RESULTS
Five patients with no clinical evidence of COVID-19 underwent
tracheostomy: 2 patients who underwent radical tonsillectomy, modified
radical neck dissection and free anterolateral thigh flap reconstruction
for carcinoma of tonsil; 1 patient who underwent maxillary swing
nasopharyngectomy for recurrent nasopharyngeal carcinoma; 2 patients who
underwent tracheostomy for aspiration pneumonia and sputum retention.
Average operation duration was 352.4 (338.0-365.0) s. Droplet
contamination was noted on all 5 plastic sheets. (Table 2) Droplet size
ranged from 0.2mm to 2.8mm. Droplet contamination was most severe over
the central surface for all patients with an average of 91.5%
(86.7%-100.0%) followed by the left lateral surface and right lateral
surface at 5.2% (6.7%-10.0%) and 3.3% (6.7%-10.0%) respectively.
(Table 3)
Droplet count contamination was mainly over the central upper half of
plastic sheet overlying the site of operation in the lower neck. Total
droplet count was highest along the centre-most column F at 25.9%
(n=15). Droplet count decreased towards the periphery on both sides. The
decline was greater on the left lateral surface at 10.3% (n=6), 6.9%
(n=4), 3.4% (n=2), 3.4% (n=2), 1.7% (n=1) and 0% along columns G, H,
I J, K and L respectively compared with columns E, D, C, B and A at
17.2% (n=10), 24.1% (n=14), 3.4% (n=2), 1.7% (n=1) and 1.7% (n=1)
respectively on the right lateral surface. (Table 3)
No droplet splash was documented on face shields of both the surgeon and
scrub nurse for all patients.