Page 63 - ACCCN's Critical Care Nursing

40 S C O P E O F C R I T I C A L C A R E

TABLE 3.1 Examples of clinical questions using the PICO format

Example P – Population I – Intervention C – Comparison O – Outcome
1 Post-operative cardiac surgery Knee-length graduated Thigh-length graduated Prevention of deep vein
patients compression stockings compression stockings thrombosis
2 Mechanically ventilated patients Nurse-led weaning protocols Standard practice Extubation
(doctor-driven)
3 Intubated patients Brushing teeth with a toothbrush Normal saline mouth rinse Ventilator-associated
and toothpaste pneumonia

TABLE 3.2 NHMRC’s level of evidence designation for TABLE 3.3 Types of outcome
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levels of evidence in the studies of effectiveness
Outcome Definition ICU example
Level of Surrogate Some physical sign or ● Oxygen saturation
evidence Study design measurement ● Vital capacity
I Evidence obtained from a systematic review of all substituted for a
relevant randomised controlled studies clinically meaningful
outcome
II Evidence obtained from at least one properly
designed randomised controlled trial Clinical Outcome defined on the ● Ventilator days
basis of the problem ● Survival
III-1 Evidence obtained from well-designed
pseudorandomised controlled trials (alternative Patient- Outcomes that are ● Functional ability
allocation or some other method) relevant important to the ● Quality of life
patient
III-2 Evidence obtained from comparative studies
(including systematic reviews of such studies),
with concurrent controls and allocation not
randomised, cohort studies, case-control studies, outcomes are those of direct relevance to clinical practice,
or interrupted time series with a control group
and patient-relevant outcomes are those likely to be artic-
III-3 Evidence obtained from comparative studies with ulated as significant by the patient/carer. When assessing
historical controls, two or more single-arm research evidence, the type of outcome used in the
studies, or interrupted time series without a
parallel control group research should be considered. Assessing the evidence
results in an understanding of its quality of evidence for
IV Evidence obtained from case series, either post-test a particular nursing practice.
or pre-test/post-test
Integrate the Evidence into Practice
When good quality evidence for a particular practice is
statistical precision (denoted by P values or confidence identified, it is important to then consider this evidence
intervals). Although there are a number of different alongside nurses’ expertise, patient preferences and avail-
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evidence hierarchies (e.g. see Jennings & Loan, 2001), able resources. In essence, evidence may suggest that a
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the framework used by the NHMRC is displayed in particular practice achieves the best patient outcomes, but
Table 3.2. if the nurse does not have the skills needed to implement
the practice, if the resources are not available, if the
The second question focuses on whether meaningful patient either does not want the intervention, or their
improvements to patient care and outcome will result if situation is such that the intervention may not be appro-
the research findings are applied in practice. It also con- priate for them, then this practice should not be imple-
siders how the intervention compares with current prac- mented. However, in many situations the practice will be
tices in terms of patient care and outcomes. applicable to the patient and nurses will have the skills
The third question conveys the notion that potential ben- and the resources to implement the practice. At times,
efits or outcomes of the intervention must be both impor- implementing this new practice may take the form of
tant to the patient, and be able to be replicated in other developing a clinical practice guideline or protocol for a
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settings. The NHMRC identifies three types of outcome: particular nursing activity. Clinical practice guidelines are
surrogate, clinical, and patient-relevant (which are not described in the next section.
mutually exclusive) (see Table 3.3). Surrogate outcomes
are often used in critical care where measurement of the Evaluate Clinical Performance
actual physiological change (e.g. oxygen-carrying capacity Once a new practice has been implemented, it is impor-
of the blood) is replaced by a more accessible, and equally tant for nurses to assess whether it is having the desired
acceptable, parameter (e.g. oxygen saturation). Clinical effect. At the individual patient level, this often involves