Andrew G Miller

Analysis of Radial Artery Catheter Placement by Respiratory Therapists Using Ultrasound Guidance

BACKGROUND: The use of ultrasound (US) guidance for radial artery cannulation has been shown to improve first attempt success rate, reduce time to successful cannulation, and reduce complications. We sought to determine whether properly trained respiratory therapists (RTs) could utilize US guidance for the placement of radial artery catheters. Primary outcome measurements were successful cannulation and first attempt success rate. Secondary outcomes included the effect of systolic blood pressure, prior attempts, palpable pulse strength, and gender in relation to US-guided radial artery cannulation success rates. METHODS: RTs certified in arterial catheter insertion were trained in radial artery catheterization using US by emergency medicine physicians. Subjects were enrolled based on the need for an arterial catheter placement. The catheters and US devices used were standardized. Data recorded included pulse strength, systolic and diastolic blood pressure, number of attempts, and successful/unsuccessful artery cannulation. All catheterization attempts were performed according to institutional policy and procedure. RESULTS: One hundred twenty-two radial artery catheter insertion attempts were made between December of 2008 and October of 2011, in patients in whom the treating physician requested RT radial artery cannulation. The overall success rate was 86.1%, whereas the first attempt success rate was 63.1%. There was no difference found between the overall mean success rate for weak or absent pulses, age, systolic blood pressure, gender, or prior attempts. Conclusion: RTs can effectively utilize US technology to place radial artery catheters. Systolic blood pressure, prior attempts, and gender are not reliable predictors of success for US-guided radial artery cannulation. Training on the use of US should be strongly encouraged for all practitioners who place radial artery catheters.

An Asthma Protocol Improved Adherence to Evidence-Based Guidelines for Pediatric Subjects With Status Asthmaticus in the Emergency Department

BACKGROUND: In our institutions pediatric emergency department, adherence to evidence-based asthma guidelines was noted to be suboptimal for patients with asthma exacerbations. We hypothesized that an evidence-based asthma protocol would improve time to treatment and adherence to National Institutes of Health guidelines for patients presenting to the emergency department with status asthmaticus. METHODS: Subjects at our institution were retrospectively identified through an electronic medical record search following institutional review board approval. The asthma protocol was initiated in February 2012. All pediatric subjects who received continuous albuterol in the emergency department before (February 26, 2009, to February 22, 2012, n = 193) and after (February 23, 2012, to December 31, 2012, n = 68) protocol initiation were analyzed. The post-protocol data were collected as part of routine quality assurance monitoring with a target of 60 post-protocol subjects. Subjects were identified at the end of each month, which resulted in a total of 68 subjects being included. Primary outcomes measured included time to initial treatment with inhaled bronchodilator therapy, time to treatment with systemic corticosteroids, and total number of ipratropium bromide treatments delivered. RESULTS: Two-hundred sixty-one subjects (7.1 ± 4.6 y of age, 66% male) were included. Demographics were similar in the pre- and post-protocol groups. Compared with the pre-protocol group, more subjects in the post-protocol group received bronchodilators within 30 min (60% vs 77%, P = .02), at least one dose of ipratropium bromide (55% vs 87%, P < .001), 3 doses of ipratropium bromide (14% vs 54%, P < .001), and corticosteroids within 60 min (62% vs 77%, P = .04). There were no statistically significant differences between the pre- and post-protocol cohorts in the mean time to first bronchodilator treatment (32 ± 41 vs 26 ± 52 min, P = .34), mean time to corticosteroid administration (74 ± 68 vs 54 ± 63 min, P = .06), or mean emergency department length of stay (342 ± 143 vs 364 ± 183 min, P = .31). CONCLUSIONS: An asthma protocol resulted in improved adherence to National Institutes of Health guidelines in children with status asthmaticus and improved efficiency in the administration of rescue bronchodilator and systemic corticosteroid therapy.

Review of Ultrasound-Guided Radial Artery Catheter Placement

Radial artery catheters are commonly placed for continuous blood pressure monitoring, frequent arterial blood gas analysis, or frequent blood sampling for diagnostic testing. Radial artery cannulation can be challenging and ultrasound guidance has emerged as a valuable adjunct for the placement of radial artery catheters. The advantages of ultrasound guidance include: real-time visualization of landmarks, improved pre-procedure planning, reduction in complications, less time spent at the bedside, and improved first-attempt success rates. Disadvantages of ultrasound guidance include: equipment cost, equipment availability, limited availability of experts to train providers, and the cost of training providers. Ultrasound machines are readily available and widely utilized in many emergency departments, operating rooms, and ICUs. We will summarize the use of ultrasound guidance for the placement of radial artery catheters and describe the techniques used during ultrasound-guided arterial catheter placement. Training on the use of ultrasound should be encouraged for all practitioners who place radial artery catheters.

Balloon Dilation of Upper Ureteral Strictures in Primates

We report the successful creation of ureteral strictures in primates and their successful management by balloon dilation 3 months later without ureteral stenting. This experimental work confirms the sporadic clinical reports of the effectiveness of balloon dilation in the management of ureteral strictures and suggests that ureteral stenting is not necessary for a successful result.

Clinical Management Strategies for Airway Pressure Release Ventilation: A Survey of Clinical Practice

BACKGROUND: Airway pressure release ventilation (APRV) is a commonly used mode of ventilation designed to increase mean airway pressure and thus oxygenation. Different strategies for clinical management have been described in the literature but are largely based on physiologic concepts, animal data, and small clinical trials. The purpose of this study was to determine how APRV is currently managed by surveying practicing respiratory therapists with experience using APRV. METHODS: A 15-item survey was developed by the authors and posted on the AARConnect online media platform in January 2016 after being declared exempt by our institutions institutional review board. Survey questions were derived from a literature review of recommended APRV settings. Responses were limited to one per institution. RESULTS: The survey was completed by 60 respondents who used APRV. Of the 4 key initial APRV settings (P high, P low, T high, and T low), there was good agreement among survey responders and published guidelines for setting initial T high (4–6 s) and initial P low (0 cm H2O). There was some disagreement regarding initial P high, with 48% of responders matching P high to conventional ventilation plateau pressures but another 31% using conventional ventilation mean airway pressure plus 2–5 cm H2O. The most disagreement was with the T low setting, with only 47% of survey responders agreeing with published guidelines about using the expiratory flow signal to set T low. There was good agreement among survey responders and published guidelines for what changes to make when gas exchange was outside of the targeted range. A substantial number of respondents accepted P high and APRV release volumes that may exceed lung-protective limits. CONCLUSIONS: There is only limited consensus among practitioners for initial APRV settings, probably reflecting the paucity of good clinical outcome data and confusion surrounding the physiology of this mode.

Endotracheal Intubation Training and Skill Maintenance for Respiratory Therapists

BACKGROUND: Endotracheal intubation is commonly performed outside the operating room (OR). Although respiratory therapists (RTs) performing endotracheal intubation is a well-established practice, the optimum way for RTs to be trained and maintain their skills is unspecified. The purpose of this study was to describe training methods and skills maintenance methods and to identify barriers that prevent RTs from intubating in some institutions. METHODS: A survey instrument was developed by the author. The survey was posted on the AARConnect online social media platform management section in March of 2015 after approval from our institutional review board and approval from the American Association for Respiratory Care board of directors. Respondents from institutions where RTs intubate received questions about RT training and skill maintenance, whereas the other respondents received questions about barriers to RTs performing endotracheal intubation. Both groups answered questions about attitudes about endotracheal intubation practice. RESULTS: There were 74 respondents who completed the survey. Half (50%) of the respondents were from institutions where RTs performed endotracheal intubation. These institutions were larger in bed capacity and had more adult ICU beds. Other demographic data were similar. The most common training methods identified were simulation training (86%), supervised intubations (84%), and classroom training (65%). Classroom training lasted a mean of 4.3 h with a range of 1–16 h. The majority (91%) were required to complete 10 or fewer supervised endotracheal intubations before competency validation. Skill recertification was automatic if a minimum number of endotracheal intubations were performed annually in 78% of centers, and 11% required a written test or classroom training annually. The primary barrier cited for RTs not intubating was lack of need. CONCLUSIONS: Endotracheal intubation training for RTs varied among those surveyed. Simulation training and supervised endotracheal intubations were the most common training methods. Endotracheal intubation recertification methods were also wide-ranging, with most RTs being recertified if completing a minimum number of endotracheal intubations.

Airway Pressure Release Ventilation Letter—Reply

We thank Dr Light for his insights on airway pressure release ventilation (APRV)[1][1] and will address his comments one by one below. However, we first re-emphasize that the purpose of our study[2][2] was not to address the clinical value of APRV—that can only be accomplished with randomized

Evaluating Endotracheal Tube Depth in Infants Weighing Less Than 1 Kilogram

BACKGROUND: Endotracheal tube (ETT) depth in premature infants is of critical importance because potentially life-threatening adverse events can occur if the tube is malpositioned. Analysis of current data indicates that the accuracy of current resuscitation guidelines for infants <1 kg is poor. We hypothesized that a weight-based formula that is used clinically in our institution would accurately predict appropriate ETT placement in infants weighing < 1 kg. METHODS: The medical records, from July 2013 to November 2016, of all infants < 1 kg who were intubated were retrospectively reviewed and included. The 2 formulas utilized were the Duke formulas 5.5 cm + 1 cm/kg for infants 500–999 g or 5.0 + 1 cm/kg for infants <500 g. The appropriate ETT position was defined as the tip of the ETT below the thoracic inlet and above the carina, at approximately thoracic vertebrae 2 or 3 on an initial chest radiograph. The formula was defined as being accurate if the documented ETT depth was within 0.2 cm of the predicted depth. Post hoc analysis of current resuscitation guidelines (6 cm plus the weight of the infant in kg) was performed after the Duke formula performed worse than expected. RESULTS: A total of 131 subjects (mean ± gestational age, 26 ± 1.8 wk; mean ± weight, 729 ± 140 g) were included. The documented depth was accurately predicted by the Duke formula for 47% of the subjects, with 69% of the ETTs appropriately positioned as seen on a chest radiograph. Sensitivity was 46.6%, specificity was 53.6%, positive predictive value was 68.8% and negative predictive value was 31.4% for the Duke formula. Post hoc analysis current resuscitation guidelines found that the documented depth was accurately predicted for 23% infants, with 70% of these appropriately positioned ETTs. CONCLUSIONS: Our weight-based, institutional formula had a low sensitivity for predicting proper ETT depth. Weight-based formulas may have clinical utility; however, analysis of current data did not support use in infants < 1 kg. Rapid radiologic assessment of ETT placement is required for this patient population.

Pediatric asthma management.

In the September 2011 issue of Respiratory Care, Myers and Tomasio provide an excellent review of current asthma management and pathophysiology in their article titled “Asthma: 2015 and Beyond.”[1][1] In the section regarding emergency department (ED) treatment the authors assert that its