ICU Flashcards
When would you avoid using a cell saver?
conditions leading to contamination
- amniotic fluid
- fecal material
- tumor cells
- betadine
- bone cement
When would you avoid using acute normovolemic hemodilution?
Pre-existing cardiac disease –> anemia in myocardial work and demand
Severe renal disease –> extra volume poorly excreted –> CHF
Baseline Hb already low (<11)
What is the cause of uremic thrombocytopenia
Dec vWF
Inc nitric oxide, prostacyclin which inhibit platelets
Uremia induced anemia dec viscosity, dec platelet interaction with endothelial surfaces
How do you treat uremic induced thrombocytopenia
DDAVP Erythropoietin Cryo Platelets Dialysis
How do you calculate MELD
Cr + Bilirubin + INR
What is Hepatopulmonary syndrome
Liver disease + A-a >20 or PaO2 <70mmHg + intrapulmonary vascular dilation
How would you determine if ESLD patient’s elevated Cr was due to hepatorenal syndrome?
Fluid challenge 1.5L - improved = pre-renal azotemia and not HRS
Urinary Na >10, casts, sediment = ATN
Look for nephrotoxic agents, contrast
What is the pathophysiology of HRS?
Inc endothelial (prostacyclin and nitric oxide) vasodilators –> splanchnic vasodilation –> reduced “effective” blood volume sensed by kidney –> activation of RAAS and sympathetics
Concern with OLT pre-op PAP >35?
> 35 - moderate pulmonary HTN at inc risk of right heart and liver failure post-op.
Contraindicated with >50
What is V-V bypass?
Femoral or portal veins cannulated –> axillary, subclavian or jugular veins to improve hemodynamic stability, perfusion during an hepatic phase, improve cardiac filling and improve surgical field.
Disadvantages - air embolism, thromboembolism, arm lymphedema, hematoma, vascular injury and nerve injury
Describe the stages of liver transplantation
- Pre-anhepatic - dissection
- Anhepatic - clamping of hepatic artery –> removal of native liver, implantation of donor
- Reperfusion - completion of anastomosis, hemostasis until completion
How do you calculate GCS
Eye opening (1-4) - none, pain, verbal, spontaneous
Verbal response (1-5) - non-verbal, sounds, inappropriate words, confused, oriented
Motor response
- none, extension, flexion, withdraws, localizes, follows commands
How would you intubate an uncooperative, morbidly obese patient with potential facial and c-spine injuries?
Goal is to safely secure airway while attempting to avoid things that may increase his ICP (hypoxia, hypercarbia, sympathetic stim), hypotension, C-spine injury, aspiration
DI equipment, surgeon for trach, reverse T-berg, Pre-O2, careful titration of ketamine to maintain spontaneous vent, remove c-collar and apply cricoid and in-line stabilization
What is vWD?
A qualitative or quantitative defect in vWF
- important role in platelet adhesion, platelet-to-platelet aggregation
Type 1 = most common, quantitative = DDAVP
Type 2 = qualitative, varying degrees
Type 3 = severely low levels
Other tx options = Cryo, FFP, Humate P if type is unknown or having major surgery
Systemic effects of renal failure?
HyperK, HypoCa, acidosis
HypoNa
- Assess for AMS, weakness, HA –> cardiac arrest, cerebral edema, coma, brainstem herniation
Autonomic neuropathy, seizures, uremic encephalopathy, delayed gastric emptying, cardiac arrhythmia, conduction blocks, uremic pericarditis
Retention of Na, and water –> HTN, LVH, CHF
Dec erythropoietin production –> hemodilution, bone marrow suppression, impaired platelet function
Exaggerated effect of drugs (dec protein binding + uremic induced disruption of BBB)
Systemic manifestations with OSA
Chronic hypoxemia and hypercarbia –> inc catecholamine levels
- pulmonary HTN –> RV failure
- systemic HTN
- arrythmias
- polycythemia
- inc platelet aggregation
How would you adjust med dose with obesity?
Lipophilic drugs - larger Vd = TBW
- Sux
- Opioids
- Benzos
- Precedex
- Neostigmine
Hydrophilic drugs = IBW
- NMBDs
However the effects are do not always mirror expectations so it would be reasonable to use IBW and titrate additional dosing to clinical effect
IBW = height (cm) - 100 LBW = IBW + 20-30%
anaphylaxis vs anaphylactoid
Anaphylaxis - IgE antibodies –> degranulation
Anaphylactoid - direct interaction of mast calls with certain allergens = do not require prior sensitization
Tx methHb
Methylene blue 2mg/kg
G6PD deficiency = exchange transfusion
Would you treat acidosis with bicarbonate?
Probably not
My concerns are:
- generation of addition CO2 –> worsening intracellular acidosis
- left shift of O2-Hb curve –> dec O2 unloading and tissue hypoxia
- hyperosmolar state due to excessive Na
- Development of hypoK
So i would avoid using unless he developed life threatening hyperK, pH <7.1 or Bicarb <10 which can lead to dysrhythmias, hypotension, myocardial depression
Cardiovascular changes with burns
First 24-48hrs:
- dec CO d/t myocardial depressants
- inc SVR
- dec coronary BF
- dec response to catecholamines
–> hyper dynamic, CO 2x, SVR reduced
Surgery begins and the patient suddenly loses 850ml of blood, would you begin transfusion?
If hx of HTN, IDDM would prefer to maintain Hct 30% but in addition to allowable blood loss i would consider current surgical hemostasis, hemodynamic stability, signs of tissue ischemia or inadequate organ perfusion
What is the pathophysiology of bone-cement implantation syndrome?
hardening and expansion of cement inc intramedullary pressure –> embolization of marrow debris
When large enough –> inc PVR, RV strain, ventricular dysfunction.
Cement –> dec SVR
Cytokines –> microthrumbus and plum HTN
Tx = supportive - 100% O2, fluids, vasopressors
Post-op from burn and trauma, temp is 38.9, are you concerned?
Early post-op fever usually not infectious.
most likely hypothalamus-mediated inc in temp assoc with major burns.
May represent hyper metabolic response to thermal injury - fat, protein wasting inc O2 consumption –> tissue hypoxia, renal failure, infection
Tx = inc room temp, pain control red catecholamine release, nutrition avoiding hyperglycemia, cholestasis
What is the mechanism of anemia in chronic renal failure?
Dec erythropoietin
Dec cell survival
Tolerated d/t metabolic acidosis and inc 2,3 DPG –> right shift offloading O2
Are there any meds you would avoid in a patient with chronic renal failure?
Meds dependent on renal elimination or with active metabolites
- pancuronim
- atropine
- glyco
- ketamine
- morphine
- diazepam
- meperidine
Red highly protein bound drugs - benzos
What are the risk factors for aspiration?
Obesity (higher volume, lower pH) Delayed gastric emptying (DM, pain) Pregnancy Bowel obstruction Hx GERD Extremes of ages
What are the biggest risk factors for developing aspiration pneumonitis?
#1 = gastric pH <2.5 Volume >25ml
No role for steroids
Antibiotics only if demonstrated a bacterial infection through cultures
What are the systemic effects of cirrhosis/liver failure?
Cardiac
- hyper dynamic circulation (low SVR, high CO)
- portal HTN, varices
- pulm HTN
Pulmonary
- intrapulmonary dilations, shunt
- Dec FRC
- restrictive lung disease
- pleural effusions
- resp alkalosis, hypoxemia
Heme
- Thrombocytopenia and factor deficiencies –> coagulopathy
Ammonia –> encephalopathy
Renal
- HRS
Metabolic
- hypoK, glycemia, albuminemia
What are causes of AGMA?
MUDPILES
- methanol
- uremia
- DKA
- paraldehyde
- Iron
- lactic acidosis
- ethylene glycol
- salicylate
Calculate maintenance fluids for 80kg patient
60ml + 1ml/kg for every 1kg over 20
60 + 60 =120ml/hr
Third space losses
- 1-3ml/kg/hr minor case
- 3-7 ml/kg/hr intermediate case
- 9-11ml/kg/hr major case
Indications for albumin
Large volume paracentesis
- > 4L w/ cirrhosis
- 6-8g/L ascites
HRS/Cr >1.5 acute renal dysfunction
SBP
Post-cardiac, liver, lung transplant with albumin <3, edema and not responsive to crystalloid therapy (>3L)
25% = 25g/100ml
What is refeeding syndrome?
syndrome of electrolyte imbalance associated with TPN use
- hypoPhos
- hypoMag
- glucose imbalance
- vitamin deficiency
What are the complications of TPN?
Infection VTE Acidosis Hypercarbia Fatty liver
When would you use lasix in response to oliguria?
It would be beneficial in avoiding fluid overload and facilitating mechanical ventilation, oxygenation in particular
CI 3.5L/min/m2, MAP 68, on epi gtt, PaO2 65 on FiO2 0.6. How will you manage ventilation?
Will you use PEEP and what are the consequences of PEEP?
Hypoxic –> yes I would use PEEP to improve oxygenation
Low tidal volume lung protective strategy
PEEP inc RV afterload, dec venous return and LV compliance compromising CO
Give volume, inc tone and contractility to compensate for effects of PEEP and dec mean airway pressure with low Tv ventilation and permissive hypercapnia
How would you determine optimal PEEP?
I would use the sliding scale from ARDS-NET
- increase PEEP based on increasing need for FiO2
What is a lung protective ventilation strategy?
- calculate 6ml/kg PBW
- Set RR and Tv to achieve optimal MV
- Permissive hypercapnia to pH 7.3-7.4
- Pplat <30
- SpO2 88-95, PaO2 55-80
- Inc PEEP with inc FiO2
What are your target Factor VIII levels before surgery?
High risk of bleeding - >80%
Normal surgery - >50%
Want >30% for 10 days post-op
What are your treatment options for hemophilia A and B?
A
- DDAVP
- factor concentrate
- cryo
B
- factor concentrate
