Chapter 34 - Postoperative management Flashcards
Benefits of ICU/stepdown units
1) decreased myocardial oxygen demand by 2) expeditious rewarming 3) effective fluid resus 4) effective analgesia 5) meticulous control of hemodynamics 6) careful monitoring 7) appropriate nursing care for diagnosis and treatment of complications
Reasons to consider post-op ICU/step down stay
1) CAD (EF < 40%, CHF, NYHA 3-4 angina) 2) COPD FEV1 < 1L 3) dialysis dependent 4) SBP < 90 or need pressor 5) intubated needing vent 6) presence of pulmonary catheter, spinal drains 7) hypothermia < 35 C 8) massive transfusion > 3L
What does CVP measure
1) right atrial pressure 2) estimate of preload inaccurate in COPD or valvular heart disease affected by high PEEP > 12 cm H2O
Normal CVP
6-12 mmHg measured at end expiration
Sudden change in CVP suggest
1) pneumothorax 2) cardiac tamponade
Peripheral art line positioning
midpoint of right atrium 5cm below sternal angle in mid axillary
Reasons to insert pulmonary artery catheters
1) measure cardiac output 2) cardiac pressure 4) mixed venous oxygen
How to estimate cardiac output from echo
1) diameter of descending aorta 2) distribution of flow to descending aorta 3) measured flow velocity of blood
Normal intraabdominal pressure
5-7 mm Hg
Intra-abdominal hypertension
IAP 12-20 mmHg
Abdominal perfusion pressure
MAP - IAP
Abdominal compartment syndrome
constellation of symptoms suggesting organ dysfunction 1) decreased CO 2) high peak airway pressure 3) oliguria 4) IAP > 20
Risk for abdominal compartment syndrome
1) Fluid resus > 10L crystalloid or >5L colloid 2) transfusion > 10 unit in 24 hr
Measurement of abdominal compartment syndrome
1) 25-50ml normal saline into catheter 2) end expiration with patient supine
Target post-operative BP
20 mmHg +/- from baseline deviation of MAP within 20% of baseline
Hypertensive emergency associated BP
SBP > 179 DBP > 109 can cause acute damage to organs (Crisis)
Pulse pressure to stroke volume ratio suggestive of hypovolemia
> 10%:15%
Treatment of acute hypotension
Phenylephrine Dopamine
Treatment of tachyarrhythmia in hemodynamic stable patient
1) Beta blocker or CCB for rate control 2) IV amiodarone 3) adenosine 4) electrical cardioversion (if unstable)
Treatment of torsades de pointes
Polymorphic VT with prolonged QT interval Magnesium
Loss of atrial kick will decrease left ventricular stroke volume by
20-35%
How often do people revert out of afib after bolus amiodarone
1/3
Treatment of new afib in hemodynamically stable patients
1) beta blocker 2) amiodarone 3) digitalis 4) cbb electrical cardioversion if unstable
Detecting cardiac ischemia 3 ways
1) symptoms 2) ECG 3) enzymes
STEMI definition
1) ECG = ST elevation 0.1 mV (1 mm) in two consecutive leads 2) CK-MB levels elevated 3-12 hours after infarction; peak 24 hour and elevate for 3 days 3) troponin detected 4-12 hours; peak 12-48 hours; elevate 1 week
Medical treatment for STEMI post-cath
1) beta blocker 2) ACEi 3) statins
NSTEMI definition
biomarker indicative of MI without ST elevation
Causes of NSTEMI
transient reduction in coronary blood flow that causes imbalance in myocardial oxygen supply and demand
Hemodynamic target for NSTEMI
block until SBP > 90 HR > 50
Two modes of mechanical ventilation
1) controlled 2) supported
Two types of ventilator settings
1) volume control = fixed tidal volume with varialbe pressure 2) pressure control = fixed pressure with variable tidal volume
Tidal volume target on ventilator for protective ventilation
6-8 ml/kg avoid overdistention or derecruitment/atelectasis
Two approaches to ventilation weaning
1) progressive reduction of support 2) spontaneous breathing trials without progressive withdrawal
Setting of weaning
1) pressure support 5-8 cm H2O 2) PEEP at 5 cm H2O 3) O2 at 30 or room
Signs of readiness to be weaned
LACK of distress: 1) resp rate > 35 for > 5 min 2) desat < 90% for > 30 sec 3) increase or decrease HR +/- 20% for > 5 min 4) SBP out of 90-180 range 5) other signs of agitation and distress (paradoxical breathing, accessory muscles, diaphoresis
Rate of reintubation
10-15%
Benefit of tracheostomy
1) decrease work of breathing 2) better oral hygiene 3) secretion management 4) improved survival in COPD 5) shorter hospital stay
Disadvantage of tracheostomy
1) procedure complication 2) stomal complication 3) tracheoinnominate fistula 4) tracheoesophageal fistula
Relative contraindication to do percutaneous tracheostomy
1) hypoxic 2) high PEEP 3) obese 4) short neck 5) coagulopathic 6) recent < 10 days) anterior cervical spine fixation
Physiologic response to hypovolemia
1) tachycardia 2) hypotension 3) low CVP 4) decreased urine output 5) peripheral vasoconstriction
Post-operative coagulopathy tests, problems and treatment
TABLE 34.1
Why does FFP not reduce heparin effect
FFP has antithrombin III which is what heparin acts on
Hemophilia type A and B
A = deficiency of factor 8 B = deficiency of factor 9 C = deficiency of factor 11
Reversal for warfarin
Vitamin K FFP prothrombin complex concentrate
DIC bloodwork will show
1) increased INR 2) increased aPTT 3) thrombocytopenia
Treatment of DIC
Cryoprecipitate if fibrinogen < 100 mg/dl FFP when other factors < 25% or abnormal iNR platelet if plt < 50
Fluid balance in shock workup and treatment
FIGURE 34.2
Transfusion threshold for RBC in CAD or without CAD
70 without CAD 80-90 with CAD
Transfusion of platelets in various situations
Cardiac surgery, bleeding - 100 coagulopathy, bleeding - 50 coagulopathy, no bleed - 20 low risk no bleed - 10
When to give FFP
active bleeding and INR > 1.5
When to give cryoprecipitate
active bleed and fibrinogen < 100 mg/dl (<2.9 mcmol/l)
What’s in cryoprecipitate
factor 8, factor 13, vWF
How much platelet in one unit of whole blood
5.5 - 10 x 10^10
how much platelet from 1 unit of platelet pheresis
40 x 10^10 from 6 units of whole blood
Amount of cryoprecipitate needed to raise fibrinogen by 0.5-1.0g/L
1 unit per 5-10kg body weight
Function of recombinant activated Factor 7
1) control bleeding in patients with hemophilia types A + B 2) generates thrombin at site of vessel injury - coagulation
Antifibrinolytic agents
1) Tranexamic acid 2) aminocaproic acid
Effect of antifibrinolytic agents
1) synthetic lysine analogues 2) inhibit plasminogen and plasmin-mediated fibrinolysis
What is aprotinin
Serine protease neutralizes trypsin, plasmin, kallikrein used when fibrinolysis contributes to bleeding
Definition of massive transfusion
replacement of 50% patient blood in 3 hour replacement of 100% patient blood in 24 hours
Causes of coagulopathy in massive transfusion
1) hemodilution 2) hypothermia 3) acidosis due to tissue hypoxia 4) DIC 5) hyperkalemia - RBC lysis 6) hypocalcemia - citrate as anticoagulat
Nutrition goals and feeding key points in ICU
1) determine goal calories 2) give 50-65% goal calorie in first week 3) increase to goal rate 4) permissive underfeeding if BMI > 30 (goal to 60-70% ideal weight)
Autonomic hyperactivity symptoms in alcohol withdrawal
1) tremulousness 2) sweating 3) nausea 4) vomiting 5) anxiety 6) agitation
Timing of autonomic hyperactivity in alcohol withdrawal
start 24-48 hours peak 3-5 days
Delirium tremens rate
5%
Delirium tremens symptoms
1) fever 2) tachycardia 3) hypertension 4) tremors 5) diaphoresis 6) hallucinations 7) disorientation 8) agitation 9) urinary incontinence
First line treatment for alcohol withdrawal syndrome
Benzodiazepine
Reasons to take thiamine and multivitamin in alcoholics
Prevent Wernicke-Korsakoff syndrome
Richmond agitation sedation scale
10 point scale from -5 to +4 -5 is unarounsable +4 is combative 0 is normal and alert
Three types of delirium
1) hyperactive 2) hypoactive 3) mixed
Non-pharmacologic methods of delirium management
1) minimize risk factors 2) early mobilization 3) sleep protocol 4) timely removal of catheters and lines 5) minimize noise and unnecessary stimuli
Pharmacologic methods of delirium management
1) avoid benzodiazepine - exacerbates 2) haloperidol 3) risperidone 4) quetiapine 5) olanzepine
