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

Novel Designed Surgical Drapes Reducing Fluid Permeability in the Surgical Critical Area of a Sterile Operation Interface: A Randomized Controlled Trial

Aim. To compare the impact and cost effects of medical long fiber polyester drapes and cotton fabric drapes on operative sterile operation interfaces. Background. The comparison of the properties of the commonly used surgical drapes materials in terms of leakage, device slip, and prevention of intraoperative adverse events is not clear. Method. A prospective randomized controlled study was conducted in the operating room of a tertiary hospital in Chengdu, China. A total of 400 patients who underwent urology surgery were enrolled and randomly divided into two groups by computer, the study group (200 cases) selected the new long-fiber polyester cloth, while the control group (200 cases) selected conventional cotton fabric surgical drapes during the operation to maintain a sterile operating interface. The impermeability and water absorption of surgical drapes, the rate of device slip and skin scald in surgical patients, and the cost effect of the two kinds of surgical drapes were compared. Results. The long fiber polyester surgical drapes were superior to conventional cotton cloth in water absorption (g/m2) (835 ± 15.8 VS 225 ± 21.0, t = 328.261, $P<0.001$ ), preventing surgical site infections (2.5% VS 8.0%, χ2 = 6.081, $P=0.014$ ), device slip (7.5% VS 17.0%, χ2 = 8.396, $P=0.004$ ), patients from burning (0 VS 1, Fisher $P=1.0$ ), and total cost per use ($) (0.83 VS 0.96–1.09). Conclusion. Long fiber polyester fabric has a stronger antipenetration ability of fluid and microorganisms thus forming an effective protective barrier. It also has strong hygroscopicity, and its special design can prevent the occurrence of sliding of surface instruments and skin scald in patients. In addition, its cost effect is superior. Implications for Nursing Management. Operating room nursing managers can introduce long fiber polyester drapes into the selection of medical textiles to construct aseptic surgical barriers and prevent surgical site infection.

Design variables with significant effect on system performance of unidirectional displacement airflow systems in hospitals

BACKGROUND

The effectiveness of an airflow system in preventing entrainment of particles carrying micro-organisms from the periphery of an operating room (OR) or instrument lay-up room (ILR) is affected by many variables. It is suspected that differences in the design of the systems affect the effective protection ratio (EPR): the ratio of the size of the protected area to the surface area of the supply canopy. However, no analysis has yet been done to determine which design variables have a significant effect on this ratio.

AIM

To evaluate which design variables have a significant effect on the performance of airflow systems (EPR) in ORs and ILRs.

METHODS

All general and teaching hospitals in the Netherlands (N = 77) were asked to provide data from their standardized (at-rest measurement method) compulsory systems assessment reports for ORs and ILRs. Nineteen hospitals (25%) with a total of 22 hospital sites supplied information of sufficient completeness and homogeneity, resulting in measurement data for 101 ORs and 23 ILRs. This dataset was analysed using Statistical Package for Social Sciences.

FINDINGS

For ORs, important predictors for the EPR were: shape of the canopy; air speed under the supply canopy; height of the canopy screen; type of system; and size of the canopy. These significant predictors (P < 0.05) explain 48% of the outcome in the dataset. For ILRs, significant predictors for the EPR were: the position of exhaust air terminals; height of the canopy screen; and size of the canopy. These significant predictors explain 66% of the outcome in the dataset.

CONCLUSION

On the basis of the dataset available for analysis, it is concluded that the ratio of the size of the protected area to the surface area of the supply canopy (EPR) improves with the presence and the height of a screen around the canopy, the surface area of the supply canopy, and the air speed of the supply air under the canopy. This information can be used as guidance for the future design of unidirectional displacement airflow systems.

Impact of Operating Room Environment on Postoperative Central Nervous System Infection in a Resource-Limited Neurosurgical Center in South Asia

BACKGROUND

Postoperative central nervous system infections (PCNSIs) are serious complications following neurosurgical intervention. We previously investigated the incidence and causative pathogens of PCNSIs at a resource-limited, neurosurgical center in south Asia. This follow-up study was conducted to analyze differences in PCNSIs at the same institution following only one apparent change: the operating room air filtration system.

METHODS

This was a retrospective study of all neurosurgical cases performed between December 1, 2013, and March 31, 2016 at our center. Providers, patient demographic data, case types, perioperative care, rate of PCNSI, and rates of other complications were reviewed. These results were then compared with the findings of our previous study of neurosurgical cases between June 1, 2012, and June 30, 2013.

RESULTS

All 623 neurosurgical operative cases over the study period were reviewed. Four patients (0.6%) had a PCNSI, and no patients had a positive cerebrospinal fluid (CSF) culture. In the previous study, among 363 cases, 71 patients (19.6%) had a PCNSI and 7 (1.9%) had a positive CSF culture (all Gram-negative organisms). The differences in both parameters are statistically significant (P < 0.001). Between the 2 studies, there was no change in treatment providers, case types, case durations, antibiotic administration practices, and patient demographics.

CONCLUSIONS

The rates of PCNSI and positive CSF culture were significantly lower in our present cohort compared with the cohort in our previous study. The sole apparent change involves the air filtration system inside the neurosurgical operating rooms; this environmental change occurred during the 5 months between the 2 studies. This study demonstrates the impact of environmental factors in reducing infections.

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.

The Effect of Operating Lamps on the Protected Area of a Unidirectional Down Flow (UDF) System

BACKGROUND

Operating lamps are often seen as the most disruptive factors within the protective area in the operating theater (OT). The effect of the operation lamps (with different shapes) should be demonstrated in an OT by trial, since research on the effects of the lamps is still limited.

OBJECTIVES

The main aim of this study was to determine the effects of a skirt, different lamps, and the position of the lamp on the protected area.

METHODS

The concentration of airborne particles was measured under different circumstances, in order to determine the size and quality of the protected area. This entrainment/segregation test is based on the deliberate and controlled emission of particles outside the zone that is protected.

FINDINGS AND CONCLUSIONS

The degree of protection (DP) at the center of the protected area was higher for the case with the skirt. This skirt stimulates more down flow and prevents the early entry of particles into the protected area. It can also be concluded that Lamp Y, due to its open shape, has the most positive effect on the DP at the center. It has also been shown that the position of the lamp has an effect on the protected area.

Mobile ultra-clean unidirectional airflow screen reduces air contamination in a simulated setting for intra-vitreal injection

The aim of this study is to determine whether the use of a mobile ultra-clean laminar airflow screen reduces the air-borne particle counts in the setting of a simulated procedure of an intra-vitreal injection. A mobile ultra-clean unidirectional airflow (UDF) screen was tested in a simulated procedure for intra-vitreal injections in a treatment room without mechanical ventilation. One UDF was passed over the instrument tray and the surgical area. The concentration of particles was measured in the background, over the instrument table, and next to the ocular area. The degree of protection was calculated at the instrument table and at the surgical site. Use of the UDF mobile screen reduced the mean particle concentration (particles > 0.3 microns) on the instrument table by a factor of at least 100.000 (p < 0.05), and over the patient's eye by at least a factor of 436 (p < 0.05), which in clinical practice translates into significantly reduced air contamination. Mobile UDF screen reduces the mean particle concentration substantially. The mobile UDF screen may therefore allow for a safer procedural environment for ambulatory care procedures such as intra-vitreal injections in treatment rooms.