Tracheostomy and related host-pathogen interaction are associated with airway inflammation as characterized by tracheal aspirate analysis

In the last years an increasing number of subjects experienced respiratory failure and underwent tracheostomy. The aim of the present study was to analyze tracheal aspirates from the inflammatory point of view. Samples were collected from 38 consecutive tracheostomized patients: 13 COPD, 6 with neurologic disorders and 19 with other different causes of respiratory failure. We analyzed cells and soluble mediators related to inflammation and/or infection. We also compared results obtained in the tracheal aspirate of COPD patients with the same determination in the sputum of another group of non-tracheostomized COPD patients (n=41). Regardless of the underlying diagnosis, most of the samples were Pseudomonas aeruginosa positive and cells and soluble mediator did not differ. Treatment with steroids was associated with lower amount of total cells, neutrophils and lymphocytes, whereas treatment with antibiotics was not. Tracheal aspirate neutrophils correlated with PaCO(2) values; neutrophils and eosinophils correlated with their percentages in blood. As compared with sputa obtained from another group of culture-positive non-tracheostomized COPDs, tracheal aspirates showed similar cell count, proportions of inflammatory cells, and infection/inflammatory mediators. In conclusion tracheal aspirates presented high amounts of viable cells and soluble mediators independently to the cause of respiratory failure leading to tracheotomy and they represent suitable specimens to study infection/inflammation interactions.

Mass casualty respiratory failure

PURPOSE OF REVIEW

The severe acute respiratory syndrome epidemic of 2002-2003, recent natural catastrophes, burgeoning concerns regarding intentional catastrophes, and the looming threat of an influenza pandemic have focused attention on large-scale, survivable respiratory failure. In this article, we review appropriate medical equipment, treatment space, and strategies to augment health professional staff in response to a massive increase in need for sustained critical care.

RECENT FINDINGS

There is insufficient modern healthcare experience with mass casualty respiratory failure to develop evidence-based preparedness efforts. For this reason, initial efforts to augment critical care capability in response to disasters have relied on extrapolation from the routine critical care knowledge base, military medicine, critical care transport, and expert opinion. We review recently published documents on augmenting supplies of positive pressure ventilation equipment, ongoing projects for increasing health professional staff, and infection control issues during epidemics.

SUMMARY

Mass casualty respiratory failure remains a largely unstudied field, but we believe informed decisions about equipment stockpiling and use, the development of creative operational concepts to increase staffing, and the careful implementation of rational infection control practices can lay a foundation for an appropriate response until additional data become available.

[Botulism in infancy - survey of literature based on a case report]

The authors have drawn attention to a rare disease called infant botulism, which raises some difficulties with regard to differential diagnosis. In the case of the six-month-old infant portrayed, infant botulism and food-born botulism appeared together. As a result of the severity of the disease and due to its rapid course observed in the presented case as well, the diagnosis has to be raised relying on the accurate patient's history and on the clinical examination, then it should be confirmed by appropriate examinations. In relation to presenting a case, the authors examine the microbiological background of the disease, its symptomatology, its epidemiological characteristics, the appropriate methods of electrophysiological examination and laboratory analysis as recommended in current literature, together with the difficulties that arise in differential diagnosis and also the possibilities of treatment. They pay special attention to the particular characteristics of the infant form of the disease, to the difficulties of making a diagnosis due to the characteristics of the age group and also to the questions in relation to the guiding principles of therapy. The rapid and fatal process observed in the presented case warns us that serious complications can occur even when up-to-date therapy is used. Therefore, despite the improvement in prognosis we have to strive to prevent the disease by spreading the proper regulations of nutritional hygiene.

Utility of Positive Bronchoalveolar Lavage in Predicting Respiratory Failure After Hematopoietic Stem Cell Transplantation: A Retrospective Analysis

Pulmonary complications occur frequently after hematopoietic stem cell transplantation (HSCT) and account for considerable mortality when associated with respiratory failure. Bronchoalveolar lavage (BAL) is commonly used in the diagnostic evaluation of pulmonary infiltrates in HSCT patients. Although the yield of BAL is well established in this setting, the impact on outcome is controversial. In addition, respiratory failure in HSCT patients is associated with high mortality. To determine if positive BAL predicted less respiratory failure and better survival, a retrospective review (between 1992 and 1998) of all HSCT patients who had bronchoscopy with BAL as part of their diagnostic evaluation for new pulmonary infiltrates was performed. Twenty-one patients met the inclusion criteria. Eleven patients (52%) had a positive BAL, defined as the isolation of infectious microorganisms or pulmonary hemorrhage in the lavage specimen. Most of the positive findings were pathogenic organisms (bacterial, fungal, and viral). Respiratory failure (defined as need for both intubation and mechanical ventilation) occurred in 11 of 21 patients (52%)-8 of 11 (73%) who had positive BAL compared with 3 of 10 (30%) who had negative BAL (P = .09). The overall mortality rate was 11 of 21 patients (52%). All deaths except one occurred as a direct result of respiratory failure. Although this study confirmed the high mortality rate in HSCT patients with respiratory failure, the BAL results were not predictive of outcome.

[Acute respiratory failure and septic shock induced by Mycobacterium bovis. A rare side effect of intravesical BCG therapy]

INTRODUCTION

Intravesical bacillus Calmette-Guerin (BCG) therapy, recommended for superficial bladder tumors, triggers side effects in fewer than 5% of patients. The most severe side effects, however, are septic shock and acute respiratory failure.

CASE

A 70-year-old man was hospitalized for septic shock with acute respiratory and renal failure after intravesical instillation of BCG, which was identified in the gastric aspiration sample. Treatment with rifampicin, ethambutol, isoniazid, and corticosteroid therapy, as well as standard reanimation measures, led to the patient's recovery.

DISCUSSION

This case shows the potentially severe side effects of intravesical BCG instillation. Although this treatment is well tolerated in more than 95% of patients and its systemic complications can be effectively treated, these side effects can be life-threatening.

Equitable resource allocation in the intensive care unit: a descriptive ethical case

A patient with respiratory failure due to undiagnosed tuberculosis in the presence of HIV infection presents to the ICU in a foreign country. This raises many ethical questions, quite apart from the medical management issues raised by the patient's serious condition. Six of these ethical questions have been presented to leading physicians and an ethicist, from a range of national, cultural and religious backgrounds, for their comment.

Adult botulism type F in the United States, 1981-2002

BACKGROUND

Clostridium botulinum neurotoxin types A, B, and E cause most cases of the paralytic disease botulism. Little is known about the epidemiology, clinical features, or microbiology of botulism type F.

METHODS

Cases of adult type F botulism were identified by review of data collected by CDC's National Botulism Surveillance System between 1981 and 2002. A case was either an individual whose serum or stool demonstrated type F toxin or whose stool culture yielded an organism producing toxin type F. A detailed review of cases' medical charts and laboratory data from CDC and local health departments was performed.

RESULTS

Between 1981 and 2002, 1,269 cases of botulism among adults and infants were reported to CDC; 13 (1%) were adult type F. The median age of type F cases was 54 years; 7 (54%) were female. None were part of outbreaks. A toxigenic Clostridium baratii was identified in 9 (69%) of 13 cases. Among 11 cases for which clinical data were available, all required mechanical ventilation for a median duration of 17 days (range, 10 to 84); 8 (73%) were intubated within 24 hours of symptom onset. All patients had nearly complete or complete quadriplegia at the nadir of neurologic dysfunction, which occurred on average on day 5. On average by day 8, improvement in neuromuscular function was noted. The median duration of acute hospitalization was 31 days (range, 20 to 60). No deaths were reported. In only one case was a possible foodborne etiology identified.

CONCLUSIONS

Toxigenic C baratii are the sole documented causes of type F botulism in the United States since 1981. These cases are characterized by a fulminant course with rapid progression to respiratory failure and paralysis, making early recognition and intervention critical to appropriate management.

Acute respiratory failure associated with cryptococcal pneumonia and disseminated cryptococcosis in an AIDS patient

A 36-year-old homosexual Mexican man was admitted to our hospital, with a 30-day history of fever and headache. Upon cerebrospinal fluid examination, the patient's white blood cell count was 1,580/L, total protein was 26 mg/dL, sugar was 17 mg/dL, and his intracranial pressure was 23 cmH2O. The patient was diagnosed with HIV (Human Immunodeficiency Virus) infection by serum Western blotting. Cryptococcus neoformans was isolated in cultures of the patient's blood and cerebrospinal fluids. Chest computerized tomography revealed diffuse reticulonodular infiltration and a ground-glass appearance in both perihilar regions, suggestive of either Pneumocystis carinii pneumonia or cryptococcal pneumonia. On the patient's 6th day in our hospital, bronchoalveolar lavage and transbronchial lung biopsy were conducted via bronchoscopy, and a pathologic examination of lung biopsy specimens revealed signs of cryptococcal pneumonia. This patient died on his 14th day in our hospital, as the result of acute respiratory failure, associated with cryptococcal pneumonia and disseminated cryptococcosis.

[Clinical case of the month. Fatal pertussis infection in a 2 month old infant]

The incidence of B pertussis has increased by 50% from the 1980s to the 1990s, primarily among those aged 4 months and younger. Worldwide, pertussis is a significant cause of infectious mortality with 40 million cases and 400.000 deaths. Most of these cases and deaths occur in infancy. Symptoms vary from common cold in adults to respiratory distress in infants. Non immune babies with respiratory disease and significant lymphocytosis should be considered to have pertussis until proven otherwise. The onset of severe pulmonary hypertension during B pertussis pneumonia is frequenly rapid and relentless. Exchange-transfusion can be life-saving by reducing the leucocyte mass. Classic vaccination or boosters given to adults and adolescents would reduce the spread from parents tho infants, but a new vaccination schedule is under investigation at Vanderbilt Children's Hospital to give baby's first pertussis vaccination at birth?

[Application of pulmonary infection control window as switching point for sequential invasive to noninvasive ventilation in treatment of severe respiratory failure of chronic obstructive pulmonary disease: a randomized controlled study]

OBJECTIVE

To evaluate the feasibility and the efficacy of early extubation and sequential noninvasive mechanical ventilation (MV) switched by pulmonary infection control window (PIC window) in chronic obstructive pulmonary disease (COPD) with exacerbated hypercapnic respiratory failure.

METHODS

Respiratory or Medical Intensive Care Units (RICU/MICU) of 12 teaching hospitals in China participated in this study. COPD patients with severe hypercapnic respiratory failure exacerbated by pulmonary infection, and for whom intubation and MV were indicated, were enrolled in the study. PIC window was defined as the time point when pulmonary infection was considered under control based on clinical parameters. At PIC window, all the cases were randomly assigned to sequential MV group or conventional MV group. The invasive MV duration, ventilator-associated pneumonia (VAP), days in ICU and mortality rate in both groups were measured.

RESULTS

Ninety cases were enrolled. Compared with conventional MV group (n = 43) sequential MV group (n = 47) had shorter duration of invasive MV [(6.4 +/- 4.4), (11.3 +/- 6.2) d, P = 0.000], lower rate of VAP (3/47, 12/43, P = 0.014), fewer days in ICU [(12 +/- 8), (16 +/- 11) d, P = 0.047] and lower mortality rate (1/47, 7/43, P = 0.025).

CONCLUSION

Early extubation followed by non-invasive MV initiated at the point of PIC window may decrease the duration of invasive MV and improve the prognosis.

Strongyloides hyperinfection presenting as acute respiratory failure and gram-negative sepsis

STUDY OBJECTIVES

Disseminated strongyloides is a rarely reported phenomenon and occurs in immunosuppressed patients with chronic Strongyloides stercoralis infection. Typically, patients present with pulmonary symptoms but subsequently acquire Gram-negative sepsis. Several cases have been noted in Minnesota, and their presentation, diagnostic evaluation, and clinical outcomes were reviewed.

DESIGN

A retrospective chart review was conducted of complicated strongyloides infections from 1993 to 2002 in Minneapolis and St. Paul, MN. Cases were identified by reviewing hospital microbiology databases.

SETTING

Metropolitan hospitals with large immigrant populations.

RESULTS

Nine patients, all of Southeast Asian heritage, were identified. Eight patients immigrated to the United States > or = 3 years prior to acute presentation. All patients were receiving antecedent corticosteroids; in five patients, therapy was for presumed asthma. Absolute eosinophil counts > 500/microL occurred in only two patients prior to steroid initiation. Eight patients presented with respiratory distress, and Gram-negative sepsis developed in four patients. Four patients had evidence of right-heart strain on ECG or echocardiography at the time of presentation. Three patients died; all had eosinophil counts of < 400/microL.

CONCLUSIONS

Serious complications, including death, may occur in patients with chronic strongyloides infection treated with corticosteroids. Strongyloides hyperinfection usually presents as acute respiratory failure and may initially mimic an asthma exacerbation or pulmonary embolism. Southeast Asian patients presenting with new-onset "asthma," acute respiratory distress, and/or Gram-negative sepsis should undergo evaluation to exclude strongyloides infection.

Leptospirosis and its pulmonary complications

OBJECTIVE

The aim of this study was to assess the incidence and factors associated with pulmonary complications of leptospirosis.

METHODOLOGY

In a retrospective study, patients with a definite diagnosis of leptospirosis following a 6-week period of severe flooding in Hadyai city, Thailand, were reviewed. Pulmonary complications of leptospirosis were defined as the occurrence of respiratory symptoms and an abnormal CXR. The clinical and laboratory test results for patients with and without pulmonary complications were compared.

RESULTS

Among the 157 patients with leptospirosis, eight patients had pulmonary complications. Three patients had acute renal failure (ARF) and pulmonary oedema. One patient had ARF and adult respiratory distress syndrome (ARDS). Two patients had ARF, congestive heart failure and pulmonary oedema. One patient had congestive heart failure and pulmonary oedema. One patient had only ARF. Factors associated with pulmonary complications were delayed antibiotic treatment and thrombocytopenia (platelet count < 100 x 10(9)/L). Three patients developed adult respiratory distress syndrome and one died from respiratory failure.

CONCLUSIONS

Pulmonary complications and death occur in a low percentage of patients with leptospirosis. Delayed antibiotic treatment and thrombocytopenia are risk factors for the development of pulmonary involvement in leptospirosis.

Nitric oxide production and immunoglobulin deposition in leptospiral hemorrhagic respiratory failure

Diffuse pulmonary hemorrhage leading to death is a syndrome which may develop in leptospirosis, but its pathophysiology is not well documented. We report an autopsy case of leptospirosis. A healthy 41-year-old man presented with low back myalgia, dry cough and fever for 4 days and a normal chest X-ray on admission. Acute respiratory failure developed hours later. Profuse bloody fluid appeared in the endotracheal tube immediately after intubation. Chest X-ray showed whiteness across all lung fields. He died of persistent shock 16 h after the onset of acute respiratory failure. Autopsy revealed diffuse pulmonary hemorrhage with hyaline-membrane formation, myocarditis, interstitial nephritis and hepatitis. Silver stain of lung and kidney tissue demonstrated leptospires. Immunohistochemical staining showed inducible nitric oxide synthase in alveolar macrophages. Immunofluorescein staining showed immunoglobulin in alveolar septum and alveolar space. This case suggests that hemorrhagic diffuse alveolar damage with persistent shock is related to over-production of nitric oxide and immunoglobulin deposition in fatal leptospirosis.

Blockade of tissue factor-factor X binding attenuates sepsis-induced respiratory and renal failure

Tissue factor expression in sepsis activates coagulation in the lung, which potentiates inflammation and leads to fibrin deposition. We hypothesized that blockade of factor X binding to the tissue factor-factor VIIa complex would prevent sepsis-induced damage to the lungs and other organs. Acute lung injury was produced in 15 adult baboons primed with killed Escherichia coli [1 x 10(9) colony-forming units (CFU)/kg], and then 12 h later, they were given 1 x 10(10) CFU/kg live E. coli by infusion. Two hours after live E. coli, animals received antibiotics with or without monoclonal antibody to tissue factor intravenously to block tissue factor-factor X binding. The animals were monitored physiologically for 34 h before being killed and their tissue harvested. The antibody treatment attenuated abnormalities in gas exchange and lung compliance, preserved renal function, and prevented tissue neutrophil influx and bowel edema relative to antibiotics alone (all P < 0.05). It also attenuated fibrinogen depletion (P < 0.01) and decreased proinflammatory cytokines, e.g., IL-6 and -8 (P < 0.01), in systemic and alveolar compartments. Similar protective effects of the antibody on IL-6 and -8 expression and permeability were found in lipopolysaccharide-stimulated endothelial cells. Blockade of factor X binding to the tissue factor-factor VIIa complex attenuates lung and organ injuries in established E. coli sepsis by attenuating the neutrophilic response and inflammatory pathways.

Life-threatening allergic bronchopulmonary aspergillosis in a well child with cystic fibrosis

Allergic bronchopulmonary aspergillosis (ABPA) is an uncommon condition which may complicate asthma and cystic fibrosis; it is seldom considered life-threatening. We report a well 8-year-old boy with cystic fibrosis and normal lung function who progressed to respiratory failure over several days, attributable to ABPA. He recovered with non-invasive ventilation and oral corticosteroid and antifungal medications, regaining normal lung function within 2 months. To our knowledge, such an acute severe presentation of ABPA in a previously well child has not been reported before.

Modern management of respiratory failure due to pulmonary mycoses following allogeneic hematopoietic stem-cell transplantation

Pulmonary mycoses count among the most dangerous complications in allogeneic hematopoietic stem cell transplantation. Despite the establishment of antifungal chemoprophylaxis and empirical antifungal treatment, they frequently lead to respiratory failure and are still associated with an extraordinarily poor prognosis. However, the emergence of new antimycotics with alternative mechanisms of actions and decreased toxicity in combination with the development of new non culture-based diagnostic techniques may allow earlier, more aggressive and more effective antifungal treatment approaches. In addition, the optimized use of new technologies designed to augment spontaneous breathing efforts by patients, mechanical ventilation, as well as the advantages of early tracheostomy lead us to expect better outcomes in the treatment of respiratory failure due to pulmonary mycoses following allogeneic hematopoietic stem cell transplantation.

Streptococcus pneumoniae and community-acquired pneumonia: a cause for concern

Community-acquired pneumonia (CAP) is the sixth most common cause of death in the United States and the leading cause of death from infectious diseases. It is associated with significant morbidity and mortality, and poses a major economic burden to the healthcare system. Streptococcus pneumoniae is the leading cause of CAP. Other common bacterial causes include Haemophilus influenzae as well as atypical bacteria (Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella species). Increasing resistance to a variety of antimicrobial agents has been documented in S. pneumoniae and is common in H. influenzae as well. Successful empiric therapy is paramount to the management of CAP to avoid treatment failure and subsequent associated costs. Given that resistance is increasing among respiratory pathogens, and S. pneumoniae is the most common etiologic agent identified in CAP, strategies for antimicrobial therapy should be based on the likely causative pathogen, the presence of risk factors for infection with resistant bacteria, and local resistance patterns.

Myelopathy due to spinal epidural abscess without cord compression: a diagnostic pitfall

Spinal epidural abscess (SEA) is a neurological emergency that requires urgent diagnosis and treatment. We report 2 patients with SEA, in whom, on neuropathological examination, the neurological signs were found to be caused by spinal cord ischemia due to thrombosis of leptomeningeal vessels and compression of spinal arteries, respectively, while evidence of spinal cord compression was absent. Clinicians and neuropathologists should be aware of the variable mechanisms underlying the neurological involvement in SEA. Absence of spinal cord compression by the abscess may hamper early diagnosis and treatment.