Evidence in Intensive Care - Haematology



Transfusion

Transfusion of packed red cells is not associated with improved central venous O2 saturation of organ function in patients with septic shock.
Fuller et al J Emerg Med 2012;43:593-598
No evidence that transfusion assists in achieving one of the goals of EGDT. The role of transfusion in sepsis is controversial.

Age of red blood cells and mortality in the critically ill.
Pettilä
et al. Crit Care 2011; 15: R116.
Prospective multicentre observational.
Those having PRCs <11 days old had lower mortality (8% absolute risk reduction).
Increase in risk was linear up to 11 days and then plateaued thereafter.
If confirmed in a larger observational study or a RCT then practice should change.

Liberal or restrictive transfusion in high risk patients after hip surgery
Carson et al NEJM 2011
Transfusion threshold of 10 compared to 8.
No benefit of higher threshold.
Only benefit shown for more liberal strategy is in AMI. NEJM 2001

Preoperative anaemia and postoperative outcomes in non-cardiac surgery
Musallam et al Lancet 2011
Preoperative anaemia is associated with increased 30 day morbidity and mortality.

Duration of RBC storage assoc with increased incidence DVT and in hospital mortality in trauma patients
Spinella et al
Critical Care 2009;13:R151

In 44 trials of transfusion in critically ill patients, 42 demonstrated an association between transfusion and poorer outcomes.
Blood older than 21 days – more DVTs
Blood older than 28 days – increased mortality from MOF

Transfusion strategies for acute upper GI bleeding.
Villanueva et al. NEJM 2013;368:11-21
Restrictive (HB >7) vs liberal (HB >9) transfusion strategy in acute GI bleeding.
Mortality and LOS better in restrictive group.
Effect greatest in those with less severe liver disease (no difference in severe Child-Pugh disease).


DVT/PE

Thromboprophylaxis with LMWH
Journal of critical care 2009;24(2):197-205

Oedema and twice daily dosing made no difference to plasma levels.
No evidence of accumulation even with severe renal impairment.
Most DVTs associated with femoral catheters.

This review done before PROTECT study 2011 NEJM which showed dalteparin compared to heparin reduced HIT and PE (no difference in DVT, bleeding or mortality).

Duration of RBC storage assoc with increased incidence DVT and in hospital mortality in trauma patients
Spinella et al
Critical Care 2009;13:R151

In 44 trials of transfusion in critically ill patients, 42 demonstrated an association between transfusion and poorer outcomes.
Blood older than 21 days – more DVTs
Blood older than 28 days – increased mortality from MOF

LMWH (Dalteparin) vs UH for DVT prophylaxis
NEJM 2011;364:1305-1314
No difference in DVT.
Less PEs in dalteparin group NNT 100.
Less HIT in dalteparin group.
No difference in bleeding.

MEDENOX NEJM 1999
Medical patients given prophylactic enoxaparin - DVT incidence reduced but no mortality benefit
LIFENOX NEJM 2011 (double blind, randomised, placebo controlled)
Acutely ill patients - no mortality difference (even PE associated mortality).
CALISTO NEJM 2010
Superficial vein thrombosis - fondaparinux vs placebo. No mortality benefit. Thrombus extension and PE reduced (NNT 300).

Papers are now cautioning the benefits of early diagnosis by CTPA and treatment of DVT and PE may be outweighed by harm related to contrast, radiation and bleeding.
Really we should only be using LMWH if we know the NNT is lower than the NNH.

Bonizzoli M (2011) Peripherally inserted central venous catheters and central venous catheters related thrombosis in post-critical patients. Intensive Care Med 37:284–289
In an observational study, Bonizzoli et al. evaluated the rate of thrombosis associated with peripherally inserted central venous catheters (PICC) and central venous catheters in patients discharged from the ICU. Patients with PICC (n = 114) had a significantly higher incidence of deep venous thrombosis than patients with central venous catheters (n = 125) (27 vs. 10%), the majority of thrombosis occurring within 2 weeks after PICC insertion. Female gender and access through the left basilic vein were associated with a higher risk of thrombosis in the PICC group. The authors concluded that, in patients discharged from the ICU, routine ultrasound surveillance for the first 2 weeks after PICC insertion and preferential use of central venous catheters may be warranted.

Factor 7

Systematic review of factor 7a
Ann Intern Med 2011;154:529-540
Blood products reduced.
No outcome improvement in ICH, cardiothoracic surgery or trauma (less ARDS in trauma). Increased incidence arterial thrombosis (MI and stroke).


Safety of recombinant activated factor 7 in randomised clinical trials
Levi it al
NEJM 2010;363:1791-800

Factor 7 licensed for haemophiliacs with factor 8 and 9 antibodies.
Only evidence of benefit so far is functional outcome in ICH not treated by surgery. No mortality benefit.
Risk of arterial thrombosis and TE increased in a dose dependent manner particularly in age >65.