Management of the febrile neutropenic cancer patient: lessons from 40 years of study

Mucositis and Infection in Hematology Patients

Survival in patients with hematological malignancies has improved over the years, both due to major developments in anticancer treatment, as well as in supportive care. Nevertheless, important and debilitating complications of intensive treatment regimens still frequently occur, including mucositis, fever and bloodstream infections. Exploring potential interacting mechanisms and directed therapies to counteract mucosal barrier injury is of the utmost importance if we are to continue to improve care for this increasingly growing patient population. In this perspective, I highlight recent advances in our understanding of the relation of mucositis and infection.

Temporary Severe Neutropenia during Administration of Atezolizumab: A Novel Case Report

Here, we describe a case of temporary severe neutropenia after atezolizumab monotherapy and its treatment course. Atezolizumab monotherapy was introduced as a 6th-line treatment for a man in his late 60s, who was diagnosed with stage Ⅳ lung adenocarcinoma. The first treatment cycle was administered during hospitalization, and the patient presented with a fever of 37.8°C on the first day. The fever resolved after the administration of acetaminophen and naproxen, and the white blood cell count, neutrophil count, and other white blood cell fractions were normal. However, grade 3 leukopenia and grade 4 neutropenia appeared at the beginning of the third cycle, and treatment was discontinued. After treatment, monocyte count in the leukocyte fraction increased from approximately 10% to 25.6%. Lenograstim 100 μg subcutaneous injection and oral levofloxacin 500 mg once daily were started of onset of neutropenia, and he was hospitalized the next day. Laboratory findings upon admission showed a significant improvement to 5,300/µL for leukocytes and 3,376/µL for neutrophils. Lenograstim was discontinued, with no further decrease in the neutrophil count. Atezolizumab therapy was resumed, and there was no further reduction in leukocyte, neutrophil, or leukocyte fractions over about a 2-year period. Concomitant drugs were maintained during the atezolizumab treatment, suggesting that they did not induce neutropenia. In conclusion, we observed temporary severe neutropenia during atezolizumab monotherapy. Neutrophil recovery with cautious monitoring has enabled longer efficacy. We should consider temporary symptom occurrence in cases of haematological immune-related adverse events.

Oncologic Emergencies-The Old, the New, and the Deadly

Cancer continues to be a leading cause of death despite a broader understanding of its biology and the development of novel therapies. Nonetheless, with an increasing survival of this population, intensivists must be aware of the associated emergencies, both old and new. Oncologic emergencies can be seen as an initial presentation of the disease or precipitated by its treatment. In this review, we present key oncologic emergencies that may be encountered in daily practice, complications associated with innovative therapies, and treatment-related adverse events.

Neutropenia in the Febrile Child

Fever in the pediatric population is a common chief complaint presenting to the emergency department and may be one of the first indications of a life-threatening infection, especially in patients with neutropenia. Given that pediatric patients with febrile neutropenia frequently present to emergency departments for emergent care, it is critical for emergency medicine physicians and pediatricians and family physicians working in the emergency department to know the key aspects of the clinical approach to these patients. This review of the clinical evaluation and treatment of the pediatric patient presenting with fever and confirmed or suspected neutropenia will provide health care providers with the necessary tools to effectively care for this patient population.

A Cluster of CNS Infections Due to B. cereus in the Setting of Acute Myeloid Leukemia: Neuropathology in 5 Patients

Bacillus cereus typically causes a self-limited foodborne gastrointestinal (GI) illness. Severe invasive infection occurs rarely, mainly among immunocompromised hosts. We describe a cluster of B. cereus infections among 5 patients with acute myeloid leukemia and chemotherapy-induced neutropenia. The initial case presented with occipital lobe abscess and was found on biopsy to have organisms consistent with Bacillus species. Within 1 week, a second patient died of fulminant brain swelling and hemorrhage. Neuropathologic autopsy and culture revealed B. cereus; hospital infection control and public health officials were notified. Three more patients died within the subsequent 9 months (2 patients had rapid massive hemorrhage and many bacilli reminiscent of Bacillus anthracis infection, and 1 patient had sparse bacilli, petechial hemorrhages, and border zone infarcts). Blood cultures yielded positive results in 3 of 5 cases. A possible route of infection was hematogenous dissemination via GI mucosal breaches (GI symptoms occurred in 3 of 5 cases, and postmortem GI ulceration was found in 3 of 4 cases). Bacilli were seen in 2 of 3 GI ulcerations. Epidemiologic work-up, including a site visit conducted by the Centers for Disease Control and Prevention, did not identify a clear common source but suggested the possibility of bananas as a food source. Bacillus cereus causes a rapidly progressive, hemorrhagic meningoencephalitis with high mortality among patients with neutropenia. Neuropathologists can play a key role in the detection of outbreaks.

Monitoring antibiotic-resistant enterobacteria faecal levels is helpful in predicting antibiotic susceptibility of bacteraemia isolates in patients with haematological malignancies

Delay of active antimicrobial therapy in haematological patients with Gram-negative bacilli bacteraemia during profound neutropenia exposes them to increased morbidity and mortality. The digestive tract is the main source of enterobacteria causing bacteraemia in these patients. We thus evaluated the usefulness of broad-spectrum beta-lactam resistant enterobacteria (BSBL-RE) faecal shedding assessment in forecasting the susceptibility to BSBLs of the strains isolated from blood cultures. From 2002 to 2011, neutropenic haematological patients with bacteraemia caused by enterobacteria who had a stool culture during the previous 7 days were retrospectively included. BSBL-RE intestinal carriers were compared with non-carriers in terms of clinical and microbiological criteria. One hundred and four patients were included and 16 of them (15.4 %) were BSBL-RE carriers. Multivariate analysis showed that BSBL-RE carriage was independently associated with BSBL-RE identified in blood cultures (P < 0.001) and the use of carbapenems as empirical treatment of the bacteraemia (P = 0.008). Sensitivity, specificity, and the positive and negative predictive values of the test were 80 %, 91 %, 50 % and 98 %, respectively. Among the carriers, those with the highest level of BSBL-RE carriage were also those with the highest risk of bacteraemia due to BSBL-RE (P < 0.001). Close monitoring of BSBL-RE intestinal carriage may help to choose the most appropriate initial antimicrobial treatment for neutropenic haematological patients with bacteraemia.

Treatment of febrile neutropenia and prophylaxis in hematologic malignancies: a critical review and update

Febrile neutropenia is one of the most serious complications in patients with haematological malignancies and chemotherapy. A prompt identification of infection and empirical antibiotic therapy can prolong survival. This paper reviews the guidelines about febrile neutropenia in the setting of hematologic malignancies, providing an overview of the definition of fever and neutropenia, and categories of risk assessment, management of infections, and prophylaxis.

Anti-infective prophylaxis in pediatric patients with acute myeloid leukemia

Pediatric patients undergoing treatment for acute myeloid leukemia (AML) are at high risk for infectious complications, predominantly due to Gram-negative bacteria, viridans group streptococci and fungal pathogens. In order to prevent infections in these patients, most institutions have implemented a number of non-pharmacological approaches to supportive care. In addition, antibiotic prophylaxis reduces bacterial infection, but may increase the emergence of resistance. Antifungal prophylaxis is generally recommended for children with AML. Whereas the use of hematopoietic growth factors has not resulted in improved survival, the efficacy of prophylactic granulocyte transfusions has to be determined.

Effect of levofloxacin prophylaxis for prevention of severe infections in multiple myeloma patients receiving bortezomib-containing regimens

Fluoroquinolone is recommended as a prophylactic antibiotic for high-risk patients with profound neutropenia. We previously reported that multiple myeloma (MM) patients who received bortezomib-based regimens were at higher risk of severe infections (30.9%) associated with lymphocytopenia. In the study, we evaluated whether severe infectious complications can be prevented by prophylactic administration of oral levofloxacin in MM patients treated with bortezomib-based regimens. A total of 80 patients received oral levofloxacin 500 mg daily during the median four cycles of treatment. The prophylactic group (n = 80) with levofloxacin showed significantly decreased severe infections compared to a historical control group (n = 139) without levofloxacin prophylaxis during treatment of bortezomib-based regimens (17.5 vs. 30.9%, P = 0.037). In the prophylactic group, two patients (2.5%) died of pneumonia and septic shock. Four patients (5%) stopped levofloxacin due to side effects that consisted of gastrointestinal discomfort (2.5%), itching sense (1.25%), and QTc prolongation (1.25%). In conclusion, prophylaxis with levofloxacin may be effective in the prevention of severe infection in MM patients receiving bortezomib-based regimens. A prospective randomized study is needed to test the prophylactic effect of levofloxacin in MM patients treated with bortezomib-based regimens.

Antimicrobial prophylaxis and outpatient management of fever and neutropenia in adults treated for malignancy: American Society of Clinical Oncology clinical practice guideline

PURPOSE

To provide guidelines on antimicrobial prophylaxis for adult neutropenic oncology outpatients and on selection and treatment as outpatients of those with fever and neutropenia.

METHODS

A literature search identified relevant studies published in English. Primary outcomes included: development of fever and/or infections in afebrile neutropenic outpatients and recovery without complications and overall mortality in febrile neutropenic outpatients. Secondary outcomes included: in afebrile neutropenic outpatients, infection-related mortality; in outpatients with fever and neutropenia, defervescence without regimen change, time to defervescence, infectious complications, and recurrent fever; and in both groups, hospital admissions, duration, and adverse effects of antimicrobials. An Expert Panel developed guidelines based on extracted data and informal consensus.

RESULTS

Forty-seven articles from 43 studies met selection criteria.

RECOMMENDATIONS

Antibacterial and antifungal prophylaxis are only recommended for patients expected to have < 100 neutrophils/μL for > 7 days, unless other factors increase risks for complications or mortality to similar levels. Inpatient treatment is standard to manage febrile neutropenic episodes, although carefully selected patients may be managed as outpatients after systematic assessment beginning with a validated risk index (eg, Multinational Association for Supportive Care in Cancer [MASCC] score or Talcott's rules). Patients with MASCC scores ≥ 21 or in Talcott group 4, and without other risk factors, can be managed safely as outpatients. Febrile neutropenic patients should receive initial doses of empirical antibacterial therapy within an hour of triage and should either be monitored for at least 4 hours to determine suitability for outpatient management or be admitted to the hospital. An oral fluoroquinolone plus amoxicillin/clavulanate (or plus clindamycin if penicillin allergic) is recommended as empiric therapy, unless fluoroquinolone prophylaxis was used before fever developed.

Evaluation and Management of Bacterial and Fungal Infections Occurring in Patients with a Hematological Malignancy: A 2011 Update

Patients with a hematological malignancy are a heterogeneous patient population who are afflicted with diseases that range from rapidly fatal acute leukemia to indolent lymphoma or chronic leukemia. Treatment options for these patients range from observation to hematopoietic stem cell transplantation (HSCT), but all patients are more susceptible to infection. The problem of infection is dynamic with continued shifts in pathogenic organisms and microbial susceptibilities, new treatment regimens that further diminish immune function, and patients receiving treatment who are now older and frailer. The classic patterns of immunodeficiency for patients with a hematological malignancy include: periods of profound neutropenia, increased iatrogenic risks (i.e., central vascular catheters), and cellular immune suppression that affects HSCT recipients, patients with lymphoid malignancies, and those receiving treatment with corticosteroids or agents like alemtuzumab [1–4]. Recent advances in antimicrobial drug development, new technology, clinical trial results, and further clinical experience have enhanced the database on which to make infection prophylaxis and treatment decisions. However, the practicing clinician must remember that the majority of basic infection management principles for patients who are neutropenic remain unchanged.

Invasive fungal sinusitis in patients with hematological malignancy: 15 years experience in a single university hospital in Taiwan

Background

Risk factors and outcomes in hematological patients who acquire invasive fungal sinusitis (IFS) are infrequently reported in the modern medical era.

Method

A retrospective study of hospitalized patients with hematological disease was conducted at National Taiwan University Hospital between January 1995 and December 2009.

Results

Clinical characteristics and outcomes with their associated radiographic and microbiological findings were analyzed. Forty-six patients with IFS and 64 patients with chronic non-invasive sinusitis were enrolled as comparsion. IFS developed more commonly in patients with acute myeloid leukemia (AML) and with prolonged neutropenia (absolute neutrophil count less than 500/mm³ for more than 10 days) (p < 0.001). Aspergillus flavus was the most common pathogen isolated (44%). Serum Aspergillus galactomannan antigen was elevated in seven of eleven patients (64%) with IFS caused by aspergillosis but negative for all three patients with mucormycosis. Bony erosion and extra-sinus infiltration was found in 15 of 46 (33%) patients on imaging. Overall, 19 of 46 patients (41.3%) died within 6 weeks. Patients with disease subtype of AML (p = 0.044; Odds Ratio [OR], 5.84; 95% confidence interval [95% CI], 1.02-30.56) and refractory leukemia status (p = 0.05; OR, 4.27; 95% CI, 1.003-18.15) had worse prognosis. Multivariate analysis identified surgical debridement as an independent good prognostic factor (p = 0.047) in patients with IFS.

Conclusions

Patients of AML with prolonged neutropenia (> 10 days) had significantly higher risk of IFS. Early introduction of anti-fungal agent and aggressive surgical debridement potentially decrease morbidity and mortality in high risk patients with IFS.

Clinical practice guideline for the use of antimicrobial agents in neutropenic patients with cancer: 2010 update by the infectious diseases society of america

This document updates and expands the initial Infectious Diseases Society of America (IDSA) Fever and Neutropenia Guideline that was published in 1997 and first updated in 2002. It is intended as a guide for the use of antimicrobial agents in managing patients with cancer who experience chemotherapy-induced fever and neutropenia. Recent advances in antimicrobial drug development and technology, clinical trial results, and extensive clinical experience have informed the approaches and recommendations herein. Because the previous iteration of this guideline in 2002, we have a developed a clearer definition of which populations of patients with cancer may benefit most from antibiotic, antifungal, and antiviral prophylaxis. Furthermore, categorizing neutropenic patients as being at high risk or low risk for infection according to presenting signs and symptoms, underlying cancer, type of therapy, and medical comorbidities has become essential to the treatment algorithm. Risk stratification is a recommended starting point for managing patients with fever and neutropenia. In addition, earlier detection of invasive fungal infections has led to debate regarding optimal use of empirical or preemptive antifungal therapy, although algorithms are still evolving. What has not changed is the indication for immediate empirical antibiotic therapy. It remains true that all patients who present with fever and neutropenia should be treated swiftly and broadly with antibiotics to treat both gram-positive and gram-negative pathogens. Finally, we note that all Panel members are from institutions in the United States or Canada; thus, these guidelines were developed in the context of North American practices. Some recommendations may not be as applicable outside of North America, in areas where differences in available antibiotics, in the predominant pathogens, and/or in health care-associated economic conditions exist. Regardless of venue, clinical vigilance and immediate treatment are the universal keys to managing neutropenic patients with fever and/or infection.

Incidence and impact of baseline electrolyte abnormalities in patients admitted with chemotherapy induced febrile neutropenia

BACKGROUND

Febrile neutropenia (FN) and myelosupression remain a challenging oncologic medical emergency and dose limiting toxicity associated with chemotherapy for cancers. Various factors are known to affect the outcomes for patients diagnosed with FN. Electrolyte abnormalities have commonly been observed, but the real incidence and their impact has been only scarcely studied in literature.

METHODS

This was a prospective, observational study. A total of two hundred and fifteen (215) patients admitted between January 2007 and August 2008 were included. Analysis of data was made using SPSS version16.0.Toxicity profile was graded according to CTC version 3.0.

RESULTS

Almost equal number of FN was observed in both solid tumors and hematological cancers with almost equal gender distribution. Of all 83.5% patients demonstrated some electrolyte abnormalities. All grades combined, hypokalemia was seen in 48% of patients, with 51.4% having grade I, 33.3% grade III and 15.2% G IV (life threatening) hypokalemia. Hyponatremia of all grades was seen in 67.9% patients, of them 60.3% had Grade I, 33.3% grade III and 0.7% patients had grade IV hyponatremia. Hypomagnesaemia (70 patients assessed) was seen in 54.3% patient, 94.7% having grade I decline. Average length of stay for patients who received IV electrolyte replacement was 6.3 days compared to 4.9 days in those who did not. Out of 90 patients who required special care unit 75 had electrolyte abnormalities, of 15 patients who expired 13 had electrolyte abnormalities

CONCLUSION

This analysis, which is first of its kind, suggests that decline in electrolyte levels is frequently observed in patients presenting with FN. These abnormalities can have independent negative impact on the outcome for such patients. Special attention should be paid to electrolyte imbalance right from the outset.

Prospective Audit of Febrile Neutropenia Management at a Tertiary University Hospital in Singapore

Introduction: Febrile neutropenia (FN) remains a major cause of morbidity and mortality in Oncology/Haematology units. We launched a new protocol for FN management that incorporates risk stratification at our institute from October 2008. An audit was performed concurrently to evaluate the protocol and to define the epidemiology of FN locally. Materials and Methods: Case records of all inpatients with FN between October 2008 and June 2009 were reviewed prospectively. Clinical and microbiological characteristics were collated along with outcomes and programme adherence. Statistical testing was performed using Stata 10.1. Results: There were 178 FN episodes (50 in patients with solid cancers) from 131 patients. Forty-two (23.6%) episodes were classified as high-risk according to MASCC criteria. Initial blood cultures were positive in 49 (27.5%) episodes, of which gram-negative bacilli (GNB) predominated. Overall compliance to the protocol was 56.7%, with the main issue being disinclination to use oral antibiotics as first-line empirical therapy for low-risk episodes. Overall mortality was 7.3% and infection-related mortality was 4.5%. High-risk FN and the presence of central venous catheters were independently associated with bacteraemia on multivariate analysis, but there were no independent predictors of infection-related mortality. Conclusions: GNB accounted for the majority of bloodstream infections at our institute, unlike data from developed countries. Uptake of the new FN protocol was satisfactory, although the use of oral antibiotics as first-line empirical therapy can be improved. A better method for predicting infections caused by antibiotic-resistant GNB is urgently required, and antibiotic resistance trends should be monitored to enable the implementation of more appropriate antibiotic regimens over time. Key words: Antimicrobial resistance, Gram-negative bacilli, MASCC score

Advances and challenges in infectious diseases supportive care of patients with hematologic malignancies, hematopoietic stem cell transplantation, and severe aplastic anemia

Infectious diseases are important causes of morbidity and mortality in immunocompromised patients with hematological malignancies, severe aplastic anemia (SAA), and myelodysplasia. Major advances in infectious diseases supportive care have been critical to improving the outcome of patients suffering from these life-threatening diseases. Advances in diagnosis, treatment, and prevention of life-threatening infections have reduced morbidity and mortality, improved quality of life, and enabled the use of potentially curative chemotherapy, radiation, hematopoietic stem cell transplantation (HSCT), and immunosuppressive therapy to patients battling these devastating diseases. Despite these advances, the continued development of antimicrobial resistance, emergence of new pathogens, and the evolution of host factors present evolving challenges to the successful management of infectious complications in this expanding patient population.

Neutropenic fever syndromes in patients undergoing cytotoxic therapy for acute leukemia and myelodysplastic syndromes

Fever represents the major surrogate of infection in neutropenic cancer patients. A number of neutropenic fever syndromes have been recognized, the causes and significance of which will vary depending upon the clinical context. First neutropenic fever syndromes are typically of bacterial origin, the character of which may be influenced by whether antibacterial chemoprophylaxis has been administered. Persistent neutropenic fevers are documented during the empirical systemic antibacterial therapy for the first neutropenic fever, the cause of which is likely outside the spectrum of activity of the initial therapy. Recrudescent neutropenic fevers, defined by the appearance of a new fever after defervescence of the first fever, are often a function of invasive fungal infection or gram-positive infections outside the spectrum of the initial empirical antibacterial regimen. The myeloid reconstitution syndrome occurs in parallel with neutrophil recovery from aplasia and may not necessarily represent new infection. Recognition of these patterns can help the clinician make better clinical judgments and management plans.

Nosocomial infections among pediatric hematology patients: results of a retrospective incidence study at a pediatric hospital in China

The occurrence of nosocomial infections (NIs) differs in different patient populations and different hospitals, and information on NI in Chinese children patients is scarce. This study fills these research gaps by evaluating the frequency of NIs, main infection sites, and common microorganisms found in pediatric hematology patients in a general children's hospital. A retrospective study was performed by analyzing the medical records of patients with NIs. The rates of NIs were calculated on the basis of cases identified during surveillance and the number of discharges annually. One thousand six hundred and four NIs were detected in 21,456 subjects (overall rate: 7.0 episodes/100 discharges). The most commonly observed infections were respiratory tract infections (1079 cases, 67.3%), followed by gastrointestinal infections (198 cases, 12.3%), skin and soft tissue infections (161 cases, 10.0%), bloodstream infections (97 cases, 6%), and urinary tract infections (16 cases, 1%). Gram-negative bacteria were the most common pathogens, followed by Gram-positive bacteria, virus, and fungal organisms. Respiratory and gastrointestinal infections were the common NIs in pediatric hematology/oncology patients. Gram-negative bacteria were responsible for most pathogens of NIs. In future studies, the prospective use of incidence density rates and postdischarge surveillance in children patient populations would be an interesting research direction.

Bacteraemia coincides with low citrulline concentrations after high-dose melphalan in autologous HSCT recipients

Mucosal damage to the intestines induced by myeloablative conditioning for allogeneic PBSC transplant (PBSCT) can be determined by the concentration of citrulline, which is a functional marker of small intestinal enterocytes. Low citrulline concentrations in blood coincide with and are a response to severe mucosal barrier injury. We treated 29 patients with high-dose melphalan 200 mg/m(2) (Mel-200) to prepare for an autologous PBSCT and collected plasma samples from each patient starting before the myeloablative regimen and three times per week thereafter until discharge. The baseline citrulline concentration was 27.6 mM+/-4.0 (mean+/-95% confidence interval; CI), and citrulline concentrations declined rapidly thereafter reaching a nadir averaging 6.7 mM+/-2.7, 12 days after starting Mel-200. Citrulline concentrations, only increased gradually and were still low (12 mM+/-4) at discharge. A total of 20 patients developed fever, which was associated with bacteraemia in 10 cases. Their mean citrulline concentrations were lower at 5.5 mM+/-1.5 than were those of patients without bacteraemia (10.2 mM+/-3.9). Importantly, neither the number of preceding neutropenic days nor the mean C-reactive protein (CRP) concentration at the onset of fever was different between these two groups. In conclusion, citrulline concentrations rapidly decline after Mel-200 reflecting intestinal mucosal barrier injury. Low citrulline, rather than the duration of neutropenia, is associated with bacteraemia indicating the importance of an intact mucosal barrier in neutropenic patients.

Bacillus spp. among hospitalized patients with haematological malignancies: clinical features, epidemics and outcomes

Between April 2000 and May 2005, 350 bacteraemic episodes occurred among patients treated in our haematology unit. Two hundred and twenty-eight of these episodes were caused by Gram-positive pathogens, most commonly coagulase-negative staphylococci and Staphylococcus aureus. One hundred and twenty-two episodes were due to Gram-negative pathogens, with a predominance of Escherichia coli, Acinetobacter baumannii and Pseudomonas aeruginosa. Bacillus bacteraemias constituted 12 of these episodes occurring in 12 patients, and accounted for 3.4% of all bacteraemic episodes. Of the 12 strains evaluated, seven were Bacillus licheniformis, three were Bacillus cereus and two were Bacillus pumilus. Seven episodes presented with bloodstream infection, three with pneumonia, one with severe abdominal pain and deterioration of liver function, and one with a catheter-related bloodstream infection. B. licheniformis was isolated from five patients who had been hospitalized at the same time. This outbreak was related to non-sterile cotton wool used during skin disinfection. B. cereus and B. licheniformis isolates were susceptible to cefepime, carbapenems, aminoglycosides and vancomycin, but B. pumilus isolates were resistant to all antibiotics except for quinolones and vancomycin. Two deaths were observed. In conclusion, Bacillus spp. may cause serious infections, diagnostic and therapeutic dilemmas, and high morbidity and mortality in patients with haematological malignancies. Both B. cereus and B. licheniformis may be among the 'new' Gram-positive pathogens to cause serious infection in patients with neutropenia.

Neutropenia febril: pasado, presente y futuro

The present review aims to provide an overall view of the changes that have occurred in the last 40 years in the etiological agents isolated in febrile neutropenic patients, as well as in their antibacterial susceptibility patterns and their involvement in empirical treatment regimes. This overall view allows us to observe how the modifications introduced in the treatment of these patients has been accompanied by continual changes in the causative microorganisms, which in turn has required treatment regimens to be redesigned. Because of these constant changes, the significant advances achieved in diagnostic techniques and the recognition of subpopulations of patients with distinct degrees of morbidity and mortality, specialists in the various fields involved in the management of febrile neutropenic patients must constantly update their knowledge.