Renal and Coagulation Flashcards

Question

What is the CAO2 formula?

Answer 1

``` CaO2=(Hgb x 1.39)SaO2 + PaO2(0.003) 1.39 = O2 bound to hemoglobin SaO2= saturation of hemoglobin with O2 PaO2= arterial partial pressure of oxygen 0.003 = dissolved oxygen ml/mmHg/dl ```

Answer 2

↓ SVR ↑ 2,3-DPG- major compensatory mechanism till 7 g/dl (Alters O2 binding- Right shift->↓Hgb affinity for O2) ↑ CO ↑ plasma Volume Redistribution of blood flow to organs with higher extraction ratio ↑Extraction ratio in vascular beds

Answer 3

Anemia according to WHO= Hemoglobin <12 g/dl (female) 13g/dl (males) Hgb and Hct are relative measurements

Answer 4

``` Duration Acute vs. chronic anemia Etiology Intravascular fluid volume Urgency of surgery Anticipated blood loss during surgery Co-existing disease Cardiovascular, cerebrovascular, and lung disease, PVD ```

Answer 5

Prior to 1980s-10/30 rule…AIDS Clinical decision to transfuse is based on the risk:benefit Minimum acceptable H & H individualized American College of Surgeons- transfuse only if symptomatic Always focus on the cause! American Assoc of Blood Banks- Hgb of 8 g/dl threshold in healthy individuals NIH Consensus Conference on Perioperative transfusions- 7g/dl ASA Task Force on Blood Component Therapy – transfuse based on risks from complications of inadequate O2 delivery

Answer 6

Perioperative risks and concerns ↑ risk of tissue hypoxia Previous splenectomy may ↑ risk of perioperative infection Erythopoietin is often prescribed for 3 days preoperatively Acute drops in Hb below < 8 g/dl and chronic reductions to below 6 g/ dl should be considered for transfusion

Answer 7

Trait: 8% African Americans are Heterozygous carriers (hgb genotype AS- 40% of their Hgb is S) Do not have anemia and do not need Rx 5% at some time have hematuria & difficulty concentrating urine-not significant clinically Do not require pre-op transfusions Disease: RBCs homozygous for Hgb S contain 70-98% Hgb type S Anemia well tolerated O2 delivery to tissues due to right shift of oxyhemoglobin dissociation curve with Hgb S

Answer 8

Patients have a 30% overall complication rate * Stroke Heart failure and Pulmonary HTN MI Hepatic or splenic sequestration Renal failure * So what are your pre-operative assessment priorities?

Answer 9

Procedures intermediate to high risk conservative transfusions preoperatively to Hgb10 g/dl = Hct of 30% Low risk procedures- no benefit Emergency surgery- High risk for postop complications-optimal transfusion support Venous access may be difficult to obtain Preoperative hydration for 12 hours prior to surgery Premed-Avoid respiratory depression = acidosis

Answer 10

Hypoxemia Hypovolemia Stasis

Answer 11

Maintain normothermia = cold patient vasoconstricts = sickling Hydration- avoid dehydration hemoconcentration = ↑ sickling Maintain oxygenation Acidosis promotes sickling Positioning prevent stasis

Answer 12

High-output CHF common with severe anemia Compensatory RBC production = craniofacial deformity and overgrowth of the maxillae increase challenge of DVL Complications of iron loading from chronic transfusions Diabetes (Blood glucose monitoring) Adrenal insufficiency (↓ response to vasopressors) Liver dysfunction & Coagulation abnormalities Hypothyroidism & hypoparathyroidism Arrhythmias (cardiac hemochromatosis) (ECG) Heart failure (cardiac hemochromatosis) (ECHO) Hypersplenism can result in thrombocytopenia and ↑ risk of infection Potential difficult airway 2° to maxillary deformities Cardiac arrhythmias of HF Coagulopathy

Answer 13

CBC results important – neutrophil, RBC and platelet counts can be extremely low! May need pre-op transfusion Know pre-op medications (many are on steroids) which means???? Airway hemorrhage possible with DVL? What does this mean to you? Other perioperative risks and concerns Infection Hemorrhage (GI & Intracranial) LV dysfunction 2° high output state and fluid overload Sepsis Co-existing congenital abnormalities Fanconi anemia Difficulty cross-matching blood products after multiple transfusions Reverse isolation Neutropenia & severe co-existing congenital heart disease  prophylactic ABX Steroid “stress” dose Avoid nasal intubation

Answer 14

Porphyrias are a group of inborn errors of metabolism = overproduction of porphyrins Porphyrins are essential for many vital processes including O2 transport and storage (heme is a porphyrin) A feedback loop is involved in the enzymatic pathway producing prophyrins Any increase in heme requirements results in an accumulation of pathway intermediates preceding the enzyme block

Answer 15

Activation of the disease via drugs, diet, and steroid hormones Drugs trigger an attack by inducing ALA synthetase or interfering with negative feedback control in final common pathway ``` Attack Symptoms: severe abd pain/GI disturbance ANS instability electrolyte disturbances CNS disturbances life threatening muscle weakness ```

Answer 16

``` Barbiturates Sulfonamide antibiotic Alcohol Diazepam Phenytoin Etomidate ?????? Nifedipine (probably avoid) Ketorolac (probably avoid) ```

Answer 17

``` Opioid analgesics Propofol Ketamine (probably safe) Aspirin Acetaminophen PCN Glucocorticoids Insulin Atropine ```

Answer 18

Factor VIII = abnl PTT | Treatment: Factor VIII infusion; Desmopressin

Answer 19

Factor IX = abnl PTT | Treatment: Factor IX

Answer 20

vWF & VIII= prolonged bleeding time | Treatment: Cryo and Desmopressin

Renal and Coagulation Flashcards

(44 cards)