Wednesday, July 31, 2013

1. Gemcitabine is especially toxic to the bone marrow.
2. The most dangerous and dreaded side effect of Avastin is bowel perforation. It can even form enterocutaneous fistulas (ECF). Most insurance companies pay for it, even though it doesn't have FDA approval for a number of the purposes for which it is used.
3. Octreotide significantly shortens time to healing of ECFs in RCTs (26-27 days to 16-17), but it doesn't make a difference in mortality. http://www.ncbi.nlm.nih.gov/pubmed/22885696 Loading dose: 50-100 ug subQ q8 hours.
4. The presence of an enterocutaneous fistula is usually associated with a phase of dense adhesions, termed “obliterative peritonitis,” making early surgery a hazardous undertaking. Obliterative peritonitis may resolve as early as six weeks in a closed abdomen, but may persist for 6 to 12 months in a patient with an open abdomen. (uptodate)
5. The decision of when to perform an ostomy on someone during a debulking surgery is a function of how easy/possible it would be to rejoin the bowel (i.e. not too much necrosis, etc)
6. Major trials comparing CDT to surgery:
--TOPAS (n=544, randomized to surgery or urokinase. amputation free survival same at 1 year, fewer major surgeries but worse bleeding complications in CDT group)
--STILE (n=393, randomized to surgery, alteplase, urokinase). Equivalent 30 day death/amputation rate, more bleeding with CDT (esp lower fibrinogen/longer PTT; risk of intracranial bleed 1-2%). Highest risk patients (diabetes, infrapopliteal clot, critical ischemia) had a better 1 year survival than surgery (32 vs 7%). CDT is better for acute ischemia, surgery better for chronic. Alteplase lyses faster than urokinase; same efficacy.
7. Urokinase was originally discovered in the urine; it is synthesized by (among many things, probably) kidney tubular epithelial cells. tPA is found on endothelial cells; it is a serine protease, and not only does it cleave plasminogen to plasmin, it can cleave extracellular matrix proteins and aid in the metastasis of tumor cells. In fact, certain aggressive tumors have upregulated tPA expression. Be wary of doing something like a pelvic cancer biopsy in someone undergoing tPA therapy. If you seed the peritoneum during the biopsy, the tPA might make things worse.
8. In OB, 38 degrees C is a fever. Other places use 38.3-38.6. Lower your threshold for anyone who may be neutropenic or otherwise immunocompromised.
9. Everyone who is on opiates, consider a bowel regimen. A good one is pericolase BID and milk of mag daily.
10. Ask during a post-chemo checkup: hearing, eyesight, swallowing, GI (d/c/n/v), GU (bleeding/dysuria/difficulty urinating), CV/pulm (SOB, CP, leg edema/pain, palp). Check hands, feet, nails.

Tuesday, July 30, 2013

1. To relax the bowels and let them heal after injury, make someone NPO, put in an NG tube to suction the stomach and give octreotide.
2. The anterior compartment is the most common common compartment affected in compartment syndrome because it is the smallest. It contains the anterior tibial artery and the deep peroneal nerve.
3. Catheter directed thrombolysis (CDT) with tPA results in less hemorraghic morbidity and less incidence of post-thrombosis syndrome (venous valve failure) compared to systemic tPA.
4. GI bleeding is a side effect of tPA. So hypothetically, if you see a lot of melena from your pt, their hct could have been crashing from 30 to 15 in a few hours, and they could code on the operating table in front of you, twice, and then require 8 units of blood in the ICU and end up with acute renal failure. Hypothetically speaking, of course.
5. CDT is an expensive, invasive procedure, usually reserved for arterial clots. Venous clots are usually managed with lovenox, unless it's in the IVC or causing ischemic symptoms.
6. Theoretically, CDT could result in the showering pieces of clot downstream; in the very least, there is tPA flowing with it downstream so it should break it up. Theoretically, this could result in further ischemia in downstream arteries (or in the case of venous clots, in iatrogenic PEs)
7. If someone has had a large ischemic injury and their pee is brown, think rhabdomyolysis.
8. Lovenox has better outcomes than coumadin in cancer patients on DVT prophylaxis. Something about anti-inflammatory properties.
9. Technique for CDT: put in wire -> advance-> put catheter over it-> inject dye/angiogram-> advance wire->advance catether-> repeat angiograms until you reach the clot -> put guidewire through the clot -> put catheter with holes through clot -> drip tPA through this catheter, max 36-48 hours.
10. Taxols and platinum agents are the cornerstones of treatment for ovarian cancer. So much that if someone is in ESRD and has ovarian cancer, you give them platinum agents anyways and dialyze it off afterwards. Taxotere (doxetaxel) has less peripheral neuropathy than taxol, which is important in young patients that you don't want to condemn to many decades of neuropathic symptoms. Unfortunately, it hits the hematocrit harder than other chemo agents, and it also causes thickening/detachment of nails, and darkening of palms/soles/blood vessels. It can also cause sudden onset severe edema, central and peripheral; treat with dexamethasone the day before, day of, and day after chemo to ameliorate/prevent this edema. On the flipside, Taxol has fewer of the systemic symptoms but causes bad peripheral neuropathy. In an older patient who already has neuropathy from diabetes and can't take the hematocrit drop, taxol may be a better choice.

Monday, July 29, 2013

1. If an old person comes in with nausea/vomiting that occurs right after eating and altered mental status, consider dehydration secondary to bowel obstruction.
2. Surgery is contraindicated in people with extensive PEs, both because of anti coagulation concerns as well as cardio-pulmonary function concerns.
3. Liver resections are very, very bloody.
4. Daptomycin covers VRE and MRSA. Enterococcus faecalis is sometimes susceptible to ampicillin.
5. There are at least three ways to remove a large DVT:
  1. Clamp the vessel, cut it open, pull out the clot. It's fast and efficient, but causes endothelial damage that often results in the clot re-forming. 
  2. Put in a balloon catheter, inflate it distal to the clot, drag out the clot. This procedure is still done, but also causes some endothelial damage. 
  3. Put in a catheter, dump TPA on the clot to break it apart. Keep the catheter in, run TPA continuously (+/- heparin to prevent more clots) and then go to the OR for daily angiograms to monitor the progress of the clot and/or dump more TPA on it. 
6. Hypercoagulable state + pleural effusion + ascites + pelvic mass -> think ovarian cancer.
7. The formula for maintenance fluids for someone that weighs over 20 kg is weight in kilos + 40= ml/hour infusion.
8. Differential for sinus tachycardia:
  1. psychological: pain, anxiety, panic 
  2. blood: anemia, dehydration, DVT, decreased peripheral resistance (vasodilation, AV fistulas, end organ failure). Intravascular fluid depletion (look for falling blood counts), third spacing. (Look for edema, effusions, ascites.)
  3. pulmonary: hypoxia from PE/chronic lung dx, 
  4. cardiac: SVT, arrhythmia, MI 
  5. infection/fever
  6. toxic: stimulant drugs, withdrawal from depressants, mercury
  7. endocrine: pheochromocytoma, hyperthyroid.
9. If someone comes in with a fever and an obvious wound infection, and you drain/debride the infection, and they are still spiking fevers after 24 hours of powerful broad-spectrum antibiotics, look for another source of infection.
10.  If you're going to give lasix to treat volume overload or edema, watch out for the patient's kidneys.

Friday, July 26, 2013

1. If you suspect abruption, get these on mom: type&screen, coagulation studies, IV access, continuous monitoring of her vitals (esp HR and BP)
2. Abruption  management. If either mom or fetus is unstable, deliver at any age. If mom and fetus are stable, deliver after 36 weeks.
3. IM progesterone to prevent preterm labor, vaginal progesterone to prevent cervical incompentence.
4. Cerclage: place between 12-14 weeks (wait until risk of miscarriage is low). No later than 20 (if fetus is viable, cerclage needle might theoretically go through amniotic sac).
5. Indications for cerclage:
  • history (2+ 2nd trim losses, 3+ preterm births & risk factors), 
  • ultrasound (hx of spontaenous birth + cervix <25 mm @24 weeks),
  • physical exam (>4 cm dilation at <24 weeks)
6. Trans-abdominal cerclage: higher up on the cervix, possibly more effective. Permanent-- c-section required.
7. Sickle cell drugs CI in pregnancy: hydroxyurea, iron chelators. Need 5 mg of folate a day (normal: 0.4-1 mg). Also, many are iron-overloaded, so avoid iron in prenatal vitamins. 
8. Triggers for pain crises/acute chest: dehydration, infection, acidosis, hypoxia, cold. Higher risk for pre-eclampsia. Screen aggressively for that and for UTI. 
9. Alloimmunity more common in SCA patients. If possible, try to match not only for ABO Rh antigens, also match for C, E, and Kell antigens. (duffy dies, kell kills, lewy lives)
10. Gastroischesis: usually right of midline, due to vascular incident, not covered by peritoneum. Omphalocele: @ midline.