Patient Blood Management Guidelines: Module 2

Perioperative

2.2 Review and research

2.2.1 Systematic review process

Systematic reviews were undertaken to attempt to answer the questions specific to perioperative transfusion, and the generic questions relevant to all six modules. The systematic review questions are listed in Box 2.1.

To answer these questions, comprehensive search strategies were designed, as detailed in Volumes 2a and 2b of the technical report. Searches were conducted in relevant electronic databases, bibliographies of studies identified as relevant, and literature recommended by expert members of the CRG.

The systematic review included only data from studies that met the relevant inclusion criteria, were of adequate quality and were published before July 2009 (for exact dates of searches, see Table D.1 in Appendix D). Identification of relevant evidence and assessment of evidence was conducted in accordance with NHMRC standards and procedures for externally developed guidelines.9 Table D.2 in Appendix D gives specific patient populations and subgroups.

The search terms did not specifically search for or limit retrieval of articles to studies that addressed socioeconomic, Aboriginal or Torres Strait Islander subgroups. However, the reviewers were required to isolate any papers addressing these populations for specific consideration by the CRG. No papers were identified that addressed these populations specifically.

Box 2.1 Systematic review questions

Questions 1–3 are specific to perioperative transfusion (i.e. to this module); questions 4–9 are relevant to all six modules of these guidelines.

  • Question 1 – In patients undergoing surgery, what is the effect of a multidisciplinary, multimodal, programmatic approach to perioperative patient blood management on patient outcomes?

    (Interventional question, referred to as POQ1 in the technical report)

  • Question 2 – In patients undergoing surgery, what effect does the cessation and timing of cessation of medication that affects haemostasis have on morbidity, mortality and RBC transfusion?

    (Interventional question, referred to as POQ2 in the technical report)

  • Question 3 – In patients undergoing surgery, what is the effect of perioperative strategies that minimise blood loss on morbidity, mortality and blood transfusion?

    (Interventional question, referred to as POQ3 in the technical report)

  • Question 4 – In patients undergoing surgery, is anaemia an independent risk factor for adverse outcomes?

    (Aetiological question, referred to as GNQ1 in the technical report)

  • Question 5 – In patients undergoing surgery, what is the effect of RBC transfusion on patient outcomes?

    (Interventional question, referred to as GNQ2 in the technical report)

  • Question 6 – In patients undergoing surgery, what is the effect of non-transfusion interventions to increase haemoglobin concentration on morbidity, mortality and the need for RBC blood transfusion?

    (Interventional question, referred to as GNQ3 in the technical report)

  • Question 7 – In patients undergoing surgery, what is the effect of rFVIIa (prophylaxis or treatment) on morbidity, mortality and transfusion rate?

    (Interventional question, referred to as GNQ4 in the technical report)

  • Question 8 – In patients undergoing surgery, what is the effect of FFP, cryoprecipitate, fibrinogen concentrate, and/or platelet transfusion on patient outcomes?

    (Interventional question, referred to as GNQ5 in the technical report)

  • Question 9 – In patients undergoing surgery, at what INR (PT/ APTT) for FFP, fibrinogen level for cryoprecipitate and platelet count for platelet concentrates should patients be transfused to avoid risks of significant adverse events?

    (Prognostic question, referred to as GNQ6 in the technical report)

APTT, activated partial thromboplastin time; FFP, fresh frozen plasma; INR, international normalised ratio; PT, prothrombin time; RBC, red blood cell; rFVIIa, recombinant activated factor VII