Small Animal Sx - Thoracic Sx 1

drraythe's version from 2015-11-24 19:52

intro- tools, dx tools

Question Answer
what are the two kinds of rib separators?
what are angled forceps for? what are crimped forceps for?(A) angled forceps are to help pass ligature around the vessel, and the curve at tip will help dissect around stuff like PDA delicately (C) crimped forceps- CV forcep- want to get vena cava-- special atraumatic teeth (wont hurt vessel) and used to get into there for thoracic surgery
how should you be inducing a pt with resp dz? how should you NOT?Proceed to intubation with no delay-- Do not use mask or chamber to induce a patient with respiratory disease!!!!! (add more stress, not a guaranteed line to trachea)
3 types of rads to use for thoracic sx?survey, contrast, angiography
how will a rad contrast study appear when there is megaeso?contrast all along length of eso <img scr=""height="250">
how will a rad contrast appear when there is a PRAA?dilation of eso Cr to base of the heart (clinically, will see regurg of food)
benefit of CT scan?allow better dx--can do 3d reconstruction of organ youre exploring
3 most common pulmonary neoplasias you will encounter?(1) Primary bronchiogenic carcinoma (2) Metastasis of other tumors coming to lungs (3) Chest wall - osteosarcoma (at CC jxn--> costochondroma)
which neoplasia has a tendency to be on chest wall?osteosarcoma (grow slowly and obscure...if pet has short hair...might notice lump at costochondral junction from outside.)


Question Answer
5 types (classifications) of pneumothoraxes?(1) Traumatic (open or closed) (2) spontaneous (congenital or acquired) (these are related to blebs and bullae) (3) iatrogenic (4) infectious (5) Hypertensive/tension (air gets in, can't get out--> more air keeps coming in)
If there is a TRAUMATIC pneumothorax, what should you keep in mind?If trauma, prolly pneumothorax in front and ruptured bladder in read--CATH the bladder!!
what is the pathophys of a pneumothorax?Air accumulates in pleural cavity, leading to loss of normal negative pleural pressure--> Lungs undergo elastic recoil and collapse
how would collapsed lungs appear on rads?((arrow pointing to "floating heart" (diff card), look above heart for image of collapsed lung)
if there is a pneumothorax, why might the heart appear to be "floating" on the rads? (what is normal heart position on rads?)heart tip usually touching sternum. (there is even a lig to attach). so if collapse one lung, and laying down on table laterally for rads, gravity pulls down heart bc heart not laying on the lung, looks floating. and then see free air in cavity (prolly small radio-opacity behind heart) (arrow points to "floating heart")
how do you do a thoracocentesis without damaging the lung parenchyma?catheter or large bore needle- once pierce through thoracic wall- feel no resistance-elevate needle or catheter-stay parallel to ribs so then tip of needle wont damage parenchyma of lungs etc
how might pneumothorax affect your ascultation?muffled sounds on ausculation- can also muffle heart sounds.
Pneumothorax--> Sources of air--> closed (2)(1) Respiratory tract (trachea, bronchi, lungs) (2) Esophageal (eso-bronchial fistula...air coming through eso go free into plural cavity.) (pic: classic eso fistula)
Pneumothorax--> Sources of air--> open (1)Wound in thoracic wall
Pneumothorax--> Sources of air--> Spontaneous / Tension (1)pulmonary source
how do you fix blebs/bullae?partial pneumonectomy to fix. bc can recur
If there is an ER tension pneumothorax, first thing you wanna do is...convert from tension/closed to open so air is able to escape and not build up
why is a tension pneumothorax a double threat?not only is one lung collapsed and getting pressure placed on it by air...since the air can't escape it keeps building and then starts pressing on the OTHER lung too
Pneumothorax--> Sources of air--> Traumatic (1)uh. Trauma, bro.
bullae and blebs can cause what kinda pneumothorax?hypertensive
how would you treat a MILD case of CLOSED pneumothorax? (what defines it as mild?) It's mild if it's Not progressive, and there is No severe hyperventilation, hypoxemia, or respiratory acidosis. In this case, Treat with cage rest and observation
how would you treat a MODERATE case of CLOSED pneumothorax? (what defines it as moderate?) It is moderate if there is resp. distress involved. Treat by thoracocentesis initially – if pneumothorax recurs, insert thoracostomy tube (image of thoracocentesis)
how would you treat a SEVERE case of CLOSED pneumothorax? (what defines it as severe?) SEVERE is when it is PROGRESSIVE and there is Marked respiratory distress. To treat, you will need: (1) Tube thoracostomy with continuous suction drainage or Heimlich valve (2) Exploratory thoracotomy if leakage is significant or persists >5-7 days
when is a Exploratory thoracotomy merited?when there is a SEVERE CLOSED pneumothorax where the leakage is SIGNIFICANT or persists for over 5-7d (he also said 3 days in class)
what makes an open pneumothorax?Penetration or rupture of chest wall (like bite wounds, stab wounds, impalement, Inadequate thoracotomy closure)
So this dog comes in with a big ol' stick sticking out of its thorax. Do you want to immediately pull it out?NO! DONT TOUCH IT TILL YOU HAVE A RAD (bc pulling it out might cause more damage than leaving it in-- maybe its acting like a cork)
If there is a chest wound, how should you bandage to make sure it doesnt slide down due to breathing?crisscross bandage over chest
what is happening to the air in a tension pneuothorax?air not going back and forth--just accumulate in pleural cavity-- continue to constrict ventilation and leads to MORE collapse of lungs
what is the two ER tx for tension pneumothorax?(1) Thoracocentesis (2) Thoracostomy tube if intractable
diff between pulmonary bullae and pulmonary bleb?Bullae= Greater than 1cm. Bleb=less than 1cm. Usually bleb is like a bubble of lung paranchyma, usually at border of lung. Bullae are larger, and can be far from edge of lung, and can rupture and cause penumothorax easily.
how might you be able to radiographically tell there is pneumomediasteinum?can see structures really well defined due to air contrast, usually harder to see
paradoxical respiration aka? what is going on?aka flail chest- This is when a few consecuative ribs are broken (usually 2-3), chest excursions are opposite of what they should be. So when inhale, usually chest goes out, but flail goes in (buckling due to neg pressure) and then when exhale, goes out instead of in
If you have a patient suffering from flail chest and you are concerned about the quality of their respiration, how might you be able to quickly improve it?DEC PAIN--> IMPROVE VENTILATION. So do local line block...block where fx rib are, and 1-2 IC spaces cr and ca to where flail chest is occurring
If you needed to, how would you repair broken ribs which were causing a flail chest?use orthopedic wires or thin pins.
how do you do a "water test"/leak test of lungs?inflate lungs, fill cavity w/ saline and squeeze lungs to look for bubbles. If you did see bubbles, might have to decide if going to remove part of lung field or not

other probs

Question Answer
Diaphragmatic hernia? or rupture?technically not a hernia but commonly called this. He prefers rupture (not a true hernia- bc does not have peri-serosal linging)
how might you be able to dx a Diaphragmatic hernia?Rads- see abd organs in thorax, if contrast, see it going past the diaphragm...
which two organs are less likely to go into the diaphragmatic hernia, and why?Kidneys and bladder bc well attached to body wall
how might you be able to dx hydrothorax on rads?can see water causing lung lobe separation
how might you dx chylothorax? pinpoint the prob? what might help tx?usually milky white fluid in thorax, with triglyceride content higher than serum. Will see chylomicrons on microscopic sample. can contrast inject the thoracic duct and see if leaks. sometimes change in diet helped-- less fat, less chylomicros. Can try to treat by draining...
what is a possible medical management tx of chylothorax?Rutin suppliments which stim protein breakdown and removal in lymphatic vessels
what is the surgical tx options for tx of chylothorax? (3)(1) thoracic duct ligation (2) subtotal pericardectomy (3) cysterna chili ligation(?)
what is a "subtotal pericardectomy" and what might this be used to tx?possible sx tx for chylothorax-- L or ventral approach-- remove pericardium below phrenic nn (pericari got thicker and didnt let lymphatic anastomose) remove pericardium, allow of development of new branching of lymphatics and veins and allow for drainage.
are you concerned about ligating the thoracic duct for tx chylothorax?naw, collateral circulation will develop
You take a chest rad and see this.. what are you thinking? METASTASIS in the lungs. so if thinking of do sx and see this, might have to think twice. IF single metastasis maybe partial pneumonectomy to buy time.
If you hear borborygomy at the 8th IC space are you worried about diaphragmatic hernia/rupture?no-- can be normal up to here bc of cupula

PDA (patent ductus arteriosis)

Question Answer
what type of problem is PDA?congenital problem-- in fetus, normal to have shunting of blood from pulm aa to aorta bc lungs not inflated or needed yet. At/after birth hormones should cause this to close and result in the ligamentum arteriosum. If it remains open as a PDA, already oxygenated blood will be forced backwards from aorta to lower pressure pulmonary artery.
what are the two kinda presentations of PDA (of the PDA itself, not the pt) and which is more worrisome?There is the thin and long and the short and wide. More concerned about the short and wide bc more friable and so more likely to damage if you try to fix it-- if short and wide hard to place ligatures, might not be prepared for high volume and pressure, can get thinner.
what are the 4 classifications of PDAs?Type I is when it's not connected but there is a diverticulum. Type IIa is 2 separate connections, Type IIb is is a stenosed connection, Type III is a complete connection
What are the three types of PDA (blood direction- basic idea of which is most sucessful ofr sx, more details on each later)(1) L--->R. This has the best prognosis for sx tx. (2) "Balanced" has moderate success with sx tx. (3) R-->L has poor success rates for sx tx (sx tx=closure of PDA)
What is happening in a L-->R PDA? Is it good or bad prog?This shunt has the best surgical prognosis. It is considered the "Post-natal" shunt. The lungs have low resistance to blood flow and so the blood pressure is greater in the Left ventricle (the systemic circulation) than in the right ventricle (pulmonary circulation) which is still how it should be physiologically, so when you close the PDA the body is already where it should be in terms of pressure.
what is happening in a R-->L PDA? IS it a good or bad prog?This shunt has the worst surgical prognosis. This is the "chronic" form where the R ventricle has tried to compensate and now the blood pressure is higher in the R ventricle than in the L. The blood in the ductus moves from R to L due to the inc pressure. The prog of sx tx is poor because if you close off the PDA suddenly, the pulmonary system will be overwhelmed with the high pressure isolated in it--> sudden death. (LESSON LEARNED: TX PDA ASAP)

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