Aanesthetic Agents for Day Surgery - NIHR Health Technology ...

244
Appendix 26
TABLE 104 Occurrence of PONV by awareness on recovery from anaesthetic in the adult study
statistically significant trend. Nevertheless, visually
there is the suggestion that the risk of PONV
declines with increasing anaesthetic experience.
This observation was tested by including the actual
number of previous anaesthetics, rather than a
grouped variable, into a logistic regression (see
chapter 5).
Duration of anaesthesia
Table 107 shows that the risk of PONV depends on
the duration of anaesthesia. A similar pattern was
found for one or more episodes of vomiting
(linear trend, p < 0.02)
No. of patients
Alert Agitated/ Drowsy Total
distressed
Total 618 (100%) 68 (100%) 367 (100%) 1053 (100%)
Nausea or vomiting – no 534 (86.4%) 39 (57.4%) 274 (74.7%) 847 (80.4%)
Nausea or vomiting – yes 84 (6.5%) 29 (42.6%) 93 (25.3%) 206 (19.6%)
χ 2 : p < 0.001
TABLE 105 Occurrence of PONV by ASA grade in the adult study
TABLE 106 Occurrence of PONV by tertile group of previous number of occasions on which anaesthesia received for the adult study
No. of patients
0 or 1 previous 2 or 3 previous 4 or more previous Total
occasions occasions occasions
Total 352 (100%) 389 (100%) 320 (100%) 1061 (100%)
Nausea or vomiting – no 275 (78.1%) 313 (80.5%) 266 (83.1%) 854 (80.5%)
Nausea or vomiting – yes 77 (21.9%) 76 (19.5%) 54 (16.9%) 207 (19.5%)
χ 2 : p > 0.1 (linear trend)
No. of patients
ASA category ASA ASA ASA Total
not known category 1 category 2 category 3
Total 15 (100%) 720 (100%) 308 (100%) 11 (100%) 1054 (100%)
Nausea or vomiting – no 13 (86.7%) 560 (77.8%) 263 (85.4%) 11 (100%) 847 (80.4%)
Nausea or vomiting – yes 2 (13.3%) 160 (22.2%) 45 (14.6%) 0 (0%) 207 (19.6%)
χ 2 : p < 0.02
Anaesthetic regimen
Tables 108 and 109 display how some of the
variables associated with the occurrence of PONV
are distributed among the anaesthetic regimens;
gender is not displayed, as random allocation was
within single gender groups. Such differences as
occur are small.
These data indicate that the marked increase
in occurrence of PONV among patients receiving
sevoflurane/sevoflurane may represent a real
effect (i.e. the effect is due neither to chance
nor confounding).