Universal decontamination of hospital surfaces in an occupied inpatient room with a continuous 405 nm light source.

BACKGROUND: Previous work has shown that a ceiling-mounted, 405 nm high-intensity narrow-spectrum light environmental decontamination system (HINS-light EDS) reduces bacterial contamination of environmental surfaces in a burns unit by between 27% and 75%. Examination of the efficacy of the light over extended exposure times and its probable mode of action was performed. AIM: To ascertain the correlation between bacterial kill achieved on sampled surface sites around the burns unit and both irradiance levels of the 405 nm light, and exposure time. METHODS: Seventy samples were taken using contact agar plates from surfaces within an occupied side-room in the burns unit before, during, and after a seven-day use of the HINS-light EDS. This was repeated in three separate studies. Statistical analysis determined whether there was significant decrease in environmental contamination during prolonged periods of HINS-light treatment, and whether there was an association between irradiance and bacterial kill. FINDINGS: A decrease of between 22% and 86% in the mean number of surface bacteria was shown during the use of the HINS-light EDS. When the light ceased to be used, increases of between 78% and 309% occurred. There was no correlation between bacterial kill and irradiance levels at each sampling site but strong correlation between bacterial kill and exposure time. CONCLUSION: Prolonged exposure to the HINS-light EDS causes a cumulative decontamination of the surfaces within a burns unit. The importance of exposure time and possible airborne effect over irradiance levels is emphasized.

Investigating end-to-end accuracy of image guided radiation treatment delivery using a micro-irradiator.

There is significant interest in delivering precisely targeted small-volume radiation treatments, in the pre-clinical setting, to study dose-volume relationships with tumour control and normal tissue damage. For these studies it is vital that image guidance systems and target positioning are accurately aligned (IGRT), in order to deliver dose precisely and accurately according to the treatment plan. In this work we investigate the IGRT targeting accuracy of the X-RAD 225 Cx system from Precision X-Ray using high-resolution 3D dosimetry techniques. Small cylindrical PRESAGE® dosimeters were used with optical-CT readout (DMOS) to verify the accuracy of 2.5, 1.0, and 5.0 mm X-RAD cone attachments. The dosimeters were equipped with four target points, visible on both CBCT and optical-CT, at which a 7-field coplanar treatment plan was delivered with the respective cone. Targeting accuracy (distance to agreement between the target point and delivery isocenter) and cone alignment (isocenter precision under gantry rotation) were measured using the optical-CT images. Optical-CT readout of the first 2.5 mm cone dosimeter revealed a significant targeting error of 2.1 ± 0.6 mm and a cone misalignment of 1.3 ± 0.1 mm. After the IGRT hardware and software had been recalibrated, these errors were reduced to 0.5 ± 0.1 and 0.18 ± 0.04 mm respectively, within the manufacturer specified 0.5 mm. Results from the 1.0 mm cone were 0.5 ± 0.3 mm targeting accuracy and 0.4 ± 0.1 mm cone misalignment, within the 0.5 mm specification. The results from the 5.0 mm cone were 1.0 ± 0.2 mm targeting accuracy and 0.18 ± 0.06 mm cone misalignment, outside of accuracy specifications. Quality assurance of small field IGRT targeting and delivery accuracy is a challenging task. The use of a 3D dosimetry technique, where targets are visible on both CBCT and optical-CT, enabled identification and quantification of a targeting error in 3D. After correction, the targeting accuracy of the irradiator was verified to be within 0.5 mm (or 1.0 mm for the 5.0 mm cone) and the cone alignment was verified to be within 0.2 mm (or 0.4 mm for the 1.0 mm cone). The PRESAGE®/DMOS system proved valuable for end-to-end verification of small field IGRT capabilities.

Problems in obtaining sufficient anaesthesia with propofol and remifentanil: three cases, a test infusion, and a review.

BACKGROUND: Over a 5 yr period, we have encountered three patients in whom remifentanil appeared to have no clinical effect during general anaesthesia (GA). We describe seven anaesthetics in these three patients. METHODS: We reviewed the literature on this subject. A simple reproducible test to explore this response was designed. This involved a controlled infusion of increasing doses of remifentanil while observing respiratory variables, pain threshold, pupil size, and Glasgow coma scale score. In addition, blood was sampled for genotyping. RESULTS: No description of this impaired response was found in the review of the literature. Two of the patients agreed to participate in the test. In both patients, we found a seemingly normal analgesic response but a lack of respiratory depression and almost no depression of consciousness, even at doses well above the recommended level for clinical use. The genotyping did not explain the results of the test. CONCLUSIONS: The potential causes of this effect are discussed. We advise clinicians to be aware of this unusual response to remifentanil. If such a response is suspected, we recommend the use of another opioid. If this is suspected before GA, we propose the use of our test as a diagnostic tool.

Effects of adductor-canal-blockade on pain and ambulation after total knee arthroplasty: a randomized study.

BACKGROUND: Total knee arthroplasty (TKA) is associated with intense post-operative pain. Besides providing optimal analgesia, reduction in side effects and enhanced mobilization are important in this elderly population. The adductor-canal-blockade is theoretically an almost pure sensory blockade. We hypothesized that the adductor-canal-blockade may reduce morphine consumption (primary endpoint), improve pain relief, enhance early ambulation ability, and reduce side effects (secondary endpoints) after TKA compared with placebo. METHODS: Patients aged 50-85 years scheduled for TKA were included in this parallel double-blind, placebo-controlled randomized trial. The patients were allocated to receive a continuous adductor-canal-blockade with intermittent boluses via a catheter with either ropivacaine 0.75% (n = 34) or placebo (n = 37) (http://www.clinicaltrials.gov Identifier: NCT01104883). RESULTS: Seventy-five patients were randomized in a 1 : 1 ratio and 71 patients were analyzed. Morphine consumption from 0 to 24 h was significantly reduced in the ropivacaine group compared with the placebo group (40 ± 21 vs. 56 ± 26 mg, P = 0.006). Pain was significantly reduced in the ropivacaine group during 45 degrees flexion of the knee (P = 0.01), but not at rest (P = 0.06). Patients in the ropivacaine group performed the ambulation test, the Timed-Up-and-Go (TUG) test, at 24 h significantly faster than patients in the placebo group (36 ± 17 vs. 50 ± 29 s, P = 0.03). CONCLUSION: The adductor-canal-blockade significantly reduced morphine consumption and pain during 45 degrees flexion of the knee compared with placebo. In addition, the adductor-canal-blockade significantly enhanced ambulation ability assessed by the TUG test.

Verification of endotracheal intubation in obese patients - temporal comparison of ultrasound vs. auscultation and capnography.

BACKGROUND: Ultrasound (US) may have an emerging role as an adjunct in verification of endotracheal intubation. Obtaining optimal US images in obese patients is generally regarded more difficult than for other patients. This study compared the time consumption of bilateral lung US with auscultation and capnography for verifying endotracheal intubation in obese patients. METHODS: A prospective, paired and investigator-blinded study performed in the operating theatre. Twenty-four adult patients requiring endotracheal intubation for bariatric surgery were included. During post-intubation bag ventilation, bilateral lung US was performed for detection of lungsliding indicating lung ventilation simultaneous with capnography and auscultation of epigastrium and chest. Primary outcome measure was the time difference to confirmed endotracheal intubation between US and auscultation alone. The secondary outcome measure was time difference between US and auscultation combined with capnography. RESULTS: Both methods verified endotracheal tube placement in all patients. No significant difference was found between US compared with auscultation alone. Median time for verification by auscultation alone was 47.5 s [interquartile (IQR) 40-51 s], with a mean difference of -0.3 s in favor of US (95% confidence interval -3.5-2.9 s) P = 0.87. Comparing US with the combination of auscultation and capnography, there was a significant difference between the two methods. Median time for verification by US was 43 s (IQR 40-51 s) vs. 55 s (IQR 46-65 s), P < 0.0001. CONCLUSION: In obese patients, verification of endotracheal tube placement with US is as fast as auscultation alone and faster than the standard method of auscultation and capnography.

Anaphylaxis to ethylene oxide - a rare and overlooked phenomenon?

Spina bifida patients have been reported to be at increased risk of anaphylactic reactions during general anaesthesia. Following a reaction, latex is often incriminated as spina bifida patients are known to have an increased incidence of latex allergy. Ethylene oxide (EO) has recently been suggested to be an alternative cause, but in many cases reported in the literature, it seems that EO has not been considered as a cause. EO is a highly reactive gas widely used to sterilise heat-sensitive medical devices, and traces of EO can be found in many of the same products as latex. We present the case of a spina bifida patient with a known latex allergy, where EO was found to be the cause of an anaphylactic reaction during general anaesthesia. In addition, we describe measures taken during preparation of a subsequent general anaesthesia to minimise exposure to EO. Spina bifida patients seem to be at increased risk of sensitisation against EO due to repeated exposure, but only limited literature is available. To ensure that EO is considered as a cause in these cases, we recommend that testing for latex and EO go hand in hand following an anaphylactic reaction in this high-risk population.

[Indirect azygos vein continuation syndrome with segmental agenesis and saccular aneurysm of the inferior vena cava]. / Indirektes Vena-azgos-Kontinuationssyndrom mit Segmentagenesie und sackulärem Aneurysma der Vena cava inferior.

Indirect vena azygos continuation syndrome and aneurysm are rare variations of the inferior vena cava (IVC). In this article we describe the ultrasound, angiographic and CT appearance of a 14-year-old girl with this congenital anormaly of the IVC.