Tracheal Sampling Research Articles

Accuracy of the Infectious Diseases Society of America and British Thoracic Society Criteria for Acute Pneumonia in Differentiating Chemical and Bacterial Complications of Aspiration in Comatose Ventilated Patients Following Drug Poisoning.

Drug poisoning frequently leads to admission to intensive care units, often resulting in aspiration, a potentially life-threatening condition if not properly managed. Aspiration can manifest as either bacterial aspiration pneumonia (BAP) or aspiration pneumonitis (AP), which are challenging to distinguish potentially leading to overprescription of antibiotics and the emergence of multidrug-resistant bacteria. This study aims to assess the accuracy of the Infectious Diseases Society of America (IDSA) and British Thoracic Society (BTS) criteria in differentiating BAP from AP in comatose ventilated patients following drug poisoning. This cross-sectional study included 95 patients admitted for drug poisoning at the Lille University Hospital intensive care department, between 2013 and 2017, requiring mechanical ventilation and receiving antibiotics for aspiration. Patients were categorized as having bacterial complications if tracheal sampling yielded positive culture results, and if they were otherwise considered to have chemical complications. The sensitivity, specificity, positive predictive value, and negative predictive value of IDSA and BTS criteria in identifying patients with bacterial complications were evaluated. Among the patients, 34 (36%) experienced BAP. The IDSA criteria demonstrated a sensitivity of 62% and specificity of 33%, while the BTS criteria showed a sensitivity of 50% and specificity of 38%. Both the IDSA and BTS criteria exhibited poor sensitivity and specificity in identifying microbiologically confirmed pneumonia in comatose ventilated patients following drug poisoning.

The Effect of Tracheal Fluid Culture Sampling Method and Culture Results on Antibiotic Use in Neonates

Abstract Objective As part of quality improvement effort to decrease antibiotic use for presumed pneumonia (PNA) in our neonatal intensive care unit, we introduced minibronchoalveolar lavage (mBAL) to obtain culture specimens. We evaluated the effect of tracheal sampling method and culture results on antibiotic use. Methods We performed a retrospective review of culture results of samples obtained by tracheal aspirates (TAs) and mBAL between January 2017 and April 2018. Noting the time cultures were obtained, we reviewed the records to determine if the patients met the Center for Disease Control and Prevention (CDC) criteria for PNA and evaluated culture results and antibiotic treatment practice. Fisher's exact and Mann–Whitney's tests when appropriate were used for the analysis. Results Thirty-five (35) mBAL (on 21 patients) and 42 TAs (on 39 patients) were done prior to antibiotic therapy. The tests were done at similar median day of life in both groups (mBAL 55 days and TA 62 days). The frequencies of positive culture were similar in both groups (mBAL 60% and TA 57%). At the time of obtaining the sample, more mBAL patients met the CDC criteria for PNA (mBAL 54% and TA 26%). Antibiotic days and duration of antibiotic treatment were significantly higher in the mBAL group compared with the TA group. In patient with no clinical PNA, antibiotic days were significantly higher in those with positive cultures (which more likely reflect colonizing microbes) than those with negative cultures and were also higher in the mBAL group than in the TA group. There was a significant increase in the frequency of positive cultures in patients with longer hospital stay. Conclusion Our results show that tracheal cultures on sick neonates with no clinical PNA and with long hospital stay might contribute to unnecessary antibiotic use regardless of the tracheal sampling method.

Practice Improvement for Standardized Evaluation and Management of Acute Tracheitis in Mechanically Ventilated Patients

Background Hospital-acquired infections contribute to morbidity and mortality while increasing healthcare resource utilization. While certain ventilator-associated infections are well defined, there is no consensus definition for ventilator-associated tracheitis and limited evidence to guide tracheal aspirate sampling and antibiotic treatment. Local Problem Evaluation of Boston Children’s Hospital Medicine Intensive Care Unit (BCH MICU) practice identified tracheal aspirate culture sampling occurred more frequently than recommended and antibiotic treatment exceeded suggested duration. This practice increases antibiotic exposure with associated risks of bacterial resistance, side effects, and increased costs. The project objective was to improve and standardize acute tracheitis evaluation and management with the intent to accomplish the …

Comparison of total immunoglobulin A levels in different samples in Leghorn and broiler chickens

ObjectiveTo standardize an ELISA protocol to quantify total immunoglobulin A (IgA) from different biological samples. MethodsTwo independent experiments were conducted. In Experiment 1, total IgA levels were quantified from the lachrymal fluid, tracheal swab, and cloacal swab at various time points from Days 30 to 89 in white Leghorn chickens. Experiment 2 was conducted to evaluate the effect of 50 or 500 ppb of aflatoxin B1 (AFB1) on total IgA quantified in samples from the lachrymal fluid, tracheal swab, gut content and cloacal swab in broiler chickens at 21 days of age. ResultsLachrymal fluid contained the highest level of IgA; however, the sampling procedure was time consuming and stressful to the bird, and the sample volume depends largely on the size of the chicken. Cloacal swabs also contained a high concentration of IgA; this sampling procedure was faster than lachrymal fluid sampling and was not affected by the age of the bird. Tracheal sampling was more difficult than cloacal sampling; the age of the bird limited the sampling, and the IgA concentration was the lowest detected at all sampling ages. 500 ppb of AFB1 significantly reduced total IgA concentration in the gut content compared with control or 50 ppb of AFB1 treated groups. Interestingly, a significant reduction in total IgA was also observed in those chickens that received 50 ppb of AFB1 in gut rinse when compared with cloacal swabs. ConclusionsThe results of this study suggest that cloacal swab is an easy and reliable way to evaluate mucosal IgA concentration in both Leghorn and broiler chickens.

Measurement of oxygen concentration delivered via nasal cannulae by tracheal sampling

Oxygen is used in many clinical scenarios, however the variable performance of nasal cannulae makes determining the precise fraction of inspired oxygen (FiO2 ) difficult. We developed a novel method for measurement of the tracheal FiO2 using a catheter placed via bronchoscopy. We investigate the effects of oxygen delivery, respiratory rate, mouth position and estimated minute ventilation (VE ) on the FiO2 delivered by nasal cannulae. The catheter was placed in 20 subjects. Tracheal gas concentrations were analysed during six 5-min treatments controlling for oxygen delivery rate, respiratory rate and mouth position. Ventilation was monitored with respiratory inductive plethysmography (RIP). The FiO2 delivered by nasal cannulae was compared between treatments, and we investigated the relationships among the FiO2 , alveolar partial pressure of oxygen (PA O2 ) and VE . The FiO2 increased by 0.038/L/min of oxygen. Respiratory rate had a significant effect on the FiO2 . A normal respiratory rate of 15 breaths/min and oxygen supplementation via nasal cannula at 2 L/min resulted in an FiO2 of 0.296; however, FiO2 decreased by 0.012 at 20 breaths/min and 0.004 at 10 breaths/min. The mean FiO2 decreased by 0.024 with the mouth open. The FiO2 and PA O2 were observed to decrease with increasing VE . Continuous measurement of the FiO2 using a transtracheal catheter provides detailed insight into inspiratory changes of the FiO2 delivered by nasal cannulae. Our study confirms that respiratory rate, VE and mouth position significantly influence the inspired oxygen concentration. These parameters should be accounted for when prescribing oxygen.

Evaluation of recovery of Salmonella from trachea and ceca in commercial poultry

Unpublished data from our laboratory suggest that the respiratory tract may be a viable portal of entry for Salmonella infection. Further, field reports have indicated that tracheal sampling can be a sensitive tool for monitoring for Salmonella incidence in commercial flocks. In the present study we conducted a series of field trials in North and South America to evaluate the association between cecal and tracheal recovery of Salmonella in chickens and turkeys from commercial flocks. Environmental humidity and temperature were measured to evaluate their effects on frequency of isolation from the organs. Salmonella was recovered from tracheal samples in all trials. In 3 of the 4 trials in which both trachea and ceca were sampled, the incidence of Salmonella recovery was higher in tracheal samples. Though Salmonella was not recovered from ceca in trial 2, 5% of liver and spleen samples indicated infection. Environmental conditions were not associated with incidence of Salmonella recovery. These data suggest that tracheal contamination can be a good indicator of Salmonella infection under commercial poultry conditions.

Status and prospect of Chinese pediatric interventional pulmonology

Pediatric bronchoscopy has been understanded by Chinese pediatricians,physicians,earnose-throat doctors and surgeons.It is quite safe and reliable.It is the effective means for the diagnosis and treatment of pediatric diseases.Neodymium doped yttrium aluminum garnet laser,high-frequency electric coagulation (high-frequency electric knife),argon plasma coagulation,microwave coagulation,cryotherapy,balloon bronchoplasty,tracheal,bronchial stent,and pollution prevention sampling brush have been used in Chinese pediatric clinic,and achieved a important breakthrough.They have really improved the level of diagnosis and treatment of pediatric diseases.We need to explore more new field and techniques of pediatric interventional pulmonology,and we should have sufficient preparation. Key words: Paediatrics; Bronchoscopy; Interventional pulmonology

What's in a name? Inflammatory airway disease in racehorses in training

The term 'inflammatory airway disease' (IAD) is often used to describe the syndrome of lower airway inflammation that frequently affects young racehorses in training around the world. In practice, this inflammation is generally diagnosed using a combination of endoscopic tracheal examination, including grading of amounts of mucus present and tracheal wash sampling. However, a recent consensus statement from the American College of Veterinary Internal Medicine concluded that bronchoalveolar lavage (BAL) sampling, rather than tracheal wash (TW) sampling, is required for cytological diagnosis of IAD and that tracheal mucus is not an essential criterion. However, as BAL is a relatively invasive procedure that is not commonly used on racing yards, this definition can only be applied routinely to a biased referral population. In contrast, many practitioners continue to diagnose IAD using endoscopic tracheal examination and sampling. We argue that, rather than restricting the use of the term IAD to phenotypes diagnosed by BAL, it is important to distinguish in the literature between airway inflammation diagnosed by BAL and that identified in the field using TW sampling. We suggest the use of the term brIAD for the former and trIAD for the latter. It is essential that we continue to endeavour to improve our understanding of the aetiology, pathogenesis and clinical relevance of airway inflammation identified in racehorses in training using tracheal examination and sampling. Future studies should focus on investigations of the component signs of airway inflammation.

Descriptive results from a longitudinal study of airway inflammation in British National Hunt racehorses

Rates of airway inflammation in young racehorses decrease with time but it is not clear whether this is associated with increasing age or time exposed to the training environment. The structure of the British National Hunt (NH) population allowed closer examination of this relationship. To compare rates of inflammatory airway disease diagnosed by tracheal sampling (trIAD), and its components, in NH racehorses by age and training history and with published rates in young racehorses. A prospective, longitudinal study was conducted on 5 NH yards over 2 years. Period sample prevalences of nasal discharge, tracheal mucus, airway neutrophilia and trIAD (defined by a combination of tracheal mucus and airway neutrophilia) were estimated and compared between horses with different ages and time in training. Horses new to training had twice the odds of visible tracheal mucus as ex-flat trained horses (OR 2.0; 95% CI: 1.4-2.8; P<0.001) but no significantly increased odds of airway neutrophilia (OR 1.3; 95% CI: 0.8-1.9; P = 0.3) and inconclusive evidence of increased odds of trIAD (OR 1.8; CI: 0.9-3.5; P = 0.08). However, a lower median time in training was significantly associated with the presence of visible mucus (P<0.001), increased mucus (P = 0.005) and trIAD (P = 0.03). No disease measure varied significantly with age. Tracheal mucus and trIAD, but not neutrophilia detected in tracheal wash samples, were less prevalent in horses that had been exposed to the training environment for longer, explaining previously reported associations with age. Neutrophil proportion in tracheal wash samples is not as useful a clinical tool as measures of visible tracheal mucus for identifying horses requiring treatment or changes in management. The inclusion of tracheal wash neutrophils in the assessment of equine airways, or at least their relative weighting in definitions of trIAD, should be re-evaluated.

Colonization of lower respiratory tract with anaerobic bacteria in mechanically ventilated patients

To study lower respiratory tract colonization by anaerobic bacteria in ICU patients on prolonged mechanical ventilation using two types of protected tracheal sampling methods. Prospective clinical investigation in the intensive care unit of a university hospital. Twenty-six consecutive patients mechanically ventilated within 24 h after their admission in ICU and with expected duration of mechanical ventilation longer than 7 days. Two types of protected tracheal sampling methods were obtained without the use of bronchoscopic guidance on the day following intubation and twice a week until extubation: protected tracheal aspiration and protected tracheal specimen brush. Specific methods for anaerobic isolation were used. Early colonization was defined if colonization occurred within the first 5 days after intubation. Of the 26 patients studied 22 were colonized by at least one bacterial strain. Twenty-one patients were colonized by aerobic and 15 by anaerobic bacteria. Twenty-eight anaerobic strains were identified, with bacterial counts higher than 10(3) cfu/ml in 11 cases. Of the 15 patients colonized by anaerobes 14 were also colonized by aerobic bacteria. The use of protected specimens ruled out oropharyngeal contamination. Early onset colonization occurred in 16 of 22 patients colonized by aerobes and in 8 of 15 patients colonized by anaerobes. Five patients developed ventilatory-acquired pneumonia following colonization (by anaerobic bacteria in two cases). In eight patients colonization by anaerobic bacteria occurred despite antimicrobial therapy. These results show that anaerobic bacteria frequently colonize the lower respiratory tract of mechanically ventilated patients and underline the potential importance of the anaerobic bacteria in ventilatory acquired pneumonia.

Tracheal wash sampling in the horse

Tracheal wash sampling in the horse

Accuracy of Expiratory Carbon Dioxide Measurements Using the Coaxial and Circle Breathing Circuits in Small Subjects

Mass spcctrometry is widely used to measure the end-tidal concentrations of inhalation anesthetics and other gases during surgery in order to estimate their arterial concentrations. When certain breathing circuits are used in newborns, however, fresh gas or ambient air may contaminate the expired sample, introducing a systematic error in the measurement of any end-tidal gas concentration. We estimated this error in newborn piglets using carbon dioxide as an indicator substance of expired gas. The capnograms and the difference between arterial carbon dioxide tension (PaCO2) and peakexpired carbon dioxide tension (PeCO2) were compared when either a coaxial (Bain) or circle breathing circuit was used. Gas was sampled from the proximal airway and distal trachea. No combination of circuit and sampling site produced a flat alveolar phase until the circle circuit was modified with diversion valves to reduce gas mixing. The mean PaCO2-PeCO2 gradients using the coaxial/proximal sampling, coaxial/distal sampling, and modified circle/proximal sampling circuits were 12.4, 9.2, and 8.8 mm Hg, respectively. The mean PeCO2 in each of these combinations was significantly different from the corresponding mean PaCO2 (p<0.05). Using the modified circle circuit with distal sampling, mean PeCO2 was not significantly different from mean PaCO2: the mean PaCO2-PcCO2 gradient was 2.2 ± 0.2 mm Hg (SEM), range, 0 to 6 mm Hg, with 95% confidence limits ⩽ 8 mm Hg. When a coaxial breathing circuit is used in small subjects, PaCO2 may be significantly underestimated regardless of sampling site, although the circle breathing circuit with distal tracheal sampling yields accurate results.

Accuracy of expiratory carbon dioxide measurements using the coaxial and circle breathing circuits in small subjects.

Mass spectrometry is widely used to measure the end-tidal concentrations of inhalation anesthetics and other gases during surgery in order to estimate their arterial concentrations. When certain breathing circuits are used in newborns, however, fresh gas or ambient air may contaminate the expired sample, introducing a systematic error in the measurement of any end-tidal gas concentration. We estimated this error in newborn piglets using carbon dioxide as an indicator substance of expired gas. The capnograms and the difference between arterial carbon dioxide tension (PaCO2) and peak-expired carbon dioxide tension (PeCO2) were compared when either a coaxial (Bain) or circle breathing circuit was used. Gas was sampled from the proximal airway and distal trachea. No combination of circuit and sampling site produced a flat alveolar phase until the circle circuit was modified with diversion valves to reduce gas mixing. The mean PaCO2-PeCO2 gradients using the coaxial/proximal sampling, coaxial/distal sampling, and modified circle/proximal sampling circuits were 12.4, 9.2, and 8.8 mm Hg, respectively. The mean PeCO2 in each of these combinations was significantly different from the corresponding mean PaCO2 (p less than 0.05). Using the modified circle circuit with distal sampling, mean PeCO2 was not significantly different from mean PaCO2: the mean PaCO2-PeCO2 gradient was 2.2 +/- 0.2 mm Hg (SEM), range, 0 to 6 mm Hg, with 95% confidence limits less than or equal to 8 mm Hg. When a coaxial breathing circuit is used in small subjects, PaCO2 may be significantly underestimated regardless of sampling site, although the circle breathing circuit with distal tracheal sampling yields accurate results.

208 ACCURACY OF EXPIRATORY CO2 MEASUREMENTS IN SMALL SUBJECTS USING THE COAXIAL AND CIRCLE BREATHING CIRCUITS

Mass spectrometry is widely used to measure end-tidal concentrations of inhalation anesthetics and other gases during and after surgery in order to estimate their arterial concentrations. When certain breathing circuits are used in newborns, however, fresh gas flow may contaminate the expired sample, introducing a systematic error in the measurement of any end-tidal gas concentration. This error was estimated using CO2 as an indicator substance of expired gas. The capnograms and the difference between PaCO2 and peak-expired CO2 (PeCO2) were compared when either a coaxial or circle circuit was used to ventilate paralyzed newborn piglets. Gas was sampled from proximal and distal tracheal sites. No combination of standard circuit and sampling site produced a flat alveolar phase until the circle circuit was modified slightly to reduce gas mixing. Mean PaCO2-PeCO2 using the coaxial/proximal sampling, coaxial/distal sampling, and modified circle/proximal sampling circuits were 12.4, 9.2, 8.8 mm Hg, respectively. Mean PeCO2 of each combination was significantly different from PaCO2 (p<.05). Using the modified circle circuit with distal sampling, mean PaCO2 in 17 piglets was 2.2 ± 0.2 mm Hg (SEM), range 0–6 mmHg, with 95%, confidence limits for each point ≤ 8 mmHg. The modified circle system with distal tracheal sampling produces accurate results, although the standard coaxial and circle circuits do not.

Monitoring of oxygen delivery systems in clinical practice.

The measurement of hypopharyngeal FIO2, is a simple and rapid method for evaluating oxygen delivery systems in clinical practice. Hypopharyngeal FIO2 measurements were compared to other established methods of inspired gas measurement, namely, tracheal gas sampling and exhaled gas analysis. Hypopharyngeal sampling and exhaled gas analysis. Hypopharyngeal sampling compared favourably with these methods. Furthermore, arterial blood gas samples from patients receiving oxygen by aerosol mask correlated with the hypopharyngeal measurements but not with the delivery system's settings. In normal, healthy subjects, the authors studied variables known to influence FIO2. Using nasal prongs as well as an aerosol mask system, the authors studied the interaction of the wall flow rates, the concentration (Venturi) settings (in the case of the aerosol mask), and the subject's respiratory rate. Under these controlled conditions of tidal breathing, the hypopharyngeal FIO2 was directly related to the total flow of gas from the delivery system and the concentration of the Venturi setting but inversely related to the respiratory rate. Hypopharyngeal gas sampling offers a simple method for evaluating and correcting a patient's inspired oxygen concentration.