Point of Care management using technology

Dr S Omar

Chris Hani Baragwanath Academic Hospital

What is Point of Care (POC)?

• A laboratory diagnostic test performed at or near the site where clinical care is delivered..

Point of Care testing. Nichols et al. Clin Lab Med 27 (2007)

Technological advances

• The term point-of-care testing (POCT) refers to any diagnostic test performed at or near the location of the patient.

Larsson et al, Upsala Journal of Medical Sciences. 2015; 120: 1–10

Xu, X., Ding, W., Wang, X., Cao, R., Zhang, M., Lv, P., Xu, F., 2016. Smartphone-Based Accurate Analysis of Retinal Vasculature towards Point-of-Care Diagnostics. Scientific Reports 6, 34603.

• All have some common concepts:

–Used at/near patient

–No permanent dedicated space required

– Entire process – test, result, interpretation, Mx decision occur at the/near patient

Is it useful?

• Satisfactory correlation when similar technologies used.

• POCT decreases the time to decisions on patient management

• POCT has the potential to provide beneficial patient outcome

• Has become standard of care in many areas

Pecoraro, V., Germagnoli, L., Banfi, G., 2014. Point-of-care testing: where is the evidence? A systematic survey. Clin. Chem. Lab. Med. 52, 313–324. doi:10.1515/cclm-2013-0386

Interesting concept to using big data for POC Mx

Monte Carlo method

• Computational power of a computer to predict outcomes with many influences

• Define a domain of possible inputs.

• Generate inputs randomly from a probability distribution over the domain.

• Perform a deterministic computation on the inputs.

• Aggregate the results.

Problem?

• Strong relationship between adequate antibiotic exposure, bacterial killing and clinical cure.

• Adequate antibiotic exposure is a real challenge in the ICU

• Numerous reasons

Why is the Vd so different

Free Drug

Albumin

Inflammation Ischemia reperfusionHypervolemiaStarches?

Changes in Vd

• Critical illness

– Capillary leak syndrome

– Decrease in Albumin

– Decreased binding to Alb

• AKI

– Vol changes

– Clearance changes

– pH/Uraemia

Fissel et al Adv Chronic Kidney Ds, 2013Choi et al CCM, 2010

Additional dosesExtended infusionsContinuous infusions

We need to know fancy pharmacology

• C = D / V and D = C x V

• Concentration - 5 X 4mg/L (MIC) = 20mg/L

• Volume of distribution = 0.38L/kg x 80kg = 30L

• Dose required = 20mg/L x 30L = 600mg

Load with 600 mg to achieve a targetconcentration of 20mg/L

Choi et al Blood Purification,2010

64

32

8

4

=8.4 hours

4 x T1/2 to 2mg/L33.6 hours to 2mg/L

2

4

Log on patient and conditions

Match in the “Heavens”

Predicted dose

POC “PK/PD dosing

We’re testing a simplified version

Second challenge

• Delays to theatre and interventional procedures because of delays immediate platelet count availability

• Delays in antibiotic therapy because becauseof similar issues with WCC

Common challenges with POC :

Barriers to Implementation of Rapid and Point-of-Care Tests for Human Immunodeficiency Virus Infection Findings From a Systematic Review (1996–2014)Nitika Pant Pai, MD, MPH, PhD, Samantha Wilkinson, MSc, [...], and Tom Wong, MD, MPH, FRCPC

Easy enough to be accurately performed by : Doctors and non medical ICU staff

Technical review checklist

1. Involve local institution2. Mx3. Health and safety4. Training5. Instructions6. SOP7. Quality Mx8. Results reviewed by appropriate persons9. Record keeping10. Maintenance

Moderately complex POC equipment

Differences in results ?

• Laboratory trained – pathologist

• Doctor

• Non medical (Clerk)

Path vs Doctor –Mann WhitneyHb N Median 25th 75th p

Path 87 9.4 8.3 10.0 >0.05

Doctor 63 8.9 8.0 9.9 No diff

WCC N Median 25th 75th p

Path 56 11.1 8.1 16.35 >0.05

Doctor 35 12.3 8.6 19.3 No diff

Plat N Median 25th 75th p

Path 76 235.5 147 422.5 >0.05

Doctor 55 204 112 323 No diff

Clerk vs Doctor- Mann WhitneyHb N Median 25th 75th p

Clerk 152 9.0 8.1 10.15 P>0.05

Doctor 63 8.9 8.0 9.9 No diff

WCC N Median 25th 75th p

Clerk 108 11.8 7.75 17.85 >0.05

Doctor 53 12.3 8.6 19.3 No diff

Plat N Median 25th 75th p

Clerk 145 229 149 354 >0.05

Doctor 55 204 112 323 No diff

POCUS for Fluid Mx

CCM 2016

Passive leg raise test

SV = 40ml

SV = 50ml

Increase in SV = 50-40 /40= 25%

For some Tea