Proximity of the Carotid Bifurcation to the Laryngeal Prominence: Results of a Cadaver Study and Recommendations for Safe Pulse Palpation.

BACKGROUND/PURPOSE: The carotid bifurcation (CB) is the location of the carotid sinus and the baroreceptors and is also a major site for atherosclerotic plaque formation. Health care providers have therefore been cautioned to avoid the CB during carotid pulse palpation (CPP) to prevent triggering the baroreflex, occluding an artery, or propagating a thrombus. Potential risks of adverse events during CPP may be greater for older adults due to age-related vascular changes and increased risk of baroreceptor hypersensitivity. The exact location of the CB relative to easily identifiable landmarks has, however, not been well-studied. The purpose of this descriptive study was to identify the location of the CB relative to key landmarks in a cadaver sample and to make recommendations allowing clinicians to avoid the CB during CPP. METHODS: The CB and other regional landmarks in 17 male and 20 female cadavers were exposed by dissection and pins were placed at all landmarks. Digital calipers were then used to measure the distance between the CB and all landmarks. RESULTS AND DISCUSSION: The mean vertical distance from the laryngeal prominence (LP) to the CB was 25.14 mm for females and 36.13 mm for males. No CBs were located below the LP. Ninety-four percent of female CBs and 100% of male CBs were located above the LP, and 74% of female subjects and 87% of male subjects had CBs greater than 20.00 mm superior to the LP. No clinically relevant relationships were found between the CB and any of the other measured landmarks. CONCLUSIONS: Based on this cadaver sample, CPP below the level of the LP in a supine individual would be unlikely to compress the CB and thus unlikely to trigger the baroreflex or occlude the region of greatest atherosclerotic buildup. If a pulse is not palpable below the LP, moving vertically up to 1 cm above the LP in a supine individual would be likely to compress the CB in only a small number of cases.

Inspiration for the Future: The Role of Inspiratory Muscle Training in Cystic Fibrosis.

Cystic fibrosis (CF) is an inherited, multi-system, life-limiting disease characterized by a progressive decline in lung function, which accounts for the majority of CF-related morbidity and mortality. Inspiratory muscle training (IMT) has been proposed as a rehabilitative strategy to treat respiratory impairments associated with CF. However, despite evidence of therapeutic benefits in healthy and other clinical populations, the routine application of IMT in CF can neither be supported nor refuted due to the paucity of methodologically rigorous research. Specifically, the interpretation of available studies regarding the efficacy of IMT in CF is hampered by methodological threats to internal and external validity. As such, it is important to highlight the inherent risk of bias that differences in patient characteristics, IMT protocols, and outcome measurements present when synthesizing this literature prior to making final clinical judgments. Future studies are required to identify the characteristics of individuals who may respond to IMT and determine whether the controlled application of IMT can elicit meaningful improvements in physiological and patient-centered clinical outcomes. Given the equivocal evidence regarding its efficacy, IMT should be utilized on a case-by-case basis with sound clinical reasoning, rather than simply dismissed, until a rigorous evidence-based consensus has been reached.

Inspiratory muscle strength relative to disease severity in adults with stable cystic fibrosis.

BACKGROUND: Due to heterogeneity in pulmonary disease, current literature may misrepresent inspiratory muscle involvement in cystic fibrosis (CF). This study investigated inspiratory muscle strength (IMS) relative to disease severity in adults with CF. METHODS: Maximal inspiratory pressure (MIP) was assessed in 58 adults with stable CF grouped by disease severity (20 mild, 20 moderate, 18 severe) and compared to 20 controls. Relationships between MIP, lung function, dyspnea and anthropometrics were evaluated using multivariable linear models. RESULTS: MIP in cmH2O and %-predicted was decreased in advanced CF lung disease as compared to mild disease and healthy controls (p<0.05). Disease severity accounted for 24% of the variance in IMS after controlling for confounding variables (p<0.001). CONCLUSIONS: IMS is decreased in some adults with stable CF with moderate and severe pulmonary disease, and is related to dyspnea. Future studies should determine if decreased IMS contributes inefficient breathing patterns, respiratory pump dysfunction, and/or exercise intolerance in advanced CF.