Liberal general multimodal prevention algorithms

The factors mentioned under the previous subheadings as shortcomings for strictly risk-based prevention protocols, including a “wait-and-see approach” for patients at low risk, gave rise to a more liberal recommendation in an updated PONV consensus recommendation[35].

The new SAMBA PONV consensus Guideline 8 advises clinicians to “use general multimodal prevention to facilitate implementation of PONV policies.” With this new section, the shortcomings of strictly risk-based protocols, and particularly the undertreatment in low-risk patients receiving no prevention and the appropriate prevention in high-risk patients, were tackled. The recommendation of the expert panel states that “in view of the poor guideline compliance with risk-adapted approaches and no general preventive measures, multimodal prevention strategy (adjusted with additional measures in high-risk patients) may be an option to facilitate clinical implementation.” Many observational data gathered to assess whether standard operating procedures work in busy clinical environments support this shift in paradigm. This is particularly true for high-risk patients in which the latter procedure may overcome the hurdle to provide multimodal prevention, since e.g., two antiemetics are given anyway, which lowers the threshold for the overall administration of three or four preventive measures. In a setting where two antiemetics are given on a routine basis, a third intervention (e.g., a total intravenous anesthesia) should be added if there are hints for an increased risk. This approach will result in a significant benefit.

Some evidence highlighting the inherent trend towards undertreatment has already been reported. In a recent study, despite intense educational strategies that resulted in lower incidence of PONV, it was surprising to note that no significant difference in the rate of administration of antiemetic prophylaxis was observed between the overall ‘‘before’’ and ‘‘after’’ patient populations (31.4% versus 36.8%)[46]. The only difference was in the rate of administration of antiemetic prophylaxis in the high-risk group (with an Apfel simplified score of >2), which reached statistical significance (36.4–52.8%). Such observational data underscore the observed extremely low compliance with institutional PONV policies. In another report, it was stated that only 37% of medium- and high-risk patients received the specified prophylaxis, leading to suboptimal PONV prevention in moderate- and high-risk patients[47]. Interestingly, the report was intended to highlight that PONV prediction actually works! In this context, we should bear in mind that as long as the change in practice does not translate into a significant increase in patient benefit, such implementation should not be recommended.

Not surprisingly, fast-track or enhanced recovery protocols often incorporate multimodal preventive PONV strategies[48,49]. General multimodal strategies may well be a starting point to facilitate clinical implementation of better PONV protection of patients[50]. Such approaches may prove more effective than strictly risk-based approaches that rely on no prevention in low-risk patients.

It is reassuring and encouraging to note that the current SAMBA guidelines explicitly state the goal for antiemetic multimodal prevention to become an integral part of anesthesia[35,51]. At the end of the day, anesthesia care providers should view PONV prevention as self-evident as preventing and treating pain.

Challenges for everyday practice

PONV has been extensively studied and there is excellent evidence to guide clinical practice. Perhaps the biggest problem is that many anesthesia providers fail to translate this knowledge into changes in practice, and thus patient benefit[33,52].

We need to accept that some of the adverse events occurring during the course of anesthesia are difficult to cope with or cannot be controlled in a sufficient manner. However, we should accept and be happy that some of the oldest problems associated with anesthesia, i.e., PONV, where there is excellent evidence based on myriads of clinical trials, can be managed quite effectively, provided we apply the attitude of “zero tolerance” and do not accept that PONV is a surrogate outcome that does not bother our patients.

The PONV-free hospital should be a realistic goal as long as we devote effort into the clinical implementation of PONV protocols. The rule of thumb and paradigm for creating and implementing PONV protocols should be “the simpler, the better,” with a more liberal use of preventive measures than a too restrictive one.