Looks like we got ourselves a Bleeder

 

The Post-Partum Hemorrhage: Notes from Anesthesiology Core Review Part Two Advanced Exam

most common cause of blood loss in OB practice
leading cause of fetal and maternal M&M globally
definition: bleeding w/in 6wks of delivery
->500ml for vaginal, >1000ml for c/s
-decrease of 10% in hct from admission
-often underestimated!
Uterine blood flow = 700ml/min
-get good access fast
Uterine Atony
2-5% of all deliversies
cause of >90% of pp hemorrhage
results from failure of uterus to contract
risk factors:
-multiparity
-macrosomia
-polyhydramnios
-long labor (+oxytocin)
-chorioamnionitis
-placenta: retained, accreta, increta, percreta
-poor perfused myometrium
-drugs: inhalationals, oxytocin, tocolytics
Management of Atony
Oxytocin to contract uterus
-rapid: hypotension, decrease svr, tachy (rare card collapse), chest pain, ischemia, anaphylaxis
-ECG changes resolve spontaneously
-similar to ADH, so watch for water intox. so never give with hypotonic solution!
Ergot Alkaloids
-0.4mg – methylergonovine IM only
-10 minutes to action, lasts 3-6hrs
-vasoconstrictive -> HTN, avoid with pre-eclempsia.eclampsia
-if given IV -> intense vasoconstric -> siezures, CVA, retinal detach – MI
-Common ade: nausea vomiting
-2 dose then move on
Prostaglandins
-increase calcium -> myosin kinase

-carboprost = 15-methyl prostaglandin f2alpha given 260ucg IM
-increase force/interval of contraction
-also don’t give IV
-side effects: diarrhea, HTN, fever, flush, tachy
-bronchospasm, pulmonary vasoconstriction – so careful with asthmatics
-Misoprostol (prostaglandin E1) oral, rectal intrauterine also effective, side effect hypothermia
Retained Placenta

1-3 in 100 deliveries

result: uterus unable to fully contract –> bleeding

Need for uterine relaxation to explore and fix

GA -> 1MAC+ Inhalational

IV or sublingual Nitorglycerin
-100 ug works in 30-45seconds
-60-90 seconds return to baseline, may need redosing
-tx hypotension with phenylephrine

The Abnormal Placenta

Normal interface between placenta and uterus : Decidua basalis
When that’s missing -> uteri gets implanted
Placenta Accreta = ON myometrium
Placenta Increta = IN myometrium
Placenta Perceta = through and to other organs!
Bleeding serious complication and common
1:2000 births have accreta
-prior c/s
-placenta previa
-more c/s higher risk

If known beforehand, discuss plan about possible hysterectomy
-this can incur massive blood loss
-cell saver, think general anesthesia, secure airway, arterial line
-also consider prophylactic internal iliac balloon catheters in IR preop

Genital Trauma

lacerations of cervix, vagina, perinuem most common injuries of childbirth
if continued hypotension: think retriperitoneal hematoma!
-CT or MRI, tx with ex lap

help along repair with IV meds, neuraxial continuation, or nitrous oxide, think low dose ketamine too

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PICC vs central line: not that clear cut 

From Patient Safety Solutions: http://www.patientsafetysolutions.com/docs/January_21_2014_The_PICC_Myth.htm

PICC lines (peripherally inserted central catheter)  are often seen as a lower risk alternative to central lines for patients with difficulty iv access, however this is a myth and piccs are not without risk including:

  • Higher risk of upper extremity dvt (2.55 or and account for 35% of all ue dvt)
  • Similar risk of infection!  Meta analysis and systematic reviews show no sig diff in clabsi! 
  • Other complications include thrombophlebitis,and dysfx and malpositioning greater for PICC than central line 

These concerns prompted the ABIM choosing wisely campaign to include piccs on their list of treatments to question:

Don’t place, or leave in place, peripherally inserted central catheters for patient or provider convenience.

Peripherally inserted central catheters (or “PICCs”) are commonly used devices in contemporary medical practice that are associated with two costly and potentially lethal health care-acquired complications: central-line associated bloodstream infection (CLABSI) and venous thromboembolism (VTE). Given the clinical and economic consequences of these complications, placement of PICCs should be limited to acceptable indications (long-term intravenous antibiotics, total parenteral nutrition, chemotherapy and frequent blood draws). PICCs should be promptly removed when acceptable indications for their use ends.

So next time someone recommends a PICC over a central line, think about the indications and necessity! 

Lactated Ringer’s: All Good, All the time

Great post from emcrit.org on the myths of using LR in renal failure, specifically pointing out the physiology then backing it up with clinical trials:

the primary reason that this myth is wrong has to do with potassium shifting between the cells and the extracellular fluid.   About 98% of the potassium in the body is present inside the cells, with an intracellular potassium concentration of ~140 mEq/L.   Therefore, even a tiny shift of potassium out of the cellular compartment will have a major effect on extracellular potassium levels.   NS causes a non-anion gap metabolic acidosis, which shifts potassium out of cells, thereby increasing the potassium level.   On the other hand, LR does not cause an acidosis, but instead may have a mild alkalinizing effect given that it contains the equivalent of 28 mEq/L of bicarbonate.   Potassium shifts have a greater effect on the serum potassium than the actual concentration of potassium in the infused solution.

The trials were quite excellent, with one comparing LR vs NS use in patients undergoing renal transplant.. the trial was actually stopped early as the LR patients were doing so much better than the NS patients:

 

They performed a prospective, randomized, double-blind controlled trial of NS versus LR among 52 patients undergoing renal transplant surgery.   The mean change in serum potassium during the procedure was +0.5 mEq/L in the NS group compared to -0.5 mEq/L in the LR group (p < 0.001; figure below).   Patients in the NS group also had lower pH levels following surgery.     
0

 

More detailed explanation at EMCRIT ( http://emcrit.org/pulmcrit/myth-busting-lactated-ringers-is-safe-in-hyperkalemia-and-is-superior-to-ns/ )

 

Another common myth associated with LR has to do with blood transfusions, according to this the calcium in LR can cause clots by overwhelming the chelating capability of the citrate in stored blood. But as a trial from 1998 demonstrated, this is also false and blood banks should recommend using LR for its advantages during trauma resuscitation vs. NS.  See: http://www.aafp.org/afp/1998/0801/p502.html

So next time someone tells you to use NS for whatever reason in the OR or elsewhere, let them know LR is the best!