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

given in Table 103 confirm the age trends within
general surgery and gynaecology. The number of
women undergoing orthopaedic surgery was too
small to characterise any trend, should one be
present. The numbers in the various categories
become too small to discern any clear pattern
for two or more episodes of vomiting.
Recovery of awareness
Table 104 shows that patients deemed to be agitated
on recovering awareness after anaesthesia
were much more likely to suffer PONV (43%)
than those who were alert (14%) or drowsy
(25%). A similar pattern occurs when one or
more episodes of vomiting is considered, but
the heterogeneity is compatible with being a
chance effect (p > 0.5).
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Health Technology Assessment 2002; Vol. 6: No. 30
TABLE 102 Occurrence of one or more episodes of vomiting by broad surgical procedure categories and gender in the adult study
No. of patients
Women, Men, Women, Women, Men, Total
general general gynaecology orthopaedic orthopaedic
Total 77 (100%) 184 (100%) 684 (100%) 31 (100%) 85 (100%) 1061 (100%)
One or more episodes of
vomiting – no
72 (93.5%) 183 (99.5%) 640 (93.6%) 27 (87.1%) 84 (98.8%) 1006 (94.8%)
One or more episodes of
vomiting – yes
5 (6.5%) 1 (0.5%) 44 (6.4%) 4 (12.9%) 1 (1.2%) 55 (5.2%)
χ 2 : p < 0.001
ASA grade
Consideration of the ASA grade (Table 105) shows
increased occurrence of PONV among patients in
ASA grade 1. There is no discernible pattern when
one or more episodes of vomiting is considered.
For one or more episodes of vomiting there is no
discernible pattern.
Previous anaesthetic experience
Patients reported a mean of 3.2 previous
anaesthetic experiences (median, 2.0; SD, 3.8;
range, 0–41). There was no difference between
randomised groups. Table 106 shows that the
occurrence of PONV was not strongly enough
associated with the number of previous anaesthetics
received by the patients to yield a
TABLE 103 Occurrence of PONV among women by surgical procedure and age quartile in the adult study
No. of patients
Quartile 1 Quartile 12 Quartile 13 Quartile 14 Total
General
Total 16 (100%) 8 (100%) 19 (100%) 34 (100%) 77 (100%)
Nausea or vomiting – no 12 (75.0%) 6 (75.0%) 15 (78.9%) 32 (94.1%) 65 (84.4%)
Nausea or vomiting – yes 4 (25.0%) 2 (25.0%) 4 (21.1%) 2 (5.9%) 12 (15.6%)
Gynaecology
Total 193 (100%) 197 (100%) 188 (100%) 106 (100%) 684 (100%)
Nausea or vomiting – no 117 (60.6%) 137 (69.5%) 155 (82.4%) 97 (91.5%) 506 (74.0%)
Nausea or vomiting – yes 76 (39.4%) 60 (30.5%) 33 (17.6%) 9 (8.5%) 178 (26.0%)
Orthopaedics
Total 5 (100%) 8 (100%) 9 (100%) 9 (100%) 31 (100%)
Nausea or vomiting – no 5 (100%) 5 (62.5%) 8 (88.9%) 6 (66.7%) 24 (77.4%)
Nausea or vomiting – yes 0 (0%) 3 (37.5%) 1 (11.1%) 3 (33.3%) 7 (22.6%)
Tests for linear trend by age: general,p < 0.07; gynaecology,p < 0.001;orthopaedics,p > 0.6
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