Impact of coronavirus disease 2019 on head and neck urgent suspected cancer referral pathways in rural Wales.

OBJECTIVE: To assess the impact of the coronavirus disease 2019 pandemic on head and neck urgent suspected cancer referral pathways in rural areas of Wales. METHOD: A retrospective audit was conducted of 2234 head and neck urgent suspected cancer referrals received from January 2019 to November 2020. RESULTS: The referrals dropped by 35 per cent in 2020 compared to the same period in 2019. The time from general practitioner referral to the first ENT appointment improved during the pandemic (8.0 vs 10.0 days; p < 0.001). Of referrals, 92.1 per cent were seen within a 14-day period in 2020, compared with 79.6 per cent in 2019 (p < 0.001). There were no differences between 2020 and 2019 in terms of: the (confirmed cancer) conversion rate (10.6 per cent vs 9.7 per cent; p = 0.60), general practitioner referral to multidisciplinary team discussion time (35.5 vs 41.5 days; p = 0.40) or general practitioner referral to initiation of treatment time (68.0 vs 78.0 days; p = 0.16). CONCLUSION: Whilst coronavirus disease 2019 reduced the number of overall head and neck urgent suspected cancer referrals, the pathways were generally unchanged, if not slightly improved, in rural Wales.

Assessment of the risk of haemorrhage and its control following minor oral surgical procedures in patients on anti-platelet therapy: a prospective study.

Controversy exists concerning the suspension or maintenance of anti-platelet drugs before elective surgical procedures. We assessed the association of the risk of prolonged postoperative bleeding with anti-platelet therapy by type of minor surgical procedure and the association between anti-platelet therapy and the level of hemostatic measures required. Five hundred and forty-six patients were included in the study group: those on aspirin (n = 310), clopidogrel (n = 97), and aspirin + clopidogrel dual therapy (n = 139); the control group comprised 575 healthy individuals. Cramer's V test was significant (P < 0.05) but showed a weak association between anti-platelet therapy and prolonged immediate postoperative bleeding. Compared to controls, the odds ratio revealed that the risk of prolonged bleeding in the immediate postoperative period was significantly higher with dual therapy, followed by clopidogrel and aspirin. Prolonged bleeding occurred in 22 patients in the study group and 20 in the control group, and was successfully controlled with local hemostatic measures. Fisher's exact test showed a significant association between dual therapy and higher levels of hemostatic measures (P = 0.004; P = 0.035). Prolonged bleeding in patients on anti-platelet therapy was independent of the type of minor surgical procedure. The greatest risk of prolonged bleeding was found in patients on dual therapy; this required higher levels of hemostatic measures.

Comparison of methods for measuring cholinesterase inhibition by carbamates.

The Acholest and tintometric methods are used widely for measuring blood cholinesterase activity after exposure to organophosphorus compounds. However, if applied for measuring blood cholinesterase activity in persons exposed to carbamates, the accuracy of the methods requires verification since carbamylated cholinesterases are unstable. The spectrophotometric method was used as a reference method and the two field methods were employed under controlled conditions. Human blood cholinesterases were inhibited in vitro by four methylcarbamates that are used as insecticides. When plasma cholinesterase activity was measured by the Acholest and spectrophotometric methods, no difference was found. The enzyme activity in whole blood determined by the tintometric method was

Toxicity of carbamates for mammals.

Toxicity studies have been carried out with a number of monomethylcarbamates, most of which reached an advanced stage in the World Health Organization insecticide evaluation programme. Both quantitative and qualitative distinctions have been found between the carbamates studied, and certain common characteristics that distinguish them in several important aspects from organophosphorus insecticides have been demonstrated.

Ortho-isopropoxphenyl methylcarbamate (OMS-33) as a residual spray for control of anopheline mosquitos. With special reference to its evaluation in the WHO programme for evaluating and testing new insecticides.

More than 1300 compounds have so far been included in the WHO Programme for Evaluating and Testing New Insecticides, which is designed to disclose compounds that may satisfactorily replace those to which insect vectors of disease have become resistant. The authors describe the successful passage of o-isopropoxyphenyl methylcarbamate (OMS-33) through the first 6 stages of the 7-stage programme that has been established for compounds intended for use against anopheline mosquitos and conclude that this product is suitable for testing in the final stage-large-scale epidemiological evaluation.In operational field trials (at 2 g/m(2)) OMS-33 has been shown capable of controlling Anopheles stephensi (in Iran), An. gambiae and An. funestus (in Nigeria) for 3-4 months, An. albimanus (in El Salvador) for 2-4 months and An. dthali (in Iran) for 2(1/2) months. It has an airborne effect by which anophelines are killed for a considerable time after OMS-33 has been sprayed, even though they do not make contact with a sprayed surface; this quality would appear advantageous in areas where anophelines enter houses and bite man but do not rest long enough on sprayed surfaces to acquire a lethal dose of insecticide or where significant outdoor biting occurs. The observance of simple safety precautions protects occupants of sprayed houses, spraymen and others from danger. Chemical studies have indicated that commercially produced water-dispersible powders of OMS-33 are stable under field conditions of storage and use.

The effect on cholinesterase activity of storage of undiluted whole blood sampled from men exposed to o-isopropoxyphenyl methylcarbamate (OMS-33).

An observation made during an operational field trial with o-isopropoxyphenyl methylcarbamate (OMS-33) suggested that the cholinesterase in undiluted blood samples from workers exposed to that insecticide was inhibited during the storage of those samples before assay.A laboratory investigation has now shown that rapid falls of whole-blood cholinesterase activity do indeed occur during the storage of undiluted samples collected from workers at different times after exposure to OMS-33, but that no such change occurs during the same period of time in circulating blood.Several possible explanations are put forward to account for the fact that, although the carbamate persists in the circulating blood for several hours after cessation of exposure, it does not appreciably inhibit cholinesterase in vivo but only under storage conditions in vitro. The implications of this phenomenon, in so far as methods for determining cholinesterase activity in persons exposed to carbamate insecticides are concerned, are discussed; and the authors point out that, whenever storage of undiluted samples precedes the assay, the spectrophotometric method should be regarded as giving results reflecting daily fluctuations of inhibitor concentration rather than as measuring the actual whole-blood cholinesterase in the body.

A study of the safety of O-isopropoxyphenylmethylcarbamate in an operational field-trial in Iran.

During an operational field-trial which was conducted as a part of the WHO Programme for Testing and Evaluating New Insecticides, a study of the safety of o-isopropoxyphenylmethylcarbamate (OMS-33) was carried out. Clinical observations associated with biochemical studies were performed. Minor reactions to over-exposure to OMS-33 were recorded among some spraymen and a few inhabitants. Their incidence was, in operators, mainly associated with heavy skin contamination and insufficient washing during work, or, in inhabitants, with entering the house while it was being sprayed. No cumulative inhibitory effect could be demonstrated on whole-blood or plasma cholinesterase in operators during the 6-week exposure. A pronounced fall in whole-blood cholinesterase activity during the work and a distinct recovery after exposure ceased was established as a daily pattern of the enzyme's activity fluctuation, erythrocyte cholinesterase being much more sensitive to OMS-33 than plasma cholinesterase. In view of the very marked symptomless daily fluctuation in cholinesterase activity and the absence of cumulative inhibitory effect, the conclusion was reached that routine cholinesterase determination has little if any practical value as an early indication of serious exposure to OMS-33. Minor complaints, from which recovery is rapid, serve as an early indication of over-exposure.OMS-33 can be used safely in malaria eradication programmes provided proper attention is paid to the exercise of those measures of general and personal hygiene which should be practised in any spraying programme.