© Acta Anæsthesiologica Belgica, 2006, 57, n° 4
Abstract : Objective : Postoperative nausea and vomit-
ing (PONV) still represent an important problem in sur-
gery. Treatment and prevention of PONV requires accu-
rate risk stratification. The simplified Apfel-score
includes the four factors female gender, no smoking,
postoperative use of opioides and previous PONV or
motion-sickness in patients’ history. Each of these risk
factors is supposed to elevate the PONV-incidence about
20%. The aim of the study was to validate this clinical
risk assessment score in patients with high risk for
Methods : In a prospective study 93 patients with high
risk preoperative score for PONV (Apfel Score III and
IV) were analyzed. Patients and nurses were interviewed
using a standardized questionnaire at the time of dis-
charge from the post-anesthesia care unit (PACU) as well
as 6 hours and 24 hours after admission to the PACU.
General anaesthesia was applied as total intravenous
anaesthesia (TIVA) with mivacurium, propofol and
remifentanil (no nitrous oxide / FI O2 0.5)
Results : In the group with Apfel score III PONV
occurred in 59.7% of patients and in the Apfel score
group IV in 91.3% of all patients. The incidence of
PONV corresponds to the predicted values of 60% for
Apfel III and 80% for Apfel IV although the use of TIVA
should have reduced the incidence of PONV about 26%.
This apparent overestimation could be explained by the
frequent questioning of patients and nurses for PONV
leading to assessment of very minor symptoms.
Conclusion : The Apfel-score is a useful and simple tool
for stratification of patients with high risk for PONV.
Key words : Postoperative nausea and vomiting ;
PONV ; Apfel-score.
25-30% of all patients who undergo surgery
will experience postoperative nausea and vomiting
(PONV) (1,4). Risk factors for PONV have been
described and include female gender, no smoking,
postoperative use of opioides and previous PONV
or motion-sickness in patients’history” (5, 7). Each
factor elevates the risk of PONV about 20%. These
factors have been summarized in the simplified
PONV-risk score (Table 1), the “Apfel-score” (3, 2).
It has been described recently that treatment
with ondasetrone as well as dexamethasone or
droperidol may reduce the incidence of PONV by
about 26%, propofol by 19% and anaesthesia with-
out nitrous oxide by 12% (1). The reduction of
PONV by the use of total intravenous anesthesia
(TIVA) with propofol and without nitrous oxide
was thus similar to that observed with each of the
antiemetic drugs. Patients with high risk score
(Apfel III or IV, i.e. 60-80% risk for PONV) require
multimodal treatment with more than one antiemet-
ic agent (2). A multimodal approach for prevention
and treatment of patients with high risk for PONV
requires accurate prediction. In the prospective
study presented herein we describe the validation of
the PONV risk assessment score by Apfel in
patients with high risk for development of PONV.
Ninety-three consecutive patients with high
risk for PONV (Apfel-score III and IV) (2), under-
going a wide range of elective surgery under gener-
al anesthesia were enrolled in this study. Inclusion
criteria were age 18-80 yr and ASA-score I-III.
Exclusion criteria were vomiting before anesthesia
and severe postoperative complication like myocar-
dial infarction. The age ranged from 20-79 yr. The
(Acta Anaesth. Belg., 2006, 57, 361-363)
Postoperative Nausea and Vomiting (PONV) : Usefulness of the
Apfel-Score for identification of high risk patients for PONV
C. WEILBACH (*), N. RAHE-MEYER (**), K. RAYMONDOS (**),A. WEISSIG (**), D. SCHEINICHEN (**) and
S. PIEPENBROCK (**)
C. WEILBACH, M.D. ; N. RAHE-MEYER, M.D. ; K. RAYMONDOS,
M.D. ; A. WEISSIG, M.D. ; D. SCHEINICHEN, M.D. ; S.
(*) Clinic for Anaesthesia, St. Josefs-Hospital Cloppenburg,
Krankenhausstraße 13, 49661 Cloppenburg, Germany.
(**) Clinic for Anaesthesia, Medical School Hannover, Carl-
Neuberg-Straße 1, 30625 Hannover, Germany.
Tel. : 49511 5322489.
Correspondence address : Dr C. Weilbach, Krankenhaus-
straße 13, 49661 Cloppenburg, Germany.
Tel. : 494471 161500. Fax : 494471 161507.
E-mail : firstname.lastname@example.org.
© Acta Anæsthesiologica Belgica, 2006, 57, n°4
C. WEILBACH et al.
study protocol was approved by the local ethics
committee for human studies (Ärztekammer
Niedersachsen / Hannover, Germany).
Using a standardized questionaire patients and
nurses were interviewed by the anesthesiologist at
the time of discharge from the post-anesthesia care
unit (PACU) and 6 h and 24 h after admission to the
PACU by the anestesiologist. Total intravenous
anesthesia (TIVA) was performed in all patients
with propofol and remifantanil without nitrous
oxide and with FiO2 of 0.5. Nausea was scored by
a 100-point numerical scale from 0-100, where zero
represents no nausea and 100 representing nausea
“as bad as it can possibly be”.
Statistical analysis : Data are given as mean ±
SD, differences between groups were analyzed
using the Mann-Whitney-U-Test.
The high risk groups Apfel III and IV were
equally distributed in the study population. Patient
characteristics are shown in table 2. For all para-
meters analyzed i.e. age, the ASA-Score (ASA I
32,3%, ASA II 63,4%, ASA III 4,3%) duration of
surgery as well as time spent in the PACU no signif-
icant differences were found between the study
groups. The vast majority of patients with high risk
for PONV were women consisting of 98.9% of all
PONV occurred in the group Apfel III in
59.7% and in the group Apfel IV in 91,3%, all
results are shown in table 3.
In this trial the occurrence of nausea and vom-
iting in 59,7% (Apfel III) and 91,3% (Apfel IV) of
all patients. The predicted range was 60% for Apfel
III and 80% for Apfel IV. These predictions howev-
er are based on anaesthesia method that includes
volatile anaesthetics as well as nitrous oxide. In our
study total intravenous anaesthesia with propofol,
remifentanil without nitrous oxide was applied.
This should have reduced the occurrence of PONV
by 26% (1). Thus, the real incidence of PONV in
our patients appears to be higher than expected.
This may be due to the fact that we questioned
patients as well as nurses three times within the first
24 hours postoperatively for symptoms of PONV.
In the largest study so far (1) the incidence of
PONV was measured by interviewing the patients
only at 2ndand 24thhour postoperatively. This
methodological difference in measurement of
PONV may have let to an overestimation of PONV
in our patients with assessment of very mild symp-
toms. It may be considered unethical to leave
patients with high risk for PONV without addition-
al treatment, except TIVA. This issue was discussed
with the local ethics committee. But, viewing the
limited efficacy of each single drug in prevention
and treatment of PONV and the need for a simple
and effective predictive score for accurate applica-
tion of a multimodal treatment including antiemet-
ic drugs we decided to start the study. One limita-
tion of this study is that patients with lower risk for
PONV were not included making a general calcula-
tion of sensitivity and specificity and receiver oper-
ating characteristic curves impossible (6). The
intention of this study however was to evaluate if
patients with very high risk for PONV could be
identified prior to operation with a simple clinical
score. Viewing that almost all patients with Apfel
Risk-estimation for PONV by the Apfel-score
Risk estimation (%)
20 (%) 40 (%)60 (%)80 (%)
Risk factors (each one “Risk-poin”t)
1 point female gender
1 point no smoking
1 point postoperative use of opioides
1 point previous PONV or motion-sickness in patients’ history.
(n = 47)
(n = 46)
Median ± standard
Median ± standard
52,8 ± 15,1
27,5 ± 5,0
60,8 ± 32,9
88,0 ± 37,4
55,6 ± 11,8
26,3 ± 5,6
59,6 ± 33,0
89,9 ± 34,5
Incidence (total) of PONV
PONVApfel IIIApfel IV
no nausea / no vomitino
nausea and vomiting
nausea score mean ±
27,84 ± 29,2514,67 ± 19,53
© Acta Anæsthesiologica Belgica, 2006, 57, n°4
IV score indeed experienced PONV we believe that
the Apfel score is an acceptable clinical tool for this
purpose. This high risk population should therefore
benefit from a multimodal PONV treatment includ-
ing perioperative therapy with dexamethasone,
droperidol, ondasetrone, haloperidol and total intra-
venous anesthesia. In addition, therapy of postoper-
ative pain in such patients should be critically
reviewed and alternative treatment strategies
including regional anaesthetics and omission of
opiates reconsidered. Such prophylactic multi-
modal approach requires correct risk assessment. In
conclusion our study confirms that the Apfel risk
assessment score for PONV is a simple and reliable
test to identify patients at high risk and could thus
be used for development of preventive treatment
We express our gratitude to all participating
physicians and Heinz Geerlings for help with statis-
No competing interests to delcare
Christian Weilbach designed and analyzed the
study, wrote the manuscript and is fully responsible
for the scientific content, Niels Rahe-Meyer,
Annette Weissig, Kostas Raymondos and Dirk
Scheinichen monitoring of patients and data man-
agement, Siegfried Piepenbrock : study design and
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VALIDATION OF THE APFEL-SCORE (PONV) 363