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Utilization of mechanical ventilators in hospital based air ambulance programs
Clinical Forum
Utilization of Mechanical Ventilators in Hospital Based Air Ambulance Programs by Richard D. Branson, James M. Hurst, Karen S. Adams and Charles W. Kessinger, Jr. INTRODUCTION
We recently completed an evaluation of transport ventilators suitable for use in EMS programs. Many of our conclusions were based on actual performance characteristics, while others were based on our experience and personal bias. Realizing institutions have different needs and preferences, we surveyed 96 EMS programs with rotor and/or fixed wing capabilities as to the type, utilization, and characteristics they required of a mechanical ventilator. An outstanding response rate of 74% (71/96) was obtained. As expected, a wide variety of frequently contradictory responses were returned. The following represents the question-and-answer survey in a running discussion. WHAT TYPE OF VENTILATOR?
At the time of this survey the number of commercially available transport ventilators was approximately half of what it is today. Not surprisingly, the Bear Pneu-Pac was the ventilator most frequently used. This is due to its compact size, ease of use and (for many years), lack of competition. The second most frequently used ventilator was the Bio-Med IC-2A. The Urgency Bird (Bird Products) came in a distant third. Modifications of the pressure limited MK series (Bird Products) rounded out the top 4 most frequently used ventilators. Three programs listed the Siemens-Servo 900 C as their transport ventilator. We assume that these were fixed wing programs as the 900 C requires both gas and electrical power to operate and weighs approximately 19 kgs. The remaining two ventilators reported were pediatric models. A list of ventilators in order of "most-to-least" used is presented in Table 1. The most interesting response received was "none". HOSPITAL AVIATION, JAN UARY 1986
Twenty-three percent of surveyed programs preferred to use a self-inflating resuscitation bag as the sole means of ventilatory support. Of these, many cited a large percentage of scene response flights and dissatisfaction with currently available ventilators as reasons for flying without one. OPERATION
The following questions regarding ventilator operation were asked: 1) What member of the flight team is responsible for set-up and maintenance of the ventilator?, and 2) What factors determine initiation of ventilatory support? Since 17 of 71 programs operated without a ventilator, these figures were based on 54 responses. As could probably be expected, the flight nurse (FN) was most frequently responsible for ventilator operation (39070). The second most frequent operator was a Respiratory Therapist (RT) (19070). Programs using RT's usually did so on a consultation basis. The RT was not a regular member of the flight crew, but was called upon when the patient was known to require ventilatory support prior to transport. These programs often served major referral centers. Paramedics (P) (13070) were the next group of personnel reported Table 1 TYPES OF VENTILATORS VENTILATORS Pneu-Pac None Bio-Med IC-2A Urgency Bird Bird MK Series Siemens-Serve 900 C Healthdyne 200 MVP-10 TOTAL
#
%
24 17 * 14 8 4 3 2 1 731-
33% 23% 19% 11% 5.5% 4.4% 2.7% 1.4% 100%
* 5 of 16 were in the process of purchasing a ventilator. 1- 2 programs reported more than one ventilator.
to be responsible for maintaining ventilatory support. Other responses listed a combination of the above personnel as sharing responsibility, FN/P (18070), and FN/RT (11070). No program reported physicians as having responsibility for ventilator operation, although ventilators cannot be used except on the order of a physician. The second question regarding operation sought the criteria used for initiation of ventilatory support. A representative group of responses is presented in Table 2. Clearly, the single most frequent criterion was related to the requirement for ventilatory support prior to transfer. Other criteria were varied and many times contradictory. In terms of duration of transport, 64°70 stated that ventilatory support was not used during flights < 20 minutes. The remaining 36070 deferred the use of ventilatory support during flights > 30 minutes. Time, was clearly a major factor leading to the decision to initiate ventilatory support. Equipment and gas available played similar roles in the decision-making process. Patients without spontaneous ventilatory effort were considered to be the prime candidates for mechanical ventilation by 40% of respondants. Others listed request by the attending physician as an important factor in the decision-making process. Contradictory responses were received regarding the use of mechanical ventilation during CPR. Eight (8) of 12 responses stated that mechanical ventilation was never used during CPR, fearing that inadequate ventilation would result. The remaining 4 responses reported using mechanical ventilation during CPR in order to free up a crew member. In our experience (and opinion), mechanical ventilation should never be used during CPR as high intrathoracic pressures created by compressions may cause termination
Clinical Forum
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.
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Table 2
FACTORS DETERMINING INITIATION OF VENTILATOR SUPPORT
Patient maintained on ventilatory support prior to transport (18) Duration of transport (17) Patient without spontaneous respiration (17) Physician Preference (12) Patients requiring CPR (12) Patients requiring high peak airway pressures (7) Need for PEEP (6) Need for hyperventilation (6)
questions reflect the needs and desires of the hospital based air ambulance community. A list of the most common responses are located in Table 3. We can only hope that this may serve as an impetus for manufacturers to focus their efforts on the needs of this unique environment. SUMMARY
Table 3 CHARACTERISTICS OF THE "IDEAL" VENTILATOR
Compact/light-weight < (5 Ibs.) PEEP/CPAP capabilities (0-20 cm. H20) Operational simplicity Accurate control of FI02 Multiple modes (IMV, CMV, etc.) Alarms (high and low patient pressure, low gas supply; alarms should be both visual and aural In-line measurement of tidal volume Low gas consumption Newborn to adult ranges of respiratory rate and tidal volume Pressure relief valve Separate manipulation of respiratory rate and tidal volume
of inspiration in pressure limited ventilators or cause volume to be released through pressure limiting valves in time-cycled models. In either event, inadequate ventilation and oxygenation may result. The remaining three responses were directly related to the capabilities of the various ventilators. Patients requiring hyperventilation, high peak airway pressures and PEEP were maintained on self-inflating resuscitation bags by programs whose ventilators were incapable of performing these tasks (63070). The other 37070 reported using ventilators in these same situations in order to more precisely control these variables. Few programs had standing policy for the initiation of mechanical ventilation! Perhaps this is an area which requires further definition. VENTILATOR USAGE
After determining the type and operation of mechanical ventilators employed during air transport, we asked programs how many flights per year they averaged; and of those, how frequently mechanical ventilation was employed. Of the 54 responses, representing 38,039 flights, mechanical ventilation was provided 4,189 times, approximately 11 °70 of flights. This figure excludes patients manually ventilated with resuscitation bags.
Three remaining questions were asked: 1) What features do you like about your current ventilator, 2) What features do you not like, and 3) What features would you like to see in the "ideal" ventilator? The first two questions were used in helping us troubleshoot and compare ventilators for a previous paper. Readers are referred to that paper for further information (Hospital Aviation, Nov. '85 pl0). Responses to the last
The growth of hospital based air EMS programs continues to escalate at an explosive rate. Despite this growth, the specialty remains in a fledgling state. The purpose of this and our previous paper is to define current "state-of-the-art", determine usage and define areas for improvement regarding mechanical ventilation during air transport. As is evident from our results, criteria for the selection of patients who require ventilatory support and the equipment to be used is in need of refinement. Dealing with these issues early in the development of the field is the only way to assure that adequate and successful service can be provided. ACKNOWLEDGEMENTS The authors would like to thank all those who were kind enough to participate in the survey. Without their cooperation, this paper would not have been possible. We also would like to thank Cynthia Leon for preparation of the manuscript.
Dedicated Air Ambulance Systems • Hospital -Based Turn Key Operation • Complete Program Design Props • Turbo Props • Jets & Helicopter System Leases • Management Contracts
MED FLIGHT SYSTEMS DIVISION 21 E. YorkSt., Savannah GA 31412 800/241-7763 In Georgia 912/238-1999 HOSPITALAVIATION,JANUARY1986 7
Utilization of Mechanical Ventilators in Hospital Based Air Ambulance Programs by Richard D. Branson, James M. Hurst, Karen S. Adams and Charles W. Kessinger, Jr. INTRODUCTION
We recently completed an evaluation of transport ventilators suitable for use in EMS programs. Many of our conclusions were based on actual performance characteristics, while others were based on our experience and personal bias. Realizing institutions have different needs and preferences, we surveyed 96 EMS programs with rotor and/or fixed wing capabilities as to the type, utilization, and characteristics they required of a mechanical ventilator. An outstanding response rate of 74% (71/96) was obtained. As expected, a wide variety of frequently contradictory responses were returned. The following represents the question-and-answer survey in a running discussion. WHAT TYPE OF VENTILATOR?
At the time of this survey the number of commercially available transport ventilators was approximately half of what it is today. Not surprisingly, the Bear Pneu-Pac was the ventilator most frequently used. This is due to its compact size, ease of use and (for many years), lack of competition. The second most frequently used ventilator was the Bio-Med IC-2A. The Urgency Bird (Bird Products) came in a distant third. Modifications of the pressure limited MK series (Bird Products) rounded out the top 4 most frequently used ventilators. Three programs listed the Siemens-Servo 900 C as their transport ventilator. We assume that these were fixed wing programs as the 900 C requires both gas and electrical power to operate and weighs approximately 19 kgs. The remaining two ventilators reported were pediatric models. A list of ventilators in order of "most-to-least" used is presented in Table 1. The most interesting response received was "none". HOSPITAL AVIATION, JAN UARY 1986
Twenty-three percent of surveyed programs preferred to use a self-inflating resuscitation bag as the sole means of ventilatory support. Of these, many cited a large percentage of scene response flights and dissatisfaction with currently available ventilators as reasons for flying without one. OPERATION
The following questions regarding ventilator operation were asked: 1) What member of the flight team is responsible for set-up and maintenance of the ventilator?, and 2) What factors determine initiation of ventilatory support? Since 17 of 71 programs operated without a ventilator, these figures were based on 54 responses. As could probably be expected, the flight nurse (FN) was most frequently responsible for ventilator operation (39070). The second most frequent operator was a Respiratory Therapist (RT) (19070). Programs using RT's usually did so on a consultation basis. The RT was not a regular member of the flight crew, but was called upon when the patient was known to require ventilatory support prior to transport. These programs often served major referral centers. Paramedics (P) (13070) were the next group of personnel reported Table 1 TYPES OF VENTILATORS VENTILATORS Pneu-Pac None Bio-Med IC-2A Urgency Bird Bird MK Series Siemens-Serve 900 C Healthdyne 200 MVP-10 TOTAL
#
%
24 17 * 14 8 4 3 2 1 731-
33% 23% 19% 11% 5.5% 4.4% 2.7% 1.4% 100%
* 5 of 16 were in the process of purchasing a ventilator. 1- 2 programs reported more than one ventilator.
to be responsible for maintaining ventilatory support. Other responses listed a combination of the above personnel as sharing responsibility, FN/P (18070), and FN/RT (11070). No program reported physicians as having responsibility for ventilator operation, although ventilators cannot be used except on the order of a physician. The second question regarding operation sought the criteria used for initiation of ventilatory support. A representative group of responses is presented in Table 2. Clearly, the single most frequent criterion was related to the requirement for ventilatory support prior to transfer. Other criteria were varied and many times contradictory. In terms of duration of transport, 64°70 stated that ventilatory support was not used during flights < 20 minutes. The remaining 36070 deferred the use of ventilatory support during flights > 30 minutes. Time, was clearly a major factor leading to the decision to initiate ventilatory support. Equipment and gas available played similar roles in the decision-making process. Patients without spontaneous ventilatory effort were considered to be the prime candidates for mechanical ventilation by 40% of respondants. Others listed request by the attending physician as an important factor in the decision-making process. Contradictory responses were received regarding the use of mechanical ventilation during CPR. Eight (8) of 12 responses stated that mechanical ventilation was never used during CPR, fearing that inadequate ventilation would result. The remaining 4 responses reported using mechanical ventilation during CPR in order to free up a crew member. In our experience (and opinion), mechanical ventilation should never be used during CPR as high intrathoracic pressures created by compressions may cause termination
Clinical Forum
.
.
.
Table 2
FACTORS DETERMINING INITIATION OF VENTILATOR SUPPORT
Patient maintained on ventilatory support prior to transport (18) Duration of transport (17) Patient without spontaneous respiration (17) Physician Preference (12) Patients requiring CPR (12) Patients requiring high peak airway pressures (7) Need for PEEP (6) Need for hyperventilation (6)
questions reflect the needs and desires of the hospital based air ambulance community. A list of the most common responses are located in Table 3. We can only hope that this may serve as an impetus for manufacturers to focus their efforts on the needs of this unique environment. SUMMARY
Table 3 CHARACTERISTICS OF THE "IDEAL" VENTILATOR
Compact/light-weight < (5 Ibs.) PEEP/CPAP capabilities (0-20 cm. H20) Operational simplicity Accurate control of FI02 Multiple modes (IMV, CMV, etc.) Alarms (high and low patient pressure, low gas supply; alarms should be both visual and aural In-line measurement of tidal volume Low gas consumption Newborn to adult ranges of respiratory rate and tidal volume Pressure relief valve Separate manipulation of respiratory rate and tidal volume
of inspiration in pressure limited ventilators or cause volume to be released through pressure limiting valves in time-cycled models. In either event, inadequate ventilation and oxygenation may result. The remaining three responses were directly related to the capabilities of the various ventilators. Patients requiring hyperventilation, high peak airway pressures and PEEP were maintained on self-inflating resuscitation bags by programs whose ventilators were incapable of performing these tasks (63070). The other 37070 reported using ventilators in these same situations in order to more precisely control these variables. Few programs had standing policy for the initiation of mechanical ventilation! Perhaps this is an area which requires further definition. VENTILATOR USAGE
After determining the type and operation of mechanical ventilators employed during air transport, we asked programs how many flights per year they averaged; and of those, how frequently mechanical ventilation was employed. Of the 54 responses, representing 38,039 flights, mechanical ventilation was provided 4,189 times, approximately 11 °70 of flights. This figure excludes patients manually ventilated with resuscitation bags.
Three remaining questions were asked: 1) What features do you like about your current ventilator, 2) What features do you not like, and 3) What features would you like to see in the "ideal" ventilator? The first two questions were used in helping us troubleshoot and compare ventilators for a previous paper. Readers are referred to that paper for further information (Hospital Aviation, Nov. '85 pl0). Responses to the last
The growth of hospital based air EMS programs continues to escalate at an explosive rate. Despite this growth, the specialty remains in a fledgling state. The purpose of this and our previous paper is to define current "state-of-the-art", determine usage and define areas for improvement regarding mechanical ventilation during air transport. As is evident from our results, criteria for the selection of patients who require ventilatory support and the equipment to be used is in need of refinement. Dealing with these issues early in the development of the field is the only way to assure that adequate and successful service can be provided. ACKNOWLEDGEMENTS The authors would like to thank all those who were kind enough to participate in the survey. Without their cooperation, this paper would not have been possible. We also would like to thank Cynthia Leon for preparation of the manuscript.
Dedicated Air Ambulance Systems • Hospital -Based Turn Key Operation • Complete Program Design Props • Turbo Props • Jets & Helicopter System Leases • Management Contracts
MED FLIGHT SYSTEMS DIVISION 21 E. YorkSt., Savannah GA 31412 800/241-7763 In Georgia 912/238-1999 HOSPITALAVIATION,JANUARY1986 7