Effect of switching off unidirectional downflow systems of operating theaters during prolonged inactivity on the period before the operating theater can safely be used.

BACKGROUND: Switching off air handling systems in operating theaters during periods of prolonged inactivity (eg, nights, weekends) can produce a substantial reduction of energy expenditure. However, little evidence is available regarding the effect of switching off the air handling system during periods of prolonged inactivity on the air quality in operating theaters during operational periods. The aim of this study is to determine the amount of time needed after restarting the ventilation system to return to a stable situation, with air quality at least equal to the situation before switching off the system. METHODS: Measurements were performed in 3 operating theaters, all of them equipped with a unidirectional downflow (UDF) system. Measurements (particle counts of emitted particles with a particle size ≥0.5 µm) were taken during the start-up of the ventilation system to determine when prespecified degrees of protection were achieved. Temperature readings were taken to determine when a stable temperature difference between the periphery and the protected area was reached, signifying achievement of a stable condition. RESULTS: After starting up the system, the protected area achieved the required degrees of protection within 20 minutes (95% upper confidence limit). A stable temperature difference was achieved within 23 minutes (95% upper confidence limit). Both findings lie well within the period of 25 minutes normally required for preparations before the start of surgical procedures. CONCLUSIONS: Switching off the ventilation system during prolonged inactivity (during the night and weekend) has no negative effect on the air quality in UDF operating theaters during normal operational hours.

Laying-up of sterile instruments in the operating theatre: equal or superior protection by using a horizontal unidirectional air flow system.

BACKGROUND: A system for the preparation of sterilized instruments with unidirectional horizontal air flow (UDHF) has several advantages over a unidirectional down flow system (UDDF). The advantages are based on the installation of the system being more flexible and easier to use, no cooling of the air flow being necessary and less air being needed for circulation, resulting in reduced energy use. OBJECTIVES: The objective of this study was to determine whether a system with UDHF performs equal or superior to a system with UDDF in terms of prevention of contamination of the air (the presence of particles and micro-organisms) during the laying-up process. METHODS: The degree of protection (DP) offered by two UDHF system variants and two UDDF system variants was determined for several static set-ups and a dynamic simulation of the process. In addition to determining the level of protection for several categories of particle size, colony-forming units (CFU) were also measured during process simulations. FINDINGS: When maximum protection (no particles present) is considered, the UDHF systems performed significantly better than the UDDF systems for particles ≥2.5µm. When particles were present, there was no significant difference between systems for particles ≥0.3 and ≥0.5µm. However, the performance of the UDHF system was superior to that of the UDDF system (DP) for particles ≥1.0µm representing the bacteria-carrying particles. During the process measurements, no CFU were found with the UDDF system in 64% of the measurements, compared with 90% for the UDHF system (P = 0.012). CONCLUSIONS: The UDHF system offers equal or superior protection to the UDDF system against contamination of the clean area within which the laying up takes place. Despite our finding that the differences did not always reach statistical significance (due to low background concentrations), there is a clear trend, from the small-sized particles (≥1.0µm) up to the largest sizes considered, including bacteria-carrying particles, that demonstrates the superiority of the horizontal flow system. The UDHF system offers a more robust solution than the UDDF system, provided that good work instructions are given and the height of the table and height of the plenum are properly adjusted.

[Guideline 'Diagnosis and treatment of oesophageal carcinoma']. / Richtlijn 'Diagnostiek en behandeling oesofaguscarcinoom'.

An evidence-based guideline for the diagnosis and treatment of oesophageal carcinoma was developed on the initiative of the Netherlands Society of Gastroenterohepatology in cooperation with the Dutch Institute for Healthcare Improvement (CBO) and the Dutch Association of Comprehensive Cancer Centres. If a patient with oesophageal carcinoma is eligible for treatment with curative intent, they should undergo thoracic and abdominal CT, ultrasound investigation of the supraclavicular region and endoscopic ultrasonography for staging purposes. Endoscopic therapy is the preferred treatment for high-grade dysplasia or early cancer in Barrett's oesophagus confined to the mucosa. Surgical resection is indicated if the tumour invades the submucosa. If resection of the oesophageal carcinoma is performed with curative intent, one should aim for radical resection. The type and extent of the resection depends on the location of the tumour. There is evidence that the mortality rate following surgery can be reduced by performing it in centres with ample experience with oesophageal cancer surgery. Preoperative chemotherapy and radiotherapy may improve survival in patients with oesophageal carcinoma. Palliative treatment for oesophageal carcinoma should be considered in cases of local invasion of surrounding organs, metastases, poor physical condition of the patient or recurrent disease after previous curative treatment. Psychosocial support is an important element in the follow-up of patients with oesophageal carcinoma.