Quick Notes on TRALI

Rare (0.04 to 0.1% of transfused patients) but fatal complication of transfusion

Plasma components and platelet concentrates historically highest risk, however mitigation strategies have reduced this. Now largest # TRALI deaths from PRBCs, see chart:

FY09:FFP:2;RBC:6;FP24:1;Platelets Pheresis:2;Pooled Platelets:0;Multiple Products:2
FDA: Incidence of TRALI Mortality

Risks

blood component
-plamsa / whole blood from Females
– increased HLA Class II ab with specificity for HLA antigen
-increased anti-HNA Ab
-NOT RBC storage duration

Patient
-liver transplant surgery
-chronic alcohol abuse
-shock
-high peak airway pressures during ventilation
-smokers
-high IL-8 levels
-positive fluid balance

References:

UpToDate: TRALI (last update July 2015)

http://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/ReportaProblem/TransfusionDonationFatalities/ucm391574.htm

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Renal Tubular Acidosis

From: http://www.anaesthesiamcq.com/AcidBaseBook/ab8_5.php

The table below provides a useful summary of some of the key points in differentiating the types of renal tubular acidosis.

Comparison of Major Types of RTA

 

 Type 1

 Type 2

 Type 4

Hyperchloraemic acidosis

 Yes

 Yes

 Yes

Minimum Urine pH

 >5.5

 <5.5 (but usually >5.5 before the acidosis becomes established)

 <5.5

Plasma potassium 

Low-normal

 Low-normal

 High

Renal stones

 Yes

 No

 No

Defect

Reduced H+excretion in distal tubule

Impaired HCO3reabsorption in proximal tubule

Impaired cation exchange in distal tubule

Mannitol

Non-reabsorbable sugar -> osmotic diuretic

inhibits water reabsportion in proximal convuluted tubule (mainly), as well as thing descending loop and collecting ducts

Water loss>>electrolyte loss

Clinical uses:

  • early oliguria
  • early brain edema
  • postischemic acute renal failure
  • Neurosurgical anesthesia for good operating conditions

Retention of mannitol –> further volume expansion –> pulmonary edema in CHF patients.

Half life 100 minutes, with 15 minute onset to ICP reduction.

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Intra-operative Use

I/O use for rapid reduction of brain volume.

Dose = 0.25g/kg (some evidence this works but doesn’t last as long) to infusion of 100g for all. 1g/kg also used.

Infusion always, if given too fast –> hyperosmolarity –> vasodilatory effect –> brain engorgement –> increase ICP

Concerns regarding entering the parenchyma, or whether it is effective only if BBB is preserved, make some reluctant to use – best to give a test dose. If it decreases ICP / improves surgical field, then repeat.

Theoretical ‘acceptable’ upper limit of osmolarity 320 mOsm/L, but evidence is “soft” and incrimental doses of 12.5g used until no longer see a clinical response.

From Miller’s Anesthesia 2015 ch70, Anesthesia for Neurosurgery; and Pharmacology and Physiology for Anesthesia: Foundations and Clinical Application 2013.

 

Pediatric Anesthesia: 4-2-1 Revisited

In 1957, Holliday and Segar found daily fluid reqs depend on metabolic demand. They derived the original maintenance fluid therapy equation (Holliday M.A., and Segar W.E.: The maintenance need for water in parenteral fluid therapy. Pediatrics 1957; 19: pp. 823-832), the so called 4-2-1 rule. As follows:

Hourly fluid requirements:
First 10kg of child weight x 4ml/kg
Second 10kg (10-20kg) x2ml/kg
every kg above this is 1ml/kg

Not included are fluid deficits, third-spacing, hypo/hyperthermia, or increased metabolic demands.

However, children that are acutely ill or with significant cardiac and renal dysfunction this formula doesn’t work as well. More recent literature recommends:

20-40ml/kg of balanced solution during anesthesia over 2-4hrs
Holliday et al. 2007

Miller also recommends reducing post-operative fluids to 2,1,0.5 rule (following same weights). Then after 12 hrs if patient cannot take PO, convert to 4-2-1 with D5 1/2NS.

If concern for Hypoglycemia, add D5 1/2NS at maintenance rate as piggyback to intra-op fluids. For patients on TPN, Miller recommends remaining on TPN but reducing rate by 1/3 to 40% and check glucose levels intraop.

Remember, mitochondrial disease children cannot get lactate containing solutions! Use glucose solutions instead, even up to 10%.

Newborn Considerations

Reduced fluid requirements in first days of life, as high ECF.

  • Day 1: 70ml/kg
  • Day 3: 80ml/kg
  • Day 5: 90ml/kg
  • Day 7: 120ml/kg

Preemies are slightly higher, and remember to give 10% glucose to prevent hypoglycemia for all newborns. Try not to bolus glucose and monitor BG.

Peri-Operative Management of Anti-thrombotics (antiplatelets, anticoagulants)

Adapted from Management of Antithrombotic Therapy in Patients Undergoing Invasive Procedures Todd H. Baron, M.D., Patrick S. Kamath, M.D., and Robert D. McBane, M.D. N Engl J Med 2013; 368:2113-2124

Agent MOA Peri-Procedural Management Labs Reversal
Anticoagulants
Warfarin inhibits Vit K dependent factors: 2,7,9,10 and Protein C and S hold 1-8 days, until INR <=1.5, this happens within 5 days for 93% of patients INR Oral or IV Vitamin K, +/- FFP, prothrombin complex concentrate (PCC) 4 factor preferred over 3
Unfractionated Heparin Antithrombin activation (inhibits 2a, 9a, 10x, 11a, 12a) IV 2-6hrs depending on dose, SubQ 12-24 hrs depend. on dose aPTT Protamine sulfate
LMW Heparins (enoxaparin = lovenox; dalteparin (fragmin)) antithrombin activation (inhibits Xa, some 2a) 24hr None – perhaps anti-Xa Ab Protamine (only partial)

Also note CKD>Stage 4 impairs elimination

Fondaparinux Antithrombin activation (Xa inhibitor) 36-48hr none, consider fondaparinux-specific anti-Xa assays none, perhaps F7a in high risk major bleed
Dabigatran (pradaxa; argatroban maybe same) direct thrombin inhibitor 1-2 days if crcl>50, otherwise 3-5days aPTT or thrombin time None, perhaps F8 inhibitor bypass activity or recomb activated 7a or dialysis
Rivaroxaban (BAM the Xa) direct Xa inhibitor >1 day in nomral renal fx, 2 d cr cl 60-90, 3d crcl 30-59, 4d crcl 15-29 ptt or anti-Xa ab none, consider PCCs
Apixaban (eliquis) Direct Xa inhibitor 1-2d crcl>60, 3d crcl 50-59, 5d cr cl <49 anti-Xa ab non, consider charcoal hemoperfusion or PCCs (4 factor best)
Desirudin (iprivask) Direct thrombin inhibitor 2hr aPTT, thrombin time, or ecarin clotting time none
Antiplatelets
Aspirin COX inhibitor – irreversible 7-10 days non, consider platelet function tests (TEG?) Platelet transfusion
ASA + Dipyridamole Phosphodiesterase inhibitor 7-10 days None, but consider platelet function testing Platelet transfusion
Cilostazol Phosphodiesterase inhibitor 2 days None Platelet transfusion
Thienopyridine agents (clopidogrel – plavix; ticlopidine, prasugrel – effient; ticagrelor – brilinta) ADP receptor antagonist 5 days None, but consider platelet function testing Consider platelet transfusion, but limited efficacy