Anesthesia and other immunity diseases Flashcards
What are the signs and symptoms of TB?
- non-productive cough (74%)
- weight loss (71%)
- fever and night sweats (30%)
- malaise (30%)
- hemoptysis and chest pain (19%)
What are the most common side effects of the drugs used to treat TB?
(Isoniazid, rifampin, pyrazinamide)
(ethambutol)
- Isoniazid, rifampin, pyrazinamide
- hepatoxicity, peripheral neurotoxicity, renal toxicity, GI upset, drug interactions
- Ethambutol
- ocular neuritis (high risk for blindness in prone position)
Can a patient with TB have elective surgery? Why not?
No, not until the patient is no longer contagious (3 negative sputum smears, improving symptoms and chest radiograph)
TB is highly contagious. CRNA is at higher riske because of the things we do that cause coughing:
intubation, suctioning, mechanical ventilation, bronchoscopy
How can we minimize the spread of TB when a patient must have emergency surgery?
(9)
- Pt must wear a tight fitting N-95 mask when outside of isolation room
- ORs are never negative pressure, try to keep pt in negative pressure room as long as possible
- Use an OR physically separated from other areas and schedule case when there are less people around
- Keep OR doors shut
- dedicated anesthesia machine if possible
- high efficiency particulate filter in the pt circuit and bacterial filter on exhalation limb
- Providers should wear N95
- Need iso room in PACU
- Close OR until 99.9% of the air has turned over
General information about prophylactic antibiotics
- Goal = to prevent SSI
- Should give antibiotic within 1 hr BEFORE incision
- Repeat dose if surgery > 4 hrs
- consider larger dose in obese patients
- tailor antibiotic to resistance patterns in local area and to surgical procedure (surgeon orders)
What other things can you do in the OR to prevent SSI besides abx?
avoid hypothermia, hypocarbia, hyperglycemia, blood transfusions and hypoxia to prevent infection
What recent changes have been made to the Endocarditis prophylaxis guidelines?
- No longer indicated to give two antibiotics just because somebody has mitral valve prolapse
- Should receive intra-op abx if they have:
- artificial heart valves
- prior history of endocarditis
- some specific congenital cardiac malformations
- usually with an unrepaired cyanotic component
- hypertrophic cardiomyopathy
- cardiac transplant
What surgical procedures require endocarditis prophylaxis in high risk patients?
- Dental or oral if mucosa is likely to be perforated
- invasive procedures of respiratory tract if mucosa is likely to be perforated
- T&A, abscess drainage
- procedure involving infection of GI/GU tract or skin/musculoskeletal tissue
- cardiac surgery
- hepatobiliary procedures with high risk of bacteremia
What antibiotics could you use for a Dental/Oral surgery for a pt at high risk of endocarditis?
- Ampicillin 2 g IV
- Cefazolin 1 g IV
- Ceftriaxone 1 g IV
- Clindamycin 600 mg IV
- **Note: you almost always give Cefazolin to every patient to prevent SSI, so all the high risk patients are almost always covered anyway
What is a chemical mediated allergy?
- there is no antigen or antibody
- a medication will directly stimulate mast cells to degranulate (and release histamine)
- an anaphalctoid or non-immune reaction
What usually determines the magnitude of histamine release in an anaphylactoid response?
Will it cause hypotension?
How can you prevent it?
- total dose of drug and rate of infusion
- Basophils release large amounts of histamine in response to muscle relaxants, opioids, and protamine
- hypotension unlikely unless histamine concentration doubles
- prophylaxis in pts with history
- corticosteroid
- H1 and H2 receptor antagonist
What is the difference between anaphylactoid and anaphylaxis?
- anaphylactoid is not an immune response. Achemical of some kind direcly activates the mast cells to degranulate
- can be pre-treated by giving decadron for H1 and H2 inhibitors
- anaphylaxis requires an antigen and antibody
- usually no response the first time somebody is exposed to whatever it is the body deems “foreign”
- they then make antibodies to it
- upon next exposure, with all the antibodies made, the person has a very quick response
Why might somebody have an anaphylactic response to an anesthetic they had never received before?
Because many of the anesthetics have chemical groups or compounds (Ex: quanternary ammoniums) that are found in every day products like cosmetics, so they actually have been previously exposed
What are the first signs of anaphylaxis?
Early signs can be missed druing anesthesia, what might you see?
- vasodilation
- vascular leakage
- smooth muscle spasm
- flushing/uticaria
- hypotension
- difficult intubation
- increased PIP
- rapid onset CV collaps (often 1sd sign)
- myocardial ischemia and dysrhythmias
what are late phase anaphylaxis symptoms?
- mucosal edema
- mucus secretion
- leukocyte infiltration
- epithelial damage
- bronchospasm
What are common offenders of anaphylaxis in the OR?
- muscle relaxants
- antibiotics
- anesthetics (except ketamine and benzos)
- radiocontrast dyes
- 1 in 1,000-14,000 (5%)
- 10% fatal
- foods
- insect venoms
What is responsible for 50-60% of intra-operative anaphylaxis?
muscle relaxants
When people are allergic to local anesthetics, what are they usually reacting to?
PAVO, which is created when esters are metabolized
Which induction agents are most likely to cause anaphylaxis?
- succ and ROC
- ROC is similar to VEC and the other aminosteroids, so if they are allergic to one, be hesitant to give them any of the others
What may predispose a pt to having an anaphylactic response?
- history of allergy (asthma, food, drug
- PCN allergy
- 3-4 x more likely to have an allergy to any drug
What antibiotics are most likely to cause anaphylaxis?
- B-lactam
- quinolones (ciprofloxacin)
- sulfonamides
- vanco
- ***observe patients skin at the beginning of a case to note any rashes
When you realize your pt may be experiencing anaphylaxis, what do you do?
- Communicate to rest of care team
- stop administration of the likely agents
- oxygenation (100%)
- elevate legs if possible
- volume infusion-10-25 ml/kg
- fluid loss from vascular space is significant
- colloids preferred to crystalloid
- Epinephrine
If patient in anaphylaxis is resistant to epi, what else would you give?
- Glucagon 1-5 mg bolus + infusion 1-2.5 mg/hr
- increases CAMP
- Norepi 0.05-0.1 mcg/kg/min
- vasopressin 2-10 unit bolus + infusion 0.01-0.1 unit/min
Pediatric and adult dose of epi during anaphylaxis
- Adult
- start with smaller dose 10 mcg - 1 mg
- wait 1-2 minutes and double the dose
- peds
- 1-10 mcg/kg
- wait 1-2 minutes and double the dose
What are some secondary medications that can help with anaphylaxis?
- albuterol
- histamine antagonist (benadryl and ranitidine
- corticosteroids
- takes a while to have effect (6-12 hrs)
- Epi will work better with cortisol
- hydrocortisone 250 mg IV (favored)
- Methylprednisolone 80 mg IV
What should you consider when providing anesthesia for a septic patient?
- Hemodynamic statis will guide your management
- Pre-op focus: ABG, VS, UOP, mental status, pressors
- need large bore IV access- at least two!
- Ensure PRBCs are IN the fridge
- figure out what kind of monitors you will want
- a-line, CVP, TEE if available
- Maintain ICU infusions (if ok with hosp policy)
- have nor-epi primed and ready
How can you optimize a spetic patient if the surgery cannot be postponed?
- normal temp
- normal glucose
- MAP > 65
- CVP 8-12
- UOP adequate
- normalize pH
- use plasmalite or normosol, closer to normal pH than LR
- mixed venous O2 sats > 70%
- lower TV 6-8 ml/kg
- PIP < 30 cm H2O
- Hgb 7-9 g/dl
- prevent additional infection
Flow chart for care of the Septic patient
What medication plan/goals for anesthia in a septic patient?
- leave ICU medication running if ok with hospital policy
- Induction
- try to maintain SVR but prevent recall
- 1/2 MAC if they tolerate
- avoid succ if they have been sick for a while
- maintenance
- vasopressors
- hydrocortisone for unresponsive shock
- improve response to catecholamines
Can a septic patient have an epidural?
NO! The risk of infection is too great.
