Immune disorders Flashcards
HIV Systemic Effects
GI, Renal, Endocrine
- diarrhea, proctitis, GI bleeding, cholecystitis, anorexia, N&V, dysphagia (Candida albicans,CMV), esophagitis, Hepatitis B and C
- Nephropathy, ATN, nephrotic syndrome
- Adrenal insufficiency (end stages)
- Glucose intolerance (HAART)
review preop labs for electrolyte abnormalities, hypoalbuminemia
HIV Systemic effects
Hematology
- drug toxicity/bone marrow suppression
- Leukopenia, lymphopenia, thrombocytopenia, anemia
check CBC & coags
HIV Systemic Effects
Neurologic
CNS = HIV “reservoir”
- Sensory neuropathy: numbness, tingling, painful dysesthesias and paresthesias
- Encephalopathy or AIDS dementia complex: cognitive, motor, and behavioral changes
- Opportunistic infections/ malignancies
- HAART related cerebral vascular disease
perform good baseline neuro exam, consider inflamm demyelinization sim to MS pts, weigh risks /benefits of regional if pt has severe neuropathy
HIV
General Anesthesia
- Extensive use of volatile agents has refuted earlier caution against use
- Monitor closely for myocardial depression r/t anesthetic agents
- Biggest factor to consider = underlying pulmonary disease (avoid intubation if extensive)
- Carefully titrate anesthetics considering co-existing anemia, autonomic neuropathy, adrenal insufficiency, and upper airway obstruction/difficult airway w/supraglottic Kaposi’s sarcoma
- Be careful with Succinylcholine with peripheral neuropathy, myopathy, spinal cord involvement
- Long term effect of GA and opioid induced immunosuppresion unknown
- Immunosuppression from GA occurs within 15 minutes of induction and persists for 3-11 days. Psychological stress.
HIV
Regional
- Once controversial now routinely used– early concerns about spreading HIV to CSF unfounded
- Use of RA in parturients well studied – no abnormal neurologic, immunologic or infectious complications noted
- Contraindications:
- coagulopathy
- infection at the site of block placement
- focal neurologic lesions w/increased ICP
- Decreases IV opioid requirement (helps avoid issue of decreased IV opioid clearance w/protease inhibitors)
- Infection control, maintain sterile conditions!
- Epidural blood patch can be used to treat PDPH - try other methods 1st
classes HAART therapy
anesthetic drug management
Currently there are 6 Categories
-
Nucleoside reverse transcriptase inhibitors
- Inhibition of CYP 450 system
- zidovudine + corticosteroids = severe myopathy, respiratory muscle dysfunction
-
Protease Inhibitors
- Inhibiton of CYP 450 3A4
-
fentanyl and versed have increased effects
- more sedation, confusion, respiratory depression
- start with low dose and titrate carefully
- fentanyl → clearance decreased by 67%
-
AVOID drugs w/active metabolites →LIFE THREATENING
- Meperidine → toxic metab → normeperedine (seizures)
- Amioderone →arrythmials →E1/2 = 29 days
- Diazepam → prolonged half life
-
Non-nucleoside reverse transcriptase inhibitors
- Delavirdine = Inhibits CYP 450
- (increased sedatives, warfarin, CCB)
-
Nevirapine = INDUCES CYP 540 by 98%
- go through NMB very fast
- Delavirdine = Inhibits CYP 450
- Integrase strand transfer inhibitors → appear well tolerated
-
Chemokine Receptor 5 antaonists and entry inhibitors
- also appear well tlerated
- may interact with the clearance and drug effects
HAART therapy
considerations in anesthesia
- institution of HAART within 6 months of anesthesia & surgery actually ↑ M&M
- Heart therapy effects every system in the body
-
Respiratory → opporunistic respiratory infections
- tracheobronchial great vessel compression and adenopathy (hemoptysis/difficult airway)
-
Cardiac → consider those on HAART as CAD risk (especially protease inhibitors)
- Cerebral vascular disease → stroke
- pericardidtis, pericardial effusions, dialated cardiomyopathy, endocardidits, pulm HTN, thromboembolism
- Development of abdominal aortic aneurism and aortic disection
- 50% have an abnormal ECHO
-
GI →
- N/V/D, proctitis, GI bleed, cholecyctitis, anorexia, dysphagia, candidia, CMV, Hep B & C
- Renal → Nephropathy, ATN, Nephrotic syndrome
-
Endocrine
- Adrenal insufficinecy → Steroids?
- Glucose intolerance (esp. protease inhibitors)
- Hematologic
- Leukopenia, lymphopenia, thrombocytopenia, anemia (CBC, coags)
-
Neurologic
- sensory neuropathies
- encephalopathy or AIDS dimetia complex
-
Respiratory → opporunistic respiratory infections
Ritonavir (Protease inhibitor) & Interactions with Anesthetic Drugs
-
Midazolam: ↑ effects
- sedation, confusion, respiratory depression
- Small carefully titrated IV dosing O.K. (just do it very slowly and carefully- working in very tiny incraments one consents are sighned)
-
Fentanyl: ↑ effects
- sedation, confusion, respiratory depression
- Start with low dose & titrate to pain
-
Avoid (pronounced effects → life threateningàdue to prolonged clearance)
- Meperidine → metabolized to normeperidine → which affects CNS (seizures) even with one dose may end up with a toxic dose
- Amiodarone (arrhythmias) → E½ life = 29 days - may not always think about this with ACLS but is something to keep in the back of your mind
- Diazepam → long ½ life
HIV and Lab results
-
CD4 counts
- low/ominous
- high/encouraging >500-700 mm3
- if low, maybe want them to go and change drug regimen prior to surgery
-
T lymphocyte counts
- low/ominous 200 cells/mg
- Viral load evaluates therapy efficacy but unclear significance to anesthetic outcome – wont tell us how they will do under anesthesia, drugs will still effect all other systems of these patients
- CBC
- BMP
- coagulation studies
- CXR
- EKG+/- ECHO
- PFTs
HIV/AIDS
Preoperative Prepration
- Follow universal precautions (as with all patients)
- Routie sterilization procedures
- Sodium hypochlorite destroys HIV
- Careful reveiw of the progression of the disease process and organ involvement
- What is their durg regimen and side effects?
TB signs and symptoms Review
- Non Productive cough (74%)
- Weight loss (71%)
- Feaver and night sweats (30%)
- Malaise (30%)
- hemoptysis (bloody cough) and chest pain (19%)
TB first line treatment and side effects
Anti TB drugs have decreased mortality by 90%
Isoniazid and Rifampin are the most use combinations
-
Isoniazid
- Hepatotoxicity, possible renal toxicity, drug interactions
- peripheral neurotoxicity
-
Rifampin
- hepatotoxicity, renal toxicity, drug interactions
- GI upset, anemia, thrombocytopenia
-
Pyrazamide
- Hepatotoxicicty
- GI upset, arthralgia
- Ethambutol → occular neuritis
when can a TB patient have an elective surgery
- 3 negative sputum smears
- improving symptoms
- clear chest X-ray
! must meet ALL 3 requirements to go to surgery !
Prophylactic antibiotics in the Normal Patient
- The goal of therapy is prevention of surgical site infection
- They should be given within 1 hr before incision
- consider larger doses in obese pateints
- (2g of ancef instead of 1g)
- Redose if surgery > 4 hrs
- The antibiotic is tailored to resistance patterns
- of the local area
- and to the surgical procedure
besides antibiotics how else do you prevent infections
AVOID:
-
Hypothermia
- Cold pts develop infections at a much higher rate!
- They also bleed more!!!
-
Hypocarbia
- promotes infection causes vasoconstriction which decreases blood flow
- make sure you are not hyperventilating the patient
- Hypoxia
- Hyperoxia (free radical damage)
- Hyperglycemia
-
Blood transfusions
- if you can avoid it is its ideal – they are at higher risk to get an infection