STANPUMP User's Manual

April 29, 1998

Overview:

STANPUMP is a computer program which drives an infusion pump to administer anesthetic drugs according to a three compartment pharmacokinetic model.  STANPUMP is available, at no charge, to interested investigators and anesthesiologists.  You may share the STANPUMP software with any interested persons.  My only request is that any manuscripts based upon work with STANPUMP acknowledge, either in the Methods or following the Discussion, the source of STANPUMP with a statement to the effect that STANPUMP is freely available from the author, Steven L. Shafer, M.D., Anesthesiology Service (112A), PAVAMC, 3801 Miranda Ave., Palo Alto, CA. 94304.  Please only include the above reference on published manuscripts as space on abstracts is too precious to waste any on an acknowledgment!

STANPUMP can be instructed to maintain a steady concentration in either the plasma or at the site of drug effect (i.e. the effect site or biophase).  STANPUMP can also be used to administer conventional zero-order infusions.  STANPUMP has a simulation mode which allows simulations of virtually any desired infusion regimen, including boluses, constant rate infusions, and infusions to achieve pseudo steady-state in the either the plasma or at the site of drug effect.

STANPUMP runs on any IBM PC compatible computer.  Versions of STANPUMP prior to April, 1990 could not run in the effect mode without at least an 8087 math coprocessor or an 80286 computer.  This has now been changed, and STANPUMP will run satisfactorily in the effect mode on any IBM PC compatible computer. 

Ira Rampil has been kind enough to port STANPUMP to the Macintosh in native MAC code (rather than require Soft-PC to emulate a PC).  The program looks the same as the DOS version, and thus lacks the warm and fuzzy characteristics of MAC programs.  However, it works and even drives the serial ports.  The function keys are replaced by the option key + a number (e.g., "Fn 1 is accessed by hitting Opt+1 as a pair.  The End Key is simply lower case 'e'.

STANPUMP will support delivery of drugs over extended periods of time.  STANPUMP has infused drug for sedation in our ICU for periods in excess of 2 weeks.  STANPUMP will stop saving data to the disk and internally if it runs out of space, but this should not affect the clinical performance of the pump.  Thus, there is no upper limit to how long STANPUMP can infuse drugs to a patient.

Pierre Maitre, M.D. and I have implemented Bayesian forecasting in the most recent version of STANPUMP.  The use of Bayesian forecasting with STANPUMP is discussed in a separate section below.

STANPUMP can run in simulation modes, or it can control an infusion pump directly over a serial interface.  When STANPUMP directly controls an infusion pump, STANPUMP becomes a medical device.  As such, it should be used only under the auspices of an appropriate institutional review board as part of an approved experimental protocol.

STANPUMP primarily supports the Harvard Pump 22.  The pump costs about $1800 and is an extremely accurate research pump.  While the Harvard Pump 22 is not approved for human use, it has been my experience that clinical engineering departments are happy to approve it for use within a research protocol.  Harvard Apparatus can be reached at 508-655-7000 or 800-272-2775.  You should ask for Diane Gargano, who is familiar with this application.

The Harvard Pump 22 has no battery.  Thus, if the Harvard Pump 22 is momentarily disconnected from AC power during a case the pump will lose it's internal memory.  STANPUMP constantly checks the pump for the volume infused during each update cycle.  When the Harvard Pump 22 loses the contents of its internal memory, STANPUMP computes what the volume infused should have been, and restarts the Harvard Pump 22.

STANPUMP has recently incorporated a driver for the GRASEBY 3400 pump. This pump is not accurate at low infusion rates. At low rates, the Graseby 3400 infuses significantly LESS than it internally calculates. There is no way for the STANPUMP program to correct for this internal error. Users of the Graseby 3400 pump are advised to regularly compare the quantity of drug delivered, as reported on the screen of the STANPUMP program, with the actually amount of drug delivered, based on the syringe volume itself. If these quantities differ, then the predicted concentration maintained by STANPUMP will have an additional source of error.

STANPUMP is easy to operate.  To run the program, just copy it into whatever directory you intend to use, and type "STANPUMP."  Then, answer the questions put forward by the program.  You may find yourself confronted with a choice of pharmacokinetic data sets for any given drug.  Most of the kinetic sets will give rea