Two-sidearm tracheal cannula for respiratory airflow measurements in small animals

1983 ◽  
Vol 55 (1) ◽  
pp. 250-253 ◽  
Author(s):  
J. P. Mortola ◽  
A. Noworaj
Keyword(s):  
Tidal Volume ◽  
Linear Response ◽  
Flow Resistance ◽  
Small Volume ◽  
The Body ◽  
Small Animals ◽  
Newborn Rats ◽  
Mean Flow ◽  
Tracheal Cannula ◽  
Respiratory Airflow

We have investigated the possibility of using a two-sidearm tracheal cannula for measurements of respiratory airflow. Measurements of mean flow and tidal volume using four such cannulas (0.7, 1.5, 1.8, and 2.5 mm ID) are described. They have a linear response up to flows of 6, 10, 12, and 28 ml X s-1, respectively, that correspond to 100 ml X s-1 X kg-1 or more, depending on the body size of the animals (15-350 g) in which they could be used. These characteristics, coupled with small volume and flow resistance, make the use of these cannulas as pneumotachographs a suitable and very practical way of measuring mean airflow and tidal volume in anesthetized small animals, ranging in size from newborn rats to newborn puppies.

Pulmonary function in different animals

1960 ◽  
Vol 15 (6) ◽  
pp. 1069-1072 ◽  
Author(s):  
James E. Drorbaugh
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Tidal Volume ◽  
Vital Capacity ◽  
Work Of Breathing ◽  
The Body ◽  
Small Animals ◽  
Similar Data ◽  
Body Weights ◽  
Rate Of Oxygen Consumption

Relaxation pressure-volume curves have been determined from the lungs and thorax of mice, rats, rabbits and dogs. From these data figures are obtained for body weights, vital capacity and compliance. These are compared with similar data for man and calculated values for tidal volumes and frequency of breathing obtained from the literature. Calculations were made of the elastic work of breathing per breath and per minute. All values were plotted on double log paper against body weight so that they could be expressed as proportional to some power of body weight. It was found that compliance, tidal volume, vital capacity and elastic work per breath are all nearly proportional to the first power of the body weight while the elastic work per minute, like the rate of oxygen consumption, is proportional to the 0.7 (or 0.73) power of body weight. It is concluded that lungs of large and small animals tend to have the same compliance per unit of vital capacity and require the same pressure for the intake of one tidal volume. A large lung may therefore be regarded as equivalent to many smaller lungs in parallel. Submitted on June 13, 1960

Airflow measurements in small animals

1994 ◽  
Vol 28 (3) ◽  
pp. 239-243 ◽  
Author(s):  
Giuseppe Marano
Keyword(s):  
Dead Space ◽  
Venous Return ◽  
Breathing Circuit ◽  
Intrathoracic Pressure ◽  
Small Animals ◽  
Total Flow ◽  
Mechanically Ventilated ◽  
Tracheal Cannula ◽  
Pharmacological Studies ◽  
Respiratory Airflow

Monitoring respiratory airflow is extremely important in pharmacological studies of the respiratory system. However, in mechanically ventilated small animals (e.g. rats and guinea pigs) the use of a commercial pneumotachometer, attached directly to the tracheal cannula, substantially increases the equipment dead space (the volume shared by inspired and expired gases). Since apparatus dead space must be added to the tidal volume (determined on the basis of ventilatory rate and animal body weight) necessary to meet the respiratory needs of the animal, the resulting stroke volume is greatly increased, specially in very small animals. This results in an increase in intrathoracic pressure which is potentially associated with a decrease in venous return, cardiac output, and arterial pressure. The author investigated the possibility of avoiding the potential problems of the added instrumental dead space by software-summing the separate flows measured on the inflation and deflation limbs of the breathing circuit. This study shows that the summation of the flow signals obtained from separate pneumotachometers on the inspiratory and expiratory arms of the breathing circuit is not dissimilar to the total flow as measured by a pneumotachometer directly attached to the tracheal cannula and that the method here described can be an advantageous alternative to the employment of a single pneumotachometer.

Relative tidal volume and respiratory airflow estimation using tracheal sound and movement during sleep

2021 ◽  
Author(s):  
Nasim Montazeri Ghahjaverestan ◽  
Muammar M. Kabir ◽  
Shumit Saha ◽  
Bojan Gavrilovic ◽  
Kaiyin Zhu ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Tracheal Sound ◽  
Respiratory Airflow

Invasive cutaneous cryptococcosis of the nasal planum in a cat – case report

2018 ◽  
Vol XXIII (133) ◽  
pp. 56-62
Author(s):  
Ana Cláudia Balda ◽  
Juliana Cristina Gonçalves ◽  
Renata Cristina Menezes ◽  
Ana Cristina Fascetti de Souza ◽  
Guilherme Durante Cruz
Keyword(s):  
Private Practice ◽  
Infectious Agent ◽  
Skin Lesions ◽  
The Body ◽  
Small Animals ◽  
Cutaneous Lesions ◽  
Mixed Breed ◽  
Deep Mycosis ◽  
The City ◽  
Cutaneous Cryptococcosis

Crytococcosis is the most common deep mycosis in cats, despite its rarity in the medical practice of small animals. The infectious agent of the disease is Cryptococcus sp, an opportunistic fungus that can spread throughout the body. An approximately two-year-old mixed breed cat, weighting 3 kg was presented to a private practice in the city of São Paulo, Brazil. Physical examination relealed pyogranulomatous skin lesions, mainly on the nasal planum and the second digit of the left thoracic lim. The animal presented no neurological or respiratory signs. The response to antifulgal on cutaneous lesions was favorable, but the animal did not resist a second sedation and died within twenty-eight days after starting treatment. This report shows an atypical case of cryptococcosis due to the lack of immunodeficiency.

A self-retaining nasal flowmeter for preterm infants

1980 ◽  
Vol 48 (3) ◽  
pp. 569-571 ◽  
Author(s):  
R. T. Brouillette ◽  
B. T. Thach
Keyword(s):  
Stainless Steel ◽  
Tidal Volume ◽  
Preterm Infants ◽  
Dead Space ◽  
Nasal Cannula ◽  
Light Weight ◽  
Low Resistance ◽  
Respiratory Airflow ◽  
The Subject ◽  
Compact Design

A nasal flowmeter suitable for preterm infants is described. It is made from a commercially available nasal cannula and 400-mesh stainless steel screen. Low dead space (0.35 ml) and low resistance (1.3 cmH2O . 100 ml-1 . s) are advantages. Light weight and compact design have eliminated the need for extensive restraint of the subject. Also, the investigator need not hold the flowmeter in place. These features make accurate measurement of respiratory airflow and tidal volume possible during polygraphic monitoring studies lasting several hours.

Effect of body position on spontaneous respiratory rate and tidal volume in patients with obesity, abdominal distension and ascites

1994 ◽  
Vol 3 (2) ◽  
pp. 102-106 ◽  
Author(s):  
SM Burns ◽  
MB Egloff ◽  
B Ryan ◽  
R Carpenter ◽  
JE Burns
Keyword(s):  
Tidal Volume ◽  
Respiratory Rate ◽  
Breathing Pattern ◽  
Body Position ◽  
Abdominal Distension ◽  
The Body ◽  
Abdominal Distention ◽  
Optimal Position ◽  
Nursing Textbooks ◽  
Spontaneously Breathing

BACKGROUND: Nursing textbooks and tradition suggest that the high-Fowler's position is best to optimize diaphragmatic excursion and effective breathing pattern. The optimal position for intubated patients with obesity, ascites or abdominal distention has yet to be determined but is important because weaning trial outcomes may reflect the effect of position rather than weaning trial tolerance. OBJECTIVE: To determine the body position that optimizes breathing pattern (tidal volume and respiratory rate) in spontaneously breathing, intubated patients with a large abdomen. METHODS: Nineteen intubated patients with abdominal distention, ascites or obesity who were on continuous positive airway pressure or the pressure support ventilation mode were studied in the 0 degrees, 45 degrees, 90 degrees and reverse Trendelenburg's at 45 degrees positions for 5 minutes prior to data collection. RESULTS: The RT at 45 degrees position resulted in a significantly larger tidal volume and lower respiratory rate than the 90 degrees position in intubated, spontaneously breathing patients with a large abdomen. The 45 degrees position resulted in a significantly lower respiratory rate than at 90 degrees; however, no difference in tidal volume was demonstrated. DISCUSSION: A high respiratory rate and low tidal volume potentiates atelectasis and ultimately failure to wean. It is important that the effect of positioning on breathing pattern in intubated patients be determined so that care planning results in optimal outcomes. CONCLUSIONS: The results of this study have implications for the selection of chair and bed positioning during weaning trials.

Respiratory adaptation to chronic hypercapnia in newborn rats

1989 ◽  
Vol 67 (1) ◽  
pp. 311-315 ◽  
Author(s):  
R. Rezzonico ◽  
J. P. Mortola
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Chronic Hypoxia ◽  
Heart Weight ◽  
Steady Increase ◽  
Lung Mass ◽  
Newborn Rats ◽  
Lung Weight ◽  
Acute Response ◽  
C Value

We asked 1) whether newborn rats respond to chronic hypercapnia with a persistent increase in ventilation and 2) whether changes in lung mass were accompanying the respiratory adaptation to chronic hypercapnia, as previously observed during neonatal chronic hypoxia. Five litters of rats were kept in 7% CO2 (with 21% O2) from day 1 to 7 after birth (CO2exp) and compared with six litters of control rats growing in normocapnia-normoxia (C). Body weight was similar between the two groups. Ventilation, measured by flow plethysmography, increased in CO2exp from day 2 and remained steadily elevated, and at day 7 it almost doubled (174%) the C value because of the large increase in tidal volume and mean inspiratory flow (192 and 189%, respectively) with no changes in respiratory frequency. Two days after return to normocapnia, ventilation was still 33% higher than in C; at this time, acute exposure to hypercapnia increased ventilation relatively less in the CO2exp than in C because of a lower increase in tidal volume. Neither the lung weight-to-body weight nor the heart weight-to-body weight ratios increased in CO2exp. We conclude that 1) chronic hypercapnia in newborn rats induces a steady increase in ventilation, which persists at least 2 days after return to normocapnia with a reduction in the acute response to CO2, and 2) hyperventilation per se is not the cause of the increased lung mass observed during chronic neonatal hypoxia.

scholarly journals The Cumulative Effects of Forest Disturbance and Climate Variability on Streamflow in the Deadman River Watershed

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 196 ◽  
Author(s):  
Krysta Giles-Hansen ◽  
Qiang Li ◽  
Xiaohua Wei
Keyword(s):  
Climate Variability ◽  
Forest Cover ◽  
Forest Disturbance ◽  
Climatic Variability ◽  
High Flow ◽  
The Body ◽  
Cumulative Effects ◽  
Low Flow ◽  
Mean Flow ◽  
River Watershed

Climatic variability and cumulative forest cover change are the two dominant factors affecting hydrological variability in forested watersheds. Separating the relative effects of each factor on streamflow is gaining increasing attention. This study adds to the body of literature by quantifying the relative contributions of those two drivers to the changes in annual mean flow, low flow, and high flow in a large forested snow dominated watershed, the Deadman River watershed (878 km2) in the Southern Interior of British Columbia, Canada. Over the study period of 1962 to 2012, the cumulative effects of forest disturbance significantly affected the annual mean streamflow. The effects became statistically significant in 1989 at the cumulative forest disturbance level of 12.4% of the watershed area. The modified double mass curve and sensitivity-based methods consistently revealed that forest disturbance and climate variability both increased annual mean streamflow during the disturbance period (1989–2012), with an average increment of 14 mm and 6 mm, respectively. The paired-year approach was used to further investigate the relative contributions to low and high flows. Our analysis showed that low and high flow increased significantly by 19% and 58%, respectively over the disturbance period (p < 0.05). We conclude that forest disturbance and climate variability have significantly increased annual mean flow, low flow and high flow over the last 50 years in a cumulative and additive manner in the Deadman River watershed.

Unsteady disturbances of streaming motions around bodies

1989 ◽  
Vol 209 ◽  
pp. 385-403 ◽  
Author(s):  
H. M. Atassi ◽  
J. Grzedzinski
Keyword(s):  
Wave Equation ◽  
Body Surface ◽  
Source Term ◽  
The Body ◽  
Entire Body ◽  
Two Dimensional ◽  
Mean Flow ◽  
Inhomogeneous Wave ◽  
Inhomogeneous Wave Equation ◽  
The Mean

For small-amplitude vortical and entropic unsteady disturbances of potential flows, Goldstein proposed a partial splitting of the velocity field into a vortical part u(I) that is a known function of the imposed upstream disturbance and a potential part ∇ϕ satisfying a linear inhomogeneous wave equation with a dipole-type source term. The present paper deals with flows around bodies with a stagnation point. It is shown that for such flows u(I) becomes singular along the entire body surface and its wake and as a result ∇ϕ will also be singular along the entire body surface. The paper proposes a modified splitting of the velocity field into a vortical part u(R) that has zero streamwise and normal components along the body surface, an entropy-dependent part and a regular part ∇ϕ* that satisfies a linear inhomogeneous wave equation with a modified source term.For periodic disturbances, explicit expressions for u(R) are given for three-dimensional flows past a single obstacle and for two-dimensional mean flows past a linear cascade. For weakly sheared flows, it is shown that if the mean flow has only a finite number of isolated stagnation points, u(R) will be finite along the body surface. On the other hand, if the mean flow has a stagnation line along the body surface such as in two-dimensional flows then the component of u(R) in this direction will have a logarithmic singularity.For incompressible flows, the boundary-value problem for ϕ* is formulated in terms of an integral equation of the Fredholm type. The theory is applied to a typical bluff body. Detailed calculations are carried out to show the velocity and pressure fields in response to incident harmonic disturbances.

Testing the feasibility of wireless sensor networks and the use of radio signal strength indicator to track the movements of wild animals

2018 ◽  
Vol 45 (8) ◽  
pp. 659 ◽  
Author(s):  
C. R. Krull ◽  
L. F. McMillan ◽  
R. M. Fewster ◽  
R. van der Ree ◽  
R. Pech ◽  
...  
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Radio Frequency ◽  
Radio Frequency Identification ◽  
Signal Strength ◽  
The Body ◽  
Data Uncertainty ◽  
Wireless Sensor ◽  
Small Animals ◽  
Significant Difference

Context Wireless sensor networks (WSNs) are revolutionising areas of animal behaviour research and are advantageous based on their ability to be deployed remotely and unobtrusively, for long time periods in inaccessible areas. Aims We aimed to determine the feasibility of using a WSN to track detailed movement paths of small animals, e.g. rats (Rattus spp.) 100–400g, too small for current GPS technology, by calibrating active Radio Frequency Identification (RFID) tags and loggers using Radio Frequency Signal Strength Indicator (RSSI) as a proxy for distance. Active RFIDs are also called Wireless Identification (WID) tags. Methods Calibration tests were conducted using a grid of loggers (n=16) spaced at 45-m intervals in clear line-of-sight conditions. WID tags (n=16) were placed between the loggers at 45-m intervals. Eight ‘walks’ were also conducted through the grid using a single WID tag. This involved attaching the tag to a small bottle of water (to simulate the body of an animal), towed around the grid using a 1-m long tow line attached to a volunteer walker. The volunteer also held a GPS device that logged their track. Models were constructed to test the effects of distance, tag movement and individual differences in loggers and tags on the reliability of movement data. Key results Loggers were most successful at detecting tags at distances &lt;50m. However, there was a significant difference in the detection probabilities of individual loggers and also the transmission performance of individual tags. Static tags were less likely to be detected than the mobile tag; and although RSSI was somewhat related to distance, the reliability of this parameter was highly variable. Implications We recommend caution in the future use of current radio frequency ID tags in wireless sensor networks to track the movement of small animals, and in the use of RSSI as an indicator of individual distance values, as extensive in situ calibration is required. ‘Off the shelf’ devices may vary in performance, rendering data unreliable. We emphasise the importance of calibrating all equipment in animal tracking studies to reduce data uncertainty and error.

Sign in / Sign up

Export Citation Format

Share Document