cases, mouth-opening was limited or impossible. in operating room capacity”. From the data presented,
Such cases include dental abscesses, patients who an equally suitable interpretation would be that
have received chemotherapy and radiation treatment changes in operating room capacity should be made
for oropharyngeal cancer, and patients with burns while considering downstream capacity limitations,
scarring for release of contractures. The value of the such as wards and intensive unit units, as reviewed by
technique is that deep anaesthesia with complete Wachtel and Dexter3. Increased usage of wards from
airway control is possible in circumstances where increased operating room capacity can be estimated4
there might otherwise be airway compromise. There most simply by calculating (increase in operating
are drawbacks, however. While it is possible to room capacity in hours)×(total ward days among all
employ the technique as a single operator, competent patients having surgery during baseline period)/(total
assistance is preferred. There is also a learning curve: operating room hours used during baseline period).
while the airway maintenance manoeuvre described is When applied, were the authors’ findings predictable
relatively simple to learn, practice is needed to be able before capacity was increased?
to maintain the airway for prolonged periods. F. dexter
p. h. V. CuMpSton r. e. WAChtel
Brisbane, Queensland Iowa City, Iowa, USA
1. Cumpston PH: Fibreoptic intubation under general anaesthesia 1. Yoon S-Z, Lee SI, Lee HW, Lim HJ, Yoon SM, Chang SH. The
– a simple method using an endotracheal tube as a conduit. effect of increasing operating room capacity on day-of-surgery
Anaesth Intensive Care 2009; 37:296-300. cancellation. Anaesth Intensive Care 2009; 37: 261-266.
2. Asai T, Shingu K. Tracheal intubation through the intubating 2. Dexter F, Marcon E, Epstein RH, Ledolter J. Validation of
laryngeal mask in patients with unstable necks. Acta statistical methods to compare cancellation rates on the day of
Anaesthesiol Scand 2001; 45:818-822. surgery. Anesth Analg 2005; 101:465-473.
3. Keller C, Brimacombe J, Keller K. Pressures exerted against 3. Wachtel RE, Dexter F. Tactical increases in operating room
the cervical vertebrae by the standard and intubating laryngeal block time for capacity planning should not be based on
mask airways: a randomized, controlled, cross-over study in utilization. Anesth Analg 2008; 106:215-226.
fresh cadavers. Anesth Analg 1999: 89:1296-1300. 4. Dexter F, Blake JT, Penning DH, Lubarsky DA. Calculating
4. Brimacombe J. Keller C. Kunzel KH. Gaber O. Boehler M. a potential increase in hospital margin for elective surgery by
Puhringer F. Cervical spine motion during airway management: changing operating room time allocations or increasing nursing
a cinefluoroscopic study of the posteriorly destabilized third staffing to permit completion of more cases: a case study.
cervical vertebrae in human cadavers. Anesth Analg 2000; Anesth Analg 2002; 94:138-142.
Analysing day-of-surgery cancellation rates – Reply
Analysing day-of-surgery cancellation rates
We appreciate the comments of Dr Dexter and
Yoon et al’s case study1 describes how an increase colleague and agree in part that the statistical method
in operating room capacity causing a statistically used in our study1 may have some limitations. We have
significant (P <0.05) increase in cancellation rates reanalysed the statistical significance of our findings
on the day of surgery (20.5% to 23.8%). There was as suggested. When we applied a chi-square test, the
an approximately 165% increase in cancellations P value for cancellation rate before and after adding
due to ward overflow. This report is a very useful two operating rooms was 0.0036. When applying a
addition to the scientific literature in operating room