The evaluation of pain is extremely difficult due to its subjective
nature. We need to move to an evaluation of acute pain that not only
takes the patient’s perception into account, but also, for the first
time, incorporates objective measures of pain into a global assessment
matrix.
When a patient is in pain, either from an injury or surgical procedure,
the pertinent question should be, “is the pain tolerable?” Each of us
has a threshold at which point the addition of an analgesic should be
considered to prevent the consequences of untreated acute pain.
This threshold should not be based on an arbitrary numerical value, but
whether the pain is tolerable for that individual. Once the patient
states that their pain is intolerable, we then attempt to correlate this
subjective feeling with the following objective measures prior to the
initiation, maintenance and escalation or de-escalation of analgesic
treatment.
Here is a mnemonic to aid in remembering the objective measures of acute pain:
Opioids Rarely Help Bodily Pain
· Observation—Is the patient grimacing,
screaming, diaphoretic, combative, crying, sleeping, drowsy, etc.? This
observation must be made after confirming that the physical/verbal
symptoms are not due to delirium, hypoxemia, hypercarbia, acidosis or
other metabolic issues that may be confused with the outward appearance
of discomfort. Once it is established that the physical signs are due to
pain, you can proceed with analgesic treatment. If, however, you have
not established that your observation is from pain, or if the patient
appears drowsy, somnolent or obtunded, do not give analgesics.
· Respiratory Rate—In my opinion,
respiratory rate in the presence of a patient stating that their pain is
intolerable is the most important indicator and guide for analgesic
therapy. A normal respiratory range is between 12-20 breaths per minute.
These are actual breaths associated with ventilation of a normal tidal
volume. They are not attempted, shallow or obstructed respirations. Once
it is confirmed that there are no abnormal neurologic, metabolic or
psychological issues involved, the respiratory rate may now be assessed.
A true respiratory rate greater than 20 with a patient stating
intolerable pain is a good indication for analgesic treatment. If,
however, the respiratory rate is less than 12, I would not initiate or
escalate opioid analgesic therapy.
· Heart Rate—Heart rate is usually elevated
when a patient has intolerable pain, but just like any other objective
measure, other factors may also come into play. If a patient is on a
beta blocker, the heart rate response to pain may be masked. In
addition, if a patient is hypovolemic, hyperthyroid, hypercarbic or has a
hyper-dynamic neuroendocrine disorder, the heart rate may be
misleading.
· Blood Pressure—Blood pressure is usually
elevated when a patient has intolerable pain. However, as with heart
rate, other factors must be taken into consideration prior to
attributing the elevated blood pressure to pain. In addition, all
objective measurements should be compared to the patient’s pre-pain
baseline. For example, if a patient had a baseline blood pressure of
160/90, then 160/90 would not be considered as an indication of acute
pain with this individual.
· Pupil Size—It is an often-missed
indicator of pain, however, pupil size may not only indicate severe
pain, but also help guide narcotic de-escalation. For example, if a
patient is in pain, there are increased circulating catecholamines from
sympathetic stimulation. This leads to pupillary dilation. On the other
hand, pinpoint pupils can indicate the central nervous system’s response
to a therapeutic narcotic level. Can narcotics be titrated to pupil
size? No, but pupil size can definitely be used as a guide in the
treatment of acute pain.
Putting it all together
Our first approach in the assessment of acute pain is to observe with
critical attention the objective indicators of pain: heart rate, blood
pressure, respiratory rate and pupil size. If your evaluation shows a
patient who is resting quietly in bed with a heart rate of 60, blood
pressure of 120/80, respiratory rate of 12, what then is your initial
impression prior to asking for the patient’s “feeling?”
Based on the objective measures, I would maintain current analgesic
levels. When asked, however, the patient does not respond how you would
expect and rates their pain as intolerable. This is the dilemma facing
healthcare providers on a daily basis and their resolution is to
escalate analgesic therapy with opioids over 90% of the time.
This mistake stems from recommendations, such as those from the Agency
for Healthcare Research and Quality, whose position is that “patients’
self-reports are the most reliable indicator of their experiences of
pain.”
This line of reasoning is devoid of any objective measures and places
the patients’ “self-reports” as the cornerstone in an acute pain
management protocol. In addition, the reliance solely on the subjective
measure of a patients’ self-report exposes providers to unnecessary
legal consequences of under-treatment as well as opioid over-treatment
resulting in possible respiratory morbidity, mortality or long-term
addiction if this model is continued into the outpatient setting.
While the legal implications of the way practitioners assess and treat
acute pain in the hospital and post discharge are beyond the scope of
this article, it is important to note that hospitals, pharmaceutical
companies and practitioners are being sued for mortalities related to
the inappropriate prescriptive use of opioids.
As for big pharma, their culpability lies in the inaccurate education
and detailing of opioids as either not as addictive or not as dangerous
as they truly are.
The objective measures of pain and critical thinking of where a patient
is relative to where they were or where they should be, is requisite
prior to the patient’s self-report of whether they view their pain as
tolerable or intolerable. When married together into a global pain
matrix, these measures will guide the practitioner with the initiation,
maintenance, escalation or de-escalation of analgesic therapy. In my
experience, nurses feel that they will be reprimanded if they withhold
analgesics from a patient who has rated their pain a nine out of 10 on
the universal pain scale. This fear routinely leads to unintended
consequences.
Myles Gart, MD
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