Shock
Emergency Center, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China.
Published: October 2020
Objective: Diaphragm dysfunction often occurs in patients with prolonged mechanical ventilation (MV) after resuscitation. Mild hypothermia (MHT) is a classical treatment to improve the outcomes of cardiac arrest (CA); however, the effect of MHT on diaphragm function remains unclear. In the present study, we aim to investigate the effect of MHT on diaphragmatic microcirculation and function using a murine cardiopulmonary resuscitation model.
Methods: Thirty-two rats were randomly assigned into a resuscitation normothermia group (RNT), an intraresuscitation hypothermia group (IRH), a postresuscitation hypothermia group (PRH), or a sham control group. CA was induced by airway occlusion, and resuscitation was implemented by precordial compression and MV. The diaphragmatic microvascular blood flow velocity, diaphragmatic microcirculation flow index (MFI), and perfused vascular density (PVD) were measured. The diaphragm was then removed for in vitro contractile property examination and cross-sectional area measurement. The lipid peroxidation and superoxide dismutase (SOD) levels in the diaphragm were also assayed.
Results: Either early or delayed MHT intervention did not improve the diaphragmatic microvascular blood flow velocity, MFI, and PVD, which were significantly decreased during prolonged MV after resuscitation. Compared with the RNT group, treatment with MHT increased the diaphragm contractility, fiber dimensions, and SOD levels and decreased diaphragm lipid peroxidation. A more significant change in these indices was observed in the IRH group compared with that in the PRH group.
Conclusion: MHT preserves the diaphragm contractility and fiber dimensions and decreases oxidative stress but does not improve the microcirculatory blood supply during prolonged MV after resuscitation. Early MHT intervention is more efficient in preventing diaphragm dysfunction than delayed intervention after CA.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1097/SHK.0000000000001501 | DOI Listing |
J Vis Exp
July 2024
Department of Internal Medicine - Nephrology, Leiden University Medical Center; Einthoven Laboratory of Vascular and Regenerative Medicine, Leiden University Medical Center; Institute Physics for Medicine Paris, Inserm, ESPCI-Paris-PSL;
Non-invasive in vivo imaging of the vasculature is a powerful tool for studying disease mechanisms in rodents. To achieve high sensitivity imaging of the microvasculature using Doppler ultrasound methods, imaging modalities employing the concept of ultrafast imaging are preferred. By increasing the frame rate of the ultrasound scanner to thousands of frames per second, it becomes possible to improve the sensitivity of the blood flow down to 2 mm/s and to obtain functional information about the microcirculation in comparison to a sensitivity of around 1 cm/s in conventional Doppler modes.
View Article and Find Full Text PDFJ Intensive Care Med
January 2024
Department of Critical Care Medicine, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
The high respiratory and cardiac drive is essential to the host-organ unregulated response. When a primary disease and an unregulated secondary response are uncontrolled, the patient may present in a high respiratory and cardiac drive state. High respiratory drive can cause damage to the lungs, pulmonary circulation, and diaphragm, while high cardiac drive can lead to fluid leakage and infiltration as well as pulmonary interstitial edema.
View Article and Find Full Text PDFMicrocirculation
November 2022
Division of Nephrology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.
Objective: The first step in renal urine formation is ultrafiltration across the glomerular barrier. The change in its nanostructure has been associated with nephrotic syndromes. Effects of physiological and hemodynamic factor alterations associated with diabetic nephropathy (DN) on glomerular permselectivity are examined through a mathematical model employing low-Reynolds-number hydrodynamics and hindered transport theory.
View Article and Find Full Text PDFAnesthesiology
May 2022
Department of Intensive Care Medicine, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Background: The effect of fluid management strategies in critical illness-associated diaphragm weakness are unknown. This study hypothesized that a liberal fluid strategy induces diaphragm muscle fiber edema, leading to reduction in diaphragmatic force generation in the early phase of experimental pediatric acute respiratory distress syndrome in lambs.
Methods: Nineteen mechanically ventilated female lambs (2 to 6 weeks old) with experimental pediatric acute respiratory distress syndrome were randomized to either a strict restrictive fluid strategy with norepinephrine or a liberal fluid strategy.
Microcirculation
November 2021
Department of Kinesiology, Kansas State University, Manhattan, KS, USA.
Introduction: Prolonged mechanical ventilation (MV; ≥6 h) results in large, time-dependent reductions in diaphragmatic blood flow and shear stress. We tested the hypothesis that MV would impair the structural and material properties (ie, increased stress/stretch relation and/or circumferential stretch) of first-order arterioles (1A) from the medial costal diaphragm.
Methods: Shear stress was estimated from isolated arterioles and prior blood flow data from the diaphragm during spontaneous breathing (SB) and prolonged MV (6 h MV).
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.