NONMEM Users Network Archive

Hosted by Cognigen

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,

J. Elassaiss-Schaap
Scientist PK/PD
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

Notice: This e-mail message, together with any attachments, contains
information of Merck & Co., Inc. (One Merck Drive, Whitehouse Station,
New Jersey, USA 08889), and/or its affiliates Direct contact information
for affiliates is available at that may be confidential,
proprietary copyrighted and/or legally privileged. It is intended solely
for the use of the individual or entity named on this message. If you are
not the intended recipient, and have received this message in error,
please notify us immediately by reply e-mail and then delete it from
your system.

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

The NONMEM Users Network is maintained by ICON plc. Requests to subscribe to the network should be sent to:

Once subscribed, you may contribute to the discussion by emailing: