Aespire 7900 Anesthesia Machine - How to change the canister

When to change the absorbent
The absorber canister is available in two versions: Disposable Multi Absorber and Reusable Multi Absorber. Both are removed and installed on the breathing system in the same way.
Each canister holds 800 g of loose absorbent. Datex-Ohmeda recommends Medisorb absorbent.
Both absorber versions should only be used with air, oxygen, nitrous oxide, halothane, enflurane, isoflurane, desflurane and sevoflurane.
A gradual color change of the soda lime in the canister indicates absorption of carbon dioxide. The color change of the soda lime is only a rough indicator.  Use carbon dioxide monitoring to determine when to change the canister.  Discard the absorbent when it has changed color. If left standing for several hours, soda lime may regain its original color giving a misleading indication of activity.

Removing a canister

The absorber canister is available in two versions: Reusable Multi Absorber and Disposable Multi Absorber. Both are removed and installed on the breathing system in the same way.

Disposable Multi Absorber canister
2. System canister release latch
3. System canister support pin
4. Canister handle
5. Absorbent
6. Reusable Multi Absorber canister
7. Water reservoir.

1. Hold the canister by the handle and push on the release latch (1) to unlock the canister.
2. Remove the canister by tilting it downward and off the two support pins.

Reusable Multi Absorber canister filling

1. Turn the canister upside down and, using your thumbs, turn the cover locking ring counterclockwise to unlock it.

2. Push up with your thumbs to release the seal.

3. Lift off the cover to remove it.

4. Remove and discard the foam filters (1), the absorbent and any water in the reservoir.

5. Clean and disinfect the canister.

 [The filters must be in place to prevent dust and particles from entering the breathing circuit.]

6. When dry, place a new filter in the bottom of the canister, pour soda lime into the canister and place a new filter over the soda lime before closing and locking the cover. Wipe off any soda lime dust. Align the cover slots with the canister locking tabs and press the cover down into place. Turn the cover locking ring clockwise to lock the cover in place. Ensure cover is properly sealed to prevent leaks and spillage. Alignment of the arrows helps to indicate correct assembly.  

7. When replacing the canister, make sure it is resting on both support pins before latching it into place.

Do not use the absorber with chloroform or trichloroethylene.
The Disposable Multi Absorber is a sealed unit which should not be opened or refilled.
Avoid skin or eye contact with the contents of the absorber. In the event of skin or eye contact, immediately rinse the affected area with water and seek medical assistance.
Do not change the absorber during ventilation.
Inspect absorbent color at the end of a case. During non-use, absorbent can go back to the original color. Refer to the absorbent labeling for more information about color changes.

Desiccated (dehydrated) absorbent material may produce dangerous reactions when exposed to inhalation anesthetics.
For systems with dual absorbent canisters, the carbon dioxide absorbent material in both canisters shall be changed at least weekly, preferably every Monday morning. For single canister systems the absorbent material shall be changed every day, preferably at the start of the day.

Carbon dioxide absorbent material shall be changed whenever users cannot assure the degree of hydration of the absorbent.  Such conditions may include finding a machine with fresh gas that has been flowing for an unknown period of time, or using a machine that is used infrequently.
All fresh gas flows shall be terminated when the machine is NOT in use. (User manuals describe how to achieve null flows).
Users are advised to consider the use of low-flow techniques when the machine is in use and whenever clinically appropriate to maintain hydration of the absorbent material.
Always perform a breathing system leak test in the Bag Mode after opening the absorber.  The absorber canister is available in two versions: Disposable Multi Absorber
and Reusable Multi Absorber. Both are removed and installed on the breathing system in the same way.  Each canister holds 800 g of loose absorbent. Datex-Ohmeda recommends Medisorb absorbent.
Both absorber versions should only be used with air, oxygen, nitrous oxide, halothane, enflurane, isoflurane, desflurane and sevoflurane.

BRAIN STROKE & SYMPTOMS

     The brain cells function requires a constant delivery of Oxygen and Glucose by the blood stream.  A stroke othewise called as Cerebro Vascular Accident {CVA} occurs when blood supply to the part of the brain is disrupted  causing brain cells to that part to die.  Blood flow can be compromised by a verity of mechanisms.  Blockage of an artery.  Narrwong of the small arteries within the brain cause a lacunar stroke.  Blockage of a single arteriole can affect a very small area of brain causing that tissue to die {infarct}.  Hardening of arteries leading to brain {atherosclerosis}.  There are four major blood vessels that supplies blood to brain.  The anterior circulation of the brain that controls most activity, sensation, thought, speech and emotion is supplied by the carotid arteries.  The posterior circulation which supplies the brain stem and the cerebellum controling the automaitc parts of brain function and co-ordination is supplied by this vertbrobasilar arteries.  If these arteries become narrow as a result of atherosclerosis, plaque or cholesterol , debris can make brake off and float downstream clogging the blood supply to a part of the brain.  As opposed to lacunar strokes, larger part of the brain can loose blood supply and this may produce more symptoms than a lacunar stroke.

  Embolism to the brain from the heart:  In some instances blood clot can form within the heart.  The potential exists for them to break off and travel to the arteries in the brain can cause stroke.  Rupture of an artery, hemorrahage, the most reason for have bleeding within the vein is un-controlled high blood pressure.  Other situations include aneurysms that a leak of a rupture or arteriovenous malfunctions in which there is an abnormal collection of blood vessels that are fragile and cal bleed. 

Brain Stroke symptoms

• Confusion.  Trouble speaking and/or understanding.

• Sometimes weakness in the muscles of the face can cause drooling.

• The loss of voluntary movements and sensation may be partial or complete.

• Trouble walking, dizziness loss of balance or co-ordination.

• Severe headache with no known cause.

HEART ATTACK AND SYMPTOMS

    If the heart muscle does not have enough blood it dies, and heart attack occurs.  An other name for the heart attack is 'myocardial infarction, cardiac infarction and coronary thrombosis'.  A hear attack is infraction of a segment of heart muscle, usually due to occlusion  of a coronary artery, the process whereby an area of dead tissue is caused by a loss of power supply.  A hear attack usually happens when a blood clot develops in one of the blood vessels that lead to the heart muscle.  The clot, if it is big enough can stop the blood supply to the heart.  Blood supply to the heart can also be undetermined if the artery suddenly narrows as in the spasm.
SYMPTOMS

1. Crushing chest pain.
2. Coughing.
3. Dizziness.
4. Chest discomfort & mild pain.
5. Shortness of breath.
6. Face seems to be gray.
7. Feeling of terror.
8. Restlessness.
9. Nausea.
10. Vomiting.

   If you experience these symptoms, or witness an other person with them, call the emergency services immediately.  A person who is having a heart attack usually feels the pain in her/his chest first.  This pain then spreads to the neck, jaw, ears, arms and wrists.  The pain also might make its way into the shoulder blades, the back and the abdomen.

  The pain does not feel any better if the patient changes position, rests, of lie down.  It will be a constant pain.  But, it can come and go.  Patient describe pain as one of pressure, something squeezing which can last from a few minute to hours.   People with diabetes and those over the age of 65 may experience a 'silent heart attack'. This is one that occurs with no pain at all.  

PREPARING A PATIENT FOR CT SCAN

     In preparation for a CT scan, patients are always asked to avoid food, especially when contrast material have to be injected.  Contrast material may be injected intravenously, or administered by mouth.  In some occasions used by enema in order to increase the distinction between various organs or areas of the body.  Fluid or food may be restricted for several hours prior to the CT scan.  If the patient has  a history of allergy to contrast material , the requesting physician and radiology staff should be notified.  All metallic materials and certain clothing around th body are removed because they can interfere with the clarity of images.    Patients are placed on a movable table and the table is slipped into the center of a large dount-shaped machine, which takes the X-ray images around the body.  The procedure can take from half an hour to an hour.  If specific tests, biopsies, or interventions are performed by the radiologist during scanning.  Additional time and monitoring might be required in some cases.  It is important that during the scan process the patient should minimize any body movements by remaining as still as possible.  This significantly increases clarity of the images.  The CT scan technologist should tell the patient when to breath of hold breath during scans of chest and abdomen.  If any problems are experienced during the scan, the technologist should be informed immediately.  The technologist directly watches the patient through the observation window during the procedure.  There should be an intercom system in the room for added patient safety.  CT scan has vastly improved the ability of doctors to diagnosis many diseases earlier in their course and with much less risk than previous methods.  Further refinements in this technology continues to evolve which promises even better quality and patient safety.  High resolution CT scanners {HRCT] are used to accurately access the lungs for inflammation and scaring  CT angiography  is a newer technique that allows non invasive imaging of coronary arteries.

WHAT IS CT SCAN

     Computerized  Tomography is said as CT scan.  It has been formerly referred to as Computerized Axial Tomography [CAT] scan, is an X'rey procedure that combines many X-Ray images with the aid of a computer to generate cross sectional views, and if needed three dimensional images of the internal organs and structures of the body.  CT is mostly known as its abbreviated names, CT scan or CAT scan.  Used to define both normal and abnormal structures in the body or to assist in procedures by helping to accurately guide the placement of instruments or treatments.  A large daunt-Shaped X-ray machine takes x-ray images at many different angles of the body.  These images are processed by a computer to produce cross sectional images of the body.  In each of these pictures, the body is seen as a slice of x-ray of the body which is recorded on a film.  This recorded image is called a TOMOGRAM. 

     Imagine the body as a loaf bread and you're looking at one end of the loaf.  As you remove each slice of bread you can see the entire surface of that slice from the crust to the center.  The body is seen on CT scan slices in similar fashion from the skin to the central part of the body being examined.  When these levels are further added together; a three dimensional picture of the organ structure cab be seen.

     A CT scan is a very low risk procedure.  The most common problem is an adverse reaction to intravenous contrast material, usually an iodine based liquid injected into the vein, which makes many organs and structures, such as blood vessels and kidneys much more visible on CT scan.  There may be resulting itching a rash hives, or a feeling of warmth throughout the body.  There are usually self limiting reactions that will go away rather quickly.  If needed antihistamines can be given to help relieve these symptoms.  A more serious allergic reaction to intravenous contrast is called an anaphylactic reaction.  When this occurs the patient may experience severe hive or extreme difficulty in breathing.  This reaction is quiet rare, but is potentially life threatening if not treated

HOW DO INFANTS CRACK THE SOUND

     They perform frequency analyses.  Take for example the sound sequence “What a pretty baby you’re”.  Through continuous exposure to human language _ babbling humans produce 10,000 words and more I a single hour.  Infants progressively understand the syllables which are part of the same word to tend to follow on another predictably [prêt_ty, ba_by], where as syllables that follow one another less frequently are word boundaries [a_prêt, ty_ba.

     This type of frequency analysis is depending on a well functioning memory that accumulates an ever-growing number of words and, of course extensive training.  The problem is speed.  As human speech can produce three and more words/second, there is little time for either childish astonishment or for adult considerations such as ‘what does that word exactly mean?, “is the verb in the present or past tense?, What the hell is that grammatical structure? Etc.  All full speed speech comprehension is therefore a triple challenge; slicing human speech into digestible units, endowing them with meaning by matching the segments with thousands of existing words stored in your brain dictionary, and, finally, doing all this without giving it a second thought.  Fortunately, our brain is genetically programmed to do these mental acrobatics, and as you have already done it once, when you learned your native language, you can do it again with other languages as often as you want.  To see what it looks like when your auditory brain cortex works at full speed, put your brain into a PET scanner.  Through training is paramount.  In experience, it took around 1500 to 2000 hours of intense listening to achieve semi perfect sequencing abilities, both in French and Italian.  Amazingly the results were similar for Arabic, a language so totally different from anything than other languages.  This seems counterintuitive because in Arabic, one needed to learn at least three times as many words as in Italian, and raises a couple of questions:  Could the time of exposure that is needed to achieve full sequencing abilities – 1500 hours would translate into 6,4 and 2 hours per day over a period of 9,12 and 24 months, respectively, be a human constant?  Should our speech reconviction abilities be independent of the type of language we learn?  Perhaps even relatively immune to the effect of ageing?  And are young children truly superior to adults in worked segmenting or do they simply dedicate more time to listening than adults?  Some of these questions will be answered by future research, but I am inclined to accept that there is a physiological threshold for human brain to get wired to the ability of dissecting the sounds of new languages.  You would need a minimum of time to perform this task, but you wouldn’t need much longer than that.  You are now able to solve the close to zero understanding after years of school problem that we exposed at the beginning of this chapter

Continued