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