Systematic Review of Effects of Sedatives on Patient Ventilation

This research proposal aims to review if daily sedation breaks can reduce ventilation time in ICU patients. The study will be a quantitative systematic review. The research will compare the total duration of mechanical ventilation for ICU patients who were managed with DSI against those with no DSI. The primary research question will be to find out if sedation breaks reduce the time for mechanical ventilation.

National University of Ireland Galway
NU502 Advanced
Research Methods
Assignment-Research Protocol
Systematic Review of Effects of Sedatives on Patient Ventilation
*Do Sedation Breaks Reduce Ventilation Time?

Introduction
Nursing care in the I.C.U. (Intensive Care Unit) is multi-faceted and challenging, with the care of
the mechanically ventilated patient at the center of their practice. The care of the ventilated
patient requires a good knowledge of mechanical ventilation and invasive monitoring. Sedation
is an important element of caring for ventilated patients. Sedation relieves anxiety and
discomfort caused by procedures such as intubation. Adequate sedation supports a calm and
comfortable experience for the patient. Multiple complications exist from over/under sedation.
Daily sedation breaks have proven to be beneficial to the patient with respect to long term
psychological outcomes (Nassar et al, 2015). The longer a patient is ventilated and sedated, the
longer the stay in ICU, the higher the risk of developing delirium. In 2011, Ely from Vanderbilt
University Hospital Tennessee suggested that 80% of ventilated patients experience delirium.
Most patients who require analgesia and sedation infusions are ventilated at the same time
(Pandharipande, 2007). The relationship between the two is paramount in ensuring patient
comfort and safety and helps in the reduction of ventilation time. Use of analgesia and sedation
can prevent pain and anxiety, allows for invasive procedures, reduces stress and oxygen
consumption, and improves patient synchrony with the ventilator. (Curley, 2015, 380) Sedation
preference depends on the hospital, patient history and the Clinician’s choice. Thiscan lead to a
wide discrepancy in patient sedation. Sedation also helps to reduce environmental pollution of
the critical care environment, which is usually filled with a high level of background noise with
people and the alarms of the machines. Sedation in the ICU can reduce the following: stress
Áine Considine-
Student Number-17234430
Date-23/04/18
Word Count-2045

endogenous catecholamine activity, increased oxygen consumption, tachycardia,
hypercoagulability, hyper metabolism, and immunosuppression and anxiety that include
sympathetic response. (Curley 2015, 382)
The time taken from the start of ventilation to the start of weaning depends largely on the
sedatives used and on the duration of sedation. Some hospitals give their patients daily sedation
breaks while some leave the patients on a continuous break or some give fewer breaks or no
breaks. Among these patients there was a notable difference in the start of weaning from
ventilation and extubating. (Kress et al 2003, 1459). Daily sedation interruptions and regular
administration of sedatives are effective in reducing ventilation time although it is not clear
which method is more favorable.
To encourage best practice with sedation management this research proposal will aim to review
if daily sedation breaks can reduce ventilation time in ICU patients. Primarily this research
centers on achieving scientific facts based on careful observation, objective sampling, data
analysis and factual conclusion. (Kress, 2003). It will be a quantitative systematic review.
Justification
Patients in intensive care units require life-support techniques including mechanical ventilation.
ICU patients experience anxiety, pain, and deprivation of sleep resulting from illness (Holm and
Dreyer 2017, p.83). As a result, proper pain control and adequate sedation are key procedures
required in the management of ICU patients. Specifically, sedation facilitates intubation,
ventilation, and tolerance of tubes (Vincent 2017, p.11). The management of these patients
requires continuous infusion of sedative drugs so the stability of blood vessels is maintained
(Page and McAuley 2015, p.141). On the contrary, administration of too many sedative drugs

can both increase the time taken on mechanical ventilation as well as enhance the side effects
such as pneumonia (Balter et al and Conti et al 2016, p.206). To avoid the build-up of sedative
drugs into body and side effects, dose adjustment methods are used. One of the principal
methods is sedation interruption.
The use of DSI as a method of reducing mechanical ventilation and the time taken in ICU has
fundamental conflicts. Devlin and Roberts (2011, p. 571), Hughes, McGrane and Panharipande
(2012, p. 41), Kress et al. (2000, p.1474), Pinder and Christensen (2008, p.68), and Kallet et al.
(2018, p.7) indicate that sedation interruption not only allows the body time to clear sedative
drugs but also makes the patient relatively more awake and ready hence earlier liberation from
the ICU. In addition, the study shows that lack of sedation breaks results in poor long-term
outcomes such as psychological stress. Similarly, Barr et al. (2013, p.301) indicates that protocol
sedation reduces the duration of mechanical ventilation. On the other hand, Shebabi et al (2012,
p. 725) argues that DSI does not alter time taken in mechanical ventilation. Instead, sedation
reduces response to environmental factors, depression, and stress. As a result, it is important to
have an updated systematic review on the effects of DSI on time taken in mechanical ventilation.
The principal objective of this systematic review will be ton compare the total duration of
mechanical ventilation for ICU patients who were managed with DSI against those with no DSI.
The primary research question will be to find out if sedation breaks reduce the time for
mechanical ventilation.
Methodology
Search Methods

We will search EMBASE, MEDLINE, and CINAHL online databases from 2008 to May 2018
with keywords sedation, Intensive Care Unit, critical care, sedation break, sedation protocol,
reduced ventilation, and ventilation time. On the other hand, conference proceedings from 2015
to 2018 will be hand-searched. The studies included for systematic review will include English
language studies conducted in the ICU. The studies must have been carried out in sedated adult
humans and must report the effect of sedation on ventilation time. The online databases will be
selected for systematic review given the nature of the study. Since the study is medical in nature,
the databases considered for systematic review needed to be medical. In addition, the databases
will provide both randomized controlled trials and observational studies. Randomized controlled
trials will be retrieved for studies whose objectives were generation of hypothesis. On the other
hand, observational studies will provide critical information about studies conducted on the
effect of sedation breaks on ventilation time.
Sample and Sampling Strategy
The studies to be included for this systematic review must have been conducted in a population
of adult patients. In addition, the patients must have been sedated and were on mechanical
ventilation within the ICU. Further, the studies must have reported the effects of sedation such as
duration of mechanical ventilation and length of stay in the hospital. Moreover, the studies to be
included for review must be those that report the incidence rates of optimal sedation. Finally, all
the studies must have been reported in English language. On the other hand, the review will
exclude studies conducted on patients sedated for less than 24 hours.
The inclusion and exclusion criteria will be vital in ensuring that the samples selected for review
are representative of the general population. For instance, studies conducted in patients sedated

for less than 24 hours will be excluded because they will not provide a significant period of stay
in the ICU that can be used to study the effects of sedation breaks on ventilation time. In
addition, studies on infants and toddlers will be considered since these populations may suffer
from other conditions that may have confounding effects on ventilation time. For these reasons it
will be crucial to select sample that reflect the generation population in terms of age and clinical
setups. In this systematic review, the studies that will be considered for review will be those
conducted in patients aged between 18 and 85 years. However, the studies considered for review
will not need to be skewed towards a particular gender since mechanical ventilation intervention
is applicable for both genders. Finally, the year of publication will be restricted for the last 10
years to ensure that mechanical ventilation interventions are consistent for all studies. It is likely
that the intervention mechanisms have significantly changed over the last ten years and therefore
including studies conducted earlier that this would have different results.
Data Collection
Data to be collected from all the included studies will include study aims and objectives, study
design, and the length of stay in mechanical ventilation. Data will be double extracted for all
studied included in the systematic review. More importantly, data will be extracted and stored in
SQL-based databases. Study aims will be vital in providing the cause factor, in this case sedation
breaks. Data will only be extracted from studies that were aimed at determining the effect of
sedation breaks on ventilation time, in this case the outcome.
Research Rigor
To ensure that the rigor of research is realized, the systematic review will consider three
fundamental mechanisms. Firstly, the full-text paper of all studies included for systematic review

will be double reviewed to ascertain that they meet the inclusion criteria. In addition, the
abstracts of all studies will be reviewed by two independent reviewers. In the event that, conflicts
will arise from the review results, the conflicts will be resolved by a third review through board
discussions. Finally, data will be double extracted from all studies included for review. Ensuring
rigor will be a critical part of this systematic review. Particularly, rigor of the research minimizes
bias and ensures reproducibility and applicability of results. It will be important the results of this
systematic review are transferable to other similar medical setups. As a consequence, it will be
important that data extraction and review of abstracts are double checked.
Data Analysis
Data collection will involve computation of geometric means and risk ratios for ICU mortality.
Computation of geometric means will be used in calculation of lengths of stay in mechanical
ventilation. The geometric mean of ventilation time will then be expressed as mean ± standard
deviation. The computed means of ventilation time will then be compared for patients with
sedation breaks and patients with no sedation breaks. On the other hand, relative risks will be
calculated to determine the effect of sedation on ventilation time. In particular, relative risk of
population without sedation breaks compared with those with sedation breaks will be computed.
The relative risks will be interpreted to ascertain if sedation breaks reduce ventilation time. More
specifically, RR>1 will be interpreted to mean that ventilation time is longer in the population
without sedation break while RR<1 will mean ventilation time is longer in population with
sedation breaks. Relative risks will be used since they provide accurate determination of cause
and effect relationship between two factors. Given the heterogeneity of the studies that will be
considered for this systematic review, statistical analysis such as meta-analysis will not be
carried out.

Ethical Considerations
Ethical consideration in systematic review will play a vital role in ensuring that the research the
results of review are ethical and of high quality. The studies included for review will be checked
to meet a number of ethical issues. Firstly, the studies reviewed will review for finical support. In
particular, the sponsors of the researchers will be considered to ensure the level of bias is
minimized. In addition, the studies will be reviewed fro justification to ensure that calculation of
sample size was done at the research stage. The review will also take into consideration any
possible sources of conflict of interest. Finally, the systematic review will take into consideration
publication bias. The highlighted ethical considerations will aim at ensuring validity and
reliability of the results of systematic review.
Conclusion
All this can be prevented by carefully taking a legally accepted patient representative through the
research, answer all the questions that arise and ensuring the consent form is duly filled for the
right patient. During the research it is also important to ensure patient comfort to ascertain high
integrity. Care of the ICU patient is costly. Reducing the duration of ventilation will probably
reduce costs of the problems that are associated with increased ventilation time such as
pneumonia and infection. Daily interruption of the sedation is a cost saving intervention as well
as all the other mental and physical benefits to the patient, it also allows Clinicians and nurses to
target the minimal sedation necessary to keep the patient comfortable.

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