Blood sampling from ECLS circuit

The purpose of this guideline is to provide a framework for the Extra Corporeal Life Support (ECLS) team when taking blood samples from the ECLS circuit.

An aseptic or non-touch technique (ANTT) (Rowley et al 2010) is the method employed when taking blood samples from Extra Corporeal Membrane Oxygenation (ECMO) patients including accessing the ECMO circuit (Rationale 1). It protects the patient from the impact of healthcare associated infections (such as delayed recovery, longer hospitalisation, increased pain and increased morbidity).

All samples except the patients’ arterial blood gas will be obtained from the ECLS circuit. A closed sampling system such as Clave^® should be used (Rationale 2).

Note: While this guideline refers to the ‘child’ throughout, all activities are applicable to young people.

Background

The multiprofessional team involved in the care of the ECLS patient should have an understanding of the physiology of ECLS, familiarity with the ECLS circuit and have reached a recognised level of competence in managing the ECLS patient and prepared to deal with any trouble shooting that may be required.

Pre-ECMO bloods

All admissions

• Urea & Electrolytes (U and Es) and liver funtion tests (LFTs):  0.5ml Orange Lithium Heparin, Chemical Pathology
• Full blood count (FBC): 0.5ml Red EDTA, Haematology
• Clotting: 1.4ml Green Coagulation, Haematology
• CRP: 0.5ml Orange Lithium Heparin, Chemical Pathology
• Cross-Match: 2ml Min Blue Tx Bottle, Blood Transfusion
• Blood Cultures: 2ml Min Culture Bottles, Microbiology

Plus: Myocarditis/cardiomyopathy tests (appendix 1)

Neonates

• Guthrie Test: 1 Spot on Guthrie Card (mark "pre-ECMO/transfusion". Save and send to lab with full (4 spot) card which should be taken on day five of life. Further single spot to be sent 72hrs post ECMO), Chemical Pathology
• DNA for Storage (DNA239): 1ml Red EDTA, Molecular Genetics
• Chromosomes for storage (samples for temporary storage only – parental consent not required unless karyotyping or specific chromosomal testing requested): 1-2ml Orange Lithium Heparin,  Cytogenetics  (use special Cytogenetics forms with blue pre-printed stickers)  
  

Respiratory paediatrics

All respiratory paediatric admissions

• Save Serum (SS): 2-4ml Brown Serum Gel, Immunology (may be tested for viral PCR)
• Save Sample (VO40): 1.2ml Brown Serum Gel, Virology (may be tested for mycoplasma etc, antibodies/antinuclear antibody (ANA)/dsDNA virus/ENA/Immunoglobulin A (IgA)/Immunoglobulin G (IgG)/Immunoglobulin M (IgM)/Immunoglobulin E (IgE))
• DNA Storage: 5-10ml (1ml Neonates) Red EDTA, Molecular Genetics

Patients less than one year of age only        

• Chromosomes for storage (samples for temporary storage only - parental consent not required unless karyotyping or specific chromosomal testing requested): 1-2ml Orange Lithium Heparin,  Cytogenetics (use special Cytogenetics forms with blue pre-printed stickers)   
  

Routine blood samples taken on ECLS

• blood cultures: 06:00 Monday, Friday
• C-reactive protein (CRP): 06:00 Monday, Friday
• FBC: BD or as clinically indicated
• U and E's: Daily or as clinically indicated
• clotting: BD or as clinically indicated
• cross match: age dependency, pathway appropriate

1. Sampling sites

Please use luer lock syringes for all samples (Rationale 3).

CentiMag pump

Post pumphead and pre heparin pigtail for:          
          

• activated clotting time (ACT)
• all laboratory samples
• mixed venous samples
  

Post oxygenator pigtail for:                                          

• post membrane arterial gases

2. Preparation

Gather the following equipment (Rationale 4):

• gloves and eye protection (Rationale 5)
• blood bottle(s)
• clean tray to hold equipment

A hygienic hand wash should be performed prior to starting the procedure (Rationale 6).

3. Obtaining the sample

Personal protective equipment (PPE) should be used, ie aprons, gloves and eye protection (Rationale 7, Rationale 8).

Equipment should be placed in a convenient position (Rationale 9):

• clean the Clave^® with Chloroprep™ (2% chlorhexidine with 70% alcohol) (Rationale 10)

• allow the area to dry (Rationale 7)
• attached luer lock syringe and obtain blood sample
• clean the Clave^® with Chloroprep™ after sample taken

4. Completing the procedure

Once the sample has been obtained:

• equipment should be disposed of according to the Hospital Waste Policy (Rationale 11)
• perform a hygienic hand wash (Rationale 12)  
• the sample should be sent for analysis as soon as possible (Rationale 13)

5. Complications

Beware of stiff 3 way taps (Rationale 14). These need to be changed to avoid failure or leakage. If clot formation is a problem, the frequency of aspiration should be increased and documented in the care plan/pathway.

Flushing of pigtails should be undertaken with care to prevent the entrainment of air or clots into the circuit and documented on the drug chart under the Patient Group Directives (PGDs) by all personnel accessing the ECMO circuit.

Access to the ECMO circuit should be minimised to reduce infection risk. In-line monitoring should be calibrated and checked for accuracy each shift to reduce the need for sampling.
Clave^® used for frequently accessed sites (Rationale 15).

These need to be changed every 24 hours.

Rationale

Rationale 1: To minimise the risk of introducing pathogens into the IV access or ECMO circuit.
Rationale 2: To reduce the risk of infection.
Rationale 3: To aid sampling technique and avoid blood spillage.
Rationale 4: To be prepared for the procedure.
Rationale 5: To protect the person obtaining the sample.
Rationale 6: To prevent cross infection.
Rationale 7: To minimise the risk of infection.
Rationale 8: To ensure effectiveness of cleaning.
Rationale 9: To protect your eyes from blood splashes.
Rationale 10: To enable the procedure to be performed with ease.
Rationale 11: To ensure safe disposal.
Rationale 12: To minimise the risk of cross infection.
Rationale 13: To promote effectiveness of testing.
Rationale 14: May contain clots.
Rationale 15: To maintain closed system and minimise risk of infection.

References

Reference 1:
Rowley S, Clare S, Macqueen S, Molyneux R (2010) ANTT v2: An updated practice framework for aseptic technique British Journal of Nursing 19 (5).

Reference 2:
Van Meurs K, Lally KP, Peek G, Zwischenberger JB (2005) ECMO Extracorporeal cardiopulmonary support in critical care. Ann Arbor, Michigan, USA, ELSO.

Document control information

Lead author
Maura O'Callaghan, ECMO Co-ordinator, ECMO

Additional authors
Helen Boardman, ECMO Co-ordinator, ECMO
Liz Smith, Lead Nurse ANP, Cardiac ANP

Document owner
Maura O'Callaghan, ECMO Co-ordinator, ECMO

Approved by
Clinical Practice Committee

First introduced: 17 June 1999   
Date approved: 17 May 2012
Review schedule: Two years
Next review: 17 May 2014
Document version: 3.0
Replaces version: 2.0