| 1. |
- Gottfridsson, Peter, et al.
(författare)
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Global longitudinal strain: effects by load and autonomic nervous system expression
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background: Intrathoracic pressure related to breathing or positive pressure ventilatory support has effects on venous return to the heart and transmyocardial pressures. In addition, autonomic nerve system activity affects cardiac inotropy, chronotropy, and loading. Knowledge of these physiological interactions is relevant when interpreting atrial and ventricular strain results as part of heart function assessment by echocardiography in patients with ventilatory support. Purpose: We aimed to assess 2-D global longitudinal strain (GLS%) for all four heart chambers (atria and ventricles) during controlled changes in intrathoracic pressure, as well as sympathetic nerve system activation. We hypothesized that GLS% is affected by both load and sympathetic tone. Methods: With ethical approval and participant consent, 20 healthy volunteers (medical students) performed a controlled Valsalva manoeuvre, a mask positive pressure inspiration (CPAP) manoeuvre (25 cm H2O) and a Hand Grip manoeuvre (squeezing a rolled towel with 75% of maximum force with one hand for 2 minutes). We monitored continuous blood pressure and heart rate (using a Finapres) during the manoeuvres to make sure that the manoeuvres caused the desired physiologic effects.GLS% of the individual chambers were measured before and during these manoeuvres using commercially available post- processing software, from the 4-chamber view. 2 different operators measured independently the GLS% for every manoeuvre. Paired measurement comparisons were performed (paired t test). Results: Both the Valsalva maneuverer and CPAP caused reductions in GLS % in all four chambers. The Hand Grip manoeuvre did not cause any change in GLS % in any chamber.Conclusion: Since both CPAP and late Valsalva causes a reduction in preload, we assume that a decrease in preload causes a reduction in GLS% in the heart chambers. Both Valsalva and Handgrip manoeuvres causes a raised sympathicus tone which does not seem to affect GLS% in any chamber. (In the Hand Grip manoeuvre there was a rise in blood pressure and pulse during the manoeuvre, as a sign of increased sympathetic tone.)From these preliminary findings, we conclude that for healthy young individuals GLS% appears to decrease in all chambers during Valsalva and CPAP, while no change in GLS% is caused by the Hand Grip manoeuvre.
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| 2. |
- Gottfridsson, Peter, et al.
(författare)
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Left atrial contraction strain and controlled preload alterations, a study in healthy individuals
- 2022
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Ingår i: Cardiovascular Ultrasound. - : BioMed Central. - 1476-7120. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In order to assess left atrial contractile function in disturbed circulatory conditions, it is necessary to have a clear understanding of how it behaves in a normal resting state with changes in loading conditions. However, currently the understanding of this relationship is incomplete. We hypothesize that in healthy individuals, left atrial contraction strain and its peak strain rate are increased or decreased by increasing or decreasing preload, respectively.METHODS: Controlled maneuvers used to change preload included continuous positive airway pressure by mask (CPAP 20 cmH2O) for preload decrease, and passive leg raise (15 degrees angle) for preload increase. Cardiac ultrasound 4-chamber views of the left atria and left ventricle were acquired at baseline and during maneuver. Acquired images were post processed and analyzed offline. Comparisons were made using paired t-test and means with 95% confidence interval.RESULTS: There were 38 participants, complete results were obtained from 23 in the CPAP maneuver and 27 in the passive leg raise maneuver. For the CPAP group, left atrial contraction strain was 11.6% (10.1 to 13.1) at baseline and 12.8% (11.0 to 14.6) during the maneuver (p = 0.16). Left atrial contraction peak strain rate was - 1.7 s- 1 (- 1.8 to - 1.5) at baseline and - 1.8 s- 1 (- 2.0 to - 1.6) during the maneuver (p = 0.29). For the passive leg raise-group, left atrial contraction strain was 10.1% (9.0 to 11.2) at baseline and 10.8% (9.4 to 12.3) during the maneuver (p = 0.28). Left atrial contraction peak strain rate was - 1.5 s- 1 (- 1.6 to - 1.4) at baseline and - 1.6 s- 1 (- 1.8 to - 1.5) during the maneuver (p = 0.29). Left atrial area, an indicator of preload, increased significantly during passive leg raise and decreased during CPAP.CONCLUSION: In healthy individuals, left atrial contraction strain and its peak strain rate seem to be preload-independent.TRIAL REGISTRATION: The study was 2018-02-19 registered at clinicaltrials.gov ( NCT03436030 ).
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| 3. |
- Gottfridsson, Peter, et al.
(författare)
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Left atrial contraction strain during a Valsalva manoeuvre : A study in healthy humans
- 2023
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Ingår i: Clinical Physiology and Functional Imaging. - : John Wiley & Sons. - 1475-0961 .- 1475-097X. ; 43:3, s. 165-169
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cardiac mechanics are influenced by loading conditions as well as sympathetic tone. Left atrial (LA) contractile function assessed by two-dimensional (2D) strain has been described in the setting of controlled preload alterations; however, studies show conflicting findings about change or direction of change. We hypothesized that the controlled preload reduction and the sympathetic nervous system activation that occurs during a standardized Valsalva manoeuvre would bring about a change in LA contraction strain.aMETHODS: Healthy young adults of both sexes were recruited. Transthoracic echocardiographic ultrasound images were collected before and during a Valsalva manoeuvre. Standard imaging windows for LA strain assessment were used and the images were copied and stored for later offline analysis. These were assessed for adequate atrial wall visualization in 2D strain assessment. Paired comparisons were carried out using Student's T test.RESULT: Thirty-eight participants were included and there were 22 complete studies with paired pre- and during Valsalva manoeuvre. LA contraction strain at baseline was 10.5 ± 2.8% (standard deviation) and during the Valsalva manoeuvre 10.6 ± 4.6%, p = 0.86.CONCLUSION: The Valsalva manoeuvre, a combination of preload reduction and sympathetic nervous system activation, seems not to be associated with a change in LA contraction strain in healthy young individuals. LA contraction strain should be interpreted in the context of both atrial loading conditions and prevailing autonomic nervous system activity.
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| 4. |
- Kirmeier, Eva, et al.
(författare)
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Post-anaesthesia pulmonary complications after use of muscle relaxants (POPULAR) : a multicentre, prospective observational study.
- 2019
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Ingår i: The Lancet Respiratory Medicine. - 2213-2600 .- 2213-2619. ; 7:2, s. 129-140
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Results from retrospective studies suggest that use of neuromuscular blocking agents during general anaesthesia might be linked to postoperative pulmonary complications. We therefore aimed to assess whether the use of neuromuscular blocking agents is associated with postoperative pulmonary complications.METHODS: We did a multicentre, prospective observational cohort study. Patients were recruited from 211 hospitals in 28 European countries. We included patients (aged ≥18 years) who received general anaesthesia for any in-hospital procedure except cardiac surgery. Patient characteristics, surgical and anaesthetic details, and chart review at discharge were prospectively collected over 2 weeks. Additionally, each patient underwent postoperative physical examination within 3 days of surgery to check for adverse pulmonary events. The study outcome was the incidence of postoperative pulmonary complications from the end of surgery up to postoperative day 28. Logistic regression analyses were adjusted for surgical factors and patients' preoperative physical status, providing adjusted odds ratios (ORadj) and adjusted absolute risk reduction (ARRadj). This study is registered with ClinicalTrials.gov, number NCT01865513.FINDINGS: Between June 16, 2014, and April 29, 2015, data from 22 803 patients were collected. The use of neuromuscular blocking agents was associated with an increased incidence of postoperative pulmonary complications in patients who had undergone general anaesthesia (1658 [7·6%] of 21 694); ORadj 1·86, 95% CI 1·53-2·26; ARRadj -4·4%, 95% CI -5·5 to -3·2). Only 2·3% of high-risk surgical patients and those with adverse respiratory profiles were anaesthetised without neuromuscular blocking agents. The use of neuromuscular monitoring (ORadj 1·31, 95% CI 1·15-1·49; ARRadj -2·6%, 95% CI -3·9 to -1·4) and the administration of reversal agents (1·23, 1·07-1·41; -1·9%, -3·2 to -0·7) were not associated with a decreased risk of postoperative pulmonary complications. Neither the choice of sugammadex instead of neostigmine for reversal (ORadj 1·03, 95% CI 0·85-1·25; ARRadj -0·3%, 95% CI -2·4 to 1·5) nor extubation at a train-of-four ratio of 0·9 or more (1·03, 0·82-1·31; -0·4%, -3·5 to 2·2) was associated with better pulmonary outcomes.INTERPRETATION: We showed that the use of neuromuscular blocking drugs in general anaesthesia is associated with an increased risk of postoperative pulmonary complications. Anaesthetists must balance the potential benefits of neuromuscular blockade against the increased risk of postoperative pulmonary complications.FUNDING: European Society of Anaesthesiology.
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| 5. |
- Samuelsson, Peter, 1984-
(författare)
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Framing service innovation in healthcare
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Healthcare faces multiple challenges. Besides a raging pandemic have the number of people struggling with mental illness and chronic illnesses increased. Service innovation is a possible way of meeting these problems. However, service innovation is a scattered concept, with many different conceptualizations and schools of thought, all providing vital research aspects. Research has unraveled three elements that form different approaches for service innovation research. Healthcare also offers a complex context for conducting change and service innovation, containing prerequisites challenging previous understanding and conceptualizations of service innovation.To study service innovation in healthcare and to clarify research, this thesis aims to develop a framework for service innovation that relates and differentiates three approaches and their key characteristics and to determine how the prerequisites for healthcare relate to this framework, and finally to study, test, and illustrate the framework in the empirical context. The thesis builds upon three studies and four individual papers. The studies consist of one literature review, providing the conceptual groundwork for constructing the framework, and two empirical studies assessing and further developing the framework. The individual papers uses the empirical studies and depart from the different approaches to service innovation and healthcare prerequisites, providing key insights and clarifying the different approaches' strengths and weaknesses. The proposed framework recognizes the need for multiple service innovation research approaches since no single approach is enough to study the multifaceted service innovation phenomena in healthcare. The individual papers also contribute to the growing literature stream addressing service innovation in healthcare by describing social entrepreneurs' motivation during the service innovation process and explaining some of the effects of different service innovation types.
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| 6. |
- Samuelsson, Peter, et al.
(författare)
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Incremental and Radical Service Innovation in Healthcare
- 2019
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Ingår i: Handbook of Service Science. - Cham : Springer. - 9783319985114 - 9783319985121 ; , s. 619-638
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Bokkapitel (refereegranskat)abstract
- The growing cost and demand of healthcare is a major concern globally. Service innovation has been put forward as a top priority to address the challenges of healthcare. However, the concept of service innovation is poorly understood, in particular the differences between incremental and radical service innovation. The chapter makes two important contributions. Firstly, it conceptualizes incremental and radical service innovation based on internal and external changes; in particular, it identifies four types of service innovations. Secondly, it explores the effects and diffusion processes of service innovation. It aids practitioners and researchers to understand radical service innovation in a new way and to shed light on effects and diffusion of service innovation in healthcare.
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