thoracic anesthesia part 2/3

Question 0

1. what is the most common symptom of bronchopulmonary issues (i.e. bronchial irritation, ulcer, obstruction, infection etc.)?
2. what are the rest

Answer 0

1. cough

2. hemoptysis, chest pain, dyspnea, wheezing

Question 1

for respiratory assessment, which is the most common complaint in regards to LUNG CARCINOMA (what brings them in to see us)?

Answer 1

hemoptysis

Question 2

what are the extrapulmonary intrathoracic symptoms seen with cancer?

Answer 2

1. pleura- EFFUSION
2. chest wall -PAIN
3. esphagus- DYSPHAGIA
4. SVC- svc syndrome (aka thoracic outlet syndrome)
5. brachial plexus- arm pain, horner’s syndrome (ptosis, miosis, anhydrosis, ipsilateral face involvement of cervical sympathetic plexus)

Question 3

extrathoracic metastitic symptoms:

what organs are affected?

Answer 3

brain, kidneys, skeleton, liver, adrenals, GI tract, pancreas

Question 4

1. what are extrathoracic nonmetastatic symptoms?
2. what is the name of the syndrome it creates?
3. 3 examples of ‘this’ syndrome:
4. what are other syndromes/ issues?

Answer 4

1. endocrine or endocrine like substances are secreted d/t cancer
2. paraneoplastic syndrome
3. examples of paraneoplastic syndromes
   -cushing syndrome (excess corticoid or cortical hyperplasia)
   -ADH secretion (SIADH)
   -Eaton-Lambert (myasthenia like) syndrome
4. OTHER: carcinoid syndrome,
   –hypercalcemia,
   –ectopic gonadotropin secretion,
   –hypoglycemia,
   –neuro muscular syndromes (mysathenia gravis)
   -

Question 5

cancer:

what are non specific symptoms

Answer 5

weakness, weight loss, anorexia, lethargy, malaise, vague respiratory febrile symptoms (flu like)

Question 6

what type patient might have Cancer?

Answer 6

avg age 60-70, heavy cigarette smoker, urban living, recent weight loss

Question 7

1. what is the nmenomic for effects of lung cancer?

2. what is the break down (a,b,c,d)?

Answer 7

1. the “4 M’s “
2. breakdown:
   a–mass effect: obstruction to lungs, abcess, svc syncrome, tracheobroncihal distortion, pancoast syndrome, laryngeal and phrenic nerve compression, chest wall or mediastinal extension
   b–medicine side effects: bleomycin causes o2 toxicity, adriamycin is cardiac toxic
   c–metabolic: Eaton-lambert, cushing syndromes; hyponatremia and hypercalcemia
   d–metastasis: to bone, liver, brain, adrenals

Question 8

what does smoking cause: (6 things…BESIDES CANCER)

Answer 8

1. changes in airflow and closing capacities
2. decrease FVC
3. decreased mucocilliary transport and increased secretions
4. increased carboxyhb (=decreased o2 transport)
5. increased myocardial work with decreased o2 supply (vasopressor/ stimulant)
6. increased airway irritability

Question 9

1. what type of flow pressure loop will a copd (obstructive) patient have?
2. what does this mean?

Answer 9

1. they will have a half moon shaped wave with decreased inspiratory and expiratory flow times; they will have a higher total lung volume than normal but will have a higher retained lung volume
2. they retain air on exhalation to keep smaller airways open and it takes them longer to exhale

Question 10

1. what type of pressure loop will a restrictive (obese, pulm fibrosis, etc.) patient have/
2. why?

Answer 10

1. restrictive pressure loop will have about half the total lung volume of norman (approx 3L) with quicker inspiratory and expiratory times
2. they are restricted from getting much in and since compliance is low, exhalation shoots air right back out.

Question 11

what are good pre-opretive respiratory manuvers?

Answer 11

1. discontinue smoking 12 hours to 8 weeks before:
   a. 8 hours prior: decreases co-Hb
   b. 4-8 weeks prior: decreases risk of pulm complications
2. B2 sympathomimetics (albuterol, terbutaline)
   - -corticosteroids (decreases edema and bronchoconstrictiong substances)
   - -cromalyn sodium, theophylline
   - -robinol (decreases broncho constriction by blocking histhamine)
   - -hydration (loosens secretions) can be done by humidifier

Question 12

1. what are the best cardiac function monitors for thoracic surgery?
2. which one is now infrequently used?

Answer 12

1. best monitors for thoracic surgery:
   - - #1 arterial line (for bp and abgs)–remember art to right and pulse ox to left;
   - -cvp
2. swan (usually goes to right and if doing a left lung (laying on right) , the PAP will be falsely high)

Question 13

where are blood flow and oxygenation greatest in the lungs?

Answer 13

closest to the moving diaphragm

Question 14

1. what region does positive ventilation (in an anesthetized/ paralyzed patient) ventilate?
2. why is this?
3. what does this result in?

Answer 14

1. positive pressure ventilation (i.e. the diaphragm is no longer pulling air; we are pushing air) ventilates the upper most part of the lung or zone 1
2. this will be the path of least resistance
3. VQ mismatch d/t most of the oxygen going to areas that have the least perfusion

Question 15

what 2 things can happen when an awake patent is lying lateral with an open chest (pleural cavity- but not lung; i.e., the lung is lung on the open chest is not attached to the chest cavity and is free floating but still holds air)?

Answer 15

1a. mediastinal shift: as the open lung deflates, the negative pressure on the good lung side pulls the heart over with it.
1b. this puts torsion on the heart and great vessels
2a. Paradoxical respiration (pendulum or pendeluft air): as the good lung inhales, it pulls air from the open lung and when the good lung exhales, it pushes air back into the open pleural cavity.
2b. this increases dead space because stale air is breathed back and forth into a non perfused lung sac (open lung side)

Question 16

what are the biggest problems with a lateral decubitus, anesthetized, paralyzed patient with open chest?

Answer 16

1. Hypoxemia is most common problem

2. greatest V/Q mismatch (d/t most oxygen going to non dependent (up) lung and most blood going to dependent lung)

Question 17

1. THOERETICALLY, what would be the perfusion ratios from each lung in the lateral position?
2. ACTUALLY, the perfusion pressures are what? why?

Answer 17

1. 60% of CO goes to dependent and 40% to non dependent.
   -normal venous admixture (physiological shunt) is 5% each lung
   -NORMALLY 55% of CO from dependent and 35% from non dependent lung participate in gas exchange;
2. BUT… because HPV (hypoxic pulmonary ventilation) decreases blood flow to lung by 1/2…
   -THEREFORE: there is a shunt of 17.5% + 5% shunt=22.5% in the non dependent lung + 5% shunt in the dependent lung for a total shunt of 27.5% (as opposed to normal 10%)
   -this greatly reduces pao2 to 150 mmHg on 100% when it should be higher than .198
   ex; if fio2 in lungs increases to 90% =.9 x 760~ 684 mmHg pao2 (give or take); this cannot occure d/t the subtraction of oxygen d/t 27.5% shunt

Question 18

Indications for one lung ventilation (DLT):
what are the ABSOLUTE indications (3reasons + examples)?
A.
B.
C.

Answer 18

1. absolute:
   A. to avoid spillage or contaminationn of good lung from:
   -infected (purulent) fluids
   -hemorrhage
   B. to divert ventilation to just one lung:
   -bronchopleural fistula
   -surgical opening of a major conducting airway
   -giant unilateral cyst or bulla
   -tracheobronchial tree disruption
   -life threatening hypoxemia r/t unilateral lung disaese
   -VATS
   C. unilateral bronchopulmonary lavege
   -pulmonary alveolar proteinosis

Question 19

Indications for one lung ventilation (DLT):
what are the RELATIVE indications for DLT (4 reasons with examples)?
A.
B.
C.
D.

Answer 19

A. surgical exposure:
-thoracic aortic aneurysm
-pneumonectomy
-thoracoscopy
-upper lobectomy
-mediastinal exposure
B. surgical exposure (medium-lower priority)
-middle and lower lobectomies and subsegmental resections
-esophageal resection
-procedures in thoracic spine
C. postcardiopulmonary bypass pulmonary edema OR
hemorrhage after removal of occluding unilateral chronic pulmonary emboli
D. severe hypoxemia related to unilateral lung disease

Question 20

how do you place a robert-shaw DLT?

lets say left DLT for example

Answer 20

1. prep and check tube; place stylet
2. lube tube
3. insert with distal curvature facing anteriorly
4. REMOVE STYLET once blue bronchial (“b=b”) cuff is thru cords
5. rotate tube 90 degrees (in direction of left lung)
6. cease advencement once resistance is encountered

Question 21

how do you inflate cuffs and check placement of a left DLT

6 steps

Answer 21

1. inflate traheal cuff (high volume; low pressure-20 mL max)
2. listen for bilat lungs -just like with standard ETT; (if not equal, tube is down too far -withdraw 2-3 cm and re-ascultate)
3. clamp the right side (connecter) marked “tracheal” (on left DLT) and remove right cap and ventilate(you may hear some leak from left lung since left bronchial cuff is still deflated).
4. slowly inflate bronchial cuff (using minimal cuff technique); 1-3 cc to inflate cuff
5. remove right clamp and replace cap; check ventilation to both lungs (checking to make sure that bronchial cuff is not blocking anything).
6. check each lung by clamping the opposite and ascultating:
   i. e. clamp left and listen on right; then clamp right and listem on left

Question 22

1. what is the most important problem with placing a DLT?

2. what are the consequences?

Answer 22

1. MALPOSITION;
2. wrong lung collapse,
   - inadequate lung separation,
   - increased PIP, instability of the DLT,
   - tracheal or bronchial laceration,
   - obstruction of RUL bronchus by left sided DLT bronchial cuff

Question 23

how is a DLT always checked (or should always)?

Answer 23

with a fiberoptic bronchoscope

Question 24

what is are (rare) potential complications of DLT?

Answer 24

1. bronchial rupture | 2. tracheal rupture

Question 25

Management of one lung ventilation: 1. vent settings: a. fio2 b. tidal volume c. resp rate d. peep

Answer 25

a. fio2=100% b. vT=5-8 cc/kg c. RR to desired ETco2 d. peep=5 cmH20

Question 26

Management of one lung ventilation: 1. what should you do 15-20 min post instituting OLV? 2. what can be done to non dependent lung to help with hypoxia? how common of a practice? 3. what can too much peep to dependent lung do?

Answer 26

1. check ABG 15-20 min post instituting one lung ventilation 2. CPAP to non dependent lung can oxygenate the shunted blood decreasing hypoxia (although not commonly done) 3. peep on dependent lung at around 5 cmH20 can help keep alveoli open; too much peep increases the pressure too much so that blood cannot enter and is shunted to the non dependent lung.

Question 27

1. when should lung deflation be done for: - a. open thoracotomy? - b. VATS? 2. if pneumonectomy, what can be done to prevent excessive shunting?

Answer 27

1. deflation of lung and OLV should be started for: - a. Open thoracotomy: when told by physician - b. VATS: as soon as placed (it may take 30 min for lung to deflate) 2. clamp surgical pulmonary artery asap.

Question 28

what is considered hypoxia with OLV?

Answer 28

SpO2 less than 90%

Question 29

1. what is a recruitment manuver? 2. what might a surgeon call it? 3. how is it done? 4. what side effects may be seen?

Answer 29

1. a peep manuver used to "pop open" previously unused alveoli (may be good to do prior to surgery to get as many alveoli as possible ready for the surgery) 2. aka: "valsalva" 3. peep of 20 x 20 seconds (then let the patient exhale); then peep of 30 for 30 seconds (let air out); then peep of 40 for 40 seconds 4. patients with poor cardiac output may really drop their blood pressure d/t all the peep in the lung prevents blood from flowing thru (you may crap your pants).

Question 30

how is cpap applied to the up (deflated/ non dependent) lung?

Answer 30

a pressure regulator connected to a c-pap valve, a 1 liter anesthesia bag and some 02 tubing connected to oxygen supply

Question 31

what are contraindications for double lumen tube placement?

Answer 31

1. too small of a patient 2. sull stomach 3. carina or proximal bronchial mainstem lesions 4. difficult airway or anatomy 5. too critically ill and cannot tolerate peep

Question 32

1. what size DLT for men? Women? | 2. approximately where should a DLT be placed to (at the lip)?

Answer 32

1. size DLT for men=37-39 french. Women=35-37 french (can use 35 fr. for both without incident). 2. average lip line for a DLT is approx 29 cm (+/- 2 cm)

Question 33

complications of double lumen tubes:

Answer 33

- traumatic laryngitis | - tracheobronchial tree disruption (bronchial ruptuer)

Question 34

1. what is HYPOXIC PULMONARY VASOCONSTRICTION (HPV)? 2. is this a good thing? 3. how does anesthesia affect this?

Answer 34

1. when a lung is hypoventilated, the co2 will increase. This causes an opposite effect in the lungs than it does in the body (in the body, it causes vasodilation- to bring oxygen to the tissues). In the lungs, the vessels constrict (if bloods job is to get oxygen, why be sent to a place with no oxygen?). 2. this is good because it doesnt allow for wasted energy sending blood where it is not needed 3. anesthesia causes (some)pulmonary vessel dilation (even in hypoxic lungs, decreaseing HPV and therefore shunting blood to un-necessary area.

Question 35

what are the advantages of general anesthesia (inhaled agents) in a thoracotomy?

Answer 35

Inhaled anesthesia agents: 1. decrease airway irritation 2. allows for higher concentration of inspired oxygen without loss of anesthesia 3. rapid elimination of inhaled agents reduces chance of post op resp depression 4. maintain reasonable cardiac stability 5. less decrease in PaO2 than with iv anesthesia

Question 36

what are the advantages of narcotics for anesthesia with a thoracotomy?

Answer 36

Narcotics: 1. have no significant effect on hemodynamics 2. keeps post opertively intubated patients comfortable 3. (when used in combination with inhaled agents), high dose narcotic technique allows for high Fio2 and less inhaled gas. 4. narcotics DO NOT INHIBIT HPV

Question 37

1. What is a good drug to use in anesthesia of a thoracotomy? 2. why is it a good drug for thoracotomy? 3. what other reasons? 4. what are disadvantages of using this drug?

Answer 37

1. ketamine 1-2 mg/kg 2. it is a sympathomimetic and therefore maintains BP and is a bronchodilator (reduces incidence of bronchospasm in asthmatics) 3. rapid onset (good for full stomach) - does not impair arterial oxygenation during OLV 4. ketamine increases secretions and can cause cardiovascular depression in hypovolemic or sympathetic nervous system exausted patients

Question 38

1. what medication do all respiratory procedures get? | 2. what other med should be given (prior to laryngoscopy)?

Answer 38

1. robinol | 2. lidocaine 1 mg/kg IV or via LTA

Question 39

how much fentanyl can be used during induction for a thoracic procedure?

Answer 39

3-10 mcg/kg (4-15 cc of fentanyl at 50 mcg/cc) | in other words 200-750 mcg of fentanyl

Question 40

how much fluid is given during these cases?

Answer 40

less than 1 liter (should be very cautious- some cases may run 6-8 L/kg/hr though)

Question 41

complications of a thoracotomy: | what can happen to the heart after PNEUMONECTOMY?

Answer 41

HEART can herniate if: - -suction is applied to the chest tube (NO SUCTION TO CHEST TUBE POST PNEUMONECTOMY) - -if turned onto affected side (GOOD LUNG DOWN FOR PNEUMONECTOMY)

Question 42

complications of a thoracotomy: | what are others (6 major complications)?

Answer 42

1. respiratory insuffeciency (MOST COMMON COMPLICATION) 2. hemorrhage 3. bronchial disruption 4. right CHF d/t increased PA / PVR pressure (which will cause a RA pressure which is higher than PCWP and a decreased CO) 5. right to left intracardiac shunt through PFO (d/t RA pressure rising higher than LA pressure>> which pushes open the foramen ovale). 6. neural injury: - phrenic nerve injury= failure to wean - vagus nerve injury=GI atony - recurrent laryngeal nerve=adductor spasm of vocal cords if bilateral injury - ischemia to greater artery of adamkowitz from aortic crossclamping(at T10 of anterior spinal cord)=paraplegia - damage to spinal branches of intercostal arteries=paraplegia

Question 43

Thoracotomy of which lung gives better oxygenation?

Answer 43

left thoracotomy (which means ventilation of right lung) has better oxygenation (RIGHT LUNG IS LARGER)

Question 44

what can obstructive disease cause in during thoracic surgery?

Answer 44

auto peeping (breath stacking) d/t prolonged expiratory times common in COPD

Question 45

which position has the least hypoxemia: | a) lateral; b) semi lateral; c) supine?

Answer 45

lateral positioning has the least hypoxia

Question 46

what are some ways to limit atalectasis and hypoxemia during OLV?

Answer 46

1. high VT (10-12 mL/kg) without peep 2. ensure that expiratory flow reaches zero before next breath (otherwise breaths will stack) may have to adjust rate and I:E ratio. 3. moderate VT (6-8 mL/kg) with peep

Question 47

1. what happens when you allow for the alveoli to snap open and snap shut during ventilation? 2. what prevents this?

Answer 47

1. causes wall stress on alveoli and may cause damage | 2. peep