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Summary: Postoperative nausea and vomiting is a common adverse effect of anaesthesia. Although dozens of different anti‐emetics are available for clinical practice, there is currently no comparative ranking of efficacy and safety of these drugs to inform clinical practice. We performed a systematic review with network meta‐analyses to compare, and rank in terms of efficacy and safety, single anti‐emetic drugs and their combinations, including 5‐hydroxytryptamine3, dopamine‐2 and neurokinin‐1 receptor antagonists; corticosteroids; antihistamines; and anticholinergics used to prevent postoperative nausea and vomiting in adults after general anaesthesia. We systematically searched for placebo‐controlled and head‐to‐head randomised controlled trials up to November 2017 (updated in April 2020). We assessed how trustworthy the evidence was using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and Confidence In Network Meta‐Analysis (CINeMA) approaches for vomiting within 24 h postoperatively, serious adverse events, any adverse event and drug class‐specific side‐effects. We included 585 trials (97,516 participants, 83% women) testing 44 single drugs and 51 drug combinations. The studies' overall risk of bias was assessed as low in only 27% of the studies. In 282 trials, 29 out of 36 drug combinations and 10 out of 28 single drugs lowered the risk of vomiting at least 20% compared with placebo. In the ranking of treatments, combinations of drugs were generally more effective than single drugs. Single neurokinin‐1 receptor antagonists were as effective as other drug combinations. Out of the 10 effective single drugs, certainty of evidence was high for aprepitant, with risk ratio (95%CI) 0.26 (0.18–0.38); ramosetron, 0.44 (0.32–0.59); granisetron, 0.45 (0.38–0.54); dexamethasone, 0.51 (0.44–0.57); and ondansetron, 0.55 (0.51–0.60). It was moderate for fosaprepitant, 0.06 (0.02–0.21) and droperidol, 0.61 (0.54–0.69). Granisetron and amisulpride are likely to have little or no increase in any adverse event compared with placebo, while dimenhydrinate and scopolamine may increase the number of patients with any adverse event compared with placebo. So far, there is no convincing evidence that other single drugs effect the incidence of serious, or any, adverse events when compared with placebo. Among drug class specific side‐effects, evidence for single drugs is mostly not convincing. There is convincing evidence regarding the prophylactic effect of at least seven single drugs for postoperative vomiting such that future studies investigating these drugs will probably not change the estimated beneficial effect. However, there is still considerable lack of evidence regarding safety aspects that does warrant investigation. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Low-dose aspirin given for secondary prevention of cardiovascular disease is frequently withdrawn prior to surgical or diagnostic procedures to reduce bleeding complications. This may expose patients to increased cardiovascular morbidity and mortality. Aim of the study was to review and quantify cardiovascular risks because of periprocedural aspirin withdrawal and bleeding risks with the continuation of aspirin. METHODS: We screened MEDLINE (January 1970-October 2004) with additional manual cross-referencing for clinical studies, surveys on the opinions of doctors and guidelines. RESULTS: Studies reporting the relative risk of acute cardiovascular events after aspirin withdrawal when compared with its continuation were not found. However, retrospective investigations revealed that aspirin withdrawal precedes up to 10.2% of acute cardiovascular syndromes. The time interval between discontinuation and acute cerebral events was 14.3 +/- 11.3 days, 8.5 +/- 3.6 days for acute coronary syndromes, and 25.8 +/- 18.1 days for acute peripheral arterial syndromes (P < 0.02 versus acute coronary syndromes). On aspirin-related bleeding risks, we obtained 41 (12 observational retrospective, 19 observational prospective, 10 randomized) studies, reporting on 49 590 patients (14 981 on aspirin). Baseline frequency of bleeding complications varied between 0 (skin lesion excision, cataract surgery) and 75% (transrectal prostate biopsy). Whilst aspirin increased the rate of bleeding complications by factor 1.5 (median, interquartile range: 1.0-2.5), it did not lead to a higher level of the severity of bleeding complications (exception: intracranial surgery, and possibly transurethral prostatectomy). Surveys amongst doctors on the management of this problem demonstrate wide variations. Available guidelines are scarce and in part contradictory. CONCLUSIONS: Only if low-dose aspirin may cause bleeding risks with increased mortality or sequels comparable with the observed cardiovascular risks after aspirin withdrawal, it should be discontinued prior to an intended operation or procedure. Controlled clinical studies are urgently needed. [ABSTRACT FROM AUTHOR]

Yarrow, Achillea millefohum L, is one of the commonest weeds of the Compositae family. Cases of allergic contact dermatitis have, been described since 1899. Although 10 sesquiterpene lactones (SL) and 3 polyines have previously been identified, the sensilizers of yarrow have eseaped detection. A reinvetigation of short either extracts of yarrow revealed the presence of 5 unsalurated hitherto unknown guaianolides of peroxide character. Tile main SL. identified as a strong, sensitizer in guinea pig sensitization experiments, was named α-peroxyachifolid. The minor SL also contribute marginally to the sensitizing capacity, while other known yarrow constituents like dehydromatricaria ester and pontica epoxide appear to play no role A 5-year follow-up (1985 1990) of Compositine-sensitive patients showed that more than 50% reacted when tested with a short either extract of ?arrows. Exacerbation of the patch test silos by irradiation with UV light was never observed. [ABSTRACT FROM AUTHOR]