The Association of Immediate-Use Steam Sterilization with the Incidence of Orthopaedic Surgical Site Infections: A Propensity Score-Matched Cohort Study.

BACKGROUND: Immediate-use steam sterilization (IUSS), formerly termed "flash" sterilization, has been historically used to sterilize surgical instruments in emergency situations. Strict guidelines deter its use, as IUSS has been theorized to increase the risk of surgical site infections (SSIs), leading to increased health-care costs and poor patient outcomes. We sought to examine the association between the use of IUSS and the rate of orthopaedic SSIs. METHODS: The cases of 70,600 patients who underwent orthopaedic surgery-total knee or hip arthroplasty, laminectomy, or spinal fusion-from January 2014 to December 2020, were retrospectively reviewed for IUSS use. Of this group, 3,526 patients had had IUSS used during surgery. A propensity score-matched (PSM) analysis was conducted to account for known predictors of SSIs and included a total of 7,052 patients. The risk difference (RD), relative risk (RR), odds ratio (OR), and McNemar test compared the SSI risk for patients whose procedure had included the use of IUSS and those whose procedure had not included IUSS. RESULTS: After propensity score matching, 111 (1.57%) of the 7,052 matched patients developed an SSI. Of the 111 patients, 61 (54.95%) were in the IUSS group and 50 (45.05%) were in the non-IUSS group. The estimated probability for developing an SSI was 1.42% for the patients in the non-IUSS group versus 1.73% for the patients in the IUSS group (RR = 0.82 [95% confidence interval (CI)]: 0.57 to 1.19], RD = -0.3% [95% CI: -0.9% to 0.27%]).There was no evidence that the proportion of SSI was greater in the IUSS group (McNemar test, p > 0.29). CONCLUSIONS: SSI rates were not significantly different between IUSS and non-IUSS patients undergoing orthopaedic surgery. Future prospective studies are warranted to further explore the utility of IUSS during orthopaedic procedures. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Steam inhalation: More harm than good? Perspective from a UK burns centre.

INTRODUCTION: Steam inhalation is common practice in UK households for coryzal symptoms in adults and children. Steam inhalation has the potential to and has caused significant scald injuries, predominantly due to unintentional contact with the hot water used. METHODS: The authors used electronic health records to retrospectively identify all patients admitted with scald injuries secondary to steam inhalation over a 2-year period from January 2018-December 2019 at Chelsea and Westminster Hospital, a regional burns centre. Data collected included patient demographics, mechanism of burn, as well as burn size, depth, treatment and any associated complications. An International Burns Injury Database enquiry assessed the national prevalence steam inhalation scalds over the same time period. RESULTS: 19 adult and paediatric patients were identified in our centre over a 2-year period, with an age range of 2 weeks to 91 years old. The majority (16/19, 84%) of patients received burns to their lower body, with three patients receiving burns to their chest and/or upper limbs. Six patients underwent surgery, 98 clinic appointments were utilised and the total length of hospital stay was 83 days. The estimated total cost of treating these 19 patients was over £31,872. Nationally, 201 cases were identified between Jan 2018-Dec 2019. CONCLUSIONS: Scald injuries secondary to steam inhalation have a significant impact both in terms of hospital stay and cost. Since this study captured only patients admitted to hospital, the true negative impact of steam inhalation is likely to be much higher than calculated. Better public awareness on the risks of steam inhalation and primary prevention policies could reduce the frequency of such injuries.

Decontamination of filtering facepiece respirators using a low-temperature-steam-2%-formaldehyde sterilization process during a pandemic: a safe alternative for re-use.

BACKGROUND: The coronavirus disease 2019 pandemic has caused problems with respirator supplies. Re-use may minimize the impact of the shortage, but requires the availability of an efficient and safe decontamination method. AIM: To determine whether low-temperature-steam-2%-formaldehyde (LTSF) sterilization is effective, preserves the properties of filtering facepiece (FFP) respirators and allows safe re-use. METHODS: Fourteen unused FFP2, FFP3 and N95 respirator models were subjected to two cycles of decontamination cycles. After the second cycle, each model was inspected visually and accumulated residual formaldehyde levels were analysed according to EN 14180. After one and two decontamination cycles, the fit factor (FF) of each model was tested, and penetration tests with sodium chloride aerosols were performed on five models. FINDINGS: Decontamination physically altered three of the 14 models. All of the residual formaldehyde values were below the permissible threshold. Irregular decreases and increases in FF were observed after each decontamination cycle. In the sodium chloride aerosol penetration test, three models obtained equivalent or superior results to those of the FFP classification with which they were marketed, both at baseline and after one and two cycles of decontamination, and two models had lower filtering capacity. CONCLUSION: One and two decontamination cycles using LTSF did not alter the structure of most (11/14) respirators tested, and did not degrade the fit or filtration capacity of any of the analysed respirators. The residual formaldehyde levels complied with EN 14180. This reprocessing method could be used in times of shortage of personal protective equipment.

Gravity steam reprocessing in healthcare facilities for the reuse of N95 respirators.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has significantly impacted the health of millions of people around the world. The shortage of personal protective equipment, including N95 respirators, in hospital facilities has put frontline healthcare professionals at high risk for contracting this virus. AIM: To develop a reproducible and safe N95 respirator reprocessing method that satisfies all presented regulatory standards and that can be directly implemented by hospitals using existing available equipment. METHODS: A non-toxic gravity steam reprocessing method has been developed for the reuse of N95 respirators consisting of 30 min of steam treatment at 121°C followed by 30 min of heat drying. Samples of model number 1860, 1860s, 1870+, and 9105 N95 respirators were either collected from hospitals (for microbiology testing) or purchased new (for functionality testing), with all functionality tests (i.e. filter efficiency, fit evaluation, and strap integrity) performed at the Centers for Disease Control and Prevention using standard procedures established by the National Institute for Occupational Safety and Health. FINDINGS: All tested models passed the minimum filter efficiency of 95% after three cycles of gravity steam reprocessing. The 1870+ N95 respirator model is the most promising model for reprocessing based on its efficient bacterial inactivation coupled with the maintenance of all other key functional respirator properties after multiple reprocessing steps. CONCLUSIONS: The gravity steam method can effectively reprocess N95 respirators over at least three reprocessing cycles without negatively impacting the functionality requirements set out by regulators. Enabling the reuse of N95 respirators is a crucial tool for managing both the current pandemic and future healthcare crises.

Can an Off-Nominal Landing by an MMRTG-Powered Spacecraft Induce a Special Region on Mars When No Ice Is Present?

This work aims at addressing whether a catastrophic failure of an entry, descent, and landing event of a Multimission Radioisotope Thermoelectric Generator-based lander could embed the heat sources into the martian subsurface and create a local environment that (1) would temporarily satisfy the conditions for a martian Special Region and (2) could establish a transport mechanism through which introduced terrestrial organisms could be mobilized to naturally occurring Special Regions elsewhere on Mars. Two models were run, a primary model by researchers at the Lawrence Berkeley National Laboratory and a secondary model by researchers at the Jet Propulsion Laboratory, both of which were based on selected starting conditions for various surface composition cases that establish the worst-case scenario, including geological data collected by the Mars Science Laboratory at Gale Crater. The summary outputs of both modeling efforts showed similar results: that the introduction of the modeled heat source could temporarily create the conditions established for a Special Region, but that there would be no transport mechanism by which an introduced terrestrial microbe, even if it was active during the temporarily induced Special Region conditions, could be transported to a naturally occurring Special Region of Mars.

Bipolar ablation of refractory atrial and ventricular arrhythmias: Importance of temperature values of intracardiac return electrodes.

INTRODUCTION: Bipolar radiofrequency catheter ablation (Bi-RFCA) emerged as an option for treatment of arrhythmias resistant to the conventional approach. Data on safety issues of Bi-RFCA, including temperature values of intracardiac return electrode (IRE) are lacking. OBJECTIVE: To determine the safety profile of Bi-RFCA regarding temperature measurements obtained from nonirrigated IRE of different sizes. METHODS: The study group consisted of consecutive patients after failed conventional RFCA who underwent Bi-RFCA. RESULTS: Out of 1510 RFCA performed in our center, 19 patients underwent Bi-RFCA due to refractory to previous RFCA ventricular arrhythmias (15 patients) or typical atrial flutter (four patients). Nonirrigated small (4 mm) and large (8 mm) tip catheters were used as IRE in 14 (including three cross-overs to 8 mm IRE) and five patients, respectively. A total number of 164 bipolar applications were performed (128 for 4 mm and 36 for 8 mm IRE). Maximal temperatures of 4 mm IRE were significantly higher than those of 8 mm IRE (63°C ± 16°C vs 43°C ± 4°C; P = .027). A significant rise of temperature and steam-pops, preventing further Bi-RFCA, occurred in seven patients treated with 4 mm IRE. Bi-RFCA using 4 mm IRE operated at significantly higher impedance values (211 ± 83 vs 143 ± 38; P = .04) and lower power values (mean 20 W ± 6 W vs 32 W ± 7 W, P = .0005; max 29 W ± 9 W vs 39 W ± 10 W, P = .027). CONCLUSION: The use of 8 mm IRE for Bi-RFCA is associated with lower temperatures of the catheter used as ground and lower incidence of steam-pops which may suggest a better safety profile than 4 mm IRE. Determination of safety/efficacy balance requires further studies.

Second-Degree Burn Sustained After Vaginal Steaming.

BACKGROUND: Vaginal steaming has gained increased popularity as a method to achieve empowerment by providing vaginal tightening and to "freshen" the vagina. CASE: A 62-year-old woman sustained second-degree burns following vaginal steaming in an attempt to reduce vaginal prolapse. CONCLUSION: Clinicians need to be aware of alternative treatments available to women so that counselling may mitigate any potential harm.

Identification of Radiofrequency Ablation Catheter Parameters That May Induce Intracardiac Steam Pops: Direct Visualization of Elicitation in Reanimated Swine Hearts.

Radiofrequency, a common ablation modality, is used clinically to terminate cardiac arrhythmias. With excessive heating, complications sometimes occur when the applied energy generates steam pops, which cause release of energy in the form of tissue and/or air emboli. In this study, we investigated numerous parameters potentially associated with intracardiac steam pops including (1) wattage, (2) catheter tip temperature, (3) catheter irrigation, (4) anatomic site, and (5) repeat ablations at a given site. Using unique Visible Heart® methodologies in reanimated swine hearts, we visualized 539 ablations; steam pops developed in 140 of these ablations. The incidence of steam pops significantly increased for both nonirrigated and irrigated ablations at 40 W (p < 0.005), and for nonirrigated ablations with catheter contact angles perpendicular to the tissue or that encompassed larger surface areas (p < 0.05). To minimize the incidence of steam pops, clinicians performing radiofrequency ablations must consider catheter parameters.

The role of meteorologic factors and air pollution on the frequency of pediatric epistaxis.

Fluctuations in atmospheric temperature, humidity, and air pollution are associated with the incidence of epistaxis. To date, no study in the literature has evaluated the effect of air pollution and meteorologic conditions on the pediatric population. We aimed to evaluate the effect of meteorologic factors and air pollution on the frequency of epistaxis in children. Children presenting to an outpatient clinical setting at a tertiary care hospital during a 5-year period (July 1, 2009, to June 30, 2014) and diagnosed with epistaxis formed the study population. Daily temperature and humidity parameters and average daily atmospheric water vapor pressure, average daily concentration of particulate matter <10 µm in diameter, and sulfur dioxide readings were obtained. The distribution of daily parameters was analyzed. Of the 1,559 children with the primary diagnosis of epistaxis, data from 1,330 children were analyzed after excluding patients with coexisting pathologies. Positive correlations were found between the frequency of epistaxis and both the average daily temperature and the difference between the maximum and minimum daily temperature. There was a negative correlation between the epistaxis frequency and the average daily humidity, the difference between the maximum and minimum daily humidity, the average daily concentration of particulate matter, and the sulfur dioxide levels. Our findings suggest that epistaxis in children is related to high temperatures and low humidity.

Knowledge, attitude, and perception of risk management of steam boilers among workers in palm oil mills.

BACKGROUND: People who work with the steam boilers in palm oil mills are vulnerable to accidents, notably to explosions, whenever failures of any kind occur during their operation. OBJECTIVE: This cross-sectional study was conducted in palm oil mills to determine the knowledge, attitude, and perception (KAP) concerning the risk management of steam boilers among workers in palm oil mills. METHODS: A total of 50 workers who were working with steam boilers and/or involved in managing the operation of steam boilers with at least three years of working experience in the palm oil industry were purposively sampled. A self-administrated questionnaire consisting of four main parts - socio-demographic and occupational information, knowledge, attitude, and perception of the risk management of steam boilers was distributed. The knowledge, attitude, and perception were calculated based on a Likert-type scale. RESULTS: This study found that 56% of boiler workers had a good level of knowledge (mean score = 77.22±19.6), 72% had a good attitude toward risk (mean score = 83.17±5.85), and 64% had a good perception of risk (mean score = 79.50±11.22). The prevalence of accidents was 16%, and, for near misses, it was 24%. The cause of the reported accidents was largely attributed to carelessness, specifically at 80%. Apart from that, there was a positive association (χ2 = 6.56; p = 0.010) between attitude and accidents. CONCLUSION: This study found that the workers had good KAP levels of risk management of steam boilers in palm oil mills. However, there is a need for the employers to revise the training of workers and ensure its effectiveness in heightening the awareness of risks and accidents despite the high level of KAP.

Prediction of Steam Burns Severity using Raman Spectroscopy on ex vivo Porcine Skin.

Skin burns due to accidental exposure to hot steam have often been reported to be more severe than the ones occurring from dry heat. While skin burns due to flames or radiant heat have been thoroughly characterized, the mechanisms leading to steam burns are not well understood and a conundrum still exists: can second degree burns occur without destruction of the epidermis, i.e. even before first degree burns are detected? Skin permeability is dependent both on temperature and on the kinetic energy of incoming water molecules. To investigate the mechanism underlying the injuries related to steam exposure, we used porcine skin as an ex vivo model. This model was exposed to either steam or dry heat before measuring the skin hydration via confocal Raman microspectroscopy. The results show that during the first minute of exposure to steam, the water content in both the epidermis and dermis increases. By analyzing different mechanisms of steam diffusion through the multiple skin layers, as well as the moisture-assisted bio-heat transfer, we provide a novel model explaining why steam burns can be more severe, and why steam can penetrate deeper and much faster than an equivalent dry heat.

What's New in Rezum?

Management of benign prostatic hyperplasia focuses on relief of lower urinary tract symptoms (LUTSs), improvement of quality of life, and prevention of symptom progression. Minimally invasive surgical treatments (MISTs) offer potential for rapid symptomatic relief, medication independence, and less perioperative risk. The Rezum system is a novel MIST that uses water vapor thermal therapy to ablate obstructive prostate tissue. In this review, we summarize the data revealing that water vapor thermal therapy provides clinically meaningful, rapid, and durable relief of LUTSs in both storage and voiding functions while providing a minimal impact on sexual function. PATIENT SUMMARY: The expanding body of literature examining Rezum water vapor thermal therapy suggests that it is a safe, efficacious, and durable treatment modality for lower urinary tract symptoms that can be offered to a wide selection of patients.

Design and Testing of an Experimental Steam-Induced Burn Model in Rats.

BACKGROUND: Most of the current models for experimental burns pose difficulties in ensuring consistency and standardization. AIM OF STUDY: We aimed to develop an automated, reproducible technique for experimental burns using steam-based heat transfer. METHODS: The system developed for steam exposure was based on a novel, integrated, computer-controlled design. Three groups of rats were exposed to steam for 1, 3, and 7 seconds. The lesions were evaluated after 20 minutes, 48 hours, and 72 hours after burn induction. RESULTS: One-second steam application produced a superficial second-degree burn; three-second application induced deep second-degree burn; and seven-second application led to a third-degree burn. CONCLUSION: The high level of automation of our integrated, computer-controlled system makes the difference between our system and other models, by ensuring the control of the duration of exposure, temperature, and pressure and eliminating as many potential human generated errors as possible. The automated system can accurately reproduce specific types of burns, according to histological assessment. This model could generate the reproducible data needed in the study of burn pathology and in order to assess new treatments.

Convective Radiofrequency Water Vapor Thermal Therapy with Rezum System.

PURPOSE: Lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) are amongst the most commonly treated conditions by urologists. Minimally invasive therapies for the treatment of BPH/LUTS have garnered increased interest as new technology has emerged, improving durability, efficacy, and safety. This paper reviews the most recent literature regarding water vapor therapy, a convective thermal therapy that ablates prostatic tissue. RECENT FINDINGS: The current literature includes a pilot study of 65 men and a randomized controlled trial (RCT) of 197 men investigating the efficacy and safety profile of water vapor therapy up to 2 years. Subjects treated with water vapor therapy demonstrated a 51% reduction in IPSS from baseline, sustained at 24 months (p < 0.0001). Durable improvements in max flow rate (Qmax) and quality of life (QoL) were also achieved, while no changes in sexual function were observed. Reporting of adverse events (AEs) reveals predominantly Clavien grade I complications that were self-limited. The clinical efficacy and safety of water vapor therapy are durable to 24 months making it an attractive alternative for patients seeking a minimally invasive treatment for LUTS due to BPH.

Heated, humidified air for the common cold.

BACKGROUND: Heated, humidified air has long been used by people with the common cold. The theoretical basis is that steam may help congested mucus drain better and that heat may destroy the cold virus as it does in vitro. This is an update of a review last published in 2013. OBJECTIVES: To assess the effects of inhaling heated water vapour (steam) in the treatment of the common cold by comparing symptoms, viral shedding, and nasal resistance. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (to February 2017), MEDLINE (1966 to 24 February 2017), Embase (1990 to 24 February 2017), and Current Contents (1998 to 24 February 2017). We also searched World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) (8 March 2017) and ClinicalTrials.gov (8 March 2017) as well as reference lists of included studies. SELECTION CRITERIA: Randomised controlled trials using heated water vapour in participants with the common cold or experimentally induced common cold were eligible for inclusion. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Three review authors independently screened titles and abstracts for inclusion of potential studies identified from the search. We recorded the selection process in sufficient detail to complete a PRISMA flow diagram. We used a data collection form for study characteristics and outcome data that was developed and used for previous versions of this review. Two review authors independently extracted data, and a third review author resolved any disagreements. We used Review Manager 5 software to analyse data. MAIN RESULTS: We included six trials from five publications involving a total of 387 participants. We included no new studies in this 2017 update. The 'Risk of bias' assessment suggested an unclear risk of bias in the domain of randomisation and a low risk of bias in performance, detection, attrition, and reporting.It was uncertain whether heated, humidified air provides symptomatic relief for the common cold, as the fixed-effect analysis showed evidence of an effect (odds ratio (OR) 0.30, 95% confidence interval (CI) 0.16 to 0.56; 2 studies, 149 participants), but the random-effects analysis showed no significant difference in the results (OR 0.22, 95% CI 0.03 to 1.95). There is an argument for using either form of analysis. No studies demonstrated an exacerbation of clinical symptom scores. One study conducted in the USA demonstrated worsened nasal resistance, but an earlier Israeli study showed improvement. One study examined viral shedding in nasal washings, finding no significant difference between treatment and placebo groups (OR 0.47, 95% CI 0.04 to 5.19). As judged by the subjective response to therapy (i.e. therapy did not help), the number of participants reporting resolution of symptoms was not significantly higher in the heated humidified group (OR 0.58, 95% CI 0.28 to 1.18; 2 studies, 124 participants). There was significant heterogeneity in the effects of heated, humidified air on different outcomes, therefore we graded the quality of the evidence as low. Some studies reported minor adverse events (including discomfort or irritation of the nose). AUTHORS' CONCLUSIONS: The current evidence does not show any benefits or harms from the use of heated, humidified air delivered via the RhinoTherm device for the treatment of the common cold. There is a need for more double-blind, randomised trials that include standardised treatment modalities.