Running Head: SAFE EARLY EXTUBATION
How Early Extubation Can Safely Be Achieved in Cardiac Surgery: A Review of Literature.
Rachel Anderson
University of Virginia School Of Nursing
GNUR 6315
Clinical Decision Making in Acute and Specialty Care-Seminar II
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Running Head: SAFE EARLY EXTUBATION
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Abstract
Early extuabation has been identified as a safe way to improve patient outcomes and possibly
reduce health care costs. A review of the literature was done to answer the question, “How can
early and effective extubation be achieved in the cardiac surgery population”. It was found
through this literature review that short acting anesthesia medication, dexmedetomidine, thoracic
epidural analgesia, post extubation positive pressure ventilation, and aggressive rewarming were
all important factors. Nursing implications across all stages of the surgical process are discussed.
Keywords: Fast track extubation, early extubation, cardiac surgery
Running Head: SAFE EARLY EXTUBATION
Introduction
Cardiac surgery has undergone almost a complete transformation since its start in 1893
(Cohn, 2008). These revolutions have been a result of anesthesia advancements, improved
utilization of cardiopulmonary bypass (CPB), and improved post-operative management. As this
surgery continues to evolve, ways to improve patient outcomes and length of stay remain high
priorities, however in the past decade, while the number of cardiac surgery case has steadily
increased, there has been little reduction in the patient’s days to discharge
(http://www.sts.org/sites/default/files/documents/pdf/ndb2010/3rdHarvestExecutiveSummary201
0.pdf, 2011). In an effort to minimize rising health care
(http://www.cms.gov/nationalhealthexpenddata/01_overview.asp?, 2011), hospitals seek to find
safe strategies to reduce expenditures for both the patients and their organizations by reducing
length of stay in both the intensive care unit and hospital.
In a Cochrane review, (Hawkes, Dhileepan, and Foxcroft, 2003) it was investigated if
early extubation in cardiac surgery patients could reduce not only the length of stay, but also
patient mortality rates. It was found that there was neither a positive nor negative effect on
mortality rates with early extubation, however there was a reduction in intensive care unit and
hospital length of stay. The review went on the suggest investigation was needed to establish the
safety and efficacy of early extubation in this patient population.
The Society of Thoracic Surgeons, an international, multi-disciplinary organization, was
formed to improve surgical outcomes in patients whose surgery is within the chest
(http://www.sts.org/about-sts, 2011). As a sub-group of this organization, the Virginia Cardiac
Surgery Quality Initiative identified early extubation as one possible way to improve outcomes
in its 2008-2009 model. In a review of centers that had achieved early extubation, as defined as
being within four to eight hours after surgery, several facilitating factors were identified. The
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Running Head: SAFE EARLY EXTUBATION
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predominant reasons were: use of less sedation and shorter-acting muscle relaxants; Bispectral
Index montoring (BIS) as part of a cardiac anesthesia protocol; allowed extubation of patients on
Intra-Aortic Balloon Pump; use of moderate hypothermia intraoperatively with more aggressive
re-warming postoperatively; using the same standing orders for all surgeons; promote
understanding by tracking extubation times for all anesthesiologists and discussing results at
quarterly meetings
(http://www.sts.org/sites/default/files/documents/pdf/newsletters/NDB/DBnewsMarch08.pdf,
2011).
Purpose
It has been seen in the literature that early extubation may be one way to reduce health
care costs through shorted length of hospital and intensive care stays, and it has been identified
by one organization that there are specific factors in how early extubation can be achieved.
Therefore the purpose of this paper is to review the literature in an effort to answer the suggested
research need proposed by the Cochrane review of, “How can early and effective extubation be
achieved in the cardiac surgery population.” Factors explored will include, but not be limited to
the suggested reason as described by the Virginia Cardiac Surgery Quality Initiative’s
investigation. How these findings can be utilized in nursing practice will then be identified.
Review Methods
A systematic review of the literature was composed using PubMed and CINAHL. Terms
used were as follows: cardiac surgery early extubation; cardiac surgery fast track extubation; and
open heart surgery early extubation. Only patient populations eighteen years and older were
included. Surgery types included were isolated coronary artery bypass grafting (CABG) done on
and off cardiopulmonary bypass (CPB), isolated aortic and/or mitral valves, and combination
Running Head: SAFE EARLY EXTUBATION
CABG with valve. Dates were limited to 2001 to 2011. Search engines included articles from all
languages and were equipped to include dissertations when available. Early extubation for the
search was defined as less than 10 hours. An additional manual review of cardiac surgery text
book was done to search for early extubation achievability. Significant studies are included in
Table 1 and corresponding levels of evidence were assigned to each study to determine their
strength in practice.
Literature Findings
Extubation Criteria
In discussing how early extubation can be achieved, it must first be discussed what
determines if a patient is extubatable. In order for the endotracheal tube to be removed, the
majority of cardiac surgery text books have agreed the following must be present: adequately
intact neurologic status to maintain an airway, stable hemodynamics, adequately rewarmed,
absence of malignant lethal arrhythmias, adequate respiratory effort, and absence of mediastinal
bleeding in excessive amounts (Andrea et al., 2009; Hardin and Kaplow, 2009; Ciulli, Thorpe,
Ciulli, and Franco, 2003).
In reviewing the literature, two lower levels of evidence studies were found that
evaluated the reasons for not extubating in less than six hours (Sato et al., 2009) (Akhtar and
Hamid, 2009). Both studies showed the recommendations from the text were being observed, as
it was found that those requiring large doses of medication for hemodynamic support, those
neurologically compromised, and those with high mediastinal chest tube output all remained
intubated longer.
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Running Head: SAFE EARLY EXTUBATION
It is important to recognize when evaluating the literature, that while most centers share
these parameters for extubation, their individual definitions of each criterion vary center to
center, and therefore adds variability to what makes a patient extubatable.
Effects of Cardiopulmonary Bypass
The dramatic and sometimes devastating effects of the CPB to the patient’s renal,
neurologic, and hematologic function as well as hemodynamic status (Henke and Eigsti, 2003)
can affect the patient’s stability post-operatively. Despite these well documented facts, the
literature is divided on the CPB’s role in achieving safe early extubation.
In Cohn’s Cardiac surgery in the adult (2008), multivariate study findings were
discussed which concluded that the duration of CPB was in direct correlation to length of postoperative intubation time. An addition study found intubation times were shorter in those with
shorter CPB times (Georghiou et al, 2006).
In contrast, in comparing CABGs that did use CPB to those who did not, one study found
equal effects exhibited on the respiratory system between the two groups (Roosens et al, 2002).
In investigating intra-operative variables on extubation times, another study supported this by
finding no significant correlation in CPB time and extubation time (Walthall and Ray, 2002).
In discussing the reasons for the differing findings, one reason may be that in light of the
known effects of CPB, several manufacturers have changed the mechanisms in their machines to
lessen the negative effects (Gravlee, Davis, Stammers, and Ungerleider, 2008) and there is not
standardization across centers in terms of which kind of machines are used. Additionally, the
length of the tubing has been shown to impact the effects of the CPB, and therefore some centers
have chosen to use shorter tubing. A final factor may be that different centers prime their pumps
with different fluids that vary from blood products to crystalloids. The use of blood intra-
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Running Head: SAFE EARLY EXTUBATION
operative has been proven to have negative post-operative outcomes (Vamvakas and Blajchman,
2010) therefore this variable may also be a reason for the conflicting findings.
Anesthesia and Post-operative medications
To preform cardiac surgery, general anesthesia is used for pain control, muscle
relaxation, and amnesia effect. A combination of inhaled, intravenous, and sometimes, epidural
agents, are used. Anesthesia medication duration, mechanism of action, and side effects all have
effects on the patient that last well into the post-operative period, and therefore are evaluated
here to determine their effects of time to extubation.
Dexmedetomidine
In 1999 the Federal Drug Administration approved Dexmedetomidine for short term use
(<24 hours) and in recent years it has gained increased use in the cardiac surgery population
(http://www.precedex.com, 2011). As an alpha-2 agonist, this drug has applications as
premedication, an anesthetic adjunct for general and regional anesthesia, and as a postoperative
sedative and analgesic. Effects are similar to benzodiazepines, but with fewer side effects, such
as heavy sedation.
In researching the effects of using Dexmedetomidine to decrease intubation times postoperatively, several studies have been done. One study showed shorter times to extubation and a
secondary finding discovered that lower doses of neuromuscular blockade agents and fewer
administrations of narcotics were need (Afanador et al., 2010). This study also showed that in the
Dexmedetomidine group, there was a reduction in the systemic inflammatory response syndrome
that often in cardiac surgery patients. This is significant because this syndrome lowers the
systemic vascular resistance and therefore the patient’s blood pressure. Persistent hypotention
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Running Head: SAFE EARLY EXTUBATION
prolongs the patient’s time to extubation, thus Dexmedetomidine may be instrumental in
decreased intubation times through this pathway as well.
When discussing early extubation as a way to decease hospital cost, it becomes important
to recognize the higher expense often associated with Dexmedetomidine, which is mainly due to
its Federal Drug Administration approval only being within the last eleven years. Two studies
compared its administration to a variety of different agents, and both studies showed
Dexmedetomidine as having a higher cost than traditional anesthesia agents (Barletta, Miedema,
Wiseman, Heiser, and McAllen, 2009; http://www.eimjm.com/Vol6-No2/Vol6-No2-B1.htm,
2011). Therefore a multi-variable analysis of effect on cost related to administration and hospital
length of stay must be evaluated before choosing this agent for the sole purpose of decrease
intubation times in an attempt to reduce costs.
Traditional Anesthesia agents
When administering intra-operative medications for sedation and pain control, the
traditional agents are usually some combination of midazolam, propofol, sufentanil, remifentanil,
and/or fentanyl. These drugs can also be combined with Dexmedetomidine both intra-operatively
and post-operatively to enhance effects and decrease dosages required.
When comparing use of sufentanil versus remifentanil versus fentanyl, what sets them
apart in their use, is the pharmacodynamics of the drugs and their half-lives. Each is selected for
surgery based on its predominate benefit in use. Fentanyl works longer than the others and is a
cheaper drug. sufentanil is five to ten times more potent fentanyl and has a half-life that is shorter
than fentanyl but longer than remifentanil. It is this superior short life of three to ten minutes that
usually is the reason for selecting reminfentanil as an anesthetic agent. One randomized control
study compared all three agents for: time to tracheal extubation, time to intensive care unit
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Running Head: SAFE EARLY EXTUBATION
discharge, time to hospital discharge, postoperative pain, and cost. It was found that were was no
significant difference among the drugs in any of these outcomes (Engoren, Luther, FennBuderer, 2001). In another randomized control study, fentanyl was compared to sufentanil for its
effects on time taken for extubation, hemodynamic stability, analgesia requirements and
incidence of awareness. The results were that those in the sufentanil group extubated faster,
however it is significant to note that in the sufentanil group there was one incidence of awareness
during surgery (Deshpande, Mohite, and Kamdi, 2009).
Propofol is often chosen because of its short half-life as a sedating agent and its ability to
be given in a continuous drip that can be continued in the cardiac surgery intensive care unit.
Midazolam, as a longer lasting benzodiazapine, it is often only given intra- and post-operatively
as intravenous boluses. In comparing the two through a study seeking to find if any intraoperative variables that could have effected extubation times after CABG, it was seen that there
was no significant difference in those using propfol versus the midazolam (Walthall and Ray,
2002). Similar findings were present in a study that compared the use of fentanyl paired with
midazolam versus propofol (Sato et al., 2009).
In addition to sedating agents, neuromuscular blocking agents are used to paralyze the
patient once sedation is achieved. As with the sedating agents, in choosing a paralytic, half-life
becomes important to achieve early extubation. In a randomized control trial it was found that
using rocuronium should be preferred over pancuronium because there were faster exubation
times with less residual muscular blockade in the post-operative recovery unit (Thomas, Smith,
and Strike, 2003). This finding is largely attributed to the shorter half of rocuronium. Murphy et
al’s (2002) randomized control study’s findings were similar, and suggested also that rocuronium
be used instead of pancuronium when early extubation is the goal. However in both of these
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Running Head: SAFE EARLY EXTUBATION
studies it was found that though extubation times were shortened, there was no decrease in
hospital or intensive care unit length of stay. There have been studies that have successfully used
panuronium in their fast track programs; however they have used the reversal agent neostigmine
to clear the pancuronium post-operatively (Najafi, 2008)
Two separate studies were conducted that found their fast track programs were
successful in reducing extubation times and the anesthesia medications used were considered for
their influence. The first study’s intervention group used oral lorazapm as premedication (Reis,
Mota, Ponce, Costa-Pereira, and Guerreiro, 2002), while the other study used clonidine in their
intervention group (Ender, et al., 2008). For induction, both studies used propofol, but differed in
their use of fentanyl (Reis et al., 2002) versus sufentanil (Ender, et al, 2008). The paralytic used
was not stated by Reis et al (2002), however Ender et al (2008) identified using rocuronium in
their fast track group. With maintenance of anesthesia, isoflurance was alone being used (Reis et
al., 2002) in the first study and a continuous infusion of remifentanil, propofol and sevoflurance
were utilized in the second study (Ender et al., 2008). Post-operatively, pain was managed by a
morphine PCA in the Reis et al. study (2002) in contrast to the bolus doses of piritramide and
paracetamol used by Ender et al, (2008).
In reviewing the agents that are used intra-operatively for cardiac surgery, it is seen that
for both narcotics and neuromuscular blocking agents, drugs that have a shorter half-life should
be selected because not only do they shorten the time to extubation, but this can be achieved
without serious consequences to other patient outcomes in most cases.
Thoracic Epidural Analgesia
For the cardiac surgery patient, effective pain relief can be difficult to achieve while
striving to maintain adequate level of consciousness for the patient to maintain effective
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Running Head: SAFE EARLY EXTUBATION
oxygenation and ventilation. For these reasons, epidurals are beneficial in surgery patients
because of their quick effects and greater pain relief at lower opioid analgesic doses.
Two separate studies were preformed that looked at how using thoracic epidural
analgesia immediately before surgery and continuing into the post-operative period would affect
times to extubation. The first found no superior outcomes with extubation in either the traditional
intravenous opiod group or the in thoracic epidural group (Hemmerling et al., 2005), however it
is of note that this was a level IV evidence study. Caputo et al (2011) however found in their
randomized control trail, that using a thoracic epidural in conjunction with conventional general
anesthesia led to not only earlier exutbation times, but also a reduction in arrhythmias and
hospital length of stay.
Ventilation
In fast track extubation programs, the parameters of readiness to extubate are not
different from those of traditional cardiac surgery ventilator weaning. The measurements of
maximal inspiratory effort, forced respiratory capacity, adequate arterial blood gases and patient
ability to protect their airway remain the same. It is, instead the path to meet these goals that is
different in the fast track programs.
The use of CPB has been well studied as having dramatic effects throughout the body in
cardiac surgery patients. To determine how to offset these effects on the lungs and subsequently
reduce time to extubation, studies have explored different theories. In a randomized control trial,
Eren et al (2003) sought to determine if giving N-acetylcysteine intravenously would counter the
effects of the CPB. It was found that while there was oxygenation improvements, there was no
effect on outcomes or differences in extubation times.
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Running Head: SAFE EARLY EXTUBATION
The proinflammatory response of the body to the CPB and subsequent transient gas
exchange abnormalities has been the rationale for research addressing how different approaches
to post-operative ventilation could effect extubation times. One study was conducted to see if
using nasal continuous positive airway pressure (CPAP) routinely immediately after extubation
was more effective at keeping the patient from reintubation. The result was that it in fact
decreased pneumonia and re-intubation rates, as well readmission to higher levels of care
(Zarbock et al., 2009). In a study of one programs implemented fast track program, it was seen
that use of bi-level positive airway pressure (BIPAP) for all patients for one hour after extubation
contributed to their success rates of safely decreasing intubation times (Ender et al., 2008). For
use in fast track extubation patients, these findings may be helpful as a way to bridge or support
patients who may still have some transient gas exchange abnormalities from the CPB while at
the same time removing the breathing tube.
Other factors
Two separate studies (Walthall and Ray, 2002; Georghiou et al., 2006) looked
retrospectively to determine what variables could have effected time to extubation after CABG,
and both studies found that the number of vessels bypassed did not effect extubation times.
In determining the effect of advanced age (as defined as those older than seventy) on
early extubation, one study (Kogan et al., 2008) found that age alone should not preclude placing
a patient into a fast track extubation plan. However it was seen through this study that those over
the age of eighty were more likely to have at least one postoperative complication. Another study
acknowledge that younger patients were more likely to extubate quicker and also that men were
had shorter intubation times (Georghiou et al., 2006).
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Running Head: SAFE EARLY EXTUBATION
Rewarming the patient more aggressively when coming off CPB with subsequent higher
presenting body temperatures in the recovery intensive care unit has also been attributed to
earlier extubation times (Reis et al, 2002; Ender et al. 2008). As discussed earlier rewarming
patients to normothermia is one prerequisite of extubation. The reason rewarming is important is
hypothermia can lead to complications of malignant lethal arrhythmias, increase systemic
vascular resistance with heightened myocardial oxygen demand, shivering with amplified
metabolic demand, and impairment of the clotting cascade which can lead to increased
mediastinal drainage.
A device called a Bispectral index monitor is often used intraoperatively to determine the
patient’s level of awareness and sedation during surgery. As stated by the Virginia Cardiac
Surgery Quality Initiative, it has been hypothesized that using this device in the postoperative
intensive care unit may decrease time to extubation. From this literature review only one study
was found, which showed that there was no difference in time to extubation with the use of the
Bispectral index monitor (Anderson, Henry, Hunt, and Ad, 2010)
Outcomes of fast track programs
Three studies compared the safety and abilities of their programs to reduce intubation
times. All three studies showed that their programs were successful in decreasing time to
extubation. Camp et al. (2009) and Ender et al. (2008) found reduction in hospital length of stay.
Ender et al. (2008) also reporting reduced mortality rates and Camp et al. (2009) found reduced
morbidities, however Reis et al (2002) found that neither morbidity, mortality or hospital length
of stay were reduced through their fast track program.
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Running Head: SAFE EARLY EXTUBATION
Nursing implications
As more hospitals move to reduce time to extubation through fast track programs, it is
important for nurses to be aware of the current literature in order to support an evidence based
practice. There was no literature found that discusses the impact these programs could have on
decreasing delays or rescheduling of cardiac surgeries as a result of shortening intensive care unit
and hospital length of stay. However, realizing how fast track programs effect work flow of the
operating room, intensive care unit and step down floors is vital to make accommodating staffing
plans.
In the preoperative setting, understanding the early extubation program is necessary for
patient education. This includes providing realistic expectations and information on the process
if the patient has the potential for not being able to extubate early. Also, understanding how such
pre-operative interventions as oral benzodiazepines and thoracic epidurals can affect things other
than pain and anxiety control, allows the nurse to teach the patient on their importance.
For the intensive care nurse, determining if a patient is an appropriate candidate for fast
track extubation should include several factors, including their intra-operative drugs. Therefore,
it should be the post-operative nurse’s practice to know which medications were given during
surgery. If longer acting neuromuscular blocking agents were used, such reversal agents as
neostigmine can be used to facilitate readiness to wean from the ventilator. When selecting a
method of pain and anxiety management, understanding the role dexmedetomidine should be
clearly understood by the recovering nurse so that advocating for adjunct or transitional drug
therapy can be done when appropriate. If short acting pain medications such as remifentanail
were used during surgery, the recovering nurse should recognize that pain medication may be
required earlier.
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When deciding if a patient is appropriate for early extubation after surgery, the nurse
should recognize that patients should not be excluded from fast track extubation because of CPB
use. It should be recognized that those with long run times on the CPB have experienced longer
times to extubation. Patient age should also not be a primary excluding factor for early
extubation, however the nurse’s expectation should be that those who are younger will extubate
sooner. Most studies excluded those with pulmonary comorbidities from their studies. For this
reason, it cannot be concluded if those with lung disease could be safely allocated for early
extubation.
The use of positive pressure applied post-extubation has been successful in fast track
programs as a routine measure. If used in a fast-track program, nursing should understand the
pathophysololgy for its application ranges beyond those with lung disease or inadequate arterial
blood gases. For those who may be questionable in their readiness to extubate, BIPAP/CPAP
may be used as a safe, successful bridge.
Aggressive rewarming should start in the operating room and be continued into the
intensive care unit. Rewarming is important to prevent postoperative complication of
arrhythmias, bleeding, and hemodynamic compromise. As part of the early extubation pathway,
using methods and devices to regain normothermia should be high priorities.
Use of multiple disciplines has been shown to be a successful practice when
implementing programs because of the depth and breadth of knowledge added to the discussion.
Though not seen as an intervention in the reviewed studies, to successfully implement an early
weaning program, a multi-disciplinary approach should be used and include physicians,
anesthesiologists, nurses, and respiratory therapists. To establish clear standards, ventilator
weaning protocols should be utilized that are easy to understand with defined, measurable
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criteria. If involved in the building team for a new fast track extubation program, the nurse must
understand the multiple factors that contribute to extubation times and their relationship to one
another.
While the literature is not certain if earlier extubation translates to lower morbidity,
mortality, or length of stay, for the cardiac surgery nurse early extubation can result in a lighter
work load. As the patient comes off of the ventilator sooner, arterial lines and pulmonary
catheters may be removed earlier and facilities ease of movement out of bed. Aggressive aims at
pain reduction have been attributed to reduced intubation times (Hawkes, Dhileepan, and
Foxcroft, 2003). Programs that implement such interventions as thoracic epidural analgesia to
meet early extubation goals, reduces the need for frequent dosing of pain medication,
subsequently reducing nurse work load. For hospitals that are structures to support a post op day
0 transfers to step down or intermediate care units, earlier extubation times allow more transfers
out to these units and reduces instances where the admitting nurse would be doubled with a fresh
post-operative cases. In hospitals that do not support early transfer from the intensive care unit, if
an admitting nurse needs to have a second patient, keeping an extubated patient could reduce that
nurses work load.
Summary
Early extuabation has been identified as a safe way to improve patient outcomes and
possibly reduce health care costs. In answering the question, “How can early and effective
extubation be achieved in the cardiac surgery population” it was found through this literature
review that short acting anesthesia medication, dexmedetomidine, thoracic epidural analgesia,
post extubation positive pressure ventilation, and aggressive rewarming were all important
factors . Nursing implications across all stages of the surgical process can be seen through this
Running Head: SAFE EARLY EXTUBATION
literature review. As patient educators, fast track program forming team members, strategy
implementation participants, and guides to patient care flow, nurses are invaluable members for
early extubations to be achieved. Further research on the impact on nursing care workloads and
the reduction of operating room delays requires further research and as studies evaluate the
effects of early extubation on reducing health care costs, nursing retention and increased cardiac
surgery operating room cases should be considered.
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18
Source
Populatio
n
Type of
Study/Level of
Evidence
Problem/Purpose
Findings
Strengths/Weaknesses
Camp,
Stamou,
Stiegel,
Reames,
Skipper,
Madjarov,
...
Lobdell,
(2009)
Isolated
CABG’s
and
valves.
Combinati
on CABG
and
Valve.
N=All
2211
patients
operated
on
between
2002 and
2006 were
included.
Not clear.
“Uncompl
icated,
elective
heart
surgery”
N=97
nonDexmedet
omidine
N=103
Dexmedet
omidine
Retrospectiv
e Cohort
study
Evaluate
implementation of
quality program to
decrease
intubation times
(to <6hrs).
Primary: Early
extubation times
increased after
quality program
started.
Secondary:
Early extubation
population
experienced lower
rates of sepsis,
PNA, readmissions, and
readmissions to
ICU. Also reduced
days in hospital
and in ICU.
No blinding used in data
review
To determine
effect of using
Dexmedetomidine
intra-op on time to
tracheal extubation
No blinding used in data
review
No disclosures made
No power analysis
Elective
CABG.
N=20
patients
Prospective,
Randomized
Control
Trial.
Doubleblinded.
Placebocontrolled
study.
Primary:
Shorter times to
extubation in
Dexmedetomidine
group.
Secondary:
Fewer/lower doses
of NMBA and
narcotics used with
Dexmedetomidine.
Reducion of SIRS
in
Dexmedetomidine
group
Group receiving
N-acetylcysteine
had a less increase
in A-a gradient,
but had no affects.
No difference in
intubation times.
Afanador,
Marulanda,
Torres,
Marín,
Vidal &
Silva.
(2010)
Eren,
Cakir,
Oruc,
Kaya, &
Erdinc.
(2003)
IIB
Retrospectiv
e cohort
study
IIB
IB
Evaluate if giving
N-acetylcysteine
IV pre-op will
counter the effects
of CPB and reduce
pulmonary
complications
post-op.
Logistic regression
analysis and propensity
score adjustment used to
compensate for preoperative confounders.
Attempts made to match
confounders between
groups.
Statistical analysis of pvalue used.
Small sample size
without power analysis.
No disclosure statement
made
Confounders excluded
from study.
Strong statistical
analysis:Manning/Whitne
y U-test, ANOVA, posthoc Tukey’s B and
Tamhane’s T test used in
addition to p-values.
Running Head: SAFE EARLY EXTUBATION
19
Source
ICU
Pop.
Type of
Study/Level of
Evidence
Problem/Purpose
Findings
Strengths/Weaknesses
Zarbock, Mueller,
Netzer, Gabriel,
Feindt, &
Kindgen-Milles
(2009)
Elective
CABG
or heart
valve
replace
ment.
N=500.
Randomized
Control Trial
To determine the
efficacy of
prophylactic nasal
Continuous Positive
Airway Pressure after
extubation when
compared with
conventional, no
application.
Several hours
of nasal
Continuous
Positive
Airway
Pressure
following
cardiac
surgery
improved
PaO2,
reduced
pneumonia
and
reintubation
rates, as well
as
readmission
to intensive
or
intermediate
care units.
No power analysis
done.
Walthall & Ray
(2002)
Isolated
CABG.
N=100
Retrospectiv
e Cohort
Investigate whether
any intraoperative
variables had a
significant effect on
extubation time after
CABG.
No
significant
extubation
time
differences in
those on
propfol vs
midazolam.
Number of
vessels
required to be
bypassed, use
of IMA graft,
and CPB time
were not
show to have
an effect of
extubation
times, as was
hypothesized
by authors.
IB
IIB
Authors included a
literature review of
studies similar to theirs
and made their
statement findings
based on their study as
well as the other
studies.
Took into account
confounders, and
separated into 4 groups
to counteract, as well
as excluded other
confounders.
Statistical analysis
used: post hoc power
analysis (t test) with
the Scheffe test, Chi
Square test, and
Bonferroni correction.
No Power analysis
done with small sample
size.
Anesthesia medications
not stated in study.
Double blinded.
Patients randomly
selected.
Same surgeon and
anesthesiologist used,
and therefore
standardization of
procedures and
medications.
Multi-variate
simultaneous linear
regression used in
addition to 1-sample
Kolomogorov-Smirnov
test. Also P value
utilized.
Running Head: SAFE EARLY EXTUBATION
20
Recognized study’s
findings were
contradictory of other
studies.
Running Head: SAFE EARLY EXTUBATION
Source
ICU
Pop.
Deshpande, Mohite Isolated
& Kamdi. (2011)
valves
and
simple
repair of
congenit
al heart
disease.
N=100.
Type of
Study/Level
of Evidence
Randomized,
prospective,
double
blinded
control trial.
IB
21
Problem/Purpose
Findings
Strengths/Weaknesses
Compare fentanyl
versus Sufentanil
when used as a part of
the balanced
anaesthesia technique
for fast track in
cardiac surgery
patients. Evaluated
the time taken for
extubation,
hemodynamic
stability, analgesia
requirements &
incidence of
awareness.
Time for
mechanical
ventilation in
Sufentanil
group was
found to be
reduced more
than that in
Fentanyl
group.
Total doses of
Tramadol
required in
the
postoperative
period till
next morning
were similar,
though those
in the
Sufentanil
group needed
dosing
sooner.
Sufentanil
group had
awareness
during
anaesthesia.
Both
sufentanil and
fentanyl
provide
hemodynamic
stability.
BIS not used in
Operating Room.
Confounders removed
before randomization.
Standardization of
other anesthesia
medications given as
well as parameters for
extubation.
Chi-square, t-test with
p-value used. Power
analysis used.
Running Head: SAFE EARLY EXTUBATION
Source
ICU Pop.
Sato,
Suenaga,
Koga,
Matsuyama,
Kawasaki
& Maki
(2009)
Isolated on
pump
CABG.
N=485 (all
done at this
center)
Akhtar &
Hamid
(2009)
Elective
CABG.
N=614 (all
patients
after
excluding
confounders
done at this
center)
Type of
Study/Level
of Evidence
Case Series
IV
22
Problem/Purpose Findings
Strengths/Weaknesses
To determine the
differences in
patients who did
and did not
extubate in less
than six hours.
p-value was the only
statistical analysis
preformed.
Because of the high
success rates to early
extubation (92%) more
description of methods
used in Operating
Room and Intensive
Care Unit could have
been given to describe
not only why those 8%
did not extubate, but
also why maybe the
92% did.
Prospective
To identify the
observational causes of delayed
study
extubation post
operatively.
IIIB
High rates of
early extubation
with standardized
medication
method in OR of
versed/fentanyl
or propofol.
Those who
scored low on the
EuroSCORE, had
more vessels to
bypass, lower
EFs, higher CT
output, and/ or
blood
administration in
ICU (but not
OR), longer OR
and CPB times
had longer times
to extubate.
Surprisingly
COPD did not
effect extubation
times.
Patients on high
dose inotropes,
hemodynamically
unstable,
reexplored for
bleeding, deep
sedation, and
confusion were
the reason for not
extubating in <6
hrs.
No blinding done.
Only 388 patients on
the original sample size
were selected for fast
track, but the reason
for the exclusions were
not given.
No statistical analysis
done, including pvalue.
Confounders excluded.
Running Head: SAFE EARLY EXTUBATION
Source
ICU Pop.
Najafi
(2008).
Isolated
CABG.
N=100
Type of
Study/Level
of Evidence
Prospective
Cohort study
IIB
Reis, Mota,
Ponce,
CostaPereira &
Guerreiro
(2002)
Isolated
CABG
using CPB.
N=323
Prospective
cohort study
IIB
23
Problem/Purpose Findings
Strengths/Weaknesses
To assess the risks
and benefits of
conduction the
fast track method
in cardiac
anesthesia and to
evaluate the role
of continuous
infusion of short
acting anesthetics.
Tracrium was
used as a NMBA
in the fast track
group (vs
Pancuronium in
the non-fast
track) and
NMBA reversal
was done using
Neostigmine in
fast track group.
Fentanyl infusion
was used in the
fast track group
both intra-op and
for 12 hours post
op (vs bolus PRN
does in non-fast
track). Fast track
group came off
of CPB at
warmer body
temperatures than
the non-fast
track.
No blinding used.
Not randomized and
not stated how the
patients were allocated
into the fast track vs
non track groups.
No power analysis
To compare nonfast track
extubations with
fast track
extubations for
safety.
Very fast track
extubation
protocol may be
safely
implemented.
Time to
extubation was
shortened in the
fast track group.
No morbidity or
mortality
difference
between groups.
One way analysis of
variance or a two-way
between group analysis
of variance with repeat
measurements over
time were done
inaddition to Chi
square test and MannWhitney U test.
Kaplan-Meier Survival
curves were calculated
for time to extubation
and LOC in ICU and
hospital stay.
Findings in light of
other studies/short
literature review of
similar studies given
also.
Patients randomly
assigned to fast track
and non-fast track
group.
T test and Chi square
test used.
The non-fast track
group had a variety of
different induction
drugs.
No power analysis
done.
Study conclusions
stated that fast track
extubation can be
safely implemented as
Running Head: SAFE EARLY EXTUBATION
24
a way to decrease
health care cost.
However, re-intubation
rates and mortality
rates were not given.
Running Head: SAFE EARLY EXTUBATION
Source
ICU Pop.
Hemmerling,
Olivier,
Choinière,
Basile &
Prieto.
(2005)
Isolated
Aortic Valve
Replacement
N=45
Caputo,
Alwair,
Rogers,
Pike, Cohen,
Monk, . . .
Angelini
(2011)
Off pump
CABG
patients
N=226
Type of
Study/Level
of Evidence
Prospective
audit, pilot
study
IV
Randomized
controlled
trial
IB
25
Problem/Purpose Findings
Strengths/Weaknesses
The feasibility and
hemodynamic
stability of
immediate
extubation (in
OR) after simple
or
combined aortic
valve surgery
using either
thoracic epidural
analgesia or
opioid-based
analgesia.
Prospective audit is
statistically weak.
To evaluate the
impact of thoracic
epidural
anesthesia on
early clinical
outcomes in
patients
undergoing offpump coronary
artery bypass
surgery.
Immediate
extubation is
feasible after aortic
valve surgery using
either high thoracic
epidural analgesia
or opioid-based
analgesia; both
techniques maintain
hemodynamic
stability throughout
surgery.
3 patients in the
epidural group
needed reexploration.
Bupivacaine, 0.5%
bolus given via
epidural in
intervention group
during induction
followed by infusion
of 0.125%
bupivacaine and
0.0003%
clonidine.
Addition of thoracic
epidural to
conventional general
anesthesia accounts
for a significant
reduction
in postoperative
arrhythmias and
improvement
in overall quality of
recovery, allowing
an earlier tracheal
extubation and
hospital discharge
Data of each recording
time point were
compared using a
Friedman test other
wise no confirming
analysis was done.
Power Analysis done
Hazard ratios used
Time-to-event curves
were constructed
using the Kaplan–
Meier method. Binary
outcomes were
compared using odds
ratios. Linear
regression, with
logarithmic
transformations were
used for skewed data.
Not blinded,
and there was no
independent resolution
of clinical endpoints.
Running Head: SAFE EARLY EXTUBATION
Source
ICU Pop.
Barletta,
Miedema,
Wiseman,
Heiser &
McAllen
(2009).
Isolated
CABG
and/or valve
N=100
Engoren,
Luther, &
FennBuderer
(2001).
Cardiac
Surgery
N=90
Thomas,
Smith &
Strike
(2003).
Cardiac
surgery
patients reelected to be
on fast track
extubation
plan.
N=20
Type of
Problem/Purpose Findings
Study/Level
of Evidence
Retrospective To compare
Dexmedetomidine
cohort study postoperative
resulted in lower
opioid
opioid requirements
IIB
requirements in
in patients after
patients who
cardiac surgery
received
versus those
dexmedetomidine receiving propofol,
versus propofol
but this did not
after cardiac
result in shorter
surgery and
durations of
determine these
mechanical
effects on time to ventilation, using a
extubation.
fast-track model.
Randomized Compare the
No differences in the
control trial
effects of
outcomes from
remifentanil,
fentanyl-, sufentanilIB
sufentanail, and
, and remifentanilfentanyl on time
based cardiac
to tracheal
anesthetics. They all
extubation, time
produce similar
to intensive care
outcomes and have
unit (ICU)
similar direct
discharge, time to variable costs
hospital discharge,
postoperative
pain, and cost.
Prospective
Compare the
In order to achieve
randomized
duration of action goal extubation of <
double-blind of pancuronium
6 hours, unless fastcontrol trial
and rocuronium in track patients have
patients
neuromuscular
undergoing fastfunction assessed
IB
track hypothermic before
cardiopulmonary
extubation,
bypass and
pancuronium should
cardiac surgery.
not be used.
26
Strengths/Weaknesses
Findings of study for
extubation times were
secondary, not primary
purpose of the study.
Matching between
groups was done.
T and U test was done.
Power analysis done.
Chi-square test done as
well as well as fisher
exact test.
Power Analysis was
done.
Standardization of all
other factors (ie other
drugs intra-operatively
and weaning standards
from vent)
Kruskal-Wallis test,
onferroni multiple
comparisons procedure
was used, Chi-square
or Fishers exact test
was done.
Power analysis done.
Standardization of
drugs/sedation among
groups not done.
Running Head: SAFE EARLY EXTUBATION
Source
ICU Pop.
Anderson,
Henry, Hunt
& Ad.
(2010).
All cardiac
surgery
patients
N=50
Roosens,
Heerman,
De Somer,
Caes, Van
Belleghem,
& Poelaert,
(2002)
Elective
CABG. N=
10 with
extracorporeal
and 13
without.
Type of
Study/Level
of Evidence
Prospective
Cohort study
IIB
Prospective
controlled
study.
IIB
27
Problem/Purpose Findings
Strengths/Weaknesses
Dose use of a BIS
monitor
postoperatively
effect time to
extubation.
Chi square test used
with student t test.
To compare
effects of cardiac
surgery with and
without
extracorporeal
circulation.
BIS monitor did not
facilitate earlier
extubation in the
stable patient after
cardiac surgery
Small sample size with
no power analysis.
Variance in staff
knowledge of device
with no prior training.
Both extracorporeal Not clear how patients
and nonwere assigned to the
extracorporeal
extracorporeal and
patients exhibited
non-extracorporeal
dramatic impairment groups.
of respiratory system Not randomized.
mechanics, and
Small sample size with
therefore off pump
no power analysis.
CABG patients
should have the
Exclusion of
same caution when
confounders
extubating as on
Standardization of
pump patients.
NMBA’s and narcotics
Repiratory
as well ventilation.
compromise was
Statistical analysis
worse during the
includes power
first 3 hours post-op analysis, Wilcoxon’s
in both groups.
signed ranks test with
Bonferroni correction,
and Mann-Whitney Utest for independent
samples.
Running Head: SAFE EARLY EXTUBATION
Source
ICU Pop.
Ender,
Borger,
Scholz,
Funkat,
Anwar,
Sommer, . . .
Fassl (2008)
Cardiac
surgery
patients
(surgery type
not given)
N=433 (all
patients in
first 6 months
of fast track
program)
Type of
Study/Level
of Evidence
Prospective
Cohort study
IIB
28
Problem/Purpose Findings
Strengths/Weaknesses
Compare the
safety
and efficacy of a
fast-track protocol
implemented by
anesthesiologists
in a directadmission PACU
to standard
perioperative
management
1:1 propensity-score
matching on many
variables to the
historical control
group. Logistic
regression model used.
Fisher exact test and of
continuous traits with
the Kolmogorov–
Smirnov test used.
Wilcoxon
rank sum test was used
if testing between
matched cohorts
and the Mann–Whitney
U test for others. P
value for significance
used.
Oral premedication
with dipotassium
clorazepate the
evening before and
clonidine on the day
of surgery. Leipzig
fast-track protocol
used Anesthetic
induction
was performed with
propofol, sufentanil
and rocuronium. For
maintenance
of anesthesia during
the pre- and
postcardiopulmonary
bypass period, a
continuous infusion
of
remifentanil and
sevoflurane was
used. During
cardiopulmonary
bypass, a continuous
propofol infusio also
was administered.
Paracetamol given
right before skin
closure. Aggressive
warming via blanket
under patient.
Postoperative
analgesia consisted
of a bolus of
piritramide and
paracetamol. All
patients were on
BIPAP for 1 hour
post extubation.
Fast-track patients
had significantly
shorter times to
No blinding used
No specification for
type of surgery
Running Head: SAFE EARLY EXTUBATION
29
extubation,
as well as
postoperative
lengths of stay.
There
was no significant
difference between
groups with regards
to readmissions to
higher levels of care
or morbidity rates.
Fast-track patients
had a significantly
lower mortality than
controls.
Running Head: SAFE EARLY EXTUBATION
Source
Georghiou,
Stamler, Erez,
Raanani, Vidne,
& Kogan (2006)
ICU
Pop.
Type of
Problem/Purpose Findings
Study/Level
of Evidence
Isolated Retrospective To determine if
Compared
coronary Cohort Study early extubation
with
artery
could be
patients
bypass
IIB
accelerated to < 6 extubated
surgery
hr after arrival at
within 6–10
the cardiothoracic hr, those
N=545
ICU.
extubated
before 6 hr
were
younger and
comprised a
higher
proportion
of men.
Crossclamp
and CPB
times were
significantly
shorter in
the patients
extubated in
less than 6
hr.
The mean
number of
grafts per
patient was
similar in
both groups.
The goal
was
achieved of
extubating
in less than
6 hrs.
30
Strengths/Weaknesses
Student’s t test;
confidence intervals with
P test used. No Power
analysis used. Excluded
confounders. BernsteinParsonnet risk estimate
done.
Note: CABG=Coronary artery bypass grafting. Levels of evidence adapted from Oxfords Center
for Evidence Based Medicine (2009)
Running Head: SAFE EARLY EXTUBATION
31
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