[CG] Intraoperative Blood Cell Salvage, Obstetrics

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Introduction

Intra-operative cell salvage (IOCS) is a useful technique for blood replacement and its practice is well established in other areas of medicine; indeed, it used routinely in some areas of surgical practice. There is a strong case for its widespread use in obstetric surgery to avoid the well recognised risks and costs of blood transfusion.

Theoretical risks have slowed the introduction of the use of IOCS in obstetric settings but NICE reviewed the evidence in 2005 and supported its use subject to1:

  1. Data collection
  2. Reporting of complications to the Medicine and Healthcare Products Regulatory Agency
  3. Patients should be fully informed ‘whenever possible’ of the potential complications
  4. Performed by a multidisciplinary team who develop regular experience of intraoperative blood cell salvage

The use of IOCS in obstetrics has also been endorsed by the RCOG2, The Confidential Enquiry into Maternal and Child Health3 and the Joint Association of Anaesthetists of Great Britain and Ireland/Obstetrics Anaesthetists Association Guidelines4.

Benefits of IOCS

  1. To avoid the risks associated with conventional homologous or allogenic/donor blood transfusion:
    1. Infection (viruses, bacteria, prions)
    2. Acute incompatibility or reactions
    3. Hypothermia
    4. Cost
    5. Increasing scarcity of blood products
  1. To enhance the safety of caesarean section for patients who decline blood products from donors

Theoretical Risks

1. Amniotic Fluid Embolism (AFE)

There have been no reported cases to date of AFE associated with the use of IOCS in obstetrics. AFE is now considered to be a type of anaphylactic reaction rather than an embolic disease. In addition, the washing and filter processes used in cell salvage have now been shown to effectively remove amniotic fluid contaminants, fetal squames and other debris.

2. Sensitisation to Fetal Red Cells

The cell salvage machine is unable to distinguish between maternal and fetal red cells. Therefore, in cases where blood is transfused back to the mother, the fetal red cell concentration may be higher than in the maternal circulation (and higher than that normally occurs naturally at delivery). Maternal sensitization to fetal red cell antigens may then occur. Rh (D) incompatibility is relatively common but sensitization can be prevented with adequate anti-D administration after delivery.

However, the development of antibodies to other antigens can occur and these may pose a risk of fetal anaemia and haemolytic disease of the newborn in future pregnancies. With modern management, good outcomes are usually achieved in such cases but treatment is invasive and poses risks to the mother and baby. Studies have shown fetal red cells still present in cell-salvaged blood during caesarean section5,6.

Indications for IOCS

Patient selection for IOCS is at the discretion of the surgeon and anaesthetist caring for the patient and must be considered on a case-by-case basis. The following may be considered indications for cell salvage:

1. Elective CS procedures at increased risk of bleeding, e.g.:

  1. Placenta praevia
  2. Abnormally invasive placenta
  3. Maternal bleeding disorders
  4. Anticipated difficulty with cross-matching due to antibodies
  5. Lower uterine segment fibroids or classical incision
  6. Women on anticoagulants
  7. Past history of significant uterine atony
  8. Significant anaemia

2. CS for women who have declined blood products but are happy to accept IOCS (an advance directive is required to be signed and filed in the front of the notes as per the Refusal of Blood Products Guideline)

In units without availability of a cell salvage machine, these women should be offered planned delivery in a unit where IOCS is available.

3. Emergency CS procedures at increased risk of bleeding:

  1. Any of the above elective cases who present and require delivery as an emergency
  2. Placental abruption
  3. Laparotomy following post-partum haemorrhage or suspected intraabdominal bleed
  4. Full dilatation CS with deeply impacted head


Contra-indications for IOCS include:

  • Contamination of the surgical field with bowel contents or substances not licensed for IV use
  • Malignancy
  • Overt infection
  • Sickle cell disease (discuss with Haematology)

Procedure/Technical Aspects

Only staff appropriately trained and competent should set up and use obstetric IOCS.

Patients should receive information about the risks and benefits of the IOCS preoperatively9.

Collection-only set up should be the standard in the majority of cases.

The use of a two suction set up is intended to reduce the exposure to the amniotic fluid.

The aspiration anticoagulation line should be used to collect the blood from the surgical site.

Standard theatre suction should be used to remove the amniotic fluid from the operative field during delivery of the baby.

Blood-stained swabs can gently be washed in a solution of normal saline and salvaged from a sterile bowl into the cell saver.

A Pall RS leucocyte depletion filter (LeukoGuard RS, Pall Biomedical Products Co., East Hills, NY) should be used for the re-transfusion of salvaged blood. The filter reduces flow rates considerably. The use of a filter on each port will double the flow rate when high volume return is required8.

The maximum capacity per filter is 450 ml of salvaged blood8.

The re-infusion bag should not be pressurised to reduce risk of air embolism and also the unknown effect on filter performance.

The salvaged blood bag should be labelled with a green patient identification label containing:

  • Full name
  • DOB
  • CHI number
  • Collection start date and time
  • Expiry date and time

Re-transfusion should be completed within four hours after completion of processing of salvaged blood.

The Intra-Operative Cell Salvage Monitoring Sheet (Appendix 1) should be completed at the end of the procedure.

Rhesus Immunisation and Kleihauer Testing

  • When intra-operative cell salvage is used during Caesarean section, reinfused blood may contain fetal red cells.
  • The volume of fetal red cells in reinfused blood can vary from 1-20ml.
  • It is therefore recommended that a minimum dose of 1500 IU anti-D Ig is administered after reinfusion of salvaged cells if baby group is confirmed as RhD positive (or blood group unknown).
  • Maternal samples for estimation of FMH should be taken 30 – 45 mins after reinfusion of salvaged red cells. Depending on the Kleihauer result, an additional dose of anti-D should be administered if necessary and additional follow up Kleihauer sent as appropriate.
  • It is important that clinicians inform Blood Bank if intra-operative cell salvage is being used to ensure that the correct dose of anti-D Ig is issued. This information should be added to the pre-operative maternal request for Group & Save/Crossmatch.

Appendix 1: Obstetrics Intra-Operative Cell Salvage Monitoring Sheet

Appendix 2: IOCS autotransfusion record

References
  1. National Institute for health and Clinical Excellence. No 144 November 2006.
  2. RCOG Green-Top Guideline No 47, Blood Transfusion in Obstetrics 2007
  3. Confidential Enquiry into Maternal and Child Health (CEMACH) (20002002). Why Mothers Die – Report of confidential enquiries into maternal deaths in the United Kingdom. Chapter 4 (Haemorrhage) p91-9 Prof M Hall
  4. OAA/AAGBI (2005) Guidelines for Obstetric Anaesthetic Services revised edition; p25
  5. Sullivan I, Faulds J, Ralph C. Contamination of salvaged maternal blood by amniotic fluid and fetal red cells during elective caesarean section. British Journal of Anaesthesia 2008; 101(2): 225-9
  6. Thornhill ML, O’Leary et al. An in-vitro assessment of amniotic fluid removal from human blood through cell saver processing. Anesthesiology 1991; 75: A830
  7. Joint United Kingdom (UK) Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee, Transfusion Handbook9:5:  Prevention of haemolytic disease of the fetus and newborn (HDFN)
  8. UK Cell Salvage Action Group, ICS Technical Factsheet: Use of filters in ICS 2012
  9. AAGBI Transfusion and the anaesthetist (2009) Intra-operative Cell Salvage 2009
  10. Use of Anti-D Immunoglobin for the Prevention of Haemolytic Disease of the Fetus and Newborn. British Society for Haematology Jan2014, updated Feb2020

Last reviewed: 28 June 2021

Next review: 01 April 2022

Author(s): Lead Authors: Dr Ruth Jewell, Consultant Obstetrician, RAH; Dr Neils Weidenhammer, Consultant Anaesthetist, Princess Royal Maternity

Approved By: Obstetric Governance Group, Approved by Obstetric Guideline Group: 18th April 2017

Document Id: 555