- Some patients yawn whilst being
rendered unconscious with thiopentone, and it
has been remarked that those who do so are
usually those who have not been given opiate
premedication. As I am not aware of any
published numerical data bearing on this matter,
I offer the following results, derived from
adult, general surgical patients.
- In a series of 100 consecutive patients
given atropine only 45 (45%) yawned. In a
further series of 500 consecutive patients given
an opiate and hyoscine or atropine 5 (1%)
yawned. The difference between the proportions
is highly significant. It might be thought that
the 5 who had been given opiate and nevertheless
yawned were patients whose premedication has
been mistmied, but this was true only for
- Yawning was much commoner in the
aged, though not due to old age per se: the aged
had been given atropine only much more commonly.
When a comparaison with respect to age was
restricted to individuals all given atropine
only, the difference in results became small,
and not sigificant.
- Relationship between clinical endpoints for
induction of anesthesia and bispectral index and
effect-site concentration values.
- Kim DW, Kil HY, White PF.
- J Clin Anesth. 2002 Jun;14(4):241-5.
- Department of
Anesthesiology, The Catholic University of
Korea, Seoul, Korea.
- STUDY OBJECTIVE: To assess the relationship
between clinical endpoints for induction of
anesthesia and the electroencephalographic (EEG)
bispectral index (BIS) and effect-site
concentration (C(E)) values when using a
target-controlled infusion (TCI) of either
thiopental sodium or propofol, by hypothesizing
that yawning may be a useful alternative
to other commonly used clinical signs for
determining loss of consciousness.
- DESIGN: Randomized observational clinical
study. SETTING: Operating room of a
university-based hospital.PATIENTS: 60 healthy
adult patients (aged 20-50 yrs) scheduled for
elective surgery with general anesthesia.
- INTERVENTIONS: During a TCI of propofol (n =
30) or thiopental (n = 30), clinical endpoints
for loss of verbal responsiveness (LOV),
loss-of-eyelash reflex (LOE), occurrence of
yawning, and apnea were assessed at 15-second
intervals. In addition, BIS and C(E) values were
recorded at each of the endpoints.
- MEASUREMENTS AND MAIN RESULTS: In both
anesthetic groups, the sequence of occurrence of
the clinical endpoints was similar, namely LOV,
LOE, yawning, and, lastly, apnea. Compared with
LOV and LOE, yawning was associated with lower
BIS and higher C(E) values with both
anesthetics. The frequency of yawning was higher
with thiopental than propofol (83% vs. 63%,
respectively). However, the frequency of apnea
was higher with propofol than thiopental (77%
vs. 53%, respectively).
- CONCLUSION: The correlation of the clinical
endpoints with BIS and C(E) values was highest
for LOV. Yawning was as unreliable as LOE
for determining the onset of unconsciousness
during induction of anesthesia. This clinical
sign failed to be observed in 17% and 37% of
patients induced with thiopental and propofol,
Murakami T, Oshima T, Dohi S. Does yawning
represent a transient arousal-shift during
intravenous induction of general anesthesia?
Anesth Analg 2005;101(2):382-3
HJV Yawning during thiopentone induction Br.
J. Anaesth 1962;34:133-134
- Oshima T et
al. Inhibitory effects of landiolol and
nicardipine on thiopental-induced yawning in
humans J Anesth 2010
yawning represent a transient
arousal-shift during intravenous induction of
- Kasuya Y, Murakami T, Oshima T, Dohi S.
- Anesth Analg. 2005 Aug;101(2):382-384
- Division of Anesthesia, Gifu
Red Cross Hospital, Japan.
- Although yawning occurs frequently
during the IV induction of general anesthesia,
the significance of this response remains
unknown. In this study, we induced 30 surgical
patients with 4 mg/kg thiopental IV, and 30
patients with 2 mg/kg propofol IV. Thereafter,
the occurrence of yawning was
continuously assessed, as the only clinical
end-point, for 1 min. The
electroencephalographic bispectral index was
monitored throughout the observation period. The
criterion for an arousal response was a
transient increase during a continuing decrease
in the bispectral index value.
- On the basis of this criterion, the
sensitivity and specificity of the
yawning response as an arousal sign were
77% and 80%, respectively. If a patient
exhibited a yawning response, the chance
of arousal was 84% (positive predictive value).
With no yawning response, the chance of
nonarousal was 71% (negative predictive value).
According to simple logistic regression, the
yawning response was predictive of a
transient arousal-shift with an odds ratio of
13.5 (95% confidence interval: 3.8-48; P <
0.001). The occurrence of a yawning
response during IV induction may be a clinical
indicator of a transient arousal-shift during
progressive loss of consciousness.
- IMPLICATIONS: Yawning elicited by IV
anesthetic induction was related to a transient
increase during the continuing decrease in the
electroencephalographic bispectral index value
(sensitivity and specificity, 77% and 80%,
respectively). This type of yawning may
be a clinical indicator of a transient
arousal-shift during progressive loss of
yawning responses induced by electrical and
chemical stimulation of paraventricular nucleus
of the rat.
- Sato-Suzuki I, Kita I, Oguri M, Arita H
- Ghisi D, Fanelli A, Tosi M, Nuzzi M, Fanelli
- Minerva Anestesiol. 2005
from bispectral index-guided anaesthesia in a
large randomized controlled trial of patients at
high risk of awareness.
- Leslie K, Myles PS, Forbes A, Chan MT, Short
TG, Swallow SK
- Anaesth Intensive Care. 2005
conditions that could result in the bispectral
index indicating an incorrect hypnotic
- Dahaba AA.
- Anesth Analg. 2005
management during anaesthesia: awareness and
- Osborne GA, Bacon AK, Runciman WB, Helps
- Qual Saf Health Care. 2005
Monitoring versus remembering what
- Kerssens C, Klein J, Bonke B.
- Anesthesiology. 2003
assessment of coma
- David E Bateman
- J. Neurol. Neurosurg.