficiency and control conditions. When compared with wild-type littermates, the mortality for SS Cttn+/- mice trended to be lower after hemin infusion and these mice exhibited less severe lung injury and less necroptotic cell death. In vitro studies confirmed that cortactin deficiency is protective against hemin-induced injury in HMLVECs, by decreasing protein expression of p38/HSP27, improving cell barrier function, and decreasing the production of ROS. Further studies examining the role of CTTN in ACS are warranted and may open a new avenue of potential treatment for this devastating disease.

Acute chest syndrome and COVID‐19 in hydroxyurea naïve sickle cell disease patient in a low resource setting

Acute chest syndrome (ACS) is a severe complication of sickle cell disease (SCD) and one of the leading causes of mortality in SCD patients. The management of ACS is challenging and requires prompt intervention to halt clinical deterioration. With the outbreak of the Coronavirus Disease 2019 (COVID‐19) pandemic, which also primarily results in acute respiratory illness, the clinical picture and treatment outcome in SCD patients with ACS remain unknown. We present a case of a 30‐year‐old male who came in with features of painful vaso‐occlusive episode and haemolysis that later evolved to acute chest syndrome. Chest X‐ray showed pneumonic changes and mild bilateral pleural effusion, and nasal Reverse Transcription‐Polymerase Chain Reaction (RT‐PCR) for COVID‐19 test came out positive. He was managed supportively with simple transfusion, antibiotics, dexamethasone and oxygen support with a good clinical outcome. Presenting with non‐specific symptoms and similar respiratory symptoms and signs, the clinical picture of COVID‐19 can prove difficult to discern from that of ACS due to other causes. This report emphasizes a need for a higher index of suspicion whenever a SCD patient presents with symptoms of acute respiratory distress.

Clinical-Epidemiological Characteristics and Mortality in Patients with Sickle Cell Anemia: A Retrospective Cohort Study of 1980 at 2018

PURPOSE

To analyze the clinical-epidemiological characteristics and mortality in patients with sickle-cell anemia (SCA).

PATIENTS AND METHODS

A cohort study with retrospective data, conducted in two reference hospitals for SCA treatment from January 1980 to December 2018, recorded in two reference services. With a 5% significance level, the Chi-Square and Student's t-tests were employed in the inferential statistical analysis.

RESULTS

A total of 128 patients with SCA were studied. Diagnosis up to the fifth day of life was made in 10 patients. There were 19 deaths, of which 12 (63.2%) were female, and the average age at death was 27.05 (± 14.78) years. The leading causes of death were septic shock and cardiogenic shock. The use of invasive medical devices was considered a risk factor for death (RR=2.63; 95% CI=1.16-5.96; p=0.018), and monitoring time up to 20 years presented a 31% reduction in the risk of dying (RR=0.31; 95% CI=0.12-0.82; p=0.011) when compared to the monitoring of more than 20 years.

CONCLUSION

These findings are to be considered in the treatment of patients with SCA, mainly regarding early diagnosis and access to the treatment immediately afterward, since they are fundamental in improving survival and reducing severe complications.

Optimizing management of sickle cell disease in patients undergoing surgery

Individuals with sickle cell disease (SCD) are likely to be referred for surgery at some point in their lifetime due to a high incidence of musculoskeletal and intrabdominal complications such as avascular necrosis and gallbladder disease. Preoperative optimization is a multidisciplinary process that involves a hematologist with SCD expertise, an anesthesiologist, and the surgical team. The type and risk classification of the surgery, disease severity, medications, baseline hemoglobin, transfusion history, and history of prior surgical complications are often documented. Clinicians should consider perioperative risk assessment that includes determining the patient's functional status and cardiovascular risk and screening for obstructive sleep apnea. Many patients will require preoperative transfusion to reduce the risk of postoperative complications such as acute chest syndrome and vaso-occlusive pain crises. The hematologist should consider the patient's preoperative transfusion requirements and ensure that the surgical team has an appropriate plan for postoperative observation and management. This often includes follow-up laboratory studies, a postoperative pain management plan, and venous thromboembolism prophylaxis. The transfusion plan should be patient-specific and take into account the SCD genotype, baseline hemoglobin, disease severity, risk classification of the surgery, and history of prior surgical complications. In the intraoperative and postoperative period, dehydration, hypothermia, hypotension, hypoxia, and acidosis should be avoided, and incentive spirometry should be utilized to minimize complications such as acute chest syndrome. In this review we discuss preoperative, intraoperative, and postoperative strategies to optimize patients with SCD undergoing surgery.

Life-Threatening Acute Chest Syndrome in a Patient With Sickle Cell Disease After Switching From Hydroxyurea Therapy to Partial Exchange Transfusions: A Case Report

Acute chest syndrome (ACS) is a severe form of vaso-occlusive crisis, which is a main feature of sickle cell disease (SCD), an inherited hemoglobinopathy. Traditionally, hydroxyurea has been the treatment of choice for SCD to prevent vaso-occlusive crises including ACS. However, hydroxyurea may be contraindicated, for example, in patients wanting to have children. We here present a young male with SCD who wanted to become a father and developed a life-threatening episode of ACS following discontinuation of hydroxyurea and switching to partial exchange blood transfusions. The patient, aged 32 years and originally from Bahrain, had been diagnosed with homozygous SCD, alpha-thalassemia, and glucose-6-phosphate dehydrogenase deficiency as a child. He had an episode of ACS with moderate severity in 2008, after which he started using hydroxyurea. From 2008 until the present, he did not experience any episodes of ACS. About six months before the present episode, he stopped using hydroxyurea and switched to partial exchange transfusions, aiming to keep hemoglobin S (HbS) below 30%. The interval between the transfusions was typically about seven to eight weeks. On the evening (day 1) before hospital admission, he developed typical symptoms and signs of vaso-occlusive crisis, and during the first day in the hospital (HbS about 55%), his pulmonary function deteriorated, and he also developed cerebral symptoms (somnolence and confusion). On suspicion of ACS, a full blood exchange transfusion was administered on day 3. He then gradually recovered clinically, and his laboratory values also normalized. He was discharged on day 10. Subsequent follow-up visits at the outpatient clinic the following month were unremarkable. Possibly, this severe episode of ACS was triggered by switching from hydroxyurea therapy to partial exchange transfusions with too long intervals between the transfusions. This novel case is a compelling reminder of the possible perils that may accompany the discontinuation of hydroxyurea, the best-documented therapy in SCD.

Homozygous sickle cell disease related mortality in Senegal (2011-2020)

Homozygous sickle cell disease (HSCD) is characterized by multiorgan morbidity and an increased risk of early death. We aim to describe the mortality rate, causes, and risk factors of death in HSCD between 2011 and 2020. We conducted a retrospective study with a duration of 10 years in the cohort of 2348 HSCD patients. The mortality rate was determined by reporting the number of deaths to the total number of patients followed in the year. Sociodemographic, clinical, biological data and causes of death were studied. Death risk factors were determined by a bivariate analysis comparing deceased and living HSCD patients. The mean age of death was 26 years (3-52). The sex ratio was 1.2. The mortality rate was 2.76%. The death rate was high in 2011 (3.2%) and low in 2020 (0.17%). We observed a significant reduction of mortality of 94.6%. Most of the common causes of death were acute anemia (40%), acute chest syndrome (24.6%), and infections (20%). Risk factors of death were age, vaso-occlusive crises ≥3, acute chest syndrome, blood transfusion, and chronic complications. Mortality among HSCD has significantly decreased over the past 10 years in Senegal, and the main causes of death were acute anemia, acute chest syndrome, and infections.

Acute chest syndrome in pediatric sickle cell disease: Associations with racial composition and neighborhood deprivation

BACKGROUND

Acute chest syndrome (ACS) is the leading cause of death for children with sickle cell disease (SCD). Recurrent ACS has detrimental effects on pulmonary health and health care costs. Neighborhood characteristics affect the outcomes of many pediatric chronic diseases, but their role in SCD is not well studied. In this study, we investigated the effects of area-level socioeconomic deprivation and racial composition on the recurrence of ACS.

STUDY DESIGN

We performed a retrospective cross-sectional analysis of clinical data from a large pediatric SCD center. Patients' residential addresses were geocoded and linked to a composite area deprivation index (ADI) and percent African American population at the level of Census block groups. The association of recurrent ACS with neighborhood characteristics was evaluated using logistic regression analysis.

RESULTS

The sample included 709 children with SCD. Residence in a socioeconomically deprived neighborhood was associated with 27% less risk of recurrent ACS, and residence in a predominantly African American neighborhood was associated with 41% less risk of ACS recurrence. The racial composition explained the protective effect of living in a high-deprivation area after adjusting for sociodemographic and clinical covariates. Demographic and clinical factors associated with recurrent ACS included older age, male gender, asthma, hydroxyurea use, and chronic transfusion therapy.

CONCLUSIONS

This is the first study to report a protective effect of residing in a predominantly African American community for ACS recurrence. Further prospective studies are needed to confirm the association and to understand the mechanisms of such relationship.

End points for sickle cell disease clinical trials: renal and cardiopulmonary, cure, and low-resource settings

To address the global burden of sickle cell disease and the need for novel therapies, the American Society of Hematology partnered with the US Food and Drug Administration to engage the work of 7 panels of clinicians, investigators, and patients to develop consensus recommendations for clinical trial end points. The panels conducted their work through literature reviews, assessment of available evidence, and expert judgment focusing on end points related to patient-reported outcome, pain (non-patient-reported outcomes), the brain, end-organ considerations, biomarkers, measurement of cure, and low-resource settings. This article presents the findings and recommendations of the end-organ considerations, measurement of cure, and low-resource settings panels as well as relevant findings and recommendations from the biomarkers panel.

Patient-Reported Outcomes and Economic Burden of Adults with Sickle Cell Disease in the United States: A Systematic Review

Purpose

To systematically estimate the patient-reported outcomes (PROs) and economic burden of sickle cell disease (SCD) among adults in the United States (US).

Patients and Methods

Two systematic literature reviews (SLRs), one each for the PROs and economic topics, were performed using MEDLINE and Embase to identify observational studies of adults with SCD. Included studies were published between 2007 and 2018 and evaluated health-related quality of life (HRQL), function, healthcare resource utilization (HCRU), or costs. Given the high degree of clinical and methodological heterogeneity, findings were summarized qualitatively.

Results

The SLRs identified 7 studies evaluating the PROs and 15 studies evaluating the economic burden meeting the pre-specified selection criteria. The PRO evidence showed the prevalence of depression and anxiety to be 21–33% and 7–36%, respectively, in adults with SCD. The mean SF-36 physical summary scores ranged from 33.6 to 59.0 and from 46.3 to 61.5 for the mental summary scores. Overall HRQL for adults with SCD was poor and significantly worse in those with opioid use. Adult SCD patients were found to have varying rates of emergency department (ED) utilization (0.3–3.5 annual ED visits), hospitalizations (0.5–27.9 per patient per year), and/or readmission (12–41%). Key factors associated with significant HCRU were age, dental infection, and SCD-related complications. SCD specialized care settings and SCD intensive management strategy were reported to significantly decrease the number of hospitalizations.

Conclusion

This systematic evidence synthesis found that disease burden measured by PROs and economic burden of SCD on adults in the US are substantial despite the availability of approved SCD treatments during 2007–2018. The use of hydroxyurea, optimal management with opioids, and employing intensive treatment strategies may help decrease the overall burden to patients and healthcare systems. Published data on costs associated with SCD are limited and highlight the need for more economic studies to characterize the full burden of the disease.

Predictors of impending acute chest syndrome in patients with sickle cell anaemia

Acute chest syndrome (ACS) is a major complication of sickle cell anaemia (SCA) and a leading cause for hospital admissions and death. We aimed to study the spectrum of clinical and laboratory features of ACS and to assess the predisposing factors and predictors of severity. A retrospective case-control cohort was studied by retrieving patient information from electronic medical records after ethical approval. One hundred adolescents and adults with SCA and hospital admissions for ACS were identified through the discharge summaries, along with 20 additional patients presenting with VOC, but without ACS (controls). Among the patients with ACS, fever (>38.5 °C), reduced oxygen saturation (<95) and asplenia significantly differed when compared to those of controls (p < 0.05, chi-squared test). The degree of severity was reflected in the use of non-invasive ventilation (NIV), simple and exchange transfusions, and the presence of bilateral pleural effusions and multi-lobar atelectasis/consolidation, which were significantly higher in the cases with ACS than in the controls. Lower haemoglobin (Hb) and high WBC counts were also significantly different between the two groups (p < 0.05, Student's t test). Using logistic regression, our study further demonstrated that asplenia, fever, and reduced O₂ saturation, along with low Hb and leukocytosis, were important predictors for the development of ACS.

Antibiotic Use and Respiratory Pathogens in Adults With Sickle Cell Disease and Acute Chest Syndrome

Background: Acute chest syndrome (ACS) is an acute complication of sickle cell disease (SCD). Historically, the most common pathogens were Chlamydophila pneumoniae, Mycoplasma pneumoniae, and respiratory syncytial virus. Pediatric patients receiving guideline-adherent therapy experienced fewer ACS-related and all-cause 30-day readmissions compared with those receiving nonadherent therapy. This has not been evaluated in adults. Objectives: The primary objectives were to characterize antibiotic use and pathogens. The secondary objective was to assess the occurrence of readmissions associated with guideline-adherent and clinically appropriate treatment compared with regimens that did not meet those criteria. Methods: A retrospective cohort analysis was conducted for adults with SCD hospitalized between August 1, 2014, and July 31, 2017, with pneumonia (PNA) or ACS. The study was approved by the institutional review board. Results: A total of 139 patients with 255 hospitalizations were reviewed. Among 41 respiratory cultures, 3 organisms were isolated: Cryptococcus neoformans, Pseudomonas aeruginosa, and budding yeast. Respiratory panels were collected on 121 admissions, with 17 positive for 1 virus; all were negative for Chlamydophila pneumoniae and M pneumoniae. There were significantly more ACS-/PNA-related 7-day readmissions from patients on guideline-adherent regimens compared with nonadherent regimens (3.7% vs 0%; P = 0.04). Conclusion and Relevance: These findings challenge existing knowledge regarding the most common pathogens in adults with SCD with ACS or PNA. Routine inclusion of a macrolide may not be necessary. Future studies focused on pathogen characterization with standardized assessment are necessary to determine appropriate empirical therapy in this population.

Morpho-functional evaluation of lung aeration as a marker of sickle-cell acute chest syndrome severity in the ICU: a prospective cohort study

Background

Acute chest syndrome (ACS) is the main cause of morbi-mortality in patients with sickle-cell disease in the intensive care unit (ICU). ACS definition encompasses many types of lung damage, making early detection of the most severe forms challenging. We aimed to describe ACS-related lung ultrasound (LU) patterns and determine LU performance to assess ACS outcome.

Results

We performed a prospective cohort study including 56 ICU patients hospitalized for ACS in a tertiary university hospital (Paris, France). LU and bedside spirometry were performed at admission (D0) and after 48 h (D2). Complicated outcome was defined by the need for transfusion of ≥ 3 red blood cell units, mechanical ventilation, ICU length-of-stay > 5 days, or death. A severe loss of lung aeration was observed in all patients, predominantly in inferior lobes, and was associated with decreased vital capacity (22 [15–33]% of predicted). The LU Score was 24 [20–28] on D0 and 20 [15–24] on D2. Twenty-five percent of patients (14/56) had a complicated outcome. Neither oxygen supply, pain score, haemoglobin, LDH and bilirubin values at D0; nor their change at D2, differed regarding patient outcome. Conversely, LU re-aeration score and spirometry change at D2 improved significantly more in patients with a favourable outcome. A negative LU re-aeration score at D2 was an independent marker of severity of ACS in ICU.

Conclusions

ACS is associated with severe loss of lung aeration, whose resolution is associated with favourable outcome. Serial bedside LU may accurately and early identify ACS patients at risk of complicated outcome.

Spontaneous breathing during extracorporeal membrane oxygenation treatment of sickle cell disease acute chest syndrome

Sickle cell disease (SCD) is a hereditary hemoglobinopathy resulting in sickling hemoglobin. Acute chest syndrome (ACS) is a serious complication of SCD and an important cause of morbidity and mortality. Management of ACS is complex and may necessitate mechanical ventilation and veno-venous extracorporeal membrane oxygenation (VV-ECMO) therapy in the more severe cases. We present herein the case of a young female adult (19 y.o.) with SCD who developed severe respiratory failure due to ACS occurring twice within 15 months and treated by VV-ECMO. We describe the management of ACS with VV-ECMO using two different approaches, namely with and without mechanical ventilation.

Using a structured clinical assessment to identify the cause of chest pain

Chest pain is a common reason for patient presentation to emergency departments and visits to primary care settings. While most causes of chest pain are not life-threatening, a small proportion require urgent intervention, particularly cardiac conditions such as acute coronary syndrome. Therefore, it is essential for healthcare practitioners, including nurses, to identify the cause of chest pain in a safe, timely and effective manner. This article outlines the main causes of chest pain and describes the aspects of chest pain assessment, including patient history-taking, physical examination and clinical investigations. Assessing chest pain requires healthcare practitioners to have knowledge of its causes and pathophysiology, the use of structured assessment tools and the latest evidence-based guidelines.

Hospital quality indicators: a systematic review

Purpose

The purpose of this paper is to identify and describe hospital quality indicators, classifying them according to Donabedian’s structure, process and outcome model and in specific domains (quality, safety, infection and mortality) in two care divisions: inpatient and emergency services.

Design/methodology/approach

A systematic review identified hospital clinical indicators. Two independent investigators evaluated 70 articles/documents located in electronic databases and nine documents from the grey literature, 35 were included in the systematic review.

Findings

In total, 248 hospital-based indicators were classified as infection, safety, quality and mortality domains. Only 10.2 percent were identified in more than one article/document and 47 percent showed how they were calculated/obtained. Although there are scientific papers on developing, validating and hospital indicator assessment, most indicators were obtained from technical reports, government publications or health professional associations.

Research limitations/implications

This review identified several hospital structure, process and outcome quality indicators, which are used by different national and international groups in both research and clinical practice. Comparing performance between healthcare organizations was difficult. Common clinical care standard indicators used by different networks, programs and institutions are essential to hospital quality benchmarking.

Originality/value

To the authors’ knowledge, this is the first systematic review to identify and describe hospital quality indicators after a comprehensive search in MEDLINE/PubMed, etc., and the grey literature, aiming to identify as many indicators as possible. Few studies evaluate the indicators, and most are found only in the grey literature, and have been published mostly by government agencies. Documents published in scientific journals usually refer to a specific indicator or to constructing an indicator. However, indicators most commonly found are not supported by reliability or validity studies.

Therapeutic strategies for sickle cell disease: towards a multi-agent approach

For over 100 years, clinicians and scientists have been unravelling the consequences of the A to T substitution in the β-globin gene that produces haemoglobin S, which leads to the systemic manifestations of sickle cell disease (SCD), including vaso-occlusion, anaemia, haemolysis, organ injury and pain. However, despite growing understanding of the mechanisms of haemoglobin S polymerization and its effects on red blood cells, only two therapies for SCD - hydroxyurea and L-glutamine - are approved by the US Food and Drug Administration. Moreover, these treatment options do not fully address the manifestations of SCD, which arise from a complex network of interdependent pathophysiological processes. In this article, we review efforts to develop new drugs targeting these processes, including agents that reactivate fetal haemoglobin, anti-sickling agents, anti-adhesion agents, modulators of ischaemia-reperfusion and oxidative stress, agents that counteract free haemoglobin and haem, anti-inflammatory agents, anti-thrombotic agents and anti-platelet agents. We also discuss gene therapy, which holds promise of a cure, although its widespread application is currently limited by technical challenges and the expense of treatment. We thus propose that developing systems-oriented multi-agent strategies on the basis of SCD pathophysiology is needed to improve the quality of life and survival of people with SCD.

High Healthcare Utilization in Adolescents with Sickle Cell Disease Prior to Transition to Adult Care: A Retrospective Study

BACKGROUND

The transition from pediatric to adult care in the US is often difficult for individuals with sickle cell disease (SCD). Young adults (18 to 25 years of age) have higher acute care utilization and an increased risk of poor outcomes. The current study was designed to provide greater insights into patients (16 to 18 years of age) with SCD prior to their transition to adult care.

OBJECTIVES

To describe current treatment patterns, pain crises prevalence, SCD-related complications, and healthcare resource utilization (HCRU) in 16-to-18-year-old patients with SCD.

METHODS

From 1/1/2015-6/30/2017 using MarketScan Databases, patients were included if they were 16 to 18 years old at the index date, had ≥1 inpatient or 2 outpatient SCD diagnosis claims during the identification period, and were continuously enrolled in the database for at least one year prior (baseline) and post index date. Outcomes included medications, disease management interventions, Charlson Comorbidity Index (CCI), vaso-occlusive (VOC) crises requiring healthcare visits, HCRU, and SCD complications.

RESULTS

1,186 patients were included; most (64.3%) were female. The mean CCI was 1.3 (SD: 0.7). In the overall cohort, patients experienced an average of 3.9 (SD: 4.2) VOCs and most patients (61.1%, n=725) had chronic complications during the one-year follow-up. Pulmonary disease (31.1%, n=369) was the most frequent complication; blood transfusions (mean: 8.4 [SD:7.0]) and iron-chelating therapies (mean: 8.6 [SD:10]) were the most common interventions and medications, respectively. In the 16 to 18 year old group, patients with SCD had 2.0 (SD = 2.3) hospital admissions, 3.4 (SD = 4.0) ER visits, and 5.0 (SD = 4.2) office visits.

CONCLUSIONS

Prior to transition to adult care, adolescents with SCD already have significant a cute and chronic disease-related complications, possibly contributing to frequent healthcare visits. Increased attention to this age group, including improvements in disease modifying therapy, are needed prior to transition to adult care systems to improve outcomes.

Care of the Critically Ill Pediatric Sickle Cell Patient

Sickle cell disease is the most common inherited disease in the United States. Through the effects of hemolysis and vaso-occlusion, it has the potential to incite critical illness involving multiple organ systems. Children with sickle cell disease are at risk of multiple types of shock resulting in a need for ICU care. Our youngest patients with sickle cell disease are at highest risk of infection due to lack of splenic function, and this can present with septic shock. Hypovolemic shock can occur secondary to severe acute anemia as seen with splenic sequestration or a delayed transfusion reaction. As one ages, the risk of cardiac dysfunction – diastolic and systolic dysfunction as well as pulmonary hypertension – can result in cardiogenic shock. In addition to shock, patients with sickle cell disease are at risk for respiratory failure from acute chest syndrome as well as acute neurologic deterioration from stroke. For these reasons, critical care physicians must be familiar with the unique management of sickle cell complications in order to provide the best possible care for this vulnerable population.

The corticosteroid compounds prednisolone and vamorolone do not alter the nociception phenotype and exacerbate liver injury in sickle cell mice

Clinicians often hesitate prescribing corticosteroids to treat corticosteroid-responsive conditions in sickle cell disease (SCD) patients because their use can be associated with complications (increased hospital readmission, rebound pain, strokes, avascular necrosis, acute chest syndrome). Consequently, SCD patients may receive suboptimal treatment for corticosteroid-responsive conditions. We conducted a preclinical trial of dissociative (vamorolone) and conventional (prednisolone) corticosteroid compounds to evaluate their effects on nociception phenotype, inflammation, and organ dysfunction in SCD mice. Prednisolone and vamorolone had no significant effects on nociception phenotype or anemia in homozygous mice. Conversely, prednisolone and vamorolone significantly decreased white blood cell counts and hepatic inflammation. Interestingly, the effects of vamorolone were milder than those of prednisolone, as vamorolone yielded less attenuation of hepatic inflammation compared to prednisolone. Compared to controls and heterozygotes, homozygotes had significant liver necrosis, which was significantly exacerbated by prednisolone and vamorolone despite decreased hepatic inflammation. These hepatic histopathologic changes were associated with increases in transaminases and alkaline phosphatase. Together, these results suggest that, even in the setting of decreasing hepatic inflammation, prednisolone and vamorolone were associated with significant hepatic toxicity in SCD mice. These findings raise the possibility that hepatic function deterioration could occur with the use of corticosteroids (conventional and dissociative) in SCD.

Pulmonary Vascular Dysfunction and Cor Pulmonale During Acute Respiratory Distress Syndrome in Sicklers

BACKGROUND

Acute chest syndrome (ACS) is the most common cause of death among sickle cell disease (SCD) adult patients. Pulmonary vascular dysfunction (PVD) and acute cor pulmonale (ACP) are common during acute respiratory distress syndrome (ARDS) and their prevalence may be even more important during ARDS related to ACS (ACS-ARDS). The objective of this study was to evaluate the prevalence and prognosis of PVD and ACP during ACS-ARDS.

PATIENTS AND METHODS

This was a retrospective analysis over a 10-year period of patients with moderate-to-severe ARDS. PVD and ACP were assessed by echocardiography. ARDS episodes were assigned to ACS-ARDS or nonACS-ARDS group according to whether the clinical insult was ACS or not, respectively. To evaluate independent factors associated with ACP, significant univariable risk factors were examined using logistic regression and propensity score analyses.

RESULTS

A total of 362 patients were analyzed, including 24 ACS-ARDS. PVD and ACP were identified, respectively, in 24 (100%) and 20 (83%) ACS-ARDS patients, as compared with 204 (60%) and 68 (20%) nonACS-ARDS patients (P < 0.0001). The mortality did not differ between ACS-ARDS and nonACS-ARDS patients. Both the crude (odds ratio [OR], 19.9; 95% confidence interval [CI], 6.6-60; P < 0.0001), multivariable adjustment (OR, 27.4; 95% CI, 8.2-91.5; P < 0.001), and propensity-matched (OR, 11.7; 95% CI, 1.2-110.8; P = 0.03) analyses found a significant association between ACS-ARDS and ACP.

CONCLUSIONS

All SCD patients presenting with moderate-to-severe ARDS as a consequence of ACS experienced PVD and more than 80% of them exhibited ACP. These results suggest a predominant role for PVD in the pathogenesis of severe forms of ACS.

Bedside Lung Ultrasound During Acute Chest Syndrome in Sickle Cell Disease

Lung ultrasound (LU) is increasingly used to assess pleural and lung disease in intensive care unit (ICU) and emergency unit at the bedside. We assessed the performance of bedside chest radiograph (CR) and LU during severe acute chest syndrome (ACS), using computed tomography (CT) as the reference standard. We prospectively explored 44 ACS episodes (in 41 patients) admitted to the medical ICU. Three imaging findings were evaluated (consolidation, ground-glass opacities, and pleural effusion). A score was used to quantify and compare loss of lung aeration with each technique and assess its association with outcome. A total number of 496, 507, and 519 lung regions could be assessed by CT scan, bedside CR, and bedside LU, respectively. Consolidations were the most common pattern and prevailed in lung bases (especially postero-inferior regions). The agreement with CT scan patterns was significantly higher for LU as compared to CR (κ coefficients of 0.45 ± 0.03 vs 0.30 ± 0.03, P < 0.01 for the parenchyma, and 0.73 ± 0.08 vs 0.06 ± 0.09, P < 0.001 for pleural effusion). The Bland and Altman analysis showed a nonfixed bias of -1.0 (P = 0.12) between LU score and CT score whereas CR score underestimated CT score with a fixed bias of -5.8 (P < 0.001). The specificity for the detection of consolidated regions or pleural effusion (using CT scan as the reference standard) was high for LU and CR, whereas the sensitivity was high for LU but low for CR. As compared to others, ACS patients with an LU score above the median value of 11 had a larger volume of transfused and exsanguinated blood, greater oxygen requirements, more need for mechanical ventilation, and a longer ICU length of stay. LU outperformed CR for the diagnosis of consolidations and pleural effusion during ACS. Higher values of LU score identified patients at risk of worse outcome.

Blood transfusion and 30-day readmission rate in adult patients hospitalized with sickle cell disease crisis

BACKGROUND

Sickle cell disease (SCD) patients hospitalized with vasoocclusive pain crisis tend to have prolonged length of stay (LOS) and high 30-day readmission rates. We investigated the associations of demographic characteristics, comorbidities, and blood transfusion during hospitalization with these outcomes.

STUDY DESIGN AND METHODS

Repeated regression analysis was used to analyze 39,324 admissions of 4348 adults with sickle cell crisis from 2007 to 2012 in the Truven Health MarketScan Medicaid Databases.

RESULTS

The mean (95% range) LOS was 5.9 (1.0-19.0) days and the 30-day readmission rate was 39.6% (95% confidence interval [CI], 39.1%-40.0%). Older age; chronic cardiopulmonary, renal, or liver disease; and sepsis were associated with both longer LOS and greater 30-day readmission rate. Female sex, iron overload, acute chest syndrome, acute renal failure, and stroke were additional predictors of longer LOS. Simple red blood cell transfusion was administered in 31.8% of the admissions, and these patients tended to have more severe disease (chronic cardiopulmonary or kidney disease, acute chest syndrome, acute kidney or liver failure, sepsis). Nevertheless, transfusion was associated with a reduced estimated odds ratio (OR) of inpatient mortality of 0.75 (95% CI, 0.57-0.99) and a decreased OR of 30-day readmission of 0.78 (95% CI, 0.73-0.83).

CONCLUSION

Our findings point to blood transfusion as a potential means to reduce the 30-day readmission rate among Medicaid patients hospitalized with sickle cell crisis. There is a need for a prospective study to examine the potential benefit and safety of simple blood transfusion for this purpose.