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Aspiration of a foreign object is uncommon in a patient with a tracheostomy. The following case history describes the consequences of failure to diagnose an aspirated object and how the aspiration of an exfoliated tooth can occur despite the presence of a tracheostomy tube. Dentists play an important role in preventing foreign body aspiration in debilitated patients.
Neisseria species other than N. meningitidis and N. gonorrhoeae are generally regarded as commensal bacterial flora of the oropharynx, and little is known regarding cases of these non-pathogenic Neisseria species in the lower respiratory tract. We clinically examined respiratory tract infections from which non-pathogenic Neisseria species were isolated by transtracheal aspiration (TTA). The incidence of non-pathogenic Neisseria isolated was 54 (15.7%) out of 344 episodes of respiratory tract infections with isolated microorganisms from TTA, and was 17.6%, 15.8%, 14.3% for pneumonia, acute bronchitis, and chronic lower respiratory tract infection, respectively. All 54 episodes were isolated with other microorganisms such as alpha-Streptococcus spp. (75.9%), Haemophilus influenzae (25.9%) and anaerobics (22.2%). The isolation ratio according to the age group increased at 45 years of age or more, but did not increase with the advance of age. Predisposing factors were identified such as overt aspiration, iatrogenic procedure and heavy smoking. Cases without overt aspiration that had fevers of 38 degrees C or more or hypoxemia of less than PaO2 70 torr when detecting non-pathogenic Neisseria were observed more frequently in the aged than the non-aged. The findings suggest the detection of non-pathogenic Neisseria by TTA is influenced by the host state that the fall of microorganisms from the upper to lower respiratory tract cannot be defended or excluded by mucociliary transportation disorder due to underlying disease and smoking, or deterioration of physical status other than overt or silent aspiration.
BACKGROUND: A biologically plausible link between gastro-oesophageal reflux (GOR), aspiration, and lung allograft dysfunction has been suggested, but there is no systematic evidence indicating the presence of gastric contents in the lung. We have tested the hypothesis that pepsin, as a marker of aspiration, is detectable in bronchoalveolar lavage (BAL) fluid of allograft recipients who had not reported symptoms of GOR. METHODS: Standardised 3 x 60 ml surveillance BAL fluid samples from 13 chronologically sequential stable lung allograft recipients without chronic rejection (10 patients treated with a prophylactic proton pump inhibitor) were studied. Lavage supernatants were assayed by an ELISA based on a monospecific goat antibody for pepsin/pepsinogen. Pepsin levels were compared with those from four normal volunteer controls. RESULTS: Pepsin levels were measurable in all allograft recipients, in keeping with gastric aspiration (median 109 ng/ml (range 35-1375)). In the control group the pepsin levels were below the limit of detection. Treatment with a proton pump inhibitor was not correlated with pepsin levels. There was no correlation between BAL fluid neutrophils and pepsin levels. CONCLUSION: These data demonstrate lung epithelial lining fluid concentrations of pepsin in lung allograft recipients which are much higher than blood reference levels, with no detectable pepsin in controls. This provides direct evidence of gastric aspiration, which is potentially injurious to the allograft.
This study examines surfactant dysfunction in rats with inflammatory lung injury from intratracheal instillation of hydrochloric acid (ACID, pH 1.25), small nonacidified gastric particles (SNAP), or combined acid and small gastric particles (CASP). Rats given CASP had the most severe lung injury at 6, 24, and 48 h based on decreases in arterial oxygenation and increases in erythrocytes, total leukocytes, neutrophils, total protein, and albumin in bronchoalveolar lavage (BAL). The content of large surfactant aggregates in BAL was reduced in all forms of aspiration injury, but decreases were greatest in rats given CASP. Large aggregates from aspiration-injured rats also had decreased levels of phosphatidylcholine (PC) and increased levels of lyso-PC and total protein compared with saline controls (abnormalities for CASP were greater than for SNAP or ACID alone). The surface tension-lowering ability of large surfactant aggregates on a bubble surfactometer was impaired in rats with aspiration injury at 6, 24, and 48 h, with the largest activity reductions found in animals given CASP. There were strong statistical correlations between surfactant dysfunction (increased minimum surface tension and reduced large aggregate content) and the severity of lung injury based on arterial oxygenation and levels of albumin, protein, and erythrocytes in BAL (P < 0.0001). Surfactant dysfunction also correlated strongly with reduced lung volumes during inflation and deflation (P = 0.0004-0.005). These results indicate that surfactant abnormalities are functionally important in gastric aspiration lung injury and contribute significantly to the increased severity of injury found in CASP compared with ACID or SNAP alone.
Meconium aspiration syndrome is a cause of significant morbidity and mortality in the perinatal period and has been implicated in the pathogenesis of airway dysfunction. In this study, we developed a murine model to evaluate the effects of meconium aspiration on airway physiology and lung cellular responses. Under light anesthesia, BALB/c mice received a single intratracheal instillation of meconium or physiological saline. Respiratory mechanics were measured in unrestrained animals and expressed as percent increase in enhanced pause to increasing concentrations of methacholine (MCh). Furthermore, we assessed the changes in cells and cytokines into the bronchoalveolar lavage fluid (BALF). We found meconium aspiration produced increased airway responsiveness to MCh at 7 days. These functional changes were associated with lymphocytic/eosinophilic inflammation, goblet cell metaplasia, and increased concentrations of IL-5 and IL-13 in the BALF. Our findings suggest meconium aspiration leads to alterations of airway function, lung eosinophilia, goblet cell metaplasia, and cytokine imbalance, thus providing the first evidence of meconium-induced airway dysfunction in a mouse model.
A model of aspiration lung injury was developed in WT C57BL/6 mice to exploit genetically modified animals on this background, i.e., MCP-1(-/-) mice. Mice were given intratracheal hydrochloric acid (ACID, pH 1.25), small nonacidified gastric particles (SNAP), or combined acid plus small gastric particles (CASP). As reported previously in rats, lung injury in WT mice was most severe for "two-hit" aspiration from CASP (40 mg/ml particulates) based on the levels of albumin, leukocytes, TNF-alpha, IL-1beta, IL-6, MCP-1, KC, and MIP-2 in bronchoalveolar lavage (BAL) at 5, 24, and 48 h. MCP-1(-/-) mice given 40 mg/ml CASP had significantly decreased survival compared with WT mice (32% vs. 80% survival at 24 h and 0% vs. 72% survival at 48 h). MCP-1(-/-) mice also had decreased survival compared with WT mice for CASP aspirates containing reduced particulate doses of 10-20 mg/ml. MCP-1(-/-) mice given 5 mg/ml CASP had survival similar to WT mice given 40 mg/ml CASP. MCP-1(-/-) mice also had differing responses from WT mice for several inflammatory mediators in BAL (KC or IL-6 depending on the particle dose of CASP and time of injury). Histopathology of WT mice with CASP (40 mg particles/ml) showed microscopic areas of compartmentalization with prominent granuloma formation by 24 h, whereas lung tissue from MCP-1(-/-) mice had severe diffuse pneumonia without granulomas. These results indicate that MCP-1 is important for survival in murine aspiration pneumonitis and appears to act partly to protect uninjured lung regions by promoting isolation and compartmentalization of tissue with active inflammation.
BACKGROUND: Pneumonia is the reported cause of death of a high proportion of Alzheimer's disease (AD) patients. OBJECTIVES: This study assessed swallowing function to explore the potential risk factors of aspiration pneumonia in AD patients. METHODS: Data were gathered on 121 AD patients (mean age 78.2, SD 7.5, male/female ratio = 48/73) treated in two psychiatric hospitals. Multiple logistic regression analysis was used to estimate odds ratios for the risk of aspiration pneumonia. The following risk factors were considered: age, severity of dementia, silent brain infarction (SBI) in the basel ganglia, use of psychotropic drugs (neuroleptics and benzodiazepines), and gender. The latency time of the swallowing reflex was analyzed (1) among groups based on the severity of dementia; (2) between groups with and without SBI in the basal ganglia; (3) before and after the use of psychotropic drugs in the group without SBI in the basal ganglia, and (4) between males and females. RESULTS: Aspiration pneumonia in ambulatory AD patients was significantly and independently associated with severe dementia, presence of SBI in the basal ganglia, intake of neuroleptics, and the male gender. The mean latency of the swallowing reflex in the severe AD group was significantly longer compared to that in the mild-to-moderate AD group. The mean latency of the swallowing reflex after the intake of neuroleptics was significantly prolonged compared to that obtained before any neuroleptic intake, whereas there was no significant difference in the mean latency of the swallowing reflex before and after benzodiazepine intake. CONCLUSION: We recommend the use of the smallest efficacious dosage of neuroleptics especially in treating severely demented AD patients with basal-ganglia infarction. As soon as the behavioral and psychiatric problems are resolved, drug tapering or discontinuation should be considered in order to prevent life-threatening aspiration pneumonia.
BACKGROUND: Exogenous surfactant should be used as early as possible in the presence of respiratory distress syndrome (RDS), but diagnosis may only become clear late in the course of the disease. The stable microbubble test (SMT) in the tracheal aspirates could help in the decision to give early surfactant to preterm babies with respiratory distress. OBJECTIVES: The objective of this study was to evaluate the accuracy of the SMT on tracheal aspirate for the diagnosis of RDS in newborns requiring mechanical ventilation. METHODS: The test was performed on specimens obtained from 74 infants requiring mechanical ventilation, through routine suctioning. RESULTS: Patients with RDS and meconium aspiration syndrome (MAS) had a significantly lower stable microbubble count than non-RDS and non-MAS patients. Preterm infants without RDS had a significantly higher microbubble count than preterm babies with RDS and a similar count to that of term babies. Considering a cutoff point of 120 microbubbles/mm(2) for the diagnosis of RDS, the sensitivity of the microbubble test was 96.3% (95% CI: 79.1-99.8) and the specificity 97.6% (95% CI: 85.9-99.9). CONCLUSIONS: The SMT on tracheal aspirates is accurate for RDS diagnosis and may be useful to support the decision to give surfactant to newborns on mechanical ventilation.
BACKGROUND AND PURPOSE: Dysphagia is common after stroke and is a marker of poor prognosis. Early identification is important. This article reviews the merits and limitations of various assessment methods available to clinicians. METHODS: An electronic database search was performed of MEDLINE, EMBASE, and the Cochrane database using such terms as stroke, aspiration, dysphagia, and assessment; extensive manual searching of articles was also conducted. RESULTS: Bedside tests are safe, relatively straightforward, and easily repeated but have variable sensitivity (42% to 92%), specificity (59% to 91%), and interrater reliability (kappa=0 to 1.0). They are also poor at detecting silent aspiration. Videofluoroscopy gives anatomic and functional information and allows testing of therapeutic techniques. However, swallowing is assessed under ideal conditions that are different from clinical settings, and reliability is often poor (kappa=0 to 0.75) in the absence of assessor training. Fiberoptic endoscopy allows swallow assessment and sensory testing but requires specialized staff and equipment. Oxygen desaturation during swallowing may be predictive of aspiration (sensitivity, 73% to 87%; specificity, 39% to 87%) but is more useful in combination with bedside testing than in isolation. Other methods of swallow testing are invasive and require specialized staff and equipment. CONCLUSIONS: Although bedside tests remain an important early screening tool for dysphagia and aspiration risk, further refinements are needed to improve their accuracy.
BACKGROUND AND PURPOSE: The aim of the present study was to examine the value of pulse oximetry in the diagnosis of aspiration by comparing it with the gold standard, videofluoroscopy, by use of a prospective, controlled, single-blind study design. METHODS: Pulse oximetry was performed simultaneously with videofluoroscopy in 54 consecutive dysphagic stroke patients. Oxygen saturation measurements were taken before the video-fluoroscopic examination (baseline), on swallowing and continuously for 2 minutes after swallowing, and 10 minutes later. RESULTS: Pulse oximetry reliably predicted aspiration or lack of it in 81.5% of cases. The predictive value of the test was low in patients aged > or = 65 years and possibly those with chronic lung disease. One smoker also had a false-negative pulse oximetry result, ie, normal oxygen saturation despite radiological evidence of aspiration. CONCLUSIONS: Pulse oximetry is a reliable method of diagnosis of aspiration in most dysphagic patients. However, careful interpretation of pulse oximetry data is necessary in older subjects, possibly those with chronic pulmonary disease, and smokers. The method is noninvasive, simple, and quick, and can be used routinely in the clinical assessment of dysphagic patients.
Twenty-five patients were treated with a laryngeal stent for potentially reversible chronic aspiration of life-threatening magnitude. The causes of the intractable aspiration were diverse and included chronic neurologic disease, extensive head and neck surgery, and severe gastroesophageal reflux. The advantages of this technique are noted in comparison to those of more invasive procedures. Disadvantages of the laryngeal stent and complications encountered are also covered. The long-term results show that all but one patient had a significant improvement in their chronic aspiration with the stent in place. However, only eight patients achieved adequate oral deglutition without aspiration following stent removal.
A national longitudinal database was used to compare the aspirations and attainment of individuals with and without learning disabilities (LD) 2 years after high school completion. Analyses revealed that individuals with LD reported lower graduation rates, were more likely to aspire to moderate- (men) or low-prestige (women) occupations, and were more likely to be employed and less likely to be enrolled in some type of postsecondary education program than their nondisabled peers. High educational aspirations in Grade 12 and successful completion of an academic or college-prep high school program were equally important in predicting 2-year postsecondary status for adolescents enrolled in postsecondary education regardless of disability status. However, depending on disability status, different predictors were identified for individuals who were either employed or out of the workforce. These results point to a continued need for transition planning and support for young adults with LD and suggest ways in which professionals can anticipate and adjust for identified differences in aspirations and postsecondary attainment.
BACKGROUND: Pneumonia is a significant clinical concern in critically ill hospitalized patients, leading to increase in the use of antibiotics, length of hospital stay, and the risk of mortality. Pneumonia caused by aspiration of gastric contents is of particular concern in patients who need mechanical ventilation and feeding through a nasogastric tube. Therefore, methods for decreasing the risk of aspiration are very important. METHODS: This review article summarizes factors that might influence the development of aspiration pneumonia, such as the position of the patient's body or type of hospital bed, methods of feeding, medications administered, suctioning of subglottic secretions, and bacterial decontamination. RESULTS: Elevating the head of the bed (45 degrees), continuous subglottic suctioning, and oral decontamination seem to be effective in the prevention of aspiration pneumonia.
The medical literature supports the use of enteral feeding to provide nutrition and improve patient outcomes. A major complication of enteral feeding is aspiration and associated morbidity and mortality. Many knowledge gaps exist that inhibit our ability to define and diagnose aspiration, identify patients at risk, and develop prevention techniques. Several areas of inquiry should be explored to help us define and prevent the disorder--for instance, standardized criteria should be developed for diagnosing aspiration pneumonia and for differentiating it from other types of pneumonia, and accurate tests should be devised for detecting it. Research also is needed to evaluate the influence of (1) various enteral feeding sites on aspiration risk, (2) the effects of risk reduction techniques such as selective decontamination and use of promotility agents, and (3) potential benefits of immunonutrition. Current parameters used in decisions about when to initiate enteral feeding in critically ill patients are defined.
BACKGROUND: Vomiting, aspiration, and pneumonia are serious side effects in enteral feeding via percutaneous endoscopic gastrostomy (PEG), which often leads to hospitalization. To this day, it has not been proven whether pump-assisted (PA) or gravity-controlled application is the safer method for long-term feeding via PEG in bedridden patients. METHODS: This study was conducted as a prospective, randomized crossover study. Fifty bedridden PEG patients were fed using the pump-assisted method (G1) and 50 patients were fed using the gravity-controlled feeding method (G2). After 6 weeks of observation (O1), the feeding methods in both groups were switched, followed by another 6 weeks of observation (O2). Daily recording was done using a standardized questionnaire. The glucose levels during O1 and O2 were determined on days 1, 21, and 42. RESULTS: The patients in both groups were compatible in age, sex, and medical illness. By comparing G1 and G2, a significantly lower regurgitation rate (p < .0002), vomiting of feeding substrate (p < .009), aspiration (p < .01), and pneumonia (p < .02) was observed. The diarrhea rate in G2 was higher than in G1 (p < .007). The glucose profiles in G1 showed a significantly better development (p < .0007) than the ones in G2. After switching the application method in G2, the PA group (now G2) showed a significantly improved rate of regurgitation, vomiting, aspiration, and diarrhea and improved glucose profiles. CONCLUSION: Feeding via PA shows improved safety, which is documented in a lower rate of diarrhea, regurgitation, vomiting, and aspiration. PA also noted a more effective glucose metabolization, which results in better glucose levels. As a result of this prospective study, pump-assisted feeding is recommended for bedridden patients requiring long-term feeding via PEG.
The use of a laryngeal stent to obturate the glottis and prevent chronic aspiration has been described. Comparison with previously described surgical techniques used in treating chronic aspiration has been made. We believe laryngeal stenting is a good alternative for the initial and temporary treatment of chronic aspiration for as long as one year. The main advantage of the procedure is that it can be performed and reversed endoscopically. Patients with uncorrectable underlying conditions, causing them to chronically aspirate will require a more permanent surgical solution to their problem.
The use of cimetidine, an H2-receptor antagonist, to minimize the complications of acid aspiration pneumonia is reviewed. Since Mendelson's early description of acid aspiration in 66 obstetrical patients, attempts have been made to decrease gastric acidity by administering perioperative antacids and/or antihistamine drugs such as atropine and glycopyrrolate. In this review of the literature, strict attention is given to study design and subject selection, methods of collecting gastric samples and reporting both pH and volume measurements, and medications taken on admission, given preoperatively, and as anesthetics. Clinical trials evaluating cimetidine alone and compared with other prophylactic regimens were reviewed, detailing the timing, route, and frequency of drug administration. Cimetidine appears to be effective in minimizing complications of acid aspiration since gastric acidity (pH less than 2.5) is a contributing factor in both the morbidity and mortality of this disease state. In general terms, cimetidine 300 mg po 1.5-2.0 h prior to intubation or 45-60 minutes iv before surgery will decrease gastric acidity below the critical level. This effect may be maintained for up to three hours. Perioperative cimetidine administration, to minimize the complications of acid aspiration, appears to be safe in terms of drug-drug interactions and effects on labor, the fetus, and the newborn child.
This study investigated the frequency of aspiration pneumonia in conscious stroke patients fed by a family member and examined the effect of introducing training in swallowing techniques by nurses. A total of 96 consecutive patients presenting with dysphagia due to acute stroke were included in the study. Patients presenting between January 2000 and July 2003 (n = 48) were fed orally by a family member given general nursing information (group A), whereas those presenting between August 2003 and March 2005 (n = 48) were fed orally by an experienced nurse trained in specific swallowing techniques (group B). All patients were examined daily for the presence of aspiration pneumonia. The incidence of aspiration pneumonia was 33.3% in group A and 6.3% in group B (P < 0.05). The incidence of aspiration pneumonia in dysphagic stroke patients who are orally fed is still high. Training in swallowing during oral feeding offers clear protection against pneumonia in conscious stroke patients.