Term
| how may a volatile agent be presented to a patient? |
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Definition
| a mask or via an andotracheal tube (ETT) |
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Term
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Definition
| -easy to use -one mask size can be used for a variety of patients |
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Term
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Definition
| -difficult to obtain a good seal -may need to be held in position -difficult to perform IPPV -decr access to head -does not protect the airways -increased dead space -if used for induction, animals may resent it and the scent of irritant volatiles -environmental contamination -suitable for SA only |
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Term
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Definition
| -easy to secure in most patients -easy to provide IPPV -access and visibility to head -airway protected |
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Term
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Definition
| -may be difficult to position and insert -risk of causing laryngospasm or laryngeal trauma -risk of cuff causing tracheal damage -may kink -need many in different sizes for different patients |
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Term
| Direct comparision of mask and ETT advantages and disadvantages |
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Definition
| -mask is easy to use while ETT may be difficult to position and insert -mask difficult to secure in postition, ETT tube easy once inserted -one mask can be used for a variety of sized patients - need many different ETTs -ETT protects airways, allows good vibibilty of head and easy to perform IPPV - not in masks -Masks cause an incr. dead space and environmental contamination |
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Term
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Definition
| -most made from rubber -in a conical shape OR -a hard, clear plastic which has a rubber diaphragm to provide a seal around the nose |
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Term
| Masks cause an increase in dead space, which is especially a problem in v. SA. How can the incidence of rebreathing be decreased? |
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Definition
| incr the fresh gas flow rate NB: this will NOT dec. the dead space! |
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Term
| problems associated w. using a mask for induction |
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Definition
| -animals may resent the placement of the mask -may resent the smell or irritant properties of the volatile anaesthetic |
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Term
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Definition
| -seal must reduce the escape of waste anaesthetic gas -animals airway must be adequate i.e. care to avoid inappropriate flexion of neck |
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Term
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Definition
| -material may be red rubber, silicon or different plastics -may be cuffed or uncuffed -has a bevelled end to facilitate placement through the larynx -blunt end to receive a standard 15mm connector which fits all anaes. breathing systems (NB larger in LA machines) -some tubes have a "Murphy's eye" - a small hole in the side of the tube at the bevelled end - to allow air passage if bevelled end becomes blocked |
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Term
| Why do some ETTs have a cuff? |
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Definition
| create a seal between the ETT and trachea - prevent gas escape or passage of material around the tube to the lungs |
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Term
| where is the inflation line of ETTs? |
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Definition
| -in older ETTS the inflation line ran alongside the ourside of the ETT - this creates an excessively large diameter -newer ETTs have the inflation line running within the wall itself |
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Term
| cuffed ETT vs uncuffed ETT |
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Definition
| -all uncuffed ETTs have larger internal diameters c.f. cuffed ETTs of the same external diameter- so cuffed ETTs have greater R to airflow (R to breathing proportional to radius4) |
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Term
| when are uncuffed ETTs used? |
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Definition
| -cats and small exotics due to the dec. diameter and so inc R caused by the inflation line in cuffed ETTs |
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Term
| consequence of overinflation of ETTs |
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Definition
| damage the trachea, possible rupture it extreme |
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Term
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Definition
| -passed orally (or nasally in some spp. e.g. horse) to enter the trachea -can be blind intubation (e.g. horse) or visualised (e.g. cat) -take care not to damage the larynx |
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Term
| what can aid visualtion of ETT placement? |
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Definition
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Term
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Definition
| largest tube which will comfortably pass through the larynx |
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Term
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Definition
| ~ reach from muzzle and not past point of shoulder |
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Term
| problems associated w. short ETTs |
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Definition
-may become dislodged
-cuff may damage larynx |
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Term
| problems associated w. long ETTs |
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Definition
| -may occlude cr. lobe of bronchus -may damage carina (point where trachea divides into L and R bronchi) - may result in pneumomediastinum -rish of endobronchial intubation and ventilation of only 1 lung -if protruding from mouth then incr. dead space |
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Term
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Definition
| -check clean, patent, correct connector fitted, not damaged, cuff not leaking etc. -lubrication can aid in traumatic insertions |
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Term
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Definition
| -in SA - a tie around the muzzle or back of the head (must not compress the tube or nose!) - the connector has "wings" to prevent the ties slipping |
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