1
Q
5 lung volumes and capacities
what is the closing capacity. What increases it
What is FRC? Why is low FRC bad
A
CC is the volume at which distal airways without cartilaginous support begin to close with a forced expiratory manuver. Sum of RV and CV
CV volume at above residual volume at which distal airways close
increasing closing capacity is ACLS-S: Age, Chronic bronchitis, LV failure, Smoking, Surgery
FRC is volume left in lung after normal breath or TV/. reduces amount of oxygen available if apnea or hypovent occur. can cause hypoxemia
2
Q
decresse FRC
A
Pregnancy ascites, neonatal, GA, obesity, supine surgery
absorption atelectasis
PANGOS
3
Q
How would you assess pts COPD
A
- focused hx and physical:
- cough, dyspnea, ETT, freq pulm infections, mucus, orthopnea,
hospitalizations, meds (compliance, effectiveness)
- PE: vitals(sat, RR) cyanosis, clubbing (chronic hypoxia), signs resp distress use of assessory muscles, nasal flaring, listed to lungs,
- look for signs cor pulmonale: JVD, hepatomegaly, edema
- CBC: erythrocytosis,
CXR (hyperinflation or scarring): rule out acute process and serve as baseline for periopcourse
EKG (RVH),
ABG (hypoxia hypercarbia), electrolytes: met alkalosis to compensate for
4
Q
Preop goals for COPD
periop goals
A
- determine type, severity, course
- optimize management: smoking cessation, treating infxn, bronchodilators, pulm toliet
periop goals
- minimize airflow obstruction
- clear secretions
- avoid preciptants of bronchospasm
- adequate pain control
5
Q
What Fev1 is predictive off failing extubation and post op resp complication
What causes low DCLO
A
<50
destruction of pulm capillaries, low CO and anemia
6
Q
predictors of post op pulm dysfxn
A
- preexisting pulm disease
- upper abdominal/throacic surgery
- smoking
- obesity
- advanced age >60
- prolonged GA
7
Q
Benefits of epidural in COPD pts
A
- lower risk of pulm complications 2/2 decrease splinting, better cough, and earlier ambulation
- decrease in DVT
- superior blunting of stress response
- superior pain control
8
Q
How would you ventilate a pt with COPD?
A
- slow RR with prolonged expiratory time to reduce air trapping. (COPD involves increased airway resistance that impede exhalation. delayed upstoke CO2 suggest incomplete emptying (consistent w obstruction)
- if bullous dz avoid nitrous, and min peak airway pressure and use PEEP cautiously to avoid rupture
- humdifiy gases to help preserve mucociliary fxn and ability to clear secretions
- ventilation should be targeted to maintain baseline. if aim for normocapnia, in chronic CO2 retainer, may end up w alkalosis which can lead to L shift oygen hemoglobin diss curve
9
Q
How to reduce chance of post op resp complication
A
- ensure pai control to limit splinting (better the sooner the pt can ambulate, cough, take deep breath)
- ensure IS, and chest physiotherpay
- continue bronchodilators expectorants etc
- avoid excess fluids to min pulm edema
10
Q
Why left side DLT preferred
How to confirm position L DLT
When would you place R DLT
A
R side closer to carina and variably located RUL, more risk of RUL occlusion
- inflate tracheal cuff should have b/l BS (ensures endotracheal intubation)
- inflate bronchial cuff, clamp tracheal. should have L side only.(confirms L sided endobronchial intubation
- If hear b/L DLT is out too far
- If hear right side: DLT wrong side (ensures tracheal balloon at carina - inflate tracheal clamp bronchial: right side only
- confirm w fiberoptic
When lesion at carina or L broncus makes L placement difficult
11
Q
How to avoid broncospasm in asthmatic pt
A
- Preop: consider delaying URI or lower resp tract infection, premed w inhaled anticholinergic or B2 agonist
- consider regional
- If GA:
minimize airway stimulation: LMA, mask
GETA: IV lidocaine prop opioid bf airway stim, consider sevo, ketamine
- avoid B2 blockers or histamine releasing drugs (meperidine, morphine, mivacuriam)
- reversal: use adequate dose glyco
- extubate deep or with good level pain control
12
Q
tx of acute broncospasm
A
- 100% Oxygen, hand ventilate, listen for breath sounds, inspect all monitors
- deepen anesthesia (prop, sevo, ketamine), B2 agonists (inhaler, epi), muscle relaxant if pt breathing against vent
- consider increasing expiratory time, higher inspiratory flow rate allow or rapid attainment of set TV (ICU vent)
- extubate and mask vent
13
Q
Factors that inhibit HPV and increase blood flow to nondependent lung
A
- vasodilators and inhaled anesthetcs decrease nondependent HPV (SNP, NTG, dobutamine, CCB, B2 agonist, glucagon
- vasoconstrictors increase dependent lung PVR (epi, dopamine, phenypehrine
- inhaled agents
- Co2: hypocapnea may dilate nondependent lung; hypercapnea augments vasoconstriction dependent lung
- high airway pressures PEEP and inspiratory pressures may constrict vessels in depend lung (mechanical compression)
14
Q
Absolute indications for DLR
A
- lung isolate to prevent spillage of infection, blood
- unilateral BPL (alevolar proteinosis
- differential ventilation (broncopleura fistuka, surgical opening of airway, tracheobroncheal tree disruption
- VATS
15
Q
Alternatives to DLT
pros and cons
A
- endobronchial intubation w SLT
- bronchial blocker
- inability to suction/ventilate isolated lung, loss of seal can result in contamination of CL side, slippage into trachea can result in airway obstruction - univent tube
- can provide CPAP and suction through brochial blocker lumen
- no need to change tube in ICU,
- ability to provide contunuous vent during insertion
16
Q
Issues with ventilator management of OLV
A
- hypoven causes dependent lung collapse and hypercapnea (augment HPV in dependent lung worsening hypoxemia)
- hyperventilation increases elevation of dependent lung vascular resisistance (divert blood to nondependent lung) and hypocapnea (inhibit nondependent lung HPV)
100% Fi02
Increase RR 20-30% TV 10cc/kg
17
Q
Considerations for pts with lung CA
A
- Signs mass effect
- Obstructive PNA
- SVC syndrome
- Pancoast tumor
- tracheal bronchial distortion- mass induced VQ mismatch
- mass compression of heart and great vessels
- Tumor invasion
- Hemoptysis, blood stained sputum
- Cancer related meds
- Bleomycin (interstitial pneumonitis, pulm fibrosis)
- Cisplatin: peripheral neuropathy, renal failure
- Paraneoplastic syndrome
- Lambert Eaton
- SIADH-hyponatremia vs loop diuretic), decreased serum osm,
- Cushing syndrome-Ectopic ACTH, hypokalemia, HTN, psychosis
- Parathyroid releasing hormone-hypercalemia-N/V, renal failure, weakness, arrhythmia
18
Q
Features of SVC syndrome and Pacoast tumor
A
- SVC syndrome-intravascular thrombosis, obstruction venous drainagemucosal edema, venous engorgement of airwaysdsypnea, coughing, orthopnea
- Increased ICP 2/2 poor venous drainage
- Signs
- Neuro: facial neck and upper limb edema, nasalstuffiness, heachache, lightheadedness, papilledema, visual changes, AMS
- Cardiac: CP, orthopnea
- Pulm: dysphagia, orthopnea, hoarsness, pleural effusion
- Pancoast tumor (compression stellate, RLN, phrenic, branchial plexus Subclavian artery, Brachiocephalic vein)
19
Q
What work up to order for pneumonectomy
A
- Cardiac (pHTN)
- EKG (RVH
- Echo: RV function (high risk of RV fxn if ppo Fev1 <40%
- Lung
- CXR (Enlarged apex RVH, Ram prominent pulm outflow tract, enlarged pulm arteries)
- ABG
- chest CT
- Pre thoracotomy assessment
- Respiratory mechanics (Fev1, FVC, MVV, RV/TLC)
- Fev1< 2L
- Post op FEv1 >40% (<20% unacceptable high risk)
- order VQ to determine contribution of resected portion to predict post resection pulm fxn (if pneumonectomy will be tolerated)
- <40% high risk right heart failure
- FVC <50% <1.5ml/kg
- Max voluntary ventilation <50%
- RV/TLC >50%
- Lung parenchyma fxn (DLCO, Pa02, PaC02)
- Ppo DLCO >40% ((<20% unacceptable high risk)
- Pa02<60
- PaCo2>45
- Cardiopulmonary reserve (Vo2 max, stair climbing, 6 min walk test, exercise Sp02)
- Max oxygen consumption >15ml/kg/min (<10 contraindicated
- Stair climb: 5 flights =Vo2 >20; 2 flights 12 <2 high risk
- 6 min walk test <200 ft Vo2 <15
- Exercise Spo02: decrease >4% increased risk
- Respiratory mechanics (Fev1, FVC, MVV, RV/TLC)
20
Q
pneumonectomy post op complications
A
- Cardiac
- RH failure, cardiac arrhythmias,
- cardiac herniation (mediastinal shift)torsion of vessels (place back in DQ
- tx: make resected side nondependent, stop suction to empty hemithorax, consider injecting air into empty hemothorax, support hemodynamics
- PULM
- Bronchial disruption, BPF, PTX,
- resp failure, postpneumonectomy pulm edema, PE
- decreased venous return from MV and PEEP
- Hemorrhage
- Renal dysfunction
- Nerve injury: phrenic, vagal, RLN
21
Q
Features of Downs syndrome
A
- Alantoaxial instability
- : alanto axial instability: subluxation, anterior atlantodental interval (AADI)>4-5mm in lateral view, neural canal; width, atalanto axial instability
- If signs consistent with cord compression/spine instability (numbness tingling weakness on flexion/extensiondelay case and have repeat cervical imagine and neuro surgical eval of cervical spine
- No signs likely don’t need imagine but avoid excessive extension flexion rotation
- Cardiac: bradycardia w/ sevo, 50% endocardial cushion defects (defects involving atrial, ventricular septum, and 1 or both AV valves), VSD, ASD, PDA, TOF
- Pulm: marcroglossia, micrognathia, subglottic stensosis, hypotonia and redundancy soft tissues
22
Q
Why is a fib common post throacic surgery
tx?
A
RF
- underlying cardiopulm dz
- . intraop cardiac manipulation
- pain induced sympathetic activation
- increased R heart afterload due to pulm vascular bed reduction,
- metabolic abnormalities
23
Q
When to decide if one should extubat after pneumonectomy?
Risk benefit of exchanging DLT for ICU
A
- ppoFev1>40% extubate
- ppoFev1 30-40%, DLCO>40% Vo2>15ml/kg extubate
- ppoFev1 20-30%, DLCO>40% Vo2>15ml/kg extubate, resection occured w VATs and/or thoracic epidural in place
con: large diameter DLT-risk mucosal injury and tracheal stenosis, lack experience ICY personelle,
pro: difficult airway
24
Q
What to do during hypoxia during OLV
A
- 100% oxygen
- Ensure adequate placement by capnography, listening to chest, fiberoptic scope for direct visualization
- Check BP to ensure adequate perfusion
- RL shunt from collapsed lung
- Recruitment breaths
- CPAP 10 Cm H20 to nondependent lung if surgically acceptable
- PEEP 5-10 cm H20 to ventilated lung ( in healthy lungs this way result in pressure induced shunting blood to nondependent lung)
- Reinflate non dependent lung
- Discuss with surgeon about ligating pulm artery to elim shunt
- Encourage hypoxic vasoconstriction (remove agents that may blunt this)-volatile, systemic vasodilators, hypocapnia (inhibit HPV nondependent lung and increased vascular resistance in dependent lung
25
Lambert eaton
etiology
signs
anesthestic considerations
tx
* Lambert Eaton –autoantibodies againist prejunctional VG calcium channelsreduced Ach release at motor end plate
* Prox muscle weakness of LE, **autonomic dysfunction** (constipation, impotence, orthostatic hypotension), improved strength with muscle activity
* Considerations
* Sensitive to muscle relaxant (nondepolarizing and depolarizing)-careful monitor muscle relaxation
* Autonomic neuropathy increased risk of **hypothermia** (impaired vasoconstriction
* Pt on , diamino pyridine, and pyridostigamine reversal less reliable
* Tx: cancer tx,
* plasma exchange, IVIG, prednisone, azathioprine for immunosuppression,
* increase release Ach with 3,4, diamino pyridine and decrease degredation with pyridostigamine (cholinesterase inhibitor)
26
How would you eval anterior mediastinal mass?
What extra equiptment or monitors would i request?
H&P focusing on dypnea, orthopnea, position changes, syncope
associated conditions: MG, SVC syndrome,
CT scan: size and location of tumor, tracheal or great vessel collapse
echo: vascular collapse (upright and supine)
surgeon: rigid broncoscope, sternal saw, consider CBP (fem-fem bypass \>70%), life threatening compression--\>consider preop radiation, chem steriodd tx
awake fiberoptic w wire reinforced ETT, a line R radial
27
Cystic fibrosis issues
how to optimize:
cardiac: pulm htn cor pulm
pulm: freq muscus plugging, inflammation, infection--\>hypoxia (V/Q mismatch), broncospasm, PTX (bbullae), bronchiestasis, resp failure,post op resp failure, lung infections
GI/hepatic: malabs (vit K def + coaggulopathy; electrolyte abnormalities), pseudocholinesterase def
endocrine: DM (pancreatic involvement)
broncodilators, abx, chest physiotherapy
28
complications from mediastinoscopy
monitoring considerations
neuro: cerebral ischemia/extremity ischemia fron inminate compression, RLN/phrenic injury
cards: mediastinal hemorrhage, CV collapse, reflex brady from compression of aorta
pulm: tracheal compression, airway collapse PTX **(need CXR in PACU),** **VAE**
GI esopahgeal tear
**A LINE/pulse ox** on R side to monitor for inominate artery compressin
**monitor peak airway pressure**s in case of tracheal compressionn
29
pathophy of CF
defect in transporter (CFTR) gene that leads to abnormal movement of salt in and out of cell with development of thick viscous secretions associated w **luminal and gradular destruction**
**mucus plugging, inflammation,** infxn--\>bronchiestasis, emphysema, hypoxemia, heart failure
GI/hepatic involvement: DM malabs
30
causes of increased PaCO2 during pneumoperitoneum
1. inadequate ventilation
2. CO2 emphysema (extraperitoneal insufflation of CO2): tx desufflate, hyperventilate pt, have surgeon insuflate at a **lower pressure**
3. capnothorax (movement Co2 into throax)
4. CO2 embolism
5. PTX
6. VQ mismatch: aspiration, CHF, COPD, hypotension
7. MH
31
post op dyspnea
* Neuro: neuro conditions-MG, pain , nerve (phrenic from blocks)
* Cardiac: cardiogenic pulm edema,
* Pulm: atelectasis, aspiration, bronchospasm, bleeding/compression, drugs ,airway edema/NPPE/cardiogenic pulm edema , larnygospasm, PTX, PE, obstruction (OSA)
32
extubation criteria
Neuro: Awake and alert; following commands; return of airway reflexes; fully reversed, normothermic
Cards: Stable vital signs, hemostasis
Resp: (VC \>10-15ml/kg, NIF \>25-30, TV \>5ml/kg)
If questionable, PS support trial w/ 5cmH2O and 5cmH2O CPAP on FiO2 0.4 x 30 min
ABG: PaO2 \>80, PCO2 35-45, pH 7.35-7.45
33
Benefits to SIMV
* * Transition from controlled to spontaneous vent
* Improve tolerance of mechanical ventilation
* Decrease **vent dysynchrony**
* Ensures a min **MV**
* Preferred over AC in pt with high MV as it reduces risk of **hyperinflation, autopeep, and volume trauma**
**set basal RR that is synchonized to avoid mechanical breath during pt initated breath**
AC: Each breath is either an **assist or control breath**, but they are all of the **same volume**. The larger the volume, the more expiratory time required. If the I:E ratio is less than 1:2, progressive hyperinflation may result.
Guarantees a certain number of breaths, but unlike ACV, patient breaths are partially their own, reducing the risk of hyperinflation or alkalosis. Mandatory breaths are synchronized to coincide with spontaneous respirations.
AC ideal for muscle recovery
34
signs of resp distress
apnea
noisy breathing aphonia
dyspnea tachypnea, use of acessory muscles, nasal flaring
signs airway obstructions: hoarseness, stridor, resp distress)
RVH cor pulm
35
What to obtain for airway that may obstruct on induction
difficult airway cart,
rigid broncoscope
tracheostommy/criothyroidiomy set surgeon
36
How to treat larngospasm
chin lift jaw thrust, oral airway
PPV
deepen anesthestic
paralytic
37
options if surgeon needs better visualization in airway
exchange for smaller tube if ventilation and intubation were easy
**intermittent apnea/extubation w spontaneous vent**
- unobstructed access to airway
- no combustible devise in airway during ablation
- movement of surgical field w spontaneous resp
- potential for inadewuate ventilation
**intermittent apnea/extubation w spontaneous vent**
- periods of ventilation 1 100% oxygen interspered w periods of apnea during which surgeon works on airway
- all of the above +added benefit of motionless surgical field
sponatneous ventilation without an ETT
i**ntermittent jetventilation through the operating larngoscope**-
- motionless field (eliminates movement of diaphagm)
- reduced risk of airway fire
- not reccomeended for those w **decreased chest wall compliance**: obesity, restrictive lung disease or conditions that may **limit full exhalation** (severe COPD, glottic lesions
risks
1. misalignment of jet to glottic inlet-poot ventilation/gastric ventilation
2. transmission of blood smoke debris into distal airways (virus)
3 . bartrauma (pneumediastinum, SQ emphysema, PTX)
38
How to jet vent
most common cause of desaturation w jet ventilator
what would you do
ventilate with 100% oxygen until surgeon ready to position suspension larngoscope w attached jet injector needle
- ensure adequate muscle relaxation and dept of anesthesia
- remove ETT and position suspension larngoscope
- iniate jet vent at 5-10 (children) or 15-20psi in adults and titrate upwards until adequate rise and fall
- inadeuquate ventilation pressure, malpositioned jet ventilator (others: PTX, aspiration from gastric distention, bronsco/larngospasm, obstruction
\*\*
1. have surgeon comfirm position of jet ventilator
2. 100% oxygen
3. listen to lungs
4. intubate, suction trachea, deepen anesthetic, B2 agnoist
5. consider CXR
39
airway fire what do u do??
1. declare an emergency
2. disconnect the ETT from circuit
3. remove ETT
4. flood surgical field w saline
5. fire out--\>ventilate w 100% oxygen and perform DL and rigid bronch to eval airway and remove debris
6. reintubate for 24 hrs due to delayed airway edema --\>airway onstruction
7. At 24 if CXR no evidence of acute lung injury, extubate when no evidene of airway edema by bronch, confirm tube leak, prepare for emergent reintubation
7. CXR, steriods, pulm consult
40
How to reduce risk of airwat fire
1. remove flammable materials from airway (intermittent extubation +/-apnea or supraglottic jet
2. laser resistent ETT, rubber tube, wrap tube
3. reduce oxidizing agemt by reducing FI02 \<40%, avoid nitrous
4. fill cuff w colored saline to rapidly identify cuff puncture and maybe quench a small fire
5. min intensity and duration of laser tx
41
DX OF TRALI
pathophys
distinguish from TACO
tx vs TACO
-acute onset hypoxemia Pa02/Fi02 \<300, pulm edema (b/l infilrates on CXR within 6 hrs of transfusion, absense of cardiac failure PAOP \<18mmHg
donot leukocytes antibodies activate neutrophils in the lungs on vascular endothelium--\>capillary leakage--\>acute lung injury
TACO: cardiogenic pulm edema, hypervolemia, increased BNP, impaired cardiac fxn, Trali usually hypo to isovolemic
supportive vs diuretics/inotrope/afteroad reducing agentd
42
signs of aspiration
hypoxemia from intrapulmonary shunting
broncospasm
atlectasis
possible pulm edema, pHTN, hypercarbia
43
etiology of broncospasm
aspiration
anaphylaxisis,,
light anesthesia
secretions/blood in airway
44
one sided diminished lung sounds
PTX
R mainstem
capnothorax (laproscopic)
45
contradinications to mediastinoscopy
Strong-Prior mediastinoscopy
relative: cerebral vascualr dz, severe cervical spine dz w limited neck extension, throacic aortic aneursym, severe tracheal deviation, prior chest radiation
46
Anesthetic considerations for SVC syndrome
- neuro: increased ICP, compromised CPP, head up position to promote venous drainage
- impaired delivery of drugs to heart L: upper and lower extremity IV
- difficult airway management w airway edema : watch fluid management,
47
biopsy of anterior mediastinal mass with \>50% compression and sx when supine
-try to do under local
or conisder reducing size of tumor w chemo, radiation, steriods before proceeding
48
Concerning signs cardiopulm issues for anterior mediastinal mass
* Tracheal compression\>50% or tracheal compression \>30% + bronchial compression
* Stridor, orthopnea, cyanosis, JVD
* SVC syndrome, pericardial effusion, pleural effusion
* Combined obstructive and restrictive finding on PFTs
49
tools to have for mediastinal mass
anesthetic considerations
* Rigid bronch: stent airway, conduit for jet ventilation
* CBP on stand by/sternal saw-cannulate femoral arteries
* Several tubes of different sizes
* Bed in room in case prone needed
* Concern for compression
* local
* Radiation or chemo to shrink it first- can compromise future histological dx and compromise treatment (dx inaccuracy)
* Keep patient spontaneously breathing to maintain airway patency
* Fiberoptic scope eval airway and which bronchus most patent in case of endobronchial intubation-assess level and degree of bronchial compression
* If paralysis needed:
* attempt to place breathing tube beyond the mass compression
* make sure pt toleratesmanual PPV
* avoid long acting muscle relaxants
50
fat embolism criteria
major: neurox2, resp x2
minor: vitals x2, fatx3, labs x2
51
etiology b/l diffuse pulm infiltrates
aspiration pneumonitis
cardiogenic (fluid overload),
noncardiogenic (ARDS, TRALI),
neurogenic pulm edema
52
What is ARDS, criteria
tx
injury to capillary alveolar memebrane (hypoxemia from shunting).
Hypoxia Pa02/Fio2 \<300 \<200 \<100
diffuse b/l ilfiltrates
no cardiac in origin
acute onset 7 days of inciting event (trauma, sepsis, aspiration, sepsis)
lung protective strategy: tx cause, TV 6cc ideal body weight, Plateau \<30, PEEP, prone, FI02\<50, paralysis
53
when to get echo for pneumonectomy
Fev1\<40% high risk RH failure
active cardiac conditions
3 or more clinical risk factors
54
expected Pa02
102-age/3
55
desaturation during OLV
* 100% oxygen
* Ensure adequate placement by capnography, listening to chest, fiberoptic scope for direct visualization
* Check BP to ensure adequate perfusion
* RL shunt from collapsed lung
* Recruitment breaths
* CPAP 10 Cm H20 to nondependent lung if surgically acceptable
* PEEP 5-10 cm H20 to ventilated lung ( in healthy lungs this way result in pressure induced shunting blood to nondependent lung)
* Reinflate non dependent lung
* Discuss with surgeon about ligating pulm artery to elim shunt
* Encourage hypoxic vasoconstriction (remove agents that may blunt this)-volatile, systemic vasodilators, hypocapnia (inhibit HPV nondependent lung and increased vascular resistance in dependent lung
56
When can extubate after pneumonectomy
ppoFev1: \>40% awake warm comfortable
ppoFev1- 30-40% the lung parenchymal and cardiopulm reserve do not exceed risk threshold \>40% and 15ml/kg/mL
ppo Fev1-20-30%
the lung parenchymal and cardiopulm reserve do not exceed risk threshold \>40% and 15ml/kg/mL
**resected w VATS and/or thoracic epidural**
57
downsides to leaving DLT in for ICU
* Increased risk of **mucosal ischemia** and **tracheal stenosis** with prolonged use of large diameter tube
* Lack experience with ICU staff
58
Benefits to smoking cessation after 8 weeks
reduction in carboxyghemoglobin and oxygen unloading, improved ciliary fxn. reduced nicotinine levels/vasoconstriction, airway hyperreactivity, sputum production, periop pulm complications
59
What shifts the oxyhemoglobun curve to left
alkalosis, hypothermia, decreased 2,3 DPG
met Hgb, carboxyhemoglobin, fetal Hgb,
60
What is Parkland formula
4% X kg X % BSA
half in first 8 hrs,; 1/4 in second 8hrs, 1/4 last 8 hrs
AW
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