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Critical Analysis of the Trauma
ASA Difficult Airway Algorithm
Dr. William C. Wilson’s algorithm for managing
the airway in trauma patients (November 2005) includes
successful oral tracheal intubation as a major option.1
Accomplishing rapid intubation, however, is predicated
on two questionable tenets. First, the algorithm assumes
intubation, as currently practiced, maximizes the
likelihood of achieving first-try endotracheal tube
placement, and second, the anesthesiologist is able
to selectively identify and avoid patients who will
become “difficult intubations.”
Historically, textbook intubation, being simple to
learn and 85 percent effective, has by default become
the gold standard for tracheal intubation. Inevitably
the remaining failed attempts, usually attributed
to abnormalities in patient anatomy, are conveniently
categorized as “difficult intubations,”
a term justifying abandonment of standard intubation.
This reasoning avoids the undeniable conclusion: Current
intubation is marginal at best since it often fails
during the critical period of “difficult intubation.”
The appropriate solution is inescapable: A novel technique
is needed for all intubations, one that is straightforward
for normal patients and yet remains equally effective
when “difficult intubation” is encountered.
The ability to intubate seamlessly, thereby reducing
patients passing through difficult airway algorithms,
is a goal worth pursuing. Does such a technique based
on defined principles exist? Yes, it does.2
The second problem stems from an inability to reliably
predict “difficult intubation” in a small
group of normal-appearing patients. These individuals,
encountered following trauma, will not benefit from
repeated attempts using a technique proven ineffective
for the situation. Recognizing the need for a system
of intubation that enables the operator to improve
first-try endotracheal tube placement under all circumstances
is clearly an advantage to both patient and anesthesiologist.
Jan M. Stasiuk, M.D.
Yakima, Washington
References:
1. Wilson WC. Trauma:
Airway management. ASA Newsl.
2005; 69(11):9-16.
2. Stasiuk RB. Improving styletted oral tracheal intubation:
Rational use of the OTSU. Can J Anaesth.
2001; 48(9):911-918.
Changing
Status of P2 and P3 Would Be a ‘Plus’
The ASA Physical Status (PS) classification has been
used for many decades as preoperative patient evaluation
for predicting anesthesia and surgical risks and as
a billing modifier. Among six classifications (ASA
PS1-PS6),1 the definitions of PS1, PS4,
PS5 and PS6 are easily distinguishable: PS1 = normal
healthy patients; PS4 = patients with severe systemic
disease that is a constant threat to life; PS5 = moribund
patients who are not expected to survive without the
operation; and PS6 = brain-dead patients whose organs
are being removed for donor purposes.
However, the definitions of ASA PS2 and PS3 are broader
and less definitive: PS2=patients with mild systemic
disease; PS3 = patients with severe systemic disease.
We cannot always be certain whether a patient’s
disease is mild or severe. In addition, some patients
have multiple mild systemic diseases. For such patients,
the ASA Physical Status should not be simply PS2 but
neither is it obviously PS4. Similarly, patients with
severe systemic disease and several mild systemic
diseases or with multiple severe systemic diseases
are not exactly ASA PS3, nor are such patients obviously
PS4.
I propose that such patients be classified as “PS2+”
and “PS3+”, respectively. Our cursory
calculation on surgical patients over a three-month
period at our university medical center revealed that
more than 70 percent of patients were classified as
ASA PS2 (1,616 patients, 36 percent) and PS3 (1,531
patients, 35 percent). Thus it is important to create
ASA PS2+ and PS3+ as subdivisions of PS2 and PS3.
This modification does not require expansion of the
current six-point scale since PS2+ and PS3+ are subdivisions,
not additional divisions.
Hiroshi Goto, M.D.
Kansas City, Kansas
References:
1. American Society of Anesthesiologists Relative
Value Guide, 2005.
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