Modes of Ventilation

2019 ◽  
Author(s):  
Michael J Harrison
Keyword(s):  
Respiratory Rate ◽  
Pulmonary Ventilation ◽  
Lung Ventilation ◽  
Intrathoracic Pressure ◽  
Jet Ventilation ◽  
Hemodynamic Stability ◽  
Advantages And Disadvantages ◽  
Basic Parameters ◽  
Anesthesia Machines ◽  
The Common

Lung ventilation is required to maintain oxygenation and eliminate carbon dioxide. The basic parameters of ventilation—tidal volume, respiratory rate, airway resistance, and lung and thoracic compliance—all combine to affect the airway pressure. These parameters, in turn, can affect cardiac output and hemodynamic stability through their effect on intrathoracic pressure and on venous return to the heart. Since the 1950s, many machines have been designed to allow the physician to optimize ventilation. These designs have revolved around three physical variables: volume, pressure, and time. Volume is required to overcome the anatomic respiratory dead space and allows gas exchange in the alveoli. Pressure is required to inflate the elastic system comprising the lungs and thorax, but must also be limited to prevent tissue damage. Time not only determines the respiratory rate but also the rate of flow of gas in and out of the lungs. Many permutations of these basic parameters in anesthesia machines are available today. Knowledge of the common forms of ventilation and their advantages and disadvantages will guide the anesthesiologist in choosing from among these various complex systems. This review contains 5 figures, 3 tables, and 27 references. Key words: CPAP, HFOV, IMV, IPPV, jet ventilation, PEEP, pressure cycled, pulmonary ventilation, SIMV, spontaneous, volume cycled

Modes of Ventilation

2019 ◽  
Author(s):  
Michael J Harrison
Keyword(s):  
Respiratory Rate ◽  
Pulmonary Ventilation ◽  
Lung Ventilation ◽  
Intrathoracic Pressure ◽  
Jet Ventilation ◽  
Hemodynamic Stability ◽  
Advantages And Disadvantages ◽  
Basic Parameters ◽  
Anesthesia Machines ◽  
The Common

Lung ventilation is required to maintain oxygenation and eliminate carbon dioxide. The basic parameters of ventilation—tidal volume, respiratory rate, airway resistance, and lung and thoracic compliance—all combine to affect the airway pressure. These parameters, in turn, can affect cardiac output and hemodynamic stability through their effect on intrathoracic pressure and on venous return to the heart. Since the 1950s, many machines have been designed to allow the physician to optimize ventilation. These designs have revolved around three physical variables: volume, pressure, and time. Volume is required to overcome the anatomic respiratory dead space and allows gas exchange in the alveoli. Pressure is required to inflate the elastic system comprising the lungs and thorax, but must also be limited to prevent tissue damage. Time not only determines the respiratory rate but also the rate of flow of gas in and out of the lungs. Many permutations of these basic parameters in anesthesia machines are available today. Knowledge of the common forms of ventilation and their advantages and disadvantages will guide the anesthesiologist in choosing from among these various complex systems. This review contains 5 figures, 3 tables, and 27 references. Key words: CPAP, HFOV, IMV, IPPV, jet ventilation, PEEP, pressure cycled, pulmonary ventilation, SIMV, spontaneous, volume cycled

scholarly journals Extraction and Analysis of Tetrahydrocannabinol, A Cannabis Compound in Oral Fluid

2016 ◽  
Vol 9 (1) ◽  
pp. 30
Author(s):  
Wei Zhang ◽  
Jun Wang ◽  
Zhiyuan Mi ◽  
Jiangtao Su ◽  
Xiangyu You ◽  
...  
Keyword(s):  
Drug Testing ◽  
Oral Fluid ◽  
Solid Phase ◽  
Extraction Methods ◽  
Liquid Extraction ◽  
Phase Extraction ◽  
Advantages And Disadvantages ◽  
Liquid Liquid Extraction ◽  
The Common ◽  
Common Target

Although misuse and abuse of Cannabis is well known, the health benefits have been proved by various biomedical studies. Tetrahydrocannabinol (THC) is the major active substance in leaves of Cannabis, which is the common target for drug testing. In field drug testing, oral fluid (OF) has its unique advantages over other specimens such as blood, urine, and hair. Thus the study of THC in OF is gaining popularity in Cannabis research. In this review, extraction methods are introduced in three categories, which are Liquid-Liquid Extraction (LLE), Solid Phase Extraction (SPE), and Supercritical Fluid Extraction (SFE). Examples of application with each method will be covered. Advantages and disadvantages of these methods will be compared. In addition, methods in analysis following extraction will be briefly discussed.

HIGH FREQUENCY JET VENTILATION DURING ONE LUNG VENTILATION IN PATIENTS UNDERGOING RESECTION OF AORTIC ANEURYSM BY THORACIC INCISION

1986 ◽  
Vol 65 (Supplement 3A) ◽  
pp. A487 ◽  
Author(s):  
G. Godet ◽  
M. Bertrand ◽  
P. Coriat ◽  
J. F. Baron ◽  
J. J. Rouby ◽  
...  
Keyword(s):  
Aortic Aneurysm ◽  
High Frequency ◽  
Lung Ventilation ◽  
Jet Ventilation ◽  
One Lung Ventilation ◽  
High Frequency Jet Ventilation

Cognitive Interview

2018 ◽  
Vol 299 ◽  
pp. 91-98
Author(s):  
Maria Witewska ◽  
Keyword(s):  
Law Enforcement ◽  
Common Law ◽  
Cognitive Interview ◽  
Western Countries ◽  
Advantages And Disadvantages ◽  
The Common ◽  
Polish Law ◽  
Judicial Systems

The article aims at presenting the topic of cognitive interview (CI) taking into account its advantages and disadvantages, as well as the usefulness of its application in Polish law enforcement during pre-trial proceedings. Due to the wide application of this method of questioning, mainly in countries with the common law judicial systems, it is worth considering which of the achievements of combined science and practice from Western Countries may be adapted in Poland. Are there any contraindications to conduct interviews by means of this method? If not, the question arises – what benefits it can bring to Polish practice.

scholarly journals Imaging Review of Skeletal Tumors of the Pelvis—Part I: Benign Tumors of the Pelvis

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Gandikota Girish ◽  
Karen Finlay ◽  
Yoav Morag ◽  
Catherine Brandon ◽  
Jon Jacobson ◽  
...  
Keyword(s):  
Plain Film ◽  
Clinical History ◽  
Benign Tumors ◽  
Resonance Imaging ◽  
Advantages And Disadvantages ◽  
Radiologic Evaluation ◽  
Imaging Characteristics ◽  
The Common ◽  
Magnetic Resonance Imaging Mri ◽  
Pelvic Lesions

The osseous pelvis is a well-recognized site of origin of numerous primary and secondary musculoskeletal tumors. The radiologic evaluation of a pelvic lesion often begins with the plain film and proceeds to computed tomography (CT), or magnetic resonance imaging (MRI) and possibly biopsy. Each of these modalities, with inherent advantages and disadvantages, has a role in the workup of pelvic osseous masses. Clinical history and imaging characteristics can significantly narrow the broad differential diagnosis for osseous pelvic lesions. The purpose of this review is to familiarize the radiologist with the presentation and appearance of some of the common benign neoplasms of the osseous pelvis and share our experience and approach in diagnosing these lesions.

Effects of temperature on acid-base balance and ventilation in desert iguanas

1981 ◽  
Vol 51 (2) ◽  
pp. 452-460 ◽  
Author(s):  
P. E. Bickler
Keyword(s):  
Steady State ◽  
Pulmonary Ventilation ◽  
Respiratory Acidosis ◽  
Lung Ventilation ◽  
Acid Base Balance ◽  
Acid Base ◽  
Arterial Ph ◽  
Blood Relative ◽  
Base Balance ◽  
History Of

The effects of constant and changing temperatures on blood acid-base status and pulmonary ventilation were studied in the eurythermal lizard Dipsosaurus dorsalis. Constant temperatures between 18 and 42 degrees C maintained for 24 h or more produced arterial pH changes of -0.0145 U X degrees C-1. Arterial CO2 tension (PCO2) increased from 9.9 to 32 Torr plasma [HCO-3] and total CO2 contents remained constant at near 19 and 22 mM, respectively. Under constant temperature conditions, ventilation-gas exchange ratios (VE/MCO2 and VE/MO2) were inversely related to temperature and can adequately explain the changes in arterial PCO2 and pH. During warming and cooling between 25 and 42 degrees C arterial pH, PCO2 [HCO-3], and respiratory exchange ratios (MCO2/MO2) were similar to steady-state values. Warming and cooling each took about 2 h. During the temperature changes, rapid changes in lung ventilation following steady-state patterns were seen. Blood relative alkalinity changed slightly with steady-state or changing body temperatures, whereas calculated charge on protein histidine imidazole was closely conserved. Cooling to 17-18 degrees C resulted in a transient respiratory acidosis correlated with a decline in the ratio VE/MCO2. After 12-24 h at 17-18 degrees C, pH, PCO2, and VE returned to steady-state values. The importance of thermal history of patterns of acid-base regulation in reptiles is discussed.

scholarly journals Helping students to understand physiological aspects of regional distribution of ventilation in humans: a experience from the electrical impedance tomography

2018 ◽  
Vol 42 (4) ◽  
pp. 655-660
Author(s):  
Marcelo Alcantara Holanda ◽  
Nathalia Parente de Sousa ◽  
Luana Torres Melo ◽  
Liégina Silveira Marinho ◽  
Helder Veras Ribeiro-Filho ◽  
...  
Keyword(s):  
Medical Students ◽  
Electrical Impedance ◽  
Respiratory Mechanics ◽  
Pulmonary Ventilation ◽  
Regional Distribution ◽  
Lung Ventilation ◽  
Respiratory Physiology ◽  
Impedance Tomography ◽  
Lateral Decubitus ◽  
Basic Concepts

Undergraduate biomedical students often have difficulties in understanding basic concepts of respiratory physiology, particularly respiratory mechanics. In this study, we report the use of electrical impedance tomography (EIT) to improve and consolidate the knowledge about physiological aspects of normal regional distribution of ventilation in humans. Initially, we assessed the previous knowledge of a group of medical students ( n = 39) about regional differences in lung ventilation. Thereafter, we recorded the regional distribution of ventilation through surface electrodes on a healthy volunteer adopting four different decubitus positions: supine, prone, and right and left lateral. The recordings clearly showed greater pulmonary ventilation in the dependent lung, mainly in the lateral decubitus. Considering the differences in pulmonary ventilation between right and left lateral decubitus, only 33% of students were able to notice it correctly beforehand. This percentage increased to 84 and 100%, respectively ( P < 0.01), after the results of the ventilation measurements obtained with EIT were examined and discussed. A self-assessment questionnaire showed that students considered the practical activity as an important tool to assist in the understanding of the basic concepts of respiratory mechanics. Experimental demonstration of the physiological variations of regional lung ventilation in volunteers by using EIT is feasible, effective, and stimulating for undergraduate medical students. Therefore, this practical activity may help faculty and students to overcome the challenges in the field of respiratory physiology learning.

scholarly journals Podejście zadaniowe (enfoque por tareas) a strategie komunikacyjne w nauczaniu języka hiszpańskiego jako obcego

Neofilolog ◽  
1970 ◽  
pp. 247-256
Author(s):  
Małgorzata Spychała
Keyword(s):  
Language Learners ◽  
Final Section ◽  
Communicative Competence ◽  
Teaching Approach ◽  
Advantages And Disadvantages ◽  
The Common ◽  
Sample Set

The article discusses task-based learning (TBL) in Spanish: enfoque por tareas, which is a teaching approach whose aim is to develop the learner’s communicative competence as well as to help the teacher activate language learners in the classroom – in this case learners of Spanish. The article describes the main objectives of the task and projects defined in the Common European Framework, including the proposed activities designed to fulfill a given task. The final section presents a sample set of lessons following TBL and analyzes the advantages and disadvantages of this approach.

An Overview of Learning Management Systems

2010 ◽  
pp. 1-19 ◽  
Author(s):  
Anthony A. Piña
Keyword(s):  
Open Source ◽  
Learning Management Systems ◽  
Macro Level ◽  
Management Systems ◽  
Common Features ◽  
Advantages And Disadvantages ◽  
The Past ◽  
The Common ◽  
Learning Management

In this chapter, the reader is taken through a macro level view of learning management systems, with a particular emphasis on systems offered by commercial vendors. Included is a consideration of the growth of learning management systems during the past decade, the common features and tools contained within these systems, and a look at the advantages and disadvantages that learning management systems provide to institutions. In addition, the reader is presented with specific resources and options for evaluating, selecting and deploying learning management systems. A section highlighting the possible advantages and disadvantages of selecting a commercial versus an open source system is followed by a series of brief profiles of the leading vendors of commercial and open source learning management systems.

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