Improved compliance with lower tidal volumes for initial ventilation setting- using a Computerized Clinical Decision Support System.

Article (PDF Available) · December 2013with 54 Reads
DOI: 10.4187/respcare.02223 · Source: PubMed
Cite this publication
Abstract
The ARDSnet-low tidal volume (Vt) trial paved the ground for mechanically ventilating patients with Acute Respiratory Distress Syndrome (ARDS) with Vt of 6 ml/kg ideal body weight [IBW]. Although there is no consensus that a low Vt is advantageous in non-ARDS patients, it is accepted that high Vt should be avoided. Since compliance rates of ventilator recommendations are thirty-percent, there is a need for process improvement. We postulated that a computerized screen prompt that recommended Vt based on height would improve compliance with the low Vt. During ventilator order entry, the computerized decision tool prompts the clinician and encourages ventilation of patients at 8cc/kg IBW, and 6cc/kg IBW for patients with ARDS. A retrospective review was performed on patients who required volume controlled mechanical ventilation over a three-year period. Patients were chosen randomly from the respiratory records of six different ICUs at a single tertiary care academic center. Half of the charts selected were prior to intervention of on screen prompt and the other half were post implementation of the computerized decision tool. The initial set tidal volumes ranged from 6.26 to 13.45 cc/kg IBW with a mean of 8.92 cc/kg. After implementation of the on-screen prompt, mean tidal volume decreased by 0.84 ml/kg to 8.07 cc/kg (p value = 0.0011) with range lower at 4.73 to 11.56 cc/kg IBW. We also noted a significant decrease in the number of patients placed on an initial tidal volume greater than 10 ml/kg IBW from 20% to 4%, p=0.003. A computerized clinical decision tool with the preferred initial tidal volume settings based on the patients' sex and height is a safe and reliable way to increase low Vt strategy compliance across multiple ICUs. Its limitations are similar to those shared by other computer-generated prompts.
Better Ventilator Settings Using a Computerized Clinical Tool
Sidharth Bagga MD, Dalton E Paluzzi, Christine Y Chen MD, Jeffrey M Riggio MD,
Manjula Nagaraja MD, Paul E Marik MD, and Michael Baram MD
BACKGROUND: The Acute Respiratory Distress Syndome (ARDS) Network low tidal volume (V
T
)
trial paved the ground for mechanically ventilating ARDS patients with a V
T
of 6 mL/kg ideal body
weight (IBW). Although there is no consensus that a low V
T
is advantageous in non-ARDS patients,
it is accepted that high V
T
should be avoided. Because compliance rates with ventilator recommen-
dations are 30%, there is a need for process improvement. We postulated that a computerized
screen prompt that recommended V
T
based on height would improve compliance with low V
T
.
During ventilator order entry, the computerized decision tool prompts the clinician and encourages
ventilation of patients at 8 mL/kg IBW, and 6 mL/kg IBW for patients with ARDS. METHODS: A
retrospective review was performed on patients who required volume controlled mechanical ven-
tilation over a 3-y period. Subjects were chosen randomly from the respiratory records of 6
different ICUs at a single tertiary care academic center. Half of the charts selected were before
intervention of on-screen prompt, and the other half were after implementation of the computerized
decision tool. RESULTS: The initial set V
T
ranged from 6.26 to 13.45 mL/kg IBW, with a mean of
8.92 mL/kg. After implementation of the on-screen prompt, mean V
T
decreased by 0.84 mL/kg to
8.07 mL/kg (P.001) with a lower range of 4.73–11.56 mL/kg IBW. We also noted a significant
decrease in the number of subjects placed on an initial V
T
>10 mL/kg IBW from 20% to 4%
(P.003). CONCLUSIONS: A computerized clinical decision tool with the preferred initial V
T
settings based on the patients’ sex and height is a safe and reliable way to increase low V
T
strategy
compliance across multiple ICUs. Its limitations are similar to those shared by other computer-
generated prompts. Key words: ARDS; computerized clinical decision support system; mechanical
ventilation. [Respir Care 2014;59(8):1172–1177. © 2014 Daedalus Enterprises]
Introduction
Mechanical ventilation is a lifesaving intervention that
allows for oxygenation and ventilation of patients while
theirunderlyingdiseaseor clinicalissues resolve.
1
Changes
in ventilator strategy over the last decade have decreased
the harmful effects of mechanical ventilation. In the evo-
lution of mechanical ventilation, many factors have
emerged as causes of injury to the lung. In 1998, ARDSnet
researchers demonstrated that limiting tidal volume (V
T
)
in patients with diffuse lung injury improved outcomes
SEE THE RELATED EDITORIAL ON PAGE 1310
and mortality.
2,3
High V
T
and high plateau pressures were
found to be injurious to the lung parenchyma and were
associated with worse outcomes.
4
The goal in treating pa-
Dr Bagga, Mr Paluzzi, Dr Chen, and Drs Riggio, Nagaraja, and Baram
are affiliated with the Division of Pulmonary and Critical Care, Jefferson
Medical College, Philadelphia, Pennsylvania; Dr Marik is affiliated with
the Division of Pulmonary and Critical Care, Eastern Virginia Medical
School, Norfolk, Virginia.
None of the authors have disclosed a conflict of interest.
Dr Bagga presented a version of this paper at the 108th International
Conference of the American Thoracic Society, held May 18–23, 2012, in
San Francisco, California.
Correspondence: Michael Baram MD, Jefferson Pulmonary Associ-
ates, 834 Walnut Street, Suite 650, Philadelphia, PA, 19017. E-mail:
Michael.Baram@jefferson.edu.
DOI: 10.4187/respcare.02223
1172 RESPIRATORY CARE AUGUST 2014 VOL 59 NO8
tients with respiratory failure receiving mechanical venti-
lation is to support the patients as their illness improves
while preventing ventilator-induced lung injury.
4,5
A low
V
T
approach decreases ventilator-induced lung injury in
patients without preexisting acute lung injury (ALI) and
suggests that a low V
T
strategy is beneficial in all pa-
tients.
6,7
Reasons for adopting a low V
T
strategy in all
patients include limiting the development of delayed ALI
and preventing barotrauma. However, there is no consen-
sus on the optimal initial V
T
in patients without ALI.
8
At our tertiary care center, pilot data showed that a large
proportion of our patients were receiving an initial V
T
of
10 mL/kg ideal body weight (IBW). Poor compliance
with ventilation strategy guidelines/expert opinions can be
seen throughout the literature.
9,10
Because the time to ir-
reversible injury is short, prompt recognition of abnormal
V
T
is imperative.
3
Minimizing ventilator-induced lung in-
jury is an integral part of patient care in the modern ICU.
A system to provide optimal current recommendations
to physicians entering the initial mechanical ventilation
orders is necessary. Previous educational efforts through
lectures, handouts, and taping IBW cards to each ventila-
tor at our institution helped, but did not protect all patients
from inappropriate settings. These efforts have been used
at other institutions as well to improve education to reduce
ARDS triggers.
11,12
Recognizing the overestimation of IBW, it was postu-
lated that computer data would help guide clinicians to
safer initial V
T
based on patient height and sex. Imple-
mentations of expert rules have traditionally lagged years
behind published trials showing efficacy.
13,14
Eslami et al
15
have demonstrated that their computer decision support
system (CDSS) was effective in changing clinical practice
for patients ventilated for 24 h. We hypothesized that an
immediate computer-generated prompt on initial mechan-
ical ventilation orders could improve compliance with or-
dering low V
T
strategy at the time of initial mechanical
ventilation orders and reduce the risk of patients receiving
V
T
10 mL/kg IBW.
Methods
Intervention
For nearly 2 decades, every patient on a ventilator at our
institution had to have an immediate order set generated
electronically by the physicians caring for the patient. The
order set requires ventilator settings to be entered, as well
as other standard orders such as mouth care, head of bed
up, and hemodynamic monitoring.
The intervention was the addition of an on-screen
prompt (Fig. 1), which was triggered with each mechani-
cal ventilation order. The computer-generated recommen-
dation was a standard pop-up box that was displayed every
time the physician initiated or changed orders for a ven-
tilator.The on-screenprompt displayedthe patient’sheight,
sex, IBW, and recommendations for initial V
T
. Height and
sex were already in the computer database and were pre-
viously collected as part of the admission database to help
pharmacy with appropriate medication dosing. Height and
weight had to be entered into the computer before entry of
any hospital order. The IBW was calculated based on stan-
dard equations for ideal height to weight ratios.
16
The
clinicians had the option to enter any V
T
they wished, but
they were given an actual number for the recommended
V
T
based on the patients’ recorded height and sex.
Study Design
We implemented and studied a computerized clinical
decision tool, on the Centricity Enterprise (GE Healthcare,
Madison, Wisconsin) platform at Thomas Jefferson Uni-
versity Hospital, a tertiary care academic medical center
in Philadelphia, Pennsylvania, developed as an internal
prompt by institutional information technologists for
supporting low V
T
strategy. This retrospective review
evaluates initial V
T
, based on IBW, before and after a
computer-generated prompt was introduced hospital-wide
on October 20, 2009 (Table 1). The order entry system
had been in place for over 2 decades. The only change in
practice was the addition of the pop-up decision tool to
prompt clinicians to use 6 or 8 mL/kg IBW for initial
ventilator settings. The prompt was a suggested V
T
, and
the physician was able to enter any V
T
when finalizing
order. No extra training was needed because the inter-
vention only required the user to look at the pop-up box
displayed in Figure 1, and acknowledge by selecting
“OK” button. All physician order entries for mechanical
QUICK LOOK
Current knowledge
The current standard of care for ARDS patients on
mechanical ventilation includes tidal volumes (V
T
)of6
mL/kg of predicted body weight. Despite the mortality
benefit, compliance with lung-protective approaches in-
cluding low V
T
remains 50%. Methods to improve
compliance are needed.
What this paper contributes to our knowledge
A computerized clinical decision support tool with the
preferred initial V
T
settings based on gender and height
proved to be a safe and reliable way to increase com-
pliance using a lung-protective, low V
T
approach across
multiple ICUs.
VENTILATOR SETTINGS WITH A COMPUTERIZED TOOL
RESPIRATORY CARE AUGUST 2014 VOL 59 NO8 1173
ventilation (volume or pressure limited), either initial set-
tings or change of settings, were presented with an inter-
vention prompt and required acknowledgment before com-
pletion of orders, but we only evaluated the initial V
T
orders for volume controlled modes.
Study Settings
This study was performed in an urban university hos-
pital with approximately 1,000 beds. The decision tool
was implemented in all adult (age 18 y) ICUs in the
hospital. The units ranged in size from 8 to 25 beds. Many
patients were referral-based, and cared for by intensivists
trained in their specific subspecialty. All ICUs were staffed
by full-time, academic intensivists. All units have teams of
house officers to help care for patients and perform elec-
tronic order entry. As in many ICUs, the house officers
rotate through the ICU on a monthly basis.
Subject Inclusion/Exclusion Criteria
The study data were collected from March 2008 to July
2010. The inclusion criteria for subjects were that they
were intubated, transferred to an adult ICU during the
above time period, and receiving volume controlled ven-
tilation. Subjects were picked randomly, based on respi-
ratory care records, from all 6 different closed ICUs. The
data list of ventilated subjects was provided by the respi-
ratory therapy department. This list was divided into 2
groups: patients cared for before and after intervention.
The list was then further divided by month of admission to
ensure that a variety of clinicians (resident/attending phy-
sician rotation schedules were monthly) were included for
review. From each month, 1 or 2 charts were randomly
(simple randomization by a non-study participant) picked
from the list and retrieved for analysis. In subjects who
were intubated multiple times, subsequent intubations were
excluded. Ultimately, data from 240 charts were recorded
for sex, height, date of intubation, mode of mechanical
ventilation, and initial V
T
recorded on respiratory records.
During the first 24 h of intubation, a diagnosis of ARDS
cannot be confirmed (while ruling out other causes of
respiratory failure); therefore, this was not used as an in-
Figure 1. Screen shot of the automatic prompt displaying recommended tidal volume settings.
Table 1. Timeline of Project
Date Event Effect
Apr 2009 H1N1 pandemic Death of many young
overweight patients
Jun 2009 M&M of deaths Recognition of high V
T
on initial vent settings
Jul 2009 Pilot data Many patients with high
V
T
Oct 2009 Implementation of rule Developed a pre- and
post-intervention
group
May 2010 Submission to IRB
Jul 2010 IRB approval collection
Sep 2010 Data collection begins Collection of data
(before and after
prompt).
May 2012 ATS poster presentation Decision to create
manuscript
M&M morbidity and mortality conference
VTtidal volume
IRB institutional review board
ATS American Thoracic Society
VENTILATOR SETTINGS WITH A COMPUTERIZED TOOL
1174 RESPIRATORY CARE AUGUST 2014 VOL 59 NO8
clusion/exclusion criterion. The Thomas Jefferson Univer-
sity human research board approved this project.
Subject exclusion criteria were any of the following:
patient was from the operating room, patient received a
bone marrow transplant (because there was an insufficient
sample size in the pre- and post-intervention periods), or
patient was not started initially on volume control mechan-
ical ventilation.
Statistical Analyses
Results of the study were analyzed using standard sta-
tistical techniques of paired ttesting to determine the dif-
ference between 2 groups. Because the data were normally
distributed, and the results showed a significant number of
outliers outside of standard practice, the variance ratio test
(F test) was used to calculate the reduction of variance in
the high outliers. Analysis of variance detects change to-
ward the mean that is reflected as a change of the SD.
Results
The demographics of the pre- and post-intervention
groups showed similar ages of 65.6 and 64.3 y, respec-
tively (P.48). Likewise, subjects’ height of 167.7 cm
versus 170.7 cm (P.17) and IBW (P.79) were
similar because they were based on height.
16
There was no
statistical difference between the groups, as can be seen in
Table 2.
The initial set V
T
ranged from 6.26 to 13.45 mL/kg
IBW with a mean of 8.92 mL/kg IBW. After imple-
mentation of the on-screen prompt, the mean initial set
V
T
decreased by 0.84 mL/kg with a new mean of
8.07 mL/kg/IBW. The post-intervention range also shrank
from 4.73 to 11.56 mL/kg IBW. The changes in the V
T
across the 6 ICUs are shown in Table 3. There was a large
decrease in the number of subjects placed on an initial V
T
10 mL/kg IBW. The rate of high V
T
ventilation was
24 of 120 (20%), and this was reduced to 5 of 120 (4%)
subjects post-intervention (P.001). This reduction was
seen across all the ICUs (see Table 4). Further analysis
using the F test to compare SD (variation) of pre- and
post-interventionsamples foundstatisticallysignificant dif-
ferences overall and in specific units (surgical cardiac ICU,
medical cardiac ICU, and neurological ICU).
Pre- and post-intervention results displayed in Table 3
show multiple improvements. Average V
T
when compar-
ing all pre-and post-intervention groups shows improve-
ment with P.001, but 4 of the 6 individual units show
improvement as well. Not only is the mean improved, but
the SD became narrower for all groups. The F test shows
the significance of this smaller SD. The Pis significant
for this test in all units except for the medical ICU.
Discussion
In our retrospective review study, we noted a decrease
in the initial V
T
after the implementation of our CDSS
with on-screen prompts. The average decrease was
0.84 mL/kg. We noted a significant reduction in the num-
ber of subjects receiving a V
T
in excess of 10 mL/kg IBW.
It is unclear from our study whether this reduction in V
T
had any clinical benefits; however, this was not the goal of
the study. In patients with ARDS, a V
T
of 6 mL/kg IBW
is considered the standard of care. It is uncertain that all
patients requiring mechanical ventilation would benefit
from a V
T
of 6 mL/kg IBW; however, having a V
T
10 mL/kg IBW is likely to be harmful.
7
By using com-
puter-generatedprompts, wesignificantlyreduced thenum-
ber of subjects who were overventilated.
In patients without ALI, many physicians will set the
initial V
T
above 8 mL/kg IBW. In patients with ARDS, a
V
T
of 6 mL/kg is considered preferable, and there was a
linear relationship between plateau pressure and mortal-
ity.
17
The ARDSnet trial is the largest and most robust
study to date to compare a V
T
of 6 mL/kg IBW to 12 mL/kg
IBW.
6
Despite clear guidelines backed by strong random-
ized,controlledtrials inpatients documentedtohaveARDS,
adherence to low V
T
remains poor. Even in centers where
the original trials were performed, follow-up studies have
found that only 70% of patients with ALI are ventilated
with a low V
T
strategy.
18
Due to the difficulty of creating and enforcing guide-
lines in management of mechanical ventilation across mul-
tiple ICUs and different disciplines, we chose to initiate a
simple informative screen prompt for all physicians re-
sponsible for placing initial mechanical ventilation orders.
The impact of this intervention has shown a decrease in
overall V
T
and a dramatic reduction in the percentage of
patients receiving a V
T
likely to be injurious. This asso-
ciation with decreasing initial set V
T
and timing of inter-
vention is encouraging, but causal relationship cannot be
established in a retrospective manner. Although our sam-
ple size was relatively small, the subjects were chosen
randomly, and there was a consistent effect across all the
ICUs. We therefore believe that our findings are real and
Table 2. Demographics of Study Population
Before
Intervention After
Intervention P
Average age (y) 65.6 64.3 .48
Average height (cm) 167.7 170.7 .17
Average IBW (kg) 64.1 64.5 .79
Male (%) 52 53
IBW ideal body weight
VENTILATOR SETTINGS WITH A COMPUTERIZED TOOL
RESPIRATORY CARE AUGUST 2014 VOL 59 NO8 1175
represent a change in the initial ventilator setting across
our entire population of patients.
There are limitations to the study, in that it was a ret-
rospective review of a single center. We do not know how
often the order entry prompt was disregarded, how accu-
rately the heights were recorded, how respiratory thera-
pists chose initial V
T
before visualizing the order, or how
soon after the initial orders the changes to V
T
were made
and recorded. Another limitation was the difficulty in as-
sessing how many different physicians placed the orders
and under which physician’s directions (attending to res-
ident vs resident to intern) these orders were placed. Re-
gardless, many positives were seen. Physicians were forced
to see IBW, inexperienced clinicians were given a tool to
help guide their choices, and the prompt maintained cli-
nicians’ autonomy to vary their practice when needed.
Another advantage was that this was a free intervention
that resulted in a difference in practice. The prompt saved
time for those clinicians who would have otherwise looked
up the height, and for those who did not care to look at the
prompt, it took only 1 s to acknowledge. This quality im-
provement project has another practical aspect, as better
evidence evolves about ideal ventilator settings, the tool
can be modified to reflect best practices and up-to-date
medicine. Furthermore, because the intervention occurred
without the clinicians knowing that a CDSS intervention
was being developed or studied, the Hawthorne affect was
also minimized.
To our knowledge, only one other group of investigators
have found a benefit of CDSS in changing clinical param-
eters in ventilator management.
15,19
Eslami et al
15
found
that computers were effective in instilling change. Eslami
et al
19
also reported that removal of the prompt resulted in
decay back to previous practice, thus showing that the
reminders must occur with every ventilator order change.
Our intervention used a frequent reminder model: a com-
puter prompt was shown with every order that had to do
with V
T
. In our study, we have demonstrated a significant
decrease in the V
T
across all ICUs with a simple low-cost
intervention that requires no training. The way this prompt
appeared on the screen created no extra work for clinicians
and helped improve adherence to guidelines. The success
of this project has made this prompt a standard part of the
order entry for all ventilator orders.
Table 3. Average Initial V
T
by ICU Before and After Intervention With Respective Statistical Analysis
Unit (n)
Average V
T
(mL/kg IBW) Paired tTest Variance Ratio Test
Before
Intervention After
Intervention Average change
(mL/kg IBW) PP
MICU (20) 8.73 1.69 7.84 1.42 –0.89 .03 .46
SICU (20) 9.32 1.51 8.35 0.92 –0.97 .01 .04
SCCU (20) 9.19 1.49 8.01 0.80 –1.18 .003 .009
MCCU (20) 8.95 1.59 8.31 0.95 –0.64 .07 .03
NICU (20) 8.26 1.13 8.04 0.53 –0.22 .17 .002
NSICU (20) 9.03 1.06 7.87 0.71 –1.17 .001 .09
Total –0.84 .001
Statistical analysis compared the variance among all ICUs before and after intervention (F test).
VTtidal volume
IBW ideal body weight
MICU medical ICU
SICU surgical ICU
SCCU surgical cardiac ICU
MCCU medical cardiac ICU
NICU neurological ICU
NSICU neurosurgical ICU
Table 4. Number of Subjects Ventilated With Initial Orders of
Greater Than 10 mL/kg IBW Before and After Intervention
Unit (n)
n10 mL/kg (%)
Before
Intervention After
Intervention
MICU (20) 4 (20) 2 (10)
SICU (20) 4 (20) 1 (5)
SCCU (20) 7 (35) 1 (5)
MCCU (20) 4 (20) 1 (5)
NICU (20) 1 (5) 0 (0)
NSICU (20) 4 (20) 0 (0)
Total (P0.003) 24 (20) 5 (4)
IBW ideal body weight
MICU medical ICU
SICU surgical ICU
SCCU surgical cardiac ICU
MCCU medical cardiac ICU
NICU neurological ICU
NSICU neurosurgical ICU
VENTILATOR SETTINGS WITH A COMPUTERIZED TOOL
1176 RESPIRATORY CARE AUGUST 2014 VOL 59 NO8
Conclusions
An on-screen, automatic visual prompt displaying initial
V
T
settings is an effective way to improve use of a low V
T
strategy. This prompt calculated ideal V
T
based on sex and
height, and also reminded clinicians to keep V
T
in the
ARDSnet range. This tool improved compliance across
multiple ICUs. The limitations are similar to those shared
by other computer-generated prompts.
ACKNOWLEDGMENTS
We thank the Jefferson Information Services & Technology staff, in
particular Peggy Beattie RN MBA and Arlene Peters.
REFERENCES
1. Pingleton SK. Complication of acute respiratory failure. Am Rev
Respir Dis 1988;137(6):1463-1493.
2. Brochard L, Roudot-Thoraval F, Roupie E, Delclaux C, Chastre J,
Fernandez-Monde´jar E, et al. Tidal volume reduction for prevention
of ventilator-induced lung injury in acute respiratory distress syn-
drome. The Multicenter trial Group on Tidal Volume Reduction in
ARDS. Am J Respir Crit Care Med 1998;158(6):1831-1838.
3. Halter JM, Steinberg JM, Gatto LA, DiRocco JD, Pavone LA,
Schiller HJ, et al. Effect of positive end-expiratory pressure and tidal
volume on lung injury induced by alveolar instability. Crit Care
2007;11:R20.
4. Stewart TE, Meade MO, Cook DJ, Granton JT, Hodder RV, Lapinsky
SE, et al. Evaluation of a ventilation strategy to prevent barotrauma
in patient at high risk for acute respiratory distress syndrome. Pres-
sure- and Volume-Limited Ventilation Strategy Group. N Engl J Med
1998;338(6):355-361.
5. Amato MB, Barbas CS, Medeiros DM, Magaldi RB, Schettino GP,
Lorenzi-Filho G, et al. Effect of a protective-ventilation strategy on
mortality in acute respiratory distress syndrome. N Engl J Med 1998;
338(6):347-354.
6. The Acute Respiratory Distress Syndrome Network. Ventilation with
lower tidal volumes as compared with traditional tidal volumes for
acute lung injury and the acute respiratory distress syndrome. N Engl
J Med 2000;342(18):1301-1308.
7. Serpa Neto A, Cardoso SO, Manetta JA, Pereira VG, Espo´sito DC,
Pasqualucci MO, et al. Association between use of lung-protective
ventilation with lower tidal volumes and clinical outcomes among pa-
tients without acute respiratory distress syndrome: a meta-analysis.
JAMA 2012;308(16):1651-1659.
8. Schultz MJ, Haitsma JJ, Slutsky AS, Gajic O. What tidal volumes
should be used in patients without acute lung injury? Anesthesiology
2007;106(6):1226-1231.
9. Needham DM, Colantuoni E, Mendez-Tellez PA, Dinglas VD, Sev-
ransky JE, Dennison Himmelfarb CR, et al. Lung protective me-
chanical ventilation and two year survival in patients with acute lung
injury: prospective cohort study. BMJ 2012;344:e2124.
10. Rubenfeld GD, Cooper C, Carter G, Thompson BT, Hudson LD.
Barriersto providing lung-protectiveventilation to patientswithacute
lung injury. Crit Care Med 2004;32(6):1289-1293.
11. Yilmaz M, Keegan MT, Iscimen R, Afessa B, Buck CF, Hubmayr
RD, Gajic O. Toward the prevention of acute lung injury: protocol-
guided limitation of large tidal volume ventilation and inappropriate
transfusion. Crit Care Med 2007;35(7):1660-1666.
12. Restrepo R, Baram M, Marik P. Blood transfusion: who knows what
to do? A survey of medical house-staff. Chest 2012;142(4):537A.
13. Wolthuis EK, Korevaar JC, Spronk P, Kuiper MA, Dzoljic M, Vroom
MB, Schultz MJ. Feedback and education improve physician com-
pliance in use of lung-protective mechanical ventilation. Intensive
Care Med 2005;31(4):540-546.
14. Weinert CR, Gross CR, Marinelli WA. Impact of randomized trial
results of acute lung injury ventilator therapy in teaching hospital.
Am J Respir Crit Care Med 2003;167(10):1304-1309.
15. Eslami S, de Keizer NF, Abu-Hanna A, de Jonge E, Schultz MJ.
Effect of a clinical decision support system on adherence to a lower
tidal volume mechanical ventilation strategy. J Crit Care 2009;24(4):
523-529.
16. Pai MP, Paloucek FP. The origin of the “ideal” body weight equa-
tions. Ann Pharmacother 2000;34(9):1066-1069.
17. Hager DN, Krishnan JA, Hayden DL, Brower RG. Tidal volume
reduction in patients with acute lung injury when plateau pressures
are not high. Am J Respir Crit Care Med. 2005;172(10):1241-1245.
18. Young MP, Manning HL, Wilson DL, Mette SA, Riker RR, Leiter
JC. Ventilation of patients with acute lung injury and acute respira-
tory distress syndrome: has new evidence changed clinical practice?
Crit Care Med 2004;32(6):1260-1265.
19. Eslami S, Abu-Hanna A, Schultz MJ, de Jonge E, de Kreizer NF.
Evaluation of consulting and critiquing decision support systems:
effect on adherence to a lower tidal volume mechanical ventilation
strategy. J Crit Care 2012;27(4):42.
This article is approved for Continuing Respiratory Care Education
credit. For information and to obtain your CRCE
(free to AARC members) visit
www.rcjournal.com
VENTILATOR SETTINGS WITH A COMPUTERIZED TOOL
RESPIRATORY CARE AUGUST 2014 VOL 59 NO8 1177
  • Article
    Objectives: Mechanical ventilation with low tidal volumes is recommended for all patients with acute respiratory distress syndrome and may be beneficial to other intubated patients, yet consistent implementation remains difficult to obtain. Using detailed electronic health record data, we examined patterns of tidal volume administration, the effect on clinical outcomes, and alternate metrics for evaluating low tidal volume compliance in clinical practice. Design: Observational cohort study. Setting: Six ICUs in a single hospital system. Patients: Adult patients who received invasive mechanical ventilation more than 12 hours. Interventions: None. Measurements and main results: Tidal volumes were analyzed across 1,905 hospitalizations. Although mean tidal volume was 6.8 mL/kg predicted body weight, 40% of patients were exposed to tidal volumes greater than 8 mL/kg predicted body weight, with 11% for more than 24 hours. At a patient level, exposure to 24 total hours of tidal volumes greater than 8 mL/kg predicted body weight was associated with increased mortality (odds ratio, 1.82; 95% CI, 1.20-2.78), whereas mean tidal volume exposure was not (odds ratio, 0.87/1 mL/kg increase; 95% CI, 0.74-1.02). Initial tidal volume settings strongly predicted exposure to volumes greater than 8 mL/kg for 24 hours; the adjusted rate was 21.5% when initial volumes were greater than 8 mL/kg predicted body weight and 7.1% when initial volumes were less than 8 mL/kg predicted body weight. Across ICUs, correlation of mean tidal volume with alternative measures of low tidal volume delivery ranged from 0.38 to 0.66. Conclusions: Despite low mean tidal volume in the cohort, a significant percentage of patients were exposed to a prolonged duration of high tidal volumes which was correlated with higher mortality. Detailed ventilator records in the electronic health record provide a unique window for evaluating low tidal volume delivery and targets for improvement.
  • Article
    Rationale: Low tidal volume ventilation lowers mortality in patients with acute respiratory distress syndrome (ARDS) but is underused. Little is known about clinician attitudes toward and perceived barriers to low tidal volume ventilation use and their association with actual low tidal volume ventilation use. Objectives: The objectives of this study were to assess clinicians' attitudes toward and perceived barriers to low tidal volume ventilation (tidal volume <6.5mL/kg predicted body weight) in ARDS, to identify differences in attitudes and perceived barriers among clinician types, and to compare attitudes and perceived barriers with actual low tidal volume ventilation use in ARDS patients. Methods: Survey of critical care physicians, nurses and respiratory therapists at four non-ARDS Network Chicago region hospitals. Comparison of survey responses to performance in a cohort of 362 ARDS patients. Results: Survey responses included clinician attitudes toward and perceived barriers to low tidal volume ventilation use. We also measured low tidal volume ventilation initiation by these clinicians in 347 ARDS patients initiated after ARDS onset and correlated with clinician attitudes and perceived barriers. 69.3% (467/674) of clinicians responded. Clinicians had positive attitudes and perceived few process barriers to ARDS diagnosis or initiation of low tidal volume ventilation. Physicians had more positive attitudes and perceived fewer barriers than nurses or respiratory therapists. However, use of low tidal volume ventilation by all three clinician groups was low. For example, while physicians believed that 92.5% of their ARDS patients warranted treatment with low tidal volume ventilation, they initiated low tidal volume ventilation for a median [interquartile range] of 7.4% [0-14.3%] of their eligible ARDS patients. Clinician attitudes and perceived barriers were not correlated with low tidal volume ventilation initiation. Conclusions: Clinicians had positive attitudes toward low tidal volume ventilation and perceived few barriers, but attitudes and perceived process barriers were not correlated with actual low tidal volume ventilation use, which was low. Implementation strategies should focus on examining other issues, such as ARDS recognition and process solutions, to improve low tidal volume ventilation use.
  • Article
    Purpose of review: Although the treatment of the acute respiratory distress syndrome (ARDS) with low tidal volume (LTV) mechanical ventilation improves mortality, it is not consistently administered in clinical practice. This review examines strategies to improve LTV and other evidence-based therapies for patients with ARDS. Recent findings: Despite the well established role of LTV in the treatment of ARDS, a recent multinational study suggests it is under-utilized in clinical practice. Strategies to improve LTV include audit and feedback, provider education, protocol development, interventions to improve ICU teamwork, computer decision support, and behavioral economic interventions such as making LTV the default-ventilator setting. These strategies typically target all patients receiving invasive mechanical ventilation, effectively avoiding the problem of poor ARDS recognition in clinical practice. To more effectively administer advanced ARDS therapies, such as prone positioning, better approaches for ARDS recognition will also be required. Summary: Multiple strategies can be utilized to improve adherence to LTV ventilation in ARDS patients.
  • Article
    ICU-acquired weakness is a common problem and carries significant morbidity. Despite evidence that early mobility can mitigate this, implementation outside of the research setting is lagging. Understanding barriers at the systems as well as individual level is a crucial step in successful implementation of an ICU mobility program. This includes taking inventory of waste, overburden and inconsistencies in the work environment. Appreciating regulative, normative as well as cultural forces at work is critical. Finally, key personnel, which include organizational leaders, innovation champions and end users of the proposed change need to be accounted for at each step during program implementation. Copyright © 2015 Elsevier Inc. All rights reserved.
  • Article
    Full-text available
    To provide a historical perspective on the origin and similarity of the "ideal" body weight (IBW) equations, and clarify the terms ideal and lean body weight (LBW). Primary and review literature were identified using MEDLINE (1966-November 1999) and International Pharmaceutical Abstracts (1970-November 1999) pertaining to ideal and lean weight, height-weight tables, and obesity. In addition, textbooks and relevant reference lists were reviewed. All articles identified through the data sources were evaluated. Information deemed to be relevant to the objectives of the review were included. Height-weight tables were generated to provide a means of comparing a population with respect to their relative weight. The weight data were found to correlate with mortality and resulted in the use of the terms desirable or ideal to describe these weights. Over the years, IBW was interpreted to represent a "fat-free" weight and thus was used as a surrogate for LBW. In addition, the pharmacokinetics of certain drugs were found to correlate with IBW and resulted in the use of IBW equations published by Devine. These equations were consistent with an old rule that was developed from height-weight tables to estimate IBW. Efforts to improve the IBW equations through regression analyses of height-weight data resulted in equations similar to those published by Devine. The similarity between the IBW equations was a result of the general agreement among the various height-weight tables from which they were derived. Therefore, any one of these equations may be used to estimate IBW.
  • Article
    SESSION TYPE: Education and Teaching in Critical Care PostersPRESENTED ON: Wednesday, October 24, 2012 at 01:30 PM - 02:30 PMPURPOSE: The objective of this study was to determine if house officers understand the current evidence based practices for transfusion of blood products and the tendency of transfusion practices of house officers in teaching institutions in US.METHODS: Eighty-three house officers from six accredited United States (US) academic medical training programs were asked to complete a survey regarding the principals of transfusions (eight questions) and the appropriateness or inappropriateness of blood transfusion by rating (inappropriate, uncertain, appropriate) 10 clinical scenarios derived from the International Consensus Conference on Transfusion Outcomes (ICCTO) in which there was 100% agreement between the panelists. The study was approved by the Institutional Review Board of the coordinating center.RESULTS: On average the group scored poorly regardless of the level of training with an average score of 61 %. Only seven (9%) subjects were correct in all scenarios. When the questions were categorized according the principals of transfusion and case based scenarios, the score for correct answers were 55 % and 69 % respectively. When the group was divided by year of training, fellows did slightly better scoring 68 % vs 56 % for residents (NS). Clinical scenarios with a hemoglobin (Hb) > 10 g/dl had the correct answer chosen 90% of the time while for cases with a Hb 8.0 - 9.9 g/dl a correct answer was chosen 60% of the time (NS). When the age of the patient presented in the clinical question was analyzed, we found that if patients were younger than 61 years the subjects answered correctly to 82% of the time compared to 59 % when the case included patients 61 years or older (NS). The scores did not differ between centers, suggesting that this is a nationwide problem.CONCLUSIONS: Indications for RBC transfusions are not well understood by trainees. Although the literature offers many resources, there is no consensus that defines all scenarios, but a few basic guidelines do exist that multi-disciplinary experts do agree on. This information must be delivered to the house officers who are taking care of hospitalized patients.CLINICAL IMPLICATIONS: Blood transfusions have become one of the most common interventions performed worldwide in modern health care. There is growing evidence suggesting that Red Blood Cell transfusion carries a limited benefit and may increase the incidence to unfavorable outcomes. The need for improvements in transfusion medicine education for residents and fellows has been recognized.DISCLOSURE: The following authors have nothing to disclose: Ricardo Restrepo, MIchael Baram, Paul MarikNo Product/Research Disclosure InformationThomas Jefferson University, Philadelphia, PA.
  • Article
    Full-text available
    Lung-protective mechanical ventilation with the use of lower tidal volumes has been found to improve outcomes of patients with acute respiratory distress syndrome (ARDS). It has been suggested that use of lower tidal volumes also benefits patients who do not have ARDS. To determine whether use of lower tidal volumes is associated with improved outcomes of patients receiving ventilation who do not have ARDS. MEDLINE, CINAHL, Web of Science, and Cochrane Central Register of Controlled Trials up to August 2012. Eligible studies evaluated use of lower vs higher tidal volumes in patients without ARDS at onset of mechanical ventilation and reported lung injury development, overall mortality, pulmonary infection, atelectasis, and biochemical alterations. Three reviewers extracted data on study characteristics, methods, and outcomes. Disagreement was resolved by consensus. Twenty articles (2822 participants) were included. Meta-analysis using a fixed-effects model showed a decrease in lung injury development (risk ratio [RR], 0.33; 95% CI, 0.23 to 0.47; I2, 0%; number needed to treat [NNT], 11), and mortality (RR, 0.64; 95% CI, 0.46 to 0.89; I2, 0%; NNT, 23) in patients receiving ventilation with lower tidal volumes. The results of lung injury development were similar when stratified by the type of study (randomized vs nonrandomized) and were significant only in randomized trials for pulmonary infection and only in nonrandomized trials for mortality. Meta-analysis using a random-effects model showed, in protective ventilation groups, a lower incidence of pulmonary infection (RR, 0.45; 95% CI, 0.22 to 0.92; I2, 32%; NNT, 26), lower mean (SD) hospital length of stay (6.91 [2.36] vs 8.87 [2.93] days, respectively; standardized mean difference [SMD], 0.51; 95% CI, 0.20 to 0.82; I2, 75%), higher mean (SD) PaCO2 levels (41.05 [3.79] vs 37.90 [4.19] mm Hg, respectively; SMD, -0.51; 95% CI, -0.70 to -0.32; I2, 54%), and lower mean (SD) pH values (7.37 [0.03] vs 7.40 [0.04], respectively; SMD, 1.16; 95% CI, 0.31 to 2.02; I2, 96%) but similar mean (SD) ratios of PaO2 to fraction of inspired oxygen (304.40 [65.7] vs 312.97 [68.13], respectively; SMD, 0.11; 95% CI, -0.06 to 0.27; I2, 60%). Tidal volume gradients between the 2 groups did not influence significantly the final results. Among patients without ARDS, protective ventilation with lower tidal volumes was associated with better clinical outcomes. Some of the limitations of the meta-analysis were the mixed setting of mechanical ventilation (intensive care unit or operating room) and the duration of mechanical ventilation.
  • Article
    Full-text available
    To evaluate the association of volume limited and pressure limited (lung protective) mechanical ventilation with two year survival in patients with acute lung injury. Prospective cohort study. 13 intensive care units at four hospitals in Baltimore, Maryland, USA. 485 consecutive mechanically ventilated patients with acute lung injury. Two year survival after onset of acute lung injury. 485 patients contributed data for 6240 eligible ventilator settings, as measured twice daily (median of eight eligible ventilator settings per patient; 41% of which adhered to lung protective ventilation). Of these patients, 311 (64%) died within two years. After adjusting for the total duration of ventilation and other relevant covariates, each additional ventilator setting adherent to lung protective ventilation was associated with a 3% decrease in the risk of mortality over two years (hazard ratio 0.97, 95% confidence interval 0.95 to 0.99, P=0.002). Compared with no adherence, the estimated absolute risk reduction in two year mortality for a prototypical patient with 50% adherence to lung protective ventilation was 4.0% (0.8% to 7.2%, P=0.012) and with 100% adherence was 7.8% (1.6% to 14.0%, P=0.011). Lung protective mechanical ventilation was associated with a substantial long term survival benefit for patients with acute lung injury. Greater use of lung protective ventilation in routine clinical practice could reduce long term mortality in patients with acute lung injury. Clinicaltrials.gov NCT00300248.
  • Article
    Our hypothesis was that both styles are effective to decrease tidal volume (V(T)) but that critiquing comprises the most effective strategy. The purpose of this study is to test this hypothesis by measuring the effect of an active computerized decision support system, in 2 communication styles, consulting and critiquing, on adherence to V(T) recommendations. We developed and implemented an active computerized decision support system (CDSS) working in a consulting style that always shows the preferred V(T) and in a critiquing style that shows the preferred V(T) only if V(T) is above the desired threshold. A prospective, off-on-off-on study evaluated the system's performance in a mixed medical-surgical intensive care unit of a university hospital. Four thousand seven hundred sixty-four patient-day mechanical ventilation from 757 patients were analyzed. The percentage of ventilation time in excess of 6 and 8 mL/kg predicted body weight decreased significantly after intervening with the consulting style (12% reduction and P < .001; 22% reduction and P < .001) and again increased after stopping the CDSS (11% increase and P < .001; 29% increase and P < .001). With the critiquing CDSS, the percentage of ventilation time in excess of 6 and 8 mL/kg predicted body weight again decreased significantly (6% reduction and P < .001; 15% reduction and P < .001). The use of a CDSS in both communication styles improved the use of lower V(T)s for ventilated patients. When decision support was not sustained, adherence to low V(T) fell back to its original value. Interestingly, the consulting style had a slightly larger effect. This may stem from the high frequency of showing reminders in this style and the relatively simple underlying guideline where its display implies the associated action of lowering V(T). The consulting style, however, was more interruptive for clinicians, calling upon the need to strike a balance between effect and intrusiveness.
  • Article
    The purpose of the study was to measure the effect of a computerized decision support system (CDSS) on adherence to tidal volume (V(T)) recommendations. We performed a prospective before-after evaluation study on applied V(T) to examine the impact of a CDSS on adherence to our local protocol in a 30-bed mixed medical-surgical intensive care unit of a university hospital. All intensive care unit patients who were intubated and mechanically ventilated for at least 1 hour were included. A total of 3 663 674 V(T) records of 696 patients were analyzed. The average volume greater than 6 mL/kg predicted body weight (PBW) and the mean percentage of ventilation time with V(T) greater than 6 mL/kg PBW decreased after intervention by 6.0% and 3.4%, respectively (not significant). A stronger effect of the decision support intervention was found among patients with longer duration of mechanical ventilation (>24 hours): for these patients, the average V(T) in exceeding 6 mL/kg PBW and the mean percentage of ventilation time with V(T) greater than 6 mL/kg PBW decreased after intervention by 18.3% (P = .01) and 9.5% (P = .01), respectively. In this group, the mean percentage of ventilation time with V(T) records between 8 and 10, between 10 and 12, and greater than 12 mL/kg PBW decreased by 21.8% (P = .006), 21.5% (P = .047), and 24.7% (P = .155), respectively. The use of a CDSS, integrated in a patient data management system, improves implementation of a lower V(T) mechanical ventilation strategy for patients ventilated for longer than 24 hours.
  • Article
    Acute respiratory failure is frequently fatal. Attempts to decrease mortality must include attention to pulmonary and extrapulmonary complications. Pulmonary complications include pulmonary emboli, barotrauma, fibrosis, and pneumonia. Swan-Ganz catheters, tracheal intubation, and mechanical ventilation can also result in pulmonary complications. Extra-pulmonary complications such as gastrointestinal hemorrhage, renal failure, infection, and thrombocytopenia may increase mortality. Early diagnosis, aggressive treatment, and prophylaxis of complications should increase survival.
  • Article
    Full-text available
    A strategy of mechanical ventilation that limits airway pressure and tidal volume while permitting hypercapnia has been recommended for patients with the acute respiratory distress syndrome. The goal is to reduce lung injury due to overdistention. However, the efficacy of this approach has not been established. Within 24 hours of intubation, patients at high risk for the acute respiratory distress syndrome were randomly assigned to either pressure- and volume-limited ventilation (limited-ventilation group), with the peak inspiratory pressure maintained at 30 cm of water or less and the tidal volume at 8 ml per kilogram of body weight or less, or to conventional ventilation (control group), with the peak inspiratory pressure allowed to rise as high as 50 cm of water and the tidal volume at 10 to 15 ml per kilogram. All other ventilatory variables were similar in the two groups. A total of 120 patients with similar clinical features underwent randomization (60 in each group). The patients in the limited-ventilation and control groups were exposed to different mean (+/-SD) tidal volumes (7.2+/-0.8 vs. 10.8+/-1.0 ml per kilogram, respectively; P<0.001) and peak inspiratory pressures (23.6+/-5.8 vs. 34.0+/-11.0 cm of water, P<0.001). Mortality was 50 percent in the limited-ventilation group and 47 percent in the control group (relative risk, 1.07; 95 percent confidence interval, 0.72 to 1.57; P=0.72). In the limited-ventilation group, permissive hypercapnia (arterial carbon dioxide tension, >50 mm Hg) was more common (52 percent vs. 28 percent, P=0.009), more marked (54.4+/-18.8 vs. 45.7+/-9.8 mm Hg, P=0.002), and more prolonged (146+/-265 vs. 25+/-22 hours, P=0.017) than in the control group. The incidence of barotrauma, the highest multiple-organ-dysfunction score, and the number of episodes of organ failure were similar in the two groups; however, the numbers of patients who required paralytic agents (23 vs. 13, P=0.05) and dialysis for renal failure (13 vs. 5, P= 0.04) were greater in the limited-ventilation group than in the control group. In patients at high risk for the acute respiratory distress syndrome, a strategy of mechanical ventilation that limits peak inspiratory pressure and tidal volume does not appear to reduce mortality and may increase morbidity.