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JSLS : Journal of the Society of... 2019Creating and maintaining a pneumoperitoneum to perform laparoscopy is governed by gas laws and the limiting physical constraints of the abdomen. (Review)
Review
BACKGROUND AND OBJECTIVES
Creating and maintaining a pneumoperitoneum to perform laparoscopy is governed by gas laws and the limiting physical constraints of the abdomen.
METHODS
A review of how gas, biomechanical and physical properties affect the abdomen and a systematic structured Medline and PubMed search was conducted to identify relevant studies related to the topic.
RESULTS
Abdominal compliance is a measure of ease of abdominal expansion and is determined by the elasticity of the abdominal wall and diaphragm. It is the change in intra-abdominal volume per change in intra-abdominal pressure. Caution should be exercised with pressures exceeding 12 millimeters mercury since this is defined as intra-abdominal hypertension.
CONCLUSIONS
Abdominal compliance has its limits, is unique for each patient and pressure-volume curves cannot be easily predicted. Using the lowest possible pressure to accomplish the surgical task without compromising surgical outcome is the desired goal. The clinical importance is caution and knowing there is a point where more pressure does not increase working space and only increases pressure.
Topics: Abdominal Cavity; Carbon Dioxide; Compliance; Humans; Insufflation; Laparoscopy; Pneumoperitoneum, Artificial; Pressure
PubMed: 30828242
DOI: 10.4293/JSLS.2018.00080 -
Physiological Research Dec 2021Arterial compliance is an important cardiovascular parameter characterizing mechanical and structural properties of arteries and significantly influencing... (Review)
Review
Arterial compliance is an important cardiovascular parameter characterizing mechanical and structural properties of arteries and significantly influencing ventricular-arterial coupling. Decreased arterial compliance is associated with several physiological states and pathological processes. Furthermore, arterial compliance is influenced by other cardiovascular parameters even at short time scales. Today, there are numerous noninvasive methods of estimation arterial compliance in vivo introducing some level of confusion about selection of the best method for particular application and measurement setting. In this review, the most common noninvasive methods of arterial compliance estimation are summarized, discussed and categorized. Finally, interpretation of estimated arterial compliance in the context of other possible confounders is discussed.
Topics: Arteries; Blood Pressure; Compliance
PubMed: 35199538
DOI: 10.33549/physiolres.934798 -
Postgraduate Medical Journal Jun 2006There is an age related decline in various physiological processes. Vascular ageing is associated with changes in the mechanical and the structural properties of the... (Review)
Review
There is an age related decline in various physiological processes. Vascular ageing is associated with changes in the mechanical and the structural properties of the vascular wall, which leads to the loss of arterial elasticity and reduced arterial compliance. Arterial compliance can be measured by different parameters like pulse wave velocity, augmentation index, and systemic arterial compliance. There is evidence that arterial compliance is reduced in disease states such as hypertension, diabetes, and end stage renal failure. Changes in arterial compliance can be present before the clinical manifestation of cardiovascular disease. Pharmacological and non-pharmacological measures have been shown to improve arterial compliance. Arterial compliance may constitute an early cardiovascular risk marker and may be useful in assessing the effects of drugs on the cardiovascular system. Pharmacogenetics and genetics of arterial compliance in the future will improve our knowledge and understanding about vascular ageing.
Topics: Aging; Arteries; Blood Flow Velocity; Blood Pressure; Cardiovascular Diseases; Cardiovascular Physiological Phenomena; Compliance; Diet; Elasticity; Exercise; Forecasting; Genotype; Hormone Replacement Therapy; Humans; Risk Factors; Sex Characteristics; Smoking
PubMed: 16754702
DOI: 10.1136/pgmj.2005.036053 -
American Journal of Physiology.... May 2022Blood oxygen is an important modulator of arterial function, but its impact on peripheral venous function is incompletely understood. Herein, we sought to determine the...
Blood oxygen is an important modulator of arterial function, but its impact on peripheral venous function is incompletely understood. Herein, we sought to determine the effect of hypoxia and hyperoxia on venous capacity and compliance in the lower limb. In 16 healthy individuals (7 women; age: 28.3 ± 7.6 yr, mean ± SD), we assessed peripheral oxygen saturation ([Formula: see text]), the cross-sectional area (CSA) of the great saphenous vein (GSV; Doppler ultrasound), and calf volume (strain-gauge plethysmography) during a standard 60 mmHg thigh cuff inflation-deflation protocol. Separate trials were undertaken during breathing of room air, hypoxia [fraction in inspired oxygen ([Formula: see text]): 0.10], and hyperoxia ([Formula: see text]: 0.50), according to a single-blinded, randomized design. Lower limb pressure-CSA and pressure-volume relationships were modeled using a quadratic regression equation and compliance derived. [Formula: see text] was decreased by hypoxia (83.6 ± 5.6%) and increased by hyperoxia (98.7 ± 0.5%) compared with room air (96.4 ± 1.0%, < 0.001). Compared with room air (17.0 ± 7.9 mm), hypoxia decreased GSV CSA (13.4 ± 5.7 mm, < 0.001), whereas no change was observed with hyperoxia (17.1 ± 8.7 mm, = 0.883). GSV compliance derived from the pressure-CSA relationships was elevated approximately twofold with hyperoxia (-0.0061 ± 0.0046 a.u.) when compared with room air (-0.0029 ± 0.002 a.u., = 0.027) and hypoxia (-0.0030 ± 0.0032 a.u., = 0.007). No differences were observed in calf pressure-volume parameters with either hypoxia or hyperoxia ( > 0.05). Our data indicate that GSV capacity is reduced by hypoxia, and that GSV compliance is increased by hyperoxia, thus highlighting the often overlooked role of oxygen in the regulation of venous circulation.
Topics: Adult; Compliance; Female; Humans; Hyperoxia; Hypoxia; Male; Oxygen; Ultrasonography; Young Adult
PubMed: 35319299
DOI: 10.1152/ajpregu.00319.2021 -
Journal of Cardiovascular Translational... Apr 2013Ventricular compliance alterations can affect cardiac performance and adaptations. Moreover, diastolic mechanics are important in assessing both diastolic and systolic... (Review)
Review
Ventricular compliance alterations can affect cardiac performance and adaptations. Moreover, diastolic mechanics are important in assessing both diastolic and systolic function, since any filling impairment can compromise systolic function. A sigmoidal passive filling pressure-volume relationship, developed using chronically instrumented, awake-animal disease models, is clinically adaptable to evaluating diastolic dynamics using subject-specific micromanometric and volumetric data from the entire filling period of any heartbeat(s). This innovative relationship is the global, integrated expression of chamber geometry, wall thickness, and passive myocardial wall properties. Chamber and myocardial compliance curves of both ventricles can be computed by the sigmoidal methodology over the entire filling period and plotted over appropriate filling pressure ranges. Important characteristics of the compliance curves can be examined and compared between the right and the left ventricle and for different physiological and pathological conditions. The sigmoidal paradigm is more accurate and, therefore, a better alternative to the conventional exponential pressure-volume approximation.
Topics: Animals; Biomechanical Phenomena; Compliance; Diastole; Heart Rate; Humans; Models, Cardiovascular; Stroke Volume; Ventricular Function, Left; Ventricular Function, Right; Ventricular Pressure
PubMed: 23179133
DOI: 10.1007/s12265-012-9424-1 -
Exercise and Sport Sciences Reviews Apr 2017The deterioration in arterial and cardiac function with aging impairs arterial ventricular coupling, an important determinant of cardiovascular performance. However,... (Review)
Review
The deterioration in arterial and cardiac function with aging impairs arterial ventricular coupling, an important determinant of cardiovascular performance. However, exercise training improves arterial ventricular coupling especially during exercise during the age and disease process. This review examines the concept of arterial-ventricular coupling, and how age, and disease uncouples but exercise training recouples the heart and arterial system.
Topics: Aging; Arteries; Blood Pressure; Cardiovascular Diseases; Compliance; Exercise; Heart; Humans
PubMed: 28072585
DOI: 10.1249/JES.0000000000000100 -
European Respiratory Review : An... Sep 2010The anatomical differences between the pulmonary and systemic arterial system are the main cause of the difference in distribution of compliance. In the pulmonary... (Review)
Review
The anatomical differences between the pulmonary and systemic arterial system are the main cause of the difference in distribution of compliance. In the pulmonary arterial system compliance is distributed over the entire arterial system, and stands at the basis of the constancy of the RC-time. This distribution depends on the number of peripheral vessels, which is ∼8-10 times more in the pulmonary system than the systemic tree. In the systemic arterial tree the compliance is mainly located in the aorta (80% of total compliance in thoracic-abdominal aorta). The constant RC-time in the pulmonary bed results in proportionality of systolic and diastolic pressure with mean pressure and, in turn, in the constant ratio of oscillatory and mean power.
Topics: Aorta; Blood Pressure; Compliance; Humans; Hypertension, Pulmonary; Models, Cardiovascular; Pulmonary Circulation; Vascular Resistance
PubMed: 20956192
DOI: 10.1183/09059180.00002210 -
Arteriosclerosis, Thrombosis, and... Feb 2017The aorta is a blood vessel that provides a low-resistance path for blood flow directed from the heart to peripheral organs and tissues. However, the aorta has another... (Review)
Review
The aorta is a blood vessel that provides a low-resistance path for blood flow directed from the heart to peripheral organs and tissues. However, the aorta has another central hemodynamic function, whereby the elastic nature of the aortic wall provides a significant biomechanical buffering capacity complementing the pulsatile cardiac blood flow, and this is often referred to as Windkessel function. Stiffening of the arterial wall leads to fundamental alterations in central hemodynamics, with widespread detrimental implications for organ function. In this Recent Highlights article, we describe recent contributions in ATVB that have highlighted the novel mechanisms and consequences of arterial stiffness and the clinical conditions in which arterial stiffness occurs, with a focus on advancements in the field.
Topics: Animals; Aorta; Cardiovascular Diseases; Comorbidity; Compliance; Hemodynamics; Humans; Life Style; Prognosis; Risk Factors; Stress, Mechanical; Vascular Stiffness
PubMed: 28122777
DOI: 10.1161/ATVBAHA.116.308563 -
Annals of the American Thoracic Society Feb 2016The normal pulmonary circulation is a low-pressure, high-compliance system. Pulmonary arterial compliance decreases in the presence of pulmonary hypertension because of... (Review)
Review
The normal pulmonary circulation is a low-pressure, high-compliance system. Pulmonary arterial compliance decreases in the presence of pulmonary hypertension because of increased extracellular matrix/collagen deposition in the pulmonary arteries. Loss of pulmonary arterial compliance has been consistently shown to be a predictor of increased mortality in patients with pulmonary hypertension, even more so than pulmonary vascular resistance in some studies. Decreased pulmonary arterial compliance causes premature reflection of waves from the distal pulmonary vasculature, leading to increased pulsatile right ventricular afterload and eventually right ventricular failure. Evidence suggests that decreased pulmonary arterial compliance is a cause rather than a consequence of distal small vessel proliferative vasculopathy. Pulmonary arterial compliance decreases early in the disease process even when pulmonary artery pressure and pulmonary vascular resistance are normal, potentially enabling early diagnosis of pulmonary vascular disease, especially in high-risk populations. With the recognition of the prognostic importance of pulmonary arterial compliance, its impact on right ventricular function, and its contributory role in the development and progression of distal small-vessel proliferative vasculopathy, pulmonary arterial compliance is an attractive target for the treatment of pulmonary hypertension.
Topics: Compliance; Heart Failure; Humans; Hypertension, Pulmonary; Neovascularization, Pathologic; Prognosis; Pulmonary Artery; Pulmonary Circulation; Vascular Stiffness; Ventricular Dysfunction, Right
PubMed: 26848601
DOI: 10.1513/AnnalsATS.201509-599FR -
Gut Sep 1999Many of the symptoms characteristic of the functional gastrointestinal disorders (FGID) are consistent with dysfunction of the motor and/or sensory apparatus of the... (Review)
Review
Many of the symptoms characteristic of the functional gastrointestinal disorders (FGID) are consistent with dysfunction of the motor and/or sensory apparatus of the digestive tract. Those aspects of sensorimotor dysfunction most relevant to the FGID include alterations in: gut contractile activity; myoelectrical activity; tone and compliance; and transit, as well as an enhanced sensitivity to distension, in each region of the gastrointestinal tract. Assessment of these phenomena involves a number of techniques, some well established and others requiring further validation. Using such techniques, researchers have reported a wide range of alterations in sensory and in motor function in the FGID. Importantly, however, relationships between such dysfunction and symptoms have been relatively weak, and so the clinical relevance of the former remains unclear. Moreover, the proportions of patients in the various symptom subgroups who display dysfunction, and the extent and severity of their symptoms, require better characterization. On a positive note, progress is occurring on several fronts, especially in relation to functional dyspepsia and irritable bowel syndrome, and based on the data gathered to date, a number of areas where further advances are required can be highlighted.
Topics: Colonic Diseases, Functional; Compliance; Dyspepsia; Forecasting; Gastrointestinal Motility; Gastrointestinal Transit; Humans; Research; Sensation Disorders
PubMed: 10457040
DOI: 10.1136/gut.45.2008.ii17