PMID- 10145333
OWN - NLM
STAT- MEDLINE
DCOM- 19901119
LR  - 20071115
IS  - 0020-1324 (Print)
IS  - 0020-1324 (Linking)
VI  - 35
IP  - 10
DP  - 1990 Oct
TI  - Laboratory and clinical evaluation of the MAX transport ventilator.
PG  - 952-9
AB  - Transport of critically ill, mechanically ventilated patients from intensive care 
      units for diagnostic and therapeutic procedures has become common in the last 
      decade. Maintenance of adequate oxygenation and ventilation during transport is 
      mandatory. We evaluated the Hamilton MAX transport ventilator in the laboratory 
      and in the clinical arena to determine its usefulness during in-hospital 
      transport. METHODS: In the laboratory, we determined the MAX's ability to assure 
      tidal volume (VT) delivery in the face of decreasing compliance of a test lung, 
      and we tested the alarm system. Using a two-compartment lung model modified to 
      simulate spontaneous breathing, we also evaluated the responsiveness of the 
      demand valve. The clinical evaluation was accomplished by comparing arterial 
      blood gases and ventilator settings in the intensive care unit to those during 
      transport. RESULTS: As lung compliance was reduced from 0.1 to 0.02 L/cm H2O [1.0 
      to 0.20 L/kPa], delivered VT fell significantly at each set VT. The alarm systems 
      performed according to manufacturer's specifications. The demand valve triggered 
      appropriately without positive end-expiratory pressure (PEEP), but as PEEP was 
      increased, triggering became more difficult. The demand valve is referenced to 
      ambient pressure and cannot compensate for elevated end-expiratory pressures. 
      During patient transport, arterial blood gases were comparable to those achieved 
      in the ICU. Because an inspired oxygen concentration of 1.0 was used during 
      transport, arterial oxygenation (PaO2) was significantly greater (123 +/- 75 vs 
      402 +/- 85 torr [16.4 +/- 10 vs 53.6 +/- 11 kPa]). A higher ventilator rate was 
      required during transport to prevent tachypnea (7 +/- 3 vs 12 +/- 6 breaths/min), 
      and peak inspiratory pressure (PIP) was higher during transport (40 +/- 8 vs 52 
      +/- 11 cm H2O [3.9 +/- 0.8 vs 5.1 +/- 1.1 kPa]). CONCLUSIONS: The MAX is a 
      reliable transport ventilator, capable of maintaining adequate ventilation and 
      oxygenation in a majority of mechanically ventilated patients. Care should be 
      taken to assure adequate VT delivery at high PIP, and ventilator rate may require 
      adjustment to prevent tachypnea associated with triggering the 
      non-PEEP-compensated demand valve when PEEP greater than 8 cm H2O [0.8 kPa] is 
      used.
FAU - Johannigman, J A
AU  - Johannigman JA
AD  - Department of Surgery, Wilford Hall, United States Air Force, San Antonio, TX.
FAU - Branson, R D
AU  - Branson RD
FAU - Campbell, R
AU  - Campbell R
FAU - Hurst, J M
AU  - Hurst JM
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Respir Care
JT  - Respiratory care
JID - 7510357
MH  - Adult
MH  - Blood Gas Analysis
MH  - Evaluation Studies as Topic
MH  - Female
MH  - Humans
MH  - Male
MH  - Positive-Pressure Respiration
MH  - *Transportation of Patients
MH  - United States
MH  - Ventilators, Mechanical/*standards
EDAT- 1990/10/01 00:00
MHDA- 1999/04/02 00:01
CRDT- 1990/10/01 00:00
PHST- 1990/10/01 00:00 [pubmed]
PHST- 1999/04/02 00:01 [medline]
PHST- 1990/10/01 00:00 [entrez]
PST - ppublish
SO  - Respir Care. 1990 Oct;35(10):952-9.