Genitourinary/Toxicology Flashcards
How do you confirm contrast induced renal failure?
- 25% increase in serum creatinine from baseline
- Temporal relationship to contrast (<72hrs ago)
- No other cause
Outliers of AKI:
- It can be linked to strep throat. As much as 6-14 days post pharyngitis, patients can develop HTN and edema.
- Build up of urea makes you itchy.
- Can cause pericardial effusions
Treatment for testicular torsion….
- A hell of a lot of analgesia.
- Twisting them back into place (opening a book)
- Ensure a negative Phren’s test (lifting the teste to take pressure off of the epididymis), fever, gradual onset in order to differentiate from epididymitis/orchid is.
Treatment for hyperkalemia:
- Membrane stability (CaCl2)
- Shift K+ (Beta agonists, sodium bicarbonate, insulin with glucose)
- Eliminate (Lasix, dialysis, kayexalate)
Calculate the osmolar gap:
Subtract the calculated osmolarity from the laboratory osmolarity.
Calculated osmolarity = 2(Na+) + glucose + BUN + EtOH(1.25)
*An osmolarity gap >10 indicates you have a toxic alcohol that the laboratory machine can’t read.
Name the four types of alcohol, their metabolites and if they’re toxic or not.
Isopropyl alcohol -> acetone (no, but still not good)
Ethanol -> acetaldehyde -> acetate (no)
Methanol -> formaldehyde -> formate acid (yes)
Ethylene glycol -> glycoldehyde -> glycolic/oxalic acid (yes)
What is the treatment of methanol and ethylene glycol intoxication?
Fompizole ($1000/shot)
Vodka, or any other EtOH (seriously!)
Cofactors (thiamine, folic acid, magnesium)
Sodium Bicarbonate
Key features of methanol intoxication:
- AGMA
- Osmolar gap >10
- Blindness
- Negative AKI/Calcium oxalate stones
- Treat with EtOH
Key features of ethylene glycol intoxication:
- AGMA
- Osmolar gap > 10
- AKI with calcium oxalate stones
- Negative for blindness
- Treat with EtOH
- Binds to calcium and can cause hypocalcemia and heart failure
Key features of Isopropyl Alcohol intoxication:
- No metabolic acidosis
- Positive Osmolar gap
- May cause gradual AKI/lung damage
Progression of ASA intoxication:
- ASA triggers medulla and causes tachypnea (resp. alk.)
- ASA (acid) causes a metabolic acidosis
- Vomiting causes a metabolic alkalosis
- Respiratory fatigue causes respiratory acidosis
Relationship between osmolar gap and anion gap for methanol and ethylene glycol toxicity
The alcohols causing the osmolar gap will get turned into acids. As the osmolar gap decreases over time, the anion gap will increase.
What is the major bacteria involved in UTIs?
-75% of UTIs are caused by gram-negative bacteria, most often E. Coli.
If you suspect UTI, check for leukocytes and nitrites in urine dip.
Tx with 2g ceftrixone, cipro or piptaz if you need a “bomb.”
GOLDMARK
G - Glycols (ethylene glycol, propylene glycol)
O - Oxoproline (acetaminophen ingestion)
L - L Lactate
D - D Lactate (short bowel, propylene glycol)
M - Methanol
A - ASA
R - Renal failure
K - Ketoacidosis (DKA, starvation, alcoholism)
Uremia can lead to fluid shifting and pericardial effusions. What is one thing you must consider before intubating a patient with a tamponade?
They are very preload dependant and PPV can quickly turn them into a PEA.
What’s a double gap acidosis?
Both anion gap and osmolar gap
DDx for Cl- sensitive Metabolic Alkalosis
NG suction
Vomitting
Diuretics (Cl- pissed out, HCO3- retained instead)
Massive blood transfusion
DDx for non-anion gap metabolic acidosis aka hyperchloremic acidosis
GI (diarrhea, pancreatic fistula)
Renal (RTA I, II, IV)
Too much N/S
DDx for AGMA (KULT)
Ketones (starvation, DKA, alcoholism)
Uraemia
Lactate (L and D lactate)
Toxins (ASA, methanol, ethylene glycol, toluene)
What circumstances must exist to diagnose a Hyperchloremic acidosis?
Urine pH > 5.5
Plasma HCO3- < 15
Anion Gap 8-12
What is the tipping point for intubating a metabolic acidosis?
When there is a superimposed respiratory acidosis as well.
What three features drive the pH?
CO2 production (basilar metabolism) Albumin (liver function, protein intake) Strong Ion Difference (Na+, Cl-)
DDx for respiratory alkalosis
- Head injury
- CVA
- Salicylic toxicity
- PE
- Early pneumonia
Broad considerations for dealing with a suspected toxicological overdose:
- Decontaminate/PPE
- Don’t assume it’s just an OD. Check for bleeds/infections/labs
- 95% of work is supportive care
Key features of serotonin syndrome:
- Altered LOC
- Tremor, hyper-reflexia, clonus, rigidity, nystagmus
- Autonomic instability
- QTc prolongation
-Doesn’t have to be from an SSRI (TCA, sympathomimetic, cough syrup, tramadol, merpedine, LSD, etc…)
Is phenytoin an appropriate agent for treating toxicology related seizures?
No. Treat with benzos/barbs/propofol/Mg++ instead.
What is an LD50/TD50, the ED50 and the therapeutic index?
LD50/ED50: The dose required to kill/toxic to 50% of patients
ED50: The effective dose for 50% of patients
The therapeutic index is calculated by dividing the ED50 from the LD50. The larger the TI, the safer the drug. Ie, if the the LD50 is 100 and the ED50 is 1, you got a lot of wiggle room!
How do some drugs switch from first order kinetics to zero order kinetics?
In overdose situations, if all of the metabolic enzymes get saturated, the drug must be eliminated more slowly by the renal system in a zero order fashion. ASA is an example of one drug that does this.
How is N-acetyl-para-aminophel (APAP) metabolized and eliminated?
It is metabolized by four different pathways in the liver. One of these pathways produces a toxic metabolite (NAPQI) that is metabolized by glutathione. If glutathione is used up, NAPQI will destroy hepatocytes. If the kidneys survive this process, that’s where APAP metabolites are eliminated… If…
How do you treat APAP ingestion?
N-acetylcysteine (NAC).
It must be given in first 8 hours following ingestion in order to preserve the liver. Patients are often asymptomatic up to two days following ingestion, but AST levels will rise after 8 hours and APAP detectable in serum after 4 hours. Use Rumack-Matthews line to guide Tx.
Can the liver regenerate following an APAP intoxication?
Yes, it will fully regenerate. The body might be fucked from the encephalopathy/coagulopathy/cerebral edema/ARDS/sepsis that the transient liver failure caused, though.
What common preparations can salicylitic acid be found in?
- ASA
- Oil of Wintergreen
- Tiger Balm
- Ben Gay
What are some system effects of salicylate poisoning?
- Acts on medulla and causes respiratory alkalosis
- Interferes with cellular metabolism and renal elimination of H+ and causes AGMA
- Stimulates vomiting which leads to metabolic alkalosis
- Pulmonary edema, cerebral edema and hypokalemia.
- Patient’s become obtruded/tired which leads to respiratory acidosis
How is respiratory alkalosis actually a benefit to ASA toxicity?
A higher pH keeps the salicylate acid neutralized so it can’t cross the BBB barrier. If the body’s pH goes down, ASA can cross the BBB and cause CNS dysfunction and cerebral edema.
Treatment considerations for Salicylate toxicity
- IV fluids to treat fluid loss (hypervent, hyperthermia, vomit).
- Correct hypoK+ since you won’t be able to alkalinize the urine otherwise. Use PO and/or high dose IV (150mL/hr of 40mEq).
- NaHCO3 to alkalinize urine and keep pH high (target pH 7.5).
When making a sodium bicarbonate infusion, what do you use?
- Draw out 150cc of D5W from a 1L bag
- Put 3 amps of NaHCO3 in to replace it
- Standard infusion rate = 250mL/hr
-If you mix it in NaCl, it can create a hypertonic solution from all the sodium.