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46 Cards in this Set
- Front
- Back
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What are four factors to consider in postoperative fluid replacement?
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1. Maintenance requirements
2. Extra needs resulting from systemic factors (e.g. burns, fever) 3. Losses from drains 4. Requirements resulting from tissue edema and ileus (3rd space losses) |
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How can you get a rough estimate of a patient's daily maintenance requirements?
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Multiply their weight (in kilograms) by 30 (e.g. 60-kg patient needs 1800mL/24hours)
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What increases maintenance requirements?
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Fever, hyperventilation, and conditions that increase the catabolic rate
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What IV solution is most typically given daily and in what quantities?
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2000-2500mL of 5% Dextrose in normal saline or in lactated Ringer solution
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Should potassium be added during the first 24 hours after surgery? Why or why not?
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No, because increased potassium has entered circulation as a result of operative trauma and increased aldosterone activity (a/w stress, cortisol)
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When should electrolyte concentrations in the fluid be measured periodically?
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Whenever external losses from any site amount to 1500 mL/d or more
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How frequently should fluid needs be evaluated on the first day following an extensive operation?
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Every 4-6 hours
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How does respiratory failure manifest?
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Tachypnea of 25-30 breaths per minute with a low tidal volume < 4mL/kg, and PCO2 > 45mmHg and PO2 < 60mmHg
Also evidence of low cardiac output |
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On which postopserative days can you remove dressings over closed wounds?
On which postoperative days can you remove stitches or skin staples? |
Dressings - 3rd or 4th day, unless otherwise compromised
Stitches or staples - 5th day - replace with tapes. They may be left in longer for incisions that cross creases (e.g. groin, popliteal area), those closed under tension, etc. |
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When are Sump (e.g. Davol) drains used? How are they different?
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Sump drains have an airflow system that keeps the lumen of the drain open when fluid is not passing through it, and they must be attached to a suction device. Some have an extra lumen through which saline solution can be infused to aid in keeping the tube clear. Gradually the large-bore catheter is replaced by smaller catheters and the cavity eventually closes.
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How much does vital capacity decrease within 1-4 hours of major intraabdominal surgery? How does it recover?
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Decreases to 40% of preoperative level within 1-4 hours after surgery
Remains at 40% for 12-14 hours By postoperative day 7 it is back to 60-70% of preoperative level VC returns to baseline level during the week after that |
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How is functional residual capacity affected by surgery?
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Immediately post-surgery: FRC is near preoperative level
24 hours post-surgery it is decreased to 70% of preoperative level FRC remains depressed for several days and typically returns to baseline by day 10 |
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FEV1 is decreased in what group and what does this predispose them to?
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FEV1 is decreased in the elderly, which impairs their ability to clear secretions and increases chance of infection postoperatively
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What is a good way to minimize atelectasis?
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Encouraging the patient to take deep breaths, can use an incentive spirometer
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What factors cause pulmonary edema postoperatively?
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High hydrostatic pressures (LVF, fluid overload, decreased oncotic pressure, etc.)
and/or Increased capillary permeability |
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What are the primary causes of early complications and death following major surgery?
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Acute pulmonary, cardiovascular and fluid derangements
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How long does it take for CV, pulmonary and neurologic function to return to baseline following surgery?
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1-3 hours
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When should you monitor CVP? Any special catheters?
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If the operation has entailed large blood losses or fluid shifts, and invasive monitoring is available.
A Swan-Ganz catheter for measurement of pulmonary artery wedge pressure is indicated under these conditions if the patient has compromised cardiac or respiratory function. |
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How should patients be mobilized/placed in bed after surgery?
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Unless contraindicated, patient should be turned from side to side every 30 minutes until conscious, and then hourly for the first 8-12 hours to minimize atelectasis.
Early ambulation is important for reducing venous stasis. Pneumatic stockings can also minimize venous stasis. Upright position increases diaphragmatic excursion |
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What are the three phases of recovery from major surgery?
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1) An immediate or postanesthetic phase
2) An intermediate phase, encompassing the hospitalization period 3) A convalescent phase |
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Why do you co-administer atropine and neostigmine (or other acetylcholinesterase inhibitor)?
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Neostigmine is used to increase acetylcholine in the synaptic cleft at Nicotinic receptors. It also increases it as Muscarinic receptors, which is not desired (DUMBBELSS) so an anti-muscarinic drug is administered to prevent those effects and leave only the nicotinic activation.
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How does neostigmine reverse curare-class non-depolarizing ganglion blockers?
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the curares bind and inhibit nicotinic acetylcholine receptors. Curare is a competitive antagonist, so increasing the amount of acetylcholine in the synaptic cleft will decrease the inhibitory effects of curare.
Neostigmine increases acetylcholine in the cleft by acting as an acetylcholinesterase inhibitor, preventing degradation of acetylcholine. |
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What measurement is most useful in determining correct placement of an endotracheal tube?
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PCO2
Can also observe clavicular rise and fall (not abdominal - can be misleading) |
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When should a nasogastric tube be used?
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Post-esophageal or gastric resection
In patients with marked ileus or very low level of consciousness (prevent aspiration) Patients who manifest acute gastric distention or vomiting postoperatively |
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How long should nasogastric tubes be in place?
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Should be connected to low intermittent suction and irrigated frequently
Leave in place 2-3 days or until there is evidence that normal peristalsis has returned (e.g. return of appetite, audible peristalsis, passage of flatus) |
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Why should gastrostomy and jejunostomy tubes not be removed prior to the third postoperative week?
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Firm adhesions should be allowed to develop between the viscera and parietal peritoneum
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What are the components of whole blood?
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450-500mL of donor blood with RBCs, plasma, clotting factors (reduced V, VIII), and anticoagulant. Platelets and granulocytes are not functional.
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What are the components of an RBC transfusion?
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RBCs are centrifuged and removed, supplemented with 100mL of adenine-containing red cell nutrient solution and the hematocrit is 55-60% - volume 300-350mL. RBCs collected in CPDA-1 anticoagulant have a hematocrit of 65-80% and storage volume of 250-300mL.
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What are typical transvusion triggers for asymptomatic patients? Symptomatic patients with cardiac, pulmonary or cerebrovascular disease?
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7g/dL for asymptomatic stable patients
Higher levels for cardiac, pulmonary, cerebrovascular symptomatic patients. |
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How much should a single unit infusion of RBCs increase hemoglobin and hematocrit in a nonbleeding 70kg recipient?
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Increase hemoglobin by 1 g/dL
Hematocrit by 3% |
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What are washed RBCs?
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RBCs are washed with saline to remove 98% of plasma proteins and resuspended in about 180mL of saline, approximate hematocrit is 75%.
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When are washed RBCs used?
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In patients with recurrent or severe allergic reactions, also patients with severe IgA deficiency who test positive for anti-IgA antibodies
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When should you give Leukocyte-Reduced RBCs?
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In patients who experience recurrent febrile nonhemolytic transfusion reactions to RBCs or platelets. Prophylactic use in patients with long-term transfusion needs decreases the likelihood of HLA alloimmunization and protects from immune platelet refractoriness and recurrent FNHTRs. ALso decreases risk of transmission of CMV in immunosuppressed CMV-seronegative patients.
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When do you use irradiated RBCs?
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RBCs irradiated by 25 Gy are used in patients at risk for transfusion-associated graft vs host disease (TA-GVHD) - inculding patients with congenital severe immunodeficiency, hematological malignancy receiving intensive chemoradiotherapy, Hodgkin and Non-Hodgkin lymphoma, some solid tumors (neuroblastoma, sarcoma), peripheral blood stem cell and marrow transplants, or recipients of fludarabine-based chemotherapy and those receiving directed donations from blood relatives or HLA-matched platelets.
Leukoreduction is NOT an acceptable substitute |
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What are frozen-deglycerolized RBCs and why are they used?
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Frozen in glycerol, washed extensively in normal saline to remove the cryoprotectant and then resuspended ni saline at a hematocrit of about 75%. More than 99.9% of plasma is removed and few leukocytes remain in the product.
Can be given to patients who are alloimmunized to multiple antigens, antibodies against high-frequency antigens, severe IgA deficiency |
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When do you give a person platelets (often random donor platelets RDPs)?
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Thrombocytopenic patients
Patients with congenital or acquired disorders of platelet function Prophylaxis in patients requiring line placement or minor surgery when platelet counts are less than 50,000/uL; major surgery when platelet counts are less than 75,000/uL; ophthalmic, upper airway, or neurisurgical procedures with counts less than 100,000/uL |
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When is it not recommended to administer platelets in a patient with thrombocytopenia?
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Heparin-induced thrombocytopenia
Type IIB von Willebrand Disease Idiopathic thrombocytopenia purpura Thrombotic thrombocytopenia purpura |
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What is fresh frozen plasma and when is it used?
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FFP contains normal levels of all clotting factors, albumin, and fibrinogen.
It is used in patients with deficiencies of multiple clotting factors: coagulopathy of liver disease, DIC, warfarin overdose, massive transfusions, rare disorders of factor deficiencies (V, X, XI, C-1 esterase inhibitor) Only if the INR is > 1.5, or the PT/aPTT are elevated more than 1.5x normal |
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How do you manage patients with liver disease and minimally altered PT/aPTT and nominal bleeding?
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Vitamin K replacement
Same for Warfarin patients |
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What is cryoprecipitate?
When indicated? |
A cold-insoluble precipitate formed when FFP is thawed at 1-6 degrees celsius, then resuspended in 10-15mL of plasma - it contains 150mg or more of fibrinogen, 80IU or more of factor VIII, 40-70% vWF, 20-30% of factor XIII present in typical FFP and 30-60mg fibronectin. Increases fibrinogen.
Indicated for correction of hypofibrinogenemia in diultional coagulopathy and hypofibrinogenemia/dysfibrinogenemias of liver disease and DIC |
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What are granulocyte transfusions? When are they indicated?
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They are collected by leukapheresis from donors stimulated with G-CSF and steroids to mobilize neutrophils from the marrow. Contain 1x10^10 or more granulocytes in 200-300mL plasma
Indicated in severely neutropenic patients (<0.5x10^3/uL) with bacterial sepsis who have not responded to optimum antibiotic therapy after 48-72 hours, provided there is a reasonable expectation of recovery of bone marrow function. |
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Describe the physiology of postoperative pain.
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Pain impulses are transmitted via the splanchnic afferent fibers to the central nervous system, where they initiate spinal, brain stem and cortical reflexes. Spinal responses result from stimulation of neurons in the anterior horn, resulting in skeletal muscle spasm, vasospasm, and GI ileus. Brainstem responses include alterations in ventilation, blood pressure and endocrine function. Cortical responses include voluntary movements and psychologic changes, fear and apprehension. Emotional responses facilitate nociceptive spinal transmission, lower the threshold for pain perception and perpetuate the pain experience.
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What is the most widely used opioid for treatment of postoperative pain?
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Morphine - IV - intermittent or continuous
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Describe the use of Ketorolac for postoperative pain management.
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It is an NSAID with potent analgesic and anti-inflammatory effects. A 30mg dose of Ketorolac produces analgesia comparable to 10mg of morphine. Potential advantage over morphine is the lack of respiratory depression. GI ulceration, impaired coagulation and reduced renal function have not been shown to be a/w short-term perioperative use of Ketorolac.
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What advantage does epidural analgesia have over topical morphine?
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Topical morphine does not depress proprioceptive pathways in the dorsal horn, so epidural opioids produce intense prolonged segmental analgesia with relatively less respiratory depression or sympathetic, motor, or other sensory disturbances. Bladder catheterization is always required.
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What is an intercostal block?
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Pain block following thoracic and abdominal operations - it does not relieve pain entirely but does eliminate muscle spasm induced by cutaneous pain and helps to restore respiratory function. Does not carry the risk of hypotension, as does continuous epidural analgesia. Produces analgesia for periods of 3-12 hours. Disadvantage is the risk of pneumothorax and need for repeated injections. Catheter placement with continuous infusion (Bupivacaine) is useful.
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