Endotracheal cuff pressures in the PICU: Incidence of underinflation and overinflation.

BACKGROUND: While uncuffed endotracheal tubes have been traditionally used in the pediatric intensive care unit (PICU) population, evidence suggests cuffed endotracheal tubes (ETTs) are also safe to use within this population. Nevertheless, risks related to the use of cuffed ETTs increase when guidelines for safe and appropriate use are not followed. The primary goal of this study was to measure the cuff pressure (CP) using a cuff pressure manometer in a group of intubated pediatric subjects and determine the rate of cuff underinflation (<20 cm H20) or overinflation (>30 cm H20). The secondary aim was to determine whether CP was associated to gender, age, ETT size, and PICU length of stay prior to CP measurement. METHODS: This was a prospective observational study conducted in an urban PICU. Pediatric subjects intubated with cuffed ETTs from 1 April 2017 to 1 May 2017 were included in the study. ETT CPs were measured daily to determine degree of inflation and compared according to gender, age, ETT size, and number of days intubated prior to CP measurement. Descriptive data are expressed as means and standard deviations. A two-sample t test was used to compare groups according to age, gender, and number of days present. And significance was considered with a P < 0.05. Pearson chi test was used to evaluate correlation between CPs and size of the ETT, number of days intubated prior to CP measurement, gender, and age. RESULTS: Twenty pediatric subjects admitted during the study period were included for analysis. Eleven cuff measurements were found to be within normal limits, while 9 cuff measurements were found to be underinflated. No cases of overinflation were found. There were no significant associations between CP and size of the ETT (r = -0.08), number of days intubated prior to CP measurement (r = 0.19), gender (r = 0.09), and age (r = 0.12). CONCLUSIONS: Our study suggests that endotracheal cuff underinflation occurs often in the PICU population. Strategies to ensure appropriate ETT CPs are maintained are essential in the intubated pediatric population. Additional studies are necessary to develop interventions and training focused on the use of a cuff pressure manometer to measure CPs in the PICU by respiratory therapists and ensure consistent measurement using inter rater evaluation processes are needed.

Aerosol delivery device selection for spontaneously breathing patients: 2012.

Using an electronic literature search for published articles indexed in PubMed between January 1990 and August 2011, the update of this clinical practice guideline is the result of reviewing 84 clinical trials, 54 reviews, 25 in vitro studies, and 7 evidence-based guidelines. The recommendations below are made following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria: 1: It is recommended that selection of the appropriate aerosol generator and interface be made based on the patient's age, physical and cognitive ability, cost, and the availability of the prescribed drug for use with a specific device. 2: Nebulizers and pressurized metered-dose inhalers (pMDIs) with valved holding chambers are suggested for use with children ≤ 4 years of age and adults who cannot coordinate the use of pMDI or dry-powder inhaler (DPI). 3: It is suggested that administration of aerosols with DPIs be restricted to patients ≥ 4 years of age who can demonstrate sufficient flow for the specific inhaler. 4: For patients who cannot correctly use a mouthpiece, aerosol masks are suggested as the interface of choice. 5: It is suggested that blow-by not be used for aerosol administration. 6: It is suggested that aerosol therapy be administered with a relaxed and nondistressed breathing pattern. 7: Unit dose medications are suggested to reduce the risk of infection. 8: It is suggested that nebulizer/drug combinations should be used as approved by the FDA. 9: It is recommended that healthcare providers know the correct use of aerosol generators; they should teach and periodically re-teach patients about how to use aerosol devices correctly. 10: It is suggested that intermittent positive-pressure breathing should not be used for aerosol therapy. 11: It is recommended that either nebulizer or pMDI can be used for aerosol delivery during noninvasive ventilation.

Humidification during invasive and noninvasive mechanical ventilation: 2012.

We searched the MEDLINE, CINAHL, and Cochrane Library databases for articles published between January 1990 and December 2011. The update of this clinical practice guideline is based on 184 clinical trials and systematic reviews, and 10 articles investigating humidification during invasive and noninvasive mechanical ventilation. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scoring system: 1. Humidification is recommended on every patient receiving invasive mechanical ventilation. 2. Active humidification is suggested for noninvasive mechanical ventilation, as it may improve adherence and comfort. 3. When providing active humidification to patients who are invasively ventilated, it is suggested that the device provide a humidity level between 33 mg H(2)O/L and 44 mg H(2)O/L and gas temperature between 34°C and 41°C at the circuit Y-piece, with a relative humidity of 100%. 4. When providing passive humidification to patients undergoing invasive mechanical ventilation, it is suggested that the HME provide a minimum of 30 mg H(2)O/L. 5. Passive humidification is not recommended for noninvasive mechanical ventilation. 6. When providing humidification to patients with low tidal volumes, such as when lung-protective ventilation strategies are used, HMEs are not recommended because they contribute additional dead space, which can increase the ventilation requirement and P(aCO(2)). 7. It is suggested that HMEs are not used as a prevention strategy for ventilator-associated pneumonia.

AARC clinical practice guideline: transcutaneous monitoring of carbon dioxide and oxygen: 2012.

An electronic literature search for articles published between January 1990 and September 2011 was conducted by using the PubMed, CINAHL, SCOPUS, and Cochrane Library databases. The update of this clinical practice guideline is the result of reviewing a total of 124 articles: 3 randomized controlled trials, 103 prospective trials, 1 retrospective study, 3 case studies, 11 review articles, 2 surveys and 1 consensus paper on transcutaneous monitoring (TCM) for P(tcO(2)) and P(tcCO(2)). The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria: (1) Although P(tcCO(2)) has a good correlation with P(aCO(2)) and is a reliable method to evaluate plasma CO(2) levels, it is recommended that arterial blood gas values be compared to transcutaneous readings taken at the time of arterial sampling, in order to verify the transcutaneous values, and periodically as dictated by the patient's clinical condition. (2) It is suggested that P(tcCO(2)) may be used in clinical settings where monitoring the adequacy of ventilation is indicated. (3) It is suggested that P(tcO(2)) and P(tcCO(2)) may be used in determining the adequacy of tissue perfusion and monitoring of reperfusion. (4) It is suggested that TCM should be avoided in the presence of increased thickness or edema of the skin and/or subcutaneous tissue where the sensor is applied. (5) It is recommended that sites used for a TCM be changed as often as necessary and that they be alternated and observed to avoid thermal injury. Manufacturer recommendations should be followed.

The role of nebulized therapy in the management of COPD: evidence and recommendations.

Current guidelines recommend inhalation therapy as the preferred route of drug administration for treating chronic obstructive pulmonary disease (COPD). Previous systematic reviews in COPD patients found similar clinical outcomes for drugs delivered by handheld inhalers - pressurized metered-dose inhalers (pMDIs), dry powder inhalers (DPIs) - and nebulizers, provided the devices were used correctly. However, in routine clinical practice critical errors in using handheld inhalers are highly prevalent and frequently result in inadequate symptom relief. In comparison with pMDIs and DPIs, effective drug delivery with conventional pneumatic nebulizers requires less intensive patient training. Moreover, by design, newer nebulizers are more portable and more efficient than traditional jet nebulizers. The current body of evidence regarding nebulizer use for maintenance therapy in patients with moderate-to-severe COPD, including use during exacerbations, suggests that the efficacy of long-term nebulizer therapy is similar, and in some respects superior, to that with pMDI/DPIs. Therefore, despite several known drawbacks associated with nebulized therapy, we recommend that maintenance therapy with nebulizers should be employed in elderly patients, those with severe disease and frequent exacerbations, and those with physical and/or cognitive limitations. Likewise, financial concerns and individual preferences that lead to better compliance may favor nebulized therapy over other inhalers. For some patients, using both nebulizers and pMDI/DPI may provide the best combination of efficacy and convenience. The impact of maintenance nebulizer treatment on other relevant clinical outcomes in patients with COPD, especially the progressive decline in lung function and frequency of exacerbations, needs further investigation.

Capnography/Capnometry during mechanical ventilation: 2011.

We searched the MEDLINE, CINAHL, and Cochrane Library databases for articles published between January 1990 and November 2010. The update of this clinical practice guideline is based on 234 clinical studies and systematic reviews, 19 review articles that investigated capnography/capnometry during mechanical ventilation, and the 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scoring system: (1) Continuous-waveform capnography is recommended, in addition to clinical assessment to confirm and monitor correct placement of an endotracheal tube. (2) If waveform capnography is not available, a non-waveform exhaled CO(2) monitor, in addition to clinical assessment, is suggested as the initial method for confirming correct tube placement in a patient in cardiac arrest. (3) End-tidal CO(2) (P(ETCO(2))) is suggested to guide ventilator management. (4) Continuous capnometry during transport of the mechanically ventilated patients is suggested. (5) Capnography is suggested to identify abnormalities of exhaled air flow. (6) Volumetric capnography is suggested to assess CO(2) elimination and the ratio of dead-space volume to tidal volume (V(D)/V(T)) to optimize mechanical ventilation. (7) Quantitative waveform capnography is suggested in intubated patients to monitor cardiopulmonary quality, optimize chest compressions, and detect return of spontaneous circulation during chest compressions or when rhythm check reveals an organized rhythm.

Incentive spirometry: 2011.

We searched the MEDLINE, CINAHL, and Cochrane Library databases for articles published between January 1995 and April 2011. The update of this clinical practice guideline is the result of reviewing a total of 54 clinical trials and systematic reviews on incentive spirometry. The following recommendations are made following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scoring system. 1: Incentive spirometry alone is not recommended for routine use in the preoperative and postoperative setting to prevent postoperative pulmonary complications. 2: It is recommended that incentive spirometry be used with deep breathing techniques, directed coughing, early mobilization, and optimal analgesia to prevent postoperative pulmonary complications. 3: It is suggested that deep breathing exercises provide the same benefit as incentive spirometry in the preoperative and postoperative setting to prevent postoperative pulmonary complications. 4: Routine use of incentive spirometry to prevent atelectasis in patients after upper-abdominal surgery is not recommended. 5: Routine use of incentive spirometry to prevent atelectasis after coronary artery bypass graft surgery is not recommended. 6: It is suggested that a volume-oriented device be selected as an incentive spirometry device.

Critical-thinking ability in respiratory care students and its correlation with age, educational background, and performance on national board examinations.

BACKGROUND: Critical thinking is an important characteristic to develop in respiratory care students. METHODS: We used the short-form Watson-Glaser Critical Thinking Appraisal instrument to measure critical-thinking ability in 55 senior respiratory care students in a baccalaureate respiratory care program. We calculated the Pearson correlation coefficient to assess the relationships between critical-thinking score, age, and student performance on the clinical-simulation component of the national respiratory care boards examination. We used chi-square analysis to assess the association between critical-thinking score and educational background. RESULTS: There was no significant relationship between critical-thinking score and age, or between critical-thinking score and student performance on the clinical-simulation component. There was a significant (P = .04) positive association between a strong science-course background and critical-thinking score, which might be useful in predicting a student's ability to perform in areas where critical thinking is of paramount importance, such as clinical competencies, and to guide candidate-selection for respiratory care programs.

Respiratory care year in review 2010: part 2. Invasive mechanical ventilation, noninvasive ventilation, pediatric mechanical ventilation, aerosol therapy.

The purpose of this paper is to review the recent literature related to invasive mechanical ventilation, NIV, pediatric mechanical ventilation, and aerosol therapy. Topics covered related to invasive mechanical ventilation topics include the role of PEEP in providing lung protection during mechanical ventilation, unconventional modes for severe hypoxemia, and strategies to improve patient-ventilator interactions. Topics covered related to NIV include real-life NIV use, NIV and extubation failure, and NIV and pandemics. For pediatric mechanical ventilation, the topics addressed are NIV, invasive respiratory support, and inhaled nitric oxide. Topics covered related to aerosol therapy include short-acting ß-adrenergic agents, long-acting ß-adrenergic agents, long-acting antimuscarinic agents, inhaled corticosteroid therapy, phosphodiesterase type 4 (PDE4) inhibitors, long-acting ß-adrenergic plus inhaled corticosteroid, long-acting antimuscarinic plus inhaled corticosteroid, nebulized hypertonic saline, inhaled mannitol, and inhaled antibiotic therapy. These topics were chosen and reviewed in a manner that is most likely to have interest to the readers of Respiratory Care.

Evaluation of Capnography Sampling Line Compatibility and Accuracy when Used with a Portable Capnography Monitor.

Capnography is commonly used to monitor patient's ventilatory status. While sidestream capnography has been shown to provide a reliable assessment of end-tidal CO2 (ETCO2), its accuracy is commonly validated using commercial kits composed of a capnography monitor and its matching disposable nasal cannula sampling lines. The purpose of this study was to assess the compatibility and accuracy of cross-paired capnography sampling lines with a single portable bedside capnography monitor. A series of 4 bench tests were performed to evaluate the tensile strength, rise time, ETCO2 accuracy as a function of respiratory rate, and ETCO2 accuracy in the presence of supplemental O2. Each bench test was performed using specialized, validated equipment to allow for a full evaluation of sampling line performance. The 4 bench tests successfully differentiated between sampling lines from different commercial sources and suggested that due to increased rise time and decreased ETCO2 accuracy, not all nasal cannula sampling lines provide reliable clinical data when cross-paired with a commercial capnography monitor. Care should be taken to ensure that any cross-pairing of capnography monitors and disposable sampling lines is fully validated for use across respiratory rates and supplemental O2 flow rates commonly encountered in clinical settings.

Adherence to an Oxygen-Weaning Protocol in Mechanically Ventilated Adults in the Medical ICU.

BACKGROUND: Patients undergoing mechanical ventilation in the ICU often receive supplemental oxygen. If not closely monitored, this may lead to hyperoxia. The use of an oxygen-weaning protocol may reduce this risk by pacing the titration of oxygen therapy to patient needs. ICU protocols are correlated with decreased mortality and length of stay and have great potential for cost savings. The goals of this study were to determine whether the oxygen-weaning protocol at a university-affiliated hospital was followed and to measure the length of time respiratory therapists took to wean patients once the oxygen-weaning parameters were met. METHODS: This was a retrospective chart review of subjects > 18 y of age admitted to the medical ICU who underwent intubation and mechanical ventilation and were placed on an oxygen therapy protocol. The following data were collected: demographics, arterial blood gases, the length of time to change [Formula: see text] after meeting weaning parameters, and the percent change in [Formula: see text]. RESULTS: Data were collected from 30 subjects. The most common oxygen saturation parameter measured via pulse oximetry ([Formula: see text]) used to initiate weaning oxygen was 92%. The mean ± SD [Formula: see text] administered to subjects was 39.6 ± 15.3% prior to extubation. The majority of subjects exhibited adequate oxygenation prior to extubation (mean ± SD): [Formula: see text] 99.3 ± 6.7 mm Hg, [Formula: see text] 95.1 ± 26.9%. The mean ± SD length of time to the first change in [Formula: see text] from the time a subject met the weaning criteria was 9.1 ± 10.6 h (range 1-39 h; interquartile range 2-13 h). CONCLUSIONS: Subjects admitted to the medical ICU who were intubated, mechanically ventilated, and placed on the oxygen therapy protocol experienced a significant delay in oxygen weaning. Closer monitoring and adherence to the oxygen-weaning protocol should be considered to reduce the potential risk for hyperoxia.

A stepwise approach to management of stable COPD with inhaled pharmacotherapy: a review.

Although existing evidence confirms that no pharmacologic agent ameliorates the decline in the lung function or changes the prognosis of chronic obstructive pulmonary disease (COPD), inhaled pharmacotherapy is a critical component of the management for patients suffering with COPD. Inhaled agents are directed to provide immediate relief of symptoms and to restore functional capacity in treatment of stable COPD. While COPD may not be cured, knowledge and implementation of currently available guidelines provide the health-care provider alternatives to treat the disease effectively. Respiratory therapists play an important role in the implementation of these guidelines, since they are often responsible for educating patients on the correct use of the inhalers. This paper reviews current evidence regarding the use of inhaled pharmacotherapy in the treatment of COPD and provides a guided approach to the use of different agents in stable COPD.

Use of inhaled anticholinergic agents in obstructive airway disease.

In the last 2 decades, anticholinergic agents have been generally regarded as the first-choice bronchodilator therapy in the routine management of stable chronic obstructive pulmonary disease (COPD) and, to a lesser extent, asthma. Anticholinergics are particularly important bronchodilators in COPD, because the vagal tone appears to be the only reversible component of airflow limitation in COPD. The inhaled anticholinergics approved for clinical use are synthetic quaternary ammonium congeners of atropine, and include ipratropium bromide, oxitropium bromide, and tiotropium bromide. This article reviews the most current evidence for inhaled anticholinergics in obstructive airway disease and summarizes outcomes reported in randomized controlled trials.

Inhaled adrenergics and anticholinergics in obstructive lung disease: do they enhance mucociliary clearance?

Pulmonary mucociliary clearance is an essential defense mechanism against bacteria and particulate matter. Mucociliary dysfunction is an important feature of obstructive lung diseases such as chronic obstructive pulmonary disease, asthma, cystic fibrosis, and bronchiectasis. This dysfunction in airway clearance is associated with accelerated loss of lung function in patients with obstructive lung disease. The involvement of the cholinergic and adrenergic neural pathways in the pathophysiology of mucus hypersecretion suggests the potential therapeutic role of bronchodilators as mucoactive agents. Although anticholinergics and adrenergic agonist bronchodilators have been routinely used, alone or in combination, to enhance mucociliary clearance in patients with obstructive lung disease, the existing evidence does not consistently show clinical effectiveness.

Effect of face mask design on inhaled mass of nebulized albuterol, using a pediatric breathing model.

BACKGROUND: Aerosol face mask design and the distance at which the face mask is held from the face affect the delivery of nebulized medication to pediatric patients. OBJECTIVE: To measure the inhaled mass of nebulized albuterol with 3 types of pediatric face mask, at 3 different distances from the face, with a model of a spontaneously breathing infant. METHODS: We compared a standard pediatric face mask and 2 proprietary pediatric face masks (one shaped to resemble a dragon face, the other shaped to resemble a fish face). The albuterol was nebulized with a widely used jet nebulizer. Aerosol delivery with each type of mask was measured with the mask at 0 cm (ie, mask directly applied to the mannequin face), 1 cm, and 2 cm from the mannequin face. In each test the nebulizer was filled with a 3-mL unit dose of albuterol sulfate and powered by oxygen at 8 L/min, with a total nebulization time of 5 min. The mannequin face was connected to a lung simulator that simulated a spontaneously breathing infant. We measured inhaled mass by collecting the aerosol on a 2-way anesthesia filter that was attached to the back of the mannequin's oral opening via a 15-mm silicon adapter. We also measured residual drug left in the nebulizer, and estimated the drug lost to the atmosphere. RESULTS: The mean +/- SD inhaled percentage of the nominal dose values at 0 cm, 1 cm, and 2 cm, respectively, were 2.18 +/- 0.53%, 1.45 +/- 0.46%, and 0.92 +/- 0.51% with the standard mask; 2.65 +/- 0.55%, 1.7 +/- 0.38%, and 1.3 +/- 0.37% with the dragon mask; and 3.67 +/- 0.8%, 2.92 +/- 0.4%, and 2.26 +/- 0.56% with the fish mask. With all 3 masks there was a statistically significant difference (p < 0.001) in inhaled mass between the 0 cm and 2 cm distance. The fish mask had a significantly higher (p < 0.001) inhaled mass than the dragon mask or the standard mask, at all 3 distances. CONCLUSIONS: The inhaled mass of albuterol is significantly reduced when the mask is moved away from the face. The fish mask had significantly higher inhaled mass than the standard mask or the dragon mask, under the conditions we studied. Mask design may affect nebulized albuterol delivery to pediatric patients.

Effects of intrapulmonary percussive ventilation on airway mucus clearance: A bench model.

AIM: To determine the ability of intrapulmonary percussive ventilation (IPV) to promote airway clearance in spontaneously breathing patients and those on mechanical ventilation. METHODS: An artificial lung was used to simulate a spontaneously breathing patient (Group 1), and was then connected to a mechanical ventilator to simulate a patient on mechanical ventilation (Group 2). An 8.5 mm endotracheal tube (ETT) connected to the test lung, simulated the patient airway. Artificial mucus was instilled into the mid-portion of the ETT. A filter was attached at both ends of the ETT to collect the mucus displaced proximally (mouth-piece filter) and distally (lung filter). The IPV machine was attached to the proximal end of the ETT and was applied for 10-min each to Group 1 and 2. After each experiment, the weight of the various circuit components were determined and compared to their dry weights to calculate the weight of the displaced mucus. RESULTS: In Group 1 (spontaneously breathing model), 26.8% ± 3.1% of the simulated mucus was displaced proximally, compared to 0% in Group 2 (the mechanically ventilated model) with a P-value of < 0.01. In fact, 17% ± 1.5% of the mucus in Group 2 remained in the mid-portion of the ETT where it was initially instilled and 80% ± 4.2% was displaced distally back towards the lung (P < 0.01). There was an overall statistically significant amount of mucus movement proximally towards the mouth-piece in the spontaneously breathing (SB) patient. There was also an overall statistically significant amount of mucus movement distally back towards the lung in the mechanically ventilated (MV) model. In the mechanically ventilated model, no mucus was observed to move towards the proximal/mouth piece section of the ETT. CONCLUSION: This bench model suggests that IPV is associated with displacement of mucus towards the proximal mouthpiece in the SB patient, and distally in the MV model.

Ability of ICU Health-Care Professionals to Identify Patient-Ventilator Asynchrony Using Waveform Analysis.

BACKGROUND: Waveform analysis by visual inspection can be a reliable, noninvasive, and useful tool for detecting patient-ventilator asynchrony. However, it is a skill that requires a properly trained professional. METHODS: This observational study was conducted in 17 urban ICUs. Health-care professionals (HCPs) working in these ICUs were asked to recognize different types of asynchrony shown in 3 evaluation videos. The health-care professionals were categorized according to years of experience, prior training in mechanical ventilation, profession, and number of asynchronies identified correctly. RESULTS: A total of 366 HCPs were evaluated. Statistically significant differences were found when HCPs with and without prior training in mechanical ventilation (trained vs non-trained HCPs) were compared according to the number of asynchronies detected correctly (of the HCPs who identified 3 asynchronies, 63 [81%] trained vs 15 [19%] non-trained, P < .001; 2 asynchronies, 72 [65%] trained vs 39 [35%] non-trained, P = .034; 1 asynchrony, 55 [47%] trained vs 61 [53%] non-trained, P = .02; 0 asynchronies, 17 [28%] trained vs 44 [72%] non-trained, P < .001). HCPs who had prior training in mechanical ventilation also increased, nearly 4-fold, their odds of identifying ≥2 asynchronies correctly (odds ratio 3.67, 95% CI 1.93-6.96, P < .001). However, neither years of experience nor profession were associated with the ability of HCPs to identify asynchrony. CONCLUSIONS: HCPs who have specific training in mechanical ventilation increase their ability to identify asynchrony using waveform analysis. Neither experience nor profession proved to be a relevant factor to identify asynchrony correctly using waveform analysis.

An investigation of nebulized bronchodilator delivery using a pediatric lung model of spontaneous breathing.

BACKGROUND: The literature lacks comparative data on nebulizer aerosol delivered via mask versus T-piece, to spontaneously breathing pediatric subjects. PURPOSE: To compare total inhaled drug mass delivered via standard pediatric aerosol mask versus via T-piece, with increasing distance. METHODS: We used a sample of 5 nebulizers, operated under manufacturers' conditions, with a standard pediatric aerosol mask and with a T-piece capped at one end, at 0 cm, 1 cm, and 2 cm from an inhalation filter placed at the inlet of a pediatric test lung. Inhaled drug mass was analyzed with spectrophotometry. Aerosol particle size was measured separately from the breathing simulations, using a laser particle sizer to determine fine-particle mass (particles < 4.7 mum) and fine-particle fraction as percent of total mass. The fine-particle fraction was used to estimate the fine-particle mass. RESULTS: The mean + SD values for inhaled drug mass as a percentage of nominal dose, at 0 cm, 1 cm, and 2 cm, with the mask were 2.88 + 0.79%, 1.61 + 0.65%, and 1.3 + 0.42%, respectively, and with the T-piece were 4.14 + 1.37%, 3.77 + 1.04%, and 3.47 + 0.64%, respectively. There was a statistically greater inhaled drug mass with T-piece than with mask, overall (p < 0.01), and a significant decrease with mask or T-piece as distance increased (p < 0.01). The difference between mask and T-piece for inhaled drug mass at 2 cm was statistically significant (p < 0.018). The mean + SD values for fine-particle mass estimated as a percentage of total drug mass at 0, 1, and 2 cm, with the mask were 1.39 + 0.36%, 0.78 + 0.29%, and 0.64 + 0.20%, respectively, and with the T-piece were 2.1 + 0.63%, 1.84 + 0.45%, and 1.71 + 0.27%, respectively. CONCLUSION: Inhaled drug mass was greater with T-piece than with a standard pediatric aerosol mask under the conditions studied.

Assessing Respiratory System Mechanical Function.

The main goals of assessing respiratory system mechanical function are to evaluate the lung function through a variety of methods and to detect early signs of abnormalities that could affect the patient's outcomes. In ventilated patients, it has become increasingly important to recognize whether respiratory function has improved or deteriorated, whether the ventilator settings match the patient's demand, and whether the selection of ventilator parameters follows a lung-protective strategy. Ventilator graphics, esophageal pressure, intra-abdominal pressure, and electric impedance tomography are some of the best-known monitoring tools to obtain measurements and adequately evaluate the respiratory system mechanical function.