1 Resp Patho Flashcards
Bronchodilation: which receptor/g protein/2nd messenger/release. Ends when
B2, Gs, Adenylate cyclase, cAMP (2nd), reduces Ca release from SR, bronchodilators. End w pd3 converting cAMP to AMP
NO: which nerves it acts on, stim what
Non cholinergic PNS nerves to release VIP and inc NO produc, stim cGMP to dilate
Bronchoconstriction: nerve, release what onto what, G protein, 2nd mess, turned off when
CN X, Ach onto M3, Gq to phos C, IP3 (2ND), ca release from SR. Turned off when IP3 to IP2
C fiber mediators that bronchoconstriction
Sub p, neurokinin A, calcitonin gene related peptide
Steroids interfere where
Block mast cells from stim arachidonic acid leading to leukotrienes
Cromolyn affects what
Release of cytokines, leukotrienes, histamine
Methylxanthines affect what
PDE to stim cAMP, dec ca release and cause relaxation
Beta 2 ag effect on K
Hypokalemia
How anticholinergics work to dilate
Antagonize M3, dec IP3 and ca release
Methylxanthines: drug example, side effects when >20 mcg/ml
Theophylline. NVD, HA, cant sleep
Theophylline SE when >30 mcg/ml
Sz, tachydysrhythmias, CHF
Fev1: Effort ____, declines w ___, nml value
Dependent, age,>80% of predicted
FVC: effort ___, M/F nml
Dependent. 5L, 3.7L
FEV1/FVC ratio nml
80%
FEF 25-75: effort ___, tests what, nml
Less effort dependent, middle airway flow, 75-100% predicted
MVV: test of ___,nml
Endurance. M: 160L, F: 100
Dlco: test of what, nml
Gas exchange, 17-25 ml/min/mmhg
Procedure high to low risk for pulm complic
Aortic > thoracic> upper abd = neuro = peripheral vascular > emergency
Which lab test does and doesnt show risk pulm postop complic
Does: albumin <3.5. Doesnt: abg and pft
Smoking cessation: when CO and p50 return to normal
T1/2 4-6 hr CO. P50 returns 12 hours
Smoking cessation: when pulm func returns and when hepatic enzyme induc subsides
6 weeks for both
How to do ARMs
PIP to 40 for 8 seconds
Obstructive disease: which tests are normal, low, or hi nml
Nml/hi nml: RV, FRC, TLC. Low: ratio and fef 25-75. Low nml: FVC and fev1.
Restrictive disease: tests that are low vs nml
Low: FVC, fev1, RV, FRC, tlc. Nml: ratio, 25-75
How to differentiate on spirometry: obstructive, restrictive, fixed
Obstruc: concave exp limb. Fixed: flat insp and exp limbs. Restrictive: smaller and shifted right
Flow volume loop: direction of breathing, exp vs insp on chart, vol on chart
Clockwise, exp on top insp bottom. Vol increases right to left
Extrathoracic vs intrathoracic obstruction on flow vol loop
Extra: insp limb flat, intra: exp limb flat
Asthma: greatest risk factor, tests that are reduced
Autopsy. FEV1, fev1/FVC ratio, 25-75 (all imp w dilator tx)
Asthma: what ekg may show, flow vol loop changes not caused by wheeze w asthma
R axis dev. Insp or exp limb totally flat
Asthma vent settings
Limit insp time, prolong exp time, mod permissive hypercapnia
Why h2 antag bad in asthma
Unopposed h1 stim leading to bronchospasm
Bronchospasm tx order
02, deepend anesthesia, B2 ag (albuterol), ipratropium inhaled, epi 1 mcg/kg iv, hydrocortisone 2-4 mg/kg to prevent complic later, aminophylline (not Theo), heliox
Why restoring paco2 to nml in COPD bad
HCO3 in blood hasn’t gone anywhere, risk severe alkalosis and apnea
COPD: rely on what for resp drive. Diagnosis when
Pa02. Ratio <70% after bronchodilator therapy
COPD: avoid block above what, what may risk rupture of blebs/ptx
T6, nitrous
COPD: tv, other vent consid
6-8 ml/kg IBW, inc exp time
Causes of auto peep
Large tv, inc rr, bronchoconstriction, inc a/w resistance
Cardiac fx auto peep
Dec venous return, hypotension, overstim cvp and paop
Restrictive disease: diagnosis, causes of chronic intrinsic
Ratio <70%. Sarcoidosis or amio
Restrictive disease: TV, RR, PIP
6 ml/kg, 14-18, <30, 1:1
Mendelsons syndrome diagnosis
Ph <2.5, vol >25 ml
First action in aspiration, other actions
Tilt head down or to side, upper then lower a/w suction, secure airway, peep, dilators, iv lido
Hallmark signs tension ptx
Hypoxemia, inc a/w p, tachycardia, hypotension, inc CVP
Where chest tube goes ptx
2nd IC mid clavicle or 4-5th IC space ant axillary line
Chylothorax risk w CVL which side
Left
Hemothorax: when thoracotomy indicated
> 1l initial drainage, >200ml/hr, white on cxr and air leak
Hemothorax: when vats ok
<150 ml/hr
Flair chest chest movement
Ribs move in with insp and out with exp
High to low risk positioning for VAE
Sitting, supine, prone, lateral
S/s highest to lowest sensitivity VAE
TEE, Doppler (no physio changes), PAP/ETCO2, CO/CVP (modest changes), BP/EKG (collapse)
Tx vae order
02, flood field, d/c insufflation, L lateral, aspirate air, hemodynamic support
Pulm htn: fixed what that’s dependent on what
CO, preload
PVR calculation, nml
(Mean PAP- PAOP) X 80 / co. 150-250
Causes inc PVR: ___ temp, drugs, ___ valve disease
Low, NO/Ketamine/des, mitral
Drugs that decrease PVR
Nitric, ntg, pde inhib, prostaglandins, Ccb, ace inhib
If elev RA pressure w/inc PVR: do what to prevent r to l shunt or reverse it
Reverse causes of inc pulm resistance
Drug of choice when too much preload w inc PVR
NTG
Carboxyhgb: shift where in curve, dx, pt appearance, pulse ox
Shift left, co oximetry. Pulse ox falsely elevated. Cherry red not cyanotic
Tx carboxyhgb
100% 02 until cohgb <5% for 6 hours. Hyperbaric if >25% or symptomatic
Risk greatest to least CO with soda lime. Which does compound a
Des, iso, sevo. Sevo
Drugs you can give down ett
Narcan atropine vaso epi lido
VC and insp force when need ett
<15, <25
Pa02 and A-a when need ett at 21%
<55 >55
Pa02 and Aa at 100% 02 when need ett
<200 and >450
RR and CO2 when need ett
> 40 or <6, >60
Best predictors of postop pulm complic from pulm sx
FEV1 <40%, dlco <40%, VO2 max <15 ml/kg/min
DLT size and insertion depth men v women
Men: 39-41, 29 cm. Women: 37-39, 27 cm
DLT sizes in peds, when you cant do one
8-9 26 fr, 10+ 28-32 fr. If <8 years old
Where scope inserted mediastinoscopy, ptx risk which side
Ant to trachea post to innominate. Right side
Mediastinoscopy: absolute v relative contraindications
Absolute: previous one. Relative: trach dev, thoracic aortic aneurysm, SVC obstruction
