Equipment Evaluations

IV Infusion Pumps: An interim report (DRAFT)

Background:  Our flight program is an air ambulance that provides rotary-wing (helicopter) and fixed-wing (airplane) to critically ill and injured persons over a large geographic area.  Currently, the program operates a large number of Allaris/IVAC Med System III ("mini-med"), ranging from model 2860D and up.  Recently nurses have expressed increasing frustration with the Allaris/IVAC pumps.  Complaints fall into one of three categories: 1) difficulty with air in the cassette and failed cassettes, 2) difficulty with battery life, and 3) difficulty with pump channels failing in the patient care setting.  Difficulties with the Allaris pump are predominately within a group of pumps that are more than 10 years old.  Allaris/IVAC has stated that these pumps are to old to continue to be reliable.  Because such a large number of pumps will need to be replaced in the immediate future, a group of nurses came together to evaluate requirements in IV pumps and select an appropriate pump for use.

Methods: A short survey was circulated among all the flight nurses via email.   Nurses were asked to define:

1. what the minimum number of pump channels were required for the environment,
2. what the desirable number of channels were,
3. the high flow rate required for the environment,
4. the low flow rate for the environment,
5. the maximum sized air emboli before the pump alarmed,
6. and ease of use (on a scale of 1-10, using the Allaris/IVAC pump as a benchmark of 5/10).

The results of this were used  to guide the definition of  minimum features an IV infusion pump should include to function within the flight environment (Table One).  This flight environment includes, but is not limited to, the care of patients aged 1 hour to the elderly adult, in the pre-hospital or inter-hospital setting, in either rotary-wing or fixed-aircraft, at a cabin pressure ranging from sea-level to 8,000 feet, in all levels of light, humidity, and temperature. It should be noted that it is a CAMTS requirement to have 3 channels available. 

Vendors from major medical equipment companies were then contacted and and asked to supply technical specifications as well as demonstration IV infusion pumps for evaluation over a period of two weeks.  Pumps over 8 pounds in weight or over 100cc in volume were not considered.  The pumps were not evaluated in flight or during patient care.  Flight nurses were asked to use the pumps in a class room setting and comment on the general ease of use, size, weight, and other features.  These nurses did not receive any training on the individual pumps.  Results are described in Table Two.

Table One: Survey Results

Table Two: IV Infusion Pumps Evaluated

Results: 

NEEDS ASSESSMENT:  Survey results showed a clear bias based on the background of the nurse.   Nurses with neonatal and pediatric backgrounds showed a desire for lower flow rate abilities with smaller incremental changes in rate, while nurses with adult patient care backgrounds sought higher flow rates.  As a result the requirements included the lowest value (0.1cc) for the low flow rate, and the average (300cc) of the high flow rate.   Similarly, the neonatal/pediatric nurses required lower volumes of air for the "air in line" alarm (avrg 0.3cc).  Ease of use was judged to need to be at least as easy as the current Allaris/IVAC pump used.  The high flow rate was multiplied by the longer expected flight times to arrive at the endurance (300cc x 4 hours = 1200cc).  We recognize that all these pumps can be powered with AC power, or batteries can be replaced during infusion, in order to increase the endurance.  KVO rate was arbitrarily agreed upon (by McCulloch and Culkin) at 3cc/hr.  The pump additionally needs to be able to pump from the floor to the patient.

PUMP EVALUATION:  Of the five pumps evaluated, only the Abbott Gem-Star and the Allaris/IVAC Med System III met or exceeded the minimum features defined by nurses in the pre-evaluation survey.  The other three had at least one feature that did not meet the requirements defined in the survey. 

While the Abbott Gem-Star is a single channel pump, it is felt that three of the pumps could be mounted side be side and still remain a fairly compact unit.  The pump is light, relatively easy to program either in weight based or cc/hour flow rate, and seems well built.   The unit is powered with commonly available disposable AA batteries, and features an adequate power endurance.  Concerns include the fiscal cost of converting to this type of pump considering that three would be required for every one of the Allaris' replaced, and the pumps lack of market-share and history in the industry.

The Allaris/IVAC Med System III is a standard in the flight environment and is the only IV infusion pump currently approved by the United States Air Force for use in it's flight environment.  It is the only pump that includes three channels in one unit, and recent models include built-in formulary (similar to the Abbott ANNE).   The Allaris/IVAC Med System III was considered the benchmark for ease of use, and was thus initially rated as "fair" (5/10). Concerns include the difficulty in priming tubing and getting air out of the cassette, the "memory" phenomena associated with NiCad batteries, as well as service and dependability.

It is felt that the comments described in Table 2 reflect the "intuitive nature" of the pump's operation, as the nurses did not receive any instruction to the pumps use prior to the evaluation.  Further these comments should not be construed to endorse or disparage any of the pumps, but are provided as opinion only.

Recommendations:  Because the Abbott Gem-Star had several excellent features and no borderline features, (other than no information on dependability) as described in Table 2, it is felt that the Gem-Star should undergo further evaluation by the Clinical Engineering Department, as well as undergo evaluation in the flight environment.  The manufacturer should be consulted, as well as aircraft mechanics, with the goal to assess the feasibility of manufacturing a mounting system so that three of the Gem-Stars could be mounted together in the least possible space.  Further, because of the significant expense with changing pumps, as well as the question of it's durability, leasing options should be explored.  The Gem-Star scenario offers the additional flexibility of adding or subtracting one channel as needed for patient care or maintenance.

Allaris/IVAC should be given the opportunity to respond to our concerns of battery life, poor service, and device dependability.  A written statement should be obtained from Allaris/IVAC stating their policy and intention for supporting any pumps purchased in the future.  In addition, three remanufactured pumps, recently ordered for evaluation from a third party at significant cost savings, should be evaluated for dependability and ease of use.  It is possible that the newer models meet the demands of our flight program.  Further, it is extremely significant that the Air Force has approved the Med System III for use in their flight environment.