<div>We the authors have nothing to disclose, no funding to declare and no
conflict of interest</div><div>Palatal ‘Beading/Sweating’ as a marker of anaesthetic depth</div><div>Assessment of the depth of anaesthesia is something that every surgeon
learns to appreciate over the course of training. This assessment can be
aided by the use of clinical signs which represent a response of the
autonomic nervous system to shallow anaesthesia. Scores that have been
developed to measure this include the PRST (pressure, rate, sweating and
tears score), along with more objective measures such as the use of
entropy/bispectral index monitoring<sup>1</sup>. We suggest an
additional feature of the PRST score which has not been previously
mentioned or documented in the ENT literature.</div><div>We have noted an interesting phenomenon during tonsillectomy which
appears to relate to depth of anaesthesia. During the emergence phase of
the procedure, palatal beading/sweating is noticed over the distribution
of the hard and soft palate. We describe the appearance as ‘sweating’
deliberately as the phenomenon has the appearance of small beads of
sweat which are separate from one another. This has also been noted
during the procedure if patients begin to ‘lighten’, which we have
identified as a harbinger to coughing, movement or other overt signs of
anaesthetic emergence.</div><div>Evidence to support this theory was shown by Sasaki et al in 2016, in
their study of sedated patients undergoing dental procedures. They
correlated movements of the arms and legs with depth of anaesthesia and
increased salivation<sup>2</sup>. Another study examined the use
of remifentanil/propofol or sevofluorane on salivation in
microlaryngoscopy and found that the group assigned to
remifentanil/propofol had greater salivation<sup>3</sup>.
Patients sedated in ICU also seem to demonstrate reduced salivary flow
but the authors of that study did not investigate the impact of
anaesthetic agents on salivary flow<sup>4</sup>.</div><div>There are 500-1,000 minor salivary glands throughout the oral cavity.
While major salivary glands such as the parotid are responsible for
secreting serous saliva, the minor salivary glands produce a mucoid
saliva. Stimulation is through sympathetic and parasympathetic
innervation, however parasympathetic input is stronger and has a longer
duration. It is also thought that while parasympathetic input produces
high volume salivary secretions, sympathetic tone may increase
contraction of myoepithelial cells and extrusion of saliva.</div><div>We hypothesise that as sympathetic suppression of anaesthetic agents
wear off, we are observing salivary secretion in keeping with a
shallower depth of anaesthesia. We believe that this is another useful
clinical indicator of anaesthetic depth and we respectfully highlight
this to our colleagues.</div><div>References</div><div>1. Sinha P, Koshy T. Monitoring Devices for Measuring the Depth of
Anaesthesia - An Overview. Indian Journal of Anaesthesia.
2007;51(5):365-.</div><div>2. Sasaki Y, Kato S, Miura M, Fukayama H. Correlation Between Body
Movements and Salivary Secretion During Sedation. Anesthesia Progress.
2016;63(4):185-91.</div><div>3. Kang JG, Kim JK, Jeong H-S, Jung S-C, Ko MH, Park SH, et al. A
Prospective, Randomized Comparison of the Effects of Inhaled Sevoflurane
Anesthesia and Propofol/Remifentanil Intravenous Anesthesia on Salivary
Excretion During Laryngeal Microsurgery. Anesthesia &amp; Analgesia.
2008;106(6):1723-7.</div><div>4. Dennesen P, Van Der Ven A, Vlasveld M, Lokker L, Ramsay G, Kessels A,
et al. Inadequate salivary flow and poor oral mucosal status in
intubated intensive care unit patients. Critical Care Medicine.
2003;31(3):781-6.</div>