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RE: Truncated Emax

From: Elassaiss - Schaap, J. <jeroen.elassaiss-schaap>
Date: Mon, 19 Dec 2011 22:11:39 +0100

Hi Francois,

For pain measurements it is not uncommon to analyze data with a upper limit=
 of quantitation. You can follow the literature on BQL, only reversing from=
 a lower limit to an upper limIt. In my experience just deleting censored d=
ata works fine, certainly as a first attempt, as long as censoring stays be=
low ~1/3 of total data.

Best regards,
Jeroen


J. Elassaiss-Schaap
Scientist PK/PD
MSD
PO Box 20, 5340 BH Oss, Netherlands
Phone: + 31 412 66 9320
Fax: + 31 412 66 2506
e-mail: jeroen.elassaiss

________________________________
From: owner-nmusers
 Behalf Of Francois Gaudreault
Sent: Monday, December 19, 2011 21:40
To: nmusers
Subject: [NMusers] Truncated Emax

Dear NM users

I am currently developing a PK PD model for local anesthetics using a seque=
ntial approach with ADVAN6. The PD model is a sigmoid Emax with an effect c=
ompartment (Ce).

The intensity and duration of nerve blockade are monitored throughout the p=
erioperative period in patients using a quantitative pharmacodynamic endpoi=
nt, i.e, the current perception threshold (CPT) REF: Can. J. Anesth, 57 (S1=
) 2010). Briefly, CPT is evaluated before and after the administration of t=
he local anesthectic. Data are normalized by baseline using the following e=
quation :
(observed-baseline) / (max-baseline) *100 (%)

Here is the problem. The device only goes to a maximum of 10 mA. In some pa=
tients, the real Emax is much higher. Any ideas on how handle a truncated E=
max ?

Thanks in advance



--
François Gaudreault, Ph.D. Candidate
Pharmacométrie / Pharmacometrics
Charger de cours / Lecturer
Faculté de pharmacie / Faculty of Pharmacy
Université de Montréal

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Received on Mon Dec 19 2011 - 16:11:39 EST

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