Orals Flashcards
Bradycardia
Primary: sick sinus, complete heart block Secondary: (vagal stim/supp) drug induced - digoxin, narcotics, anticholinesterase, beta blockers, dexmedetidine [alpha2 stim], CCB & vagal stim - oculocardiac reflex, traction on viscera, laryngoscopy, baroreceptor [carotid]
Tachycardia
Primary: SVT, ventricular arrhythmia Secondary: hypoxemia, hypercapnia, decreased O2 output (anemia, low CO), pain (somatic, visceral, sympathetic), hypovolemia (absolute - dehydration, hemorrhage & relative - tamponade, pneumo, PEEP) Unusual: inotrope, pheo, carcinoid
Hypertension
Primary: Long standing, associated with disease (pre-e, kidney failure) Secondary: hypoxemia, hypercapnia, decreased O2 output (anemia, low CO), pain (somatic, visceral, sympathetic), hypovolemia (absolute - dehydration, hemorrhage & relative - tamponade, pneumo, PEEP) Unusual: inotrope, pheo, carcinoid
Hypotension
Preload - not enough or blocked from getting to heart (tamponade, PEEP, tension pneumo, aorto-caval compression, pinched vessel, CABG bent/twisted heart) & heart itself - muscle not strong (cardiomyopathy, MI), bradycardia/tachycardia/valvulopathy & afterload - too low (spinal shock, anaphylaxis, meds) & blood - low hematocrit and not enough to generate pressure
Hypoxemia (1)
Wall to ETT: wrong gas composition, no has delivery; ETT to lungs: endobronchial/esophageal intubation, kink/clog/aspiration, disconnect, subQ tube
Hypoxemia (2)
Thorax (out to in): weak chest wall from NMB, kyphoscoliosis/flail chest/phrenic nerve, pleura (fluid/air), parenchyma (aspiration, PNA, ARDS, CHF, atelectasis, V/Q mismatch), pulm vasculature (emboli), cardiac R-L shunt
Hypercapnia
Making too much: MH, thyrotoxicosis, sepsis Eliminating too little: hypoventilation Rebreathing: CO2 absorber, valve, flows
High risk procedure
Risk > 5% - aortic and other major vascular surgery, peripheral vascular surgery
Intermediate risk procedure
Cardiac risk ~ 1-5% - intraperitoneal and intrathoracic, carotid endarterectomy, head and neck surgery
Low risk procedure
Cardiac risk < 1% - endoscopic procedures, superficial procedure, cataract surgery, breast surgery, ambulatory
Major clinical risk conditions
Unstable coronary syndromes, decompensated heart failure, significant arrhythmias, severe valvular disease
Intermediate clinical risk conditions
h/o ischemic heart disease, h/o compensated or prior heart failure, h/o CVA, DM, renal insufficiency
Minor clinical risk conditions
Abnormal EKG, rhythm other than sinus, uncontrolled systemic HTN
CAD risk factors
Age, male, heredity, tobacco, cholesterol, sedentary, overweight/obese, DM, stress, alcohol, diet and nutrition
Beta blockers and pregnancy
Bradycardia, hypoglycemia, respiratory depression, intrauterine growth retardation
Rapid shallow breathing index
ratio of respiratory frequency to tidal volume (f/VT), <105 for extubation
Postoperative pulmonary complications risk factors
Preexisting pulmonary disease, thoracic or upper abdominal surgery, smoking, obesity, age >60, prolonged GA >6 hours
Normal FEV1 values
> 3L men, >2L women
Normal FEV1/FVC percentage
> 70%
Preop thoracic evaluation
FEV1 >800ml then postoperative FEV1 = % blood flow to remaining lung x total FEV1; FEV1 40mm Hg or PaO2 <45mm Hg means not a pneumonectomy candidate)
High risk preop lab criteria for pneumonectomy
ABG (PaCO2 >45, PaO2 <10 ml/kg/min
One lung maneuvers
100% O2, periodic inflation of collapsed lung, CPAP (5-10), early ligation/clamping of ipsilateral PA (pneumonectomy), position, PEEP, continuous insufflation of O2 to collapsed lung, changing tidal volume and RR
Nitrous
35x more soluble than nitrogen in blood so it diffuses into air containing cavities more rapidly than nitrogen is absorbed by the bloodstream
Hypothermia effects
<36 C, reduces metabolic requirements, increasing O2 consumption x5 2/2 shivering, cardiac arrhythmias an ischemia, increased peripheral vasc resistance, left shift hemoglobin-O2, reversible platelet dysfunction, postoperative protein catabolism and stress response, AMS, renal dysfunction, decreased drug metabolism, poor healing, increased infection
