Publications by authors named "Andrew R Tomlinson"

7 Publications

  • Page 1 of 1

Estimating exercise PCO in patients with heart failure with preserved ejection fraction.

J Appl Physiol (1985) 2021 Nov 11. Epub 2021 Nov 11.

Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX, United States.

Heart failure with preserved ejection fraction (HFpEF) patients exhibit cardiopulmonary abnormalities that could affect the predictability of exercise PCO from the Jones (PCO) equation (PCO=5.5+0.9xPCO-2.1xV). Since the dead space to tidal volume (V/V) calculation also includes PCO measurements, estimates of V/V from PCO may also be affected. Because using noninvasive estimates of PCO and V/V could save patient discomfort, time, and cost, we examined whether PCO and PCO can be used to estimate PCO and V/V in 13 HFpEF patients. PCO was measured from expired gases measured simultaneously with radial arterial blood gases at rest, constant-load (20W), and peak exercise. V/V was calculated using the Enghoff modification of the Bohr equation, and estimates of V/V were calculated using PCO (V/V) and PCO (V/V) in place of PCO. PCO was similar to PCO at rest (-1.46±2.63, P=0.112) and peak exercise (0.66±2.56, P=0.392), but overestimated PCO at 20W (-2.09±2.55, P=0.020). PCO was similar to PCO at rest (-1.29±2.57, P=0.119) and 20W (-1.06±2.29, P=0.154); but, underestimated PCO at peak exercise (1.90±2.13, P=0.009). V/V was similar to V/V at rest (-0.01±0.03, P=0.127) and peak exercise (0.01±0.04, P=0.210), but overestimated V/V at 20W (-0.02±0.03, P=0.025). Although V/V was similar to V/V at rest (-0.01±0.03, P=0.156) and 20W (-0.01±0.03, P=0.133), V/V underestimated V/V at peak exercise (0.03±0.04, P=0.013). Exercise PCO and V/V provide better estimates of PCO and V/V than PCO and V/V does at peak exercise. Thus, estimates of PCO and V/V should only be used if sampling arterial blood during CPET is not feasible.
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http://dx.doi.org/10.1152/japplphysiol.00474.2021DOI Listing
November 2021

Obesity Blunts the Ventilatory Response to Exercise in Men and Women.

Ann Am Thorac Soc 2021 07;18(7):1167-1174

Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and University of Texas Southwestern Medical Center, Dallas, Texas.

Obesity presents a mechanical load to the thorax, which could perturb the generation of minute ventilation (V̇e) during exercise. Because the respiratory effects of obesity are not homogenous among all individuals with obesity and obesity-related effects could vary depending on the magnitude of obesity, we hypothesized that the exercise ventilatory response (slope of the V̇e and carbon dioxide elimination [V̇co] relationship) would manifest itself differently as the magnitude of obesity increases. To investigate the V̇e/V̇co slope in an obese population that spanned across a wide body mass index (BMI) range. A total of 533 patients who presented to a surgical weight loss center for pre-bariatric surgery testing performed an incremental maximal cycling test and were studied retrospectively. The V̇e/V̇co slope was calculated up to the ventilatory threshold. Patients were examined in groups based on BMI (category 1: 30-39.9 kg/m, category 2: 40-49.9 kg/m, and category 3: ≥50 kg/m). Because the respiratory effects of obesity could be sex and/or age specific, we further examined patients in groups by sex and age (younger: <50 yr and older: ≥50 yr). Differences in the V̇e/V̇co slope were then compared between BMI category, age, and sex using a three-way ANOVA. No significant BMI category by sex by age interactions was detected ( = 0.75). The V̇e/V̇co slope decreased with increases in BMI (category 1, 29.1 ± 4.0; category 2, 28.4 ± 4.1; and category 3, 27.1 ± 3.3) and was elevated in women (28.9 ± 4.1) compared with men (26.7 ± 3.2) (BMI category by sex interaction,  < 0.05). No age-related differences were observed (BMI category by age interaction,  = 0.55). The partial pressure for end-tidal CO was elevated at the ventilatory threshold in BMI category 3 compared with BMI categories 1 and 2 (both  < 0.01). These findings suggest that obesity presents a unique challenge to augmenting ventilatory output relative to CO elimination, such that the increase in the exercise ventilatory response becomes blunted as the magnitude of obesity increases. Further studies are required to investigate the clinical consequences and the mechanisms that may explain the attenuation of exercise ventilatory response with increasing BMI in men and women with obesity.
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http://dx.doi.org/10.1513/AnnalsATS.202006-746OCDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8328370PMC
July 2021

Multidimensional aspects of dyspnea in obese patients referred for cardiopulmonary exercise testing.

Respir Physiol Neurobiol 2020 03 30;274:103365. Epub 2019 Dec 30.

Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas and UT Southwestern Medical Center, Dallas, TX, United States. Electronic address:

We investigated the contributions of obesity on multidimensional aspects of dyspnea on exertion (DOE) in patients referred for clinical cardiopulmonary exercise testing (CPET). Ratings of perceived breathlessness (RPB, Borg scale 0-10) were collected in obese (BMI ≥ 30; n = 47) and nonobese (BMI ≤ 25; n = 27) patients during two (one lower: ∼30 W; and one higher: ∼50 W) 4-6 min constant load cycling bouts. Multidimensional dyspnea profiles (MDP) were collected in the final 26 obese and 14 nonobese patients of the sample. RPB was greater (p = 0.05) in obese (3.3 ± 2.2 vs 2.4 ± 1.4) at lower work rates, but similar at higher work rates (4.9 ± 2.2 vs 4.4 ± 1.8). MDP sensory score including unpleasantness was 4.3 ± 2.2 in obese vs 2.5 ± 1.9 in nonobese (p < 0.001). The affective score was 1.9 ± 2.2 vs 0.7 ± 0.7, respectively (p < 0.01). Breathing sensations including 'air hunger', 'effort', and 'breathing at lot' were greater (p < 0.05) in obese, making these patients more frustrated/angry (p < 0.05). Obesity should be considered as a potential independent influencing factor that provokes DOE and unpleasantness when assessing breathlessness during CPET.
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http://dx.doi.org/10.1016/j.resp.2019.103365DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7002243PMC
March 2020

Pediatric Calvarial Bone Thickness in Patients With and Without Aural Atresia.

Otol Neurotol 2017 12;38(10):1470-1475

*University of New Mexico Health Sciences Center †Presbyterian Ear Institute, Albuquerque, New Mexico.

Objective: To compare temporal bone thickness along a three-dimensional arc of potential osseointegrated implant sites for bone-anchored hearing aids in children with and without aural atresia using computed tomographic imaging (CT).

Study Design: Retrospective case review.

Setting: Tertiary children's hospital.

Patients: Children with or without aural atresia aged less than 11 years who had a temporal bone CT.

Intervention (s): Calvarial bone volume on CT was rendered in three-dimensional and thickness was reconstructed and measured at up to 12 defined sites along an arc of recommended implant sites.

Main Outcome Measure (s): Determining whether a majority of observed potential implant sites have 2, 3, or 4 mm of bone thickness while controlling for age differences and atresia status.

Results: A total of 40 atretic (from 34 patients) and 34 control (from 34 patients) temporal bones were compared using CT. Likelihood ratio tests indicated that diagnosis did not have a statistically significant effect on whether patients reached thresholds of 2, 3, or 4 mm at most observed sites (p = 0.781, 0.773, and 0.529, respectively) when adjusting for age. For all children measured, 93% had >50% of measured points greater than or equal to 2 mm thick.

Conclusion: Most children had greater than 2 mm of temporal bone thickness at >50% of the sites measured regardless of age or atresia diagnosis. The likelihood of reaching 4 mm of thickness at most sites improves with age. In unilateral patients, there was not a significant difference in thickness between affected and unaffected sides. There was also no significant difference in thickness when comparing patients with atresia to those without.
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http://dx.doi.org/10.1097/MAO.0000000000001579DOI Listing
December 2017

Low Pulse Oximetry Reading: Time for Action or Reflection?

Chest 2017 04;151(4):735-736

Division of Pulmonary and Critical Care Medicine, University of Texas Southwestern Medical Center, Dallas, TX; Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, TX.

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http://dx.doi.org/10.1016/j.chest.2016.11.001DOI Listing
April 2017

IgE cross-linking impairs monocyte antiviral responses and inhibits influenza-driven T1 differentiation.

J Allergy Clin Immunol 2017 07 10;140(1):294-298.e8. Epub 2017 Jan 10.

Department of Pediatrics, University of Texas Southwestern, Dallas, Tex; Department of Immunology, University of Texas Southwestern, Dallas, Texas; Department of Internal Medicine, University of Texas Southwestern, Dallas, Texas. Electronic address:

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http://dx.doi.org/10.1016/j.jaci.2016.11.035DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5794014PMC
July 2017

Use of the Teres Major Muscle in Chimeric Subscapular System Free Flaps for Head and Neck Reconstruction.

JAMA Otolaryngol Head Neck Surg 2015 Sep;141(9):816-21

Division of Otolaryngology-Head and Neck Surgery, Department of Surgery, University of New Mexico Health Science Center, Albuquerque.

Importance: We present what we believe to be the first case series in which the teres major muscle is used as a free flap in head and neck reconstruction.

Objectives: To describe our experience with the teres major muscle in free flap reconstruction of head and neck defects and to identify advantages of this approach.

Design, Setting, And Participants: A retrospective review was performed at 2 tertiary care centers between February 1, 2007, and June 30, 2012. Data analysis was conducted from July 31, 2014, through December 1, 2014.

Intervention: Teres major muscle free flap for use in head and neck reconstruction.

Main Outcomes And Measures: Indications for use, complications, and outcomes including donor site morbidity.

Results: The teres major free flap was used in 11 patients as a component of chimeric subscapular system free flaps for a variety of complex head and neck defects. The teres major muscle was used to fill soft-tissue defects of the neck, face, and nasal cavity; it provided substantial soft-tissue volume but was less bulky than the latissimus dorsi muscle. The teres major muscle was also used to provide protection for vascular anastomoses and/or great vessels and to enhance soft-tissue coverage of the mandibular reconstruction plate. In addition, the muscle was selected as a substrate for skin grafting where inadequate neck skin remained. Flap survival occurred in 10 of 11 flaps (91%). Two flaps (18%) demonstrated venous congestion that was managed successfully. Two patients (18%) developed minor recipient-site complications (submental fistula and infection with recurrent wound dehiscence and plate exposure). All donor sites healed well, with chronic, mild shoulder pain noted in 2 patients (18%) and no postoperative seromas observed in any patient.

Conclusions And Relevance: Addition of the teres major muscle to a subscapular system free flap is an option for reconstruction of a variety of complex head and neck defects, particularly when a moderate amount of soft tissue is required. In select cases, the teres major muscle may have advantages over the latissimus dorsi muscle.
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http://dx.doi.org/10.1001/jamaoto.2015.1485DOI Listing
September 2015
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