Fires and explosions

Fire and explosions require three elements in order to occur (the ‘fire triangle’): oxygen, fuel and a heat or ignition source. Fuel reacts with an oxidizing agent to release energy that may sustain the reaction. An explosion is a rapid physical or chemical change accompanied by a large pressure increase. In the operating theatre environment different team members have control over the three limbs of the fire triangle; good teamwork is paramount in the management of fire. It is the anaesthetist’s responsibility to use oxygen and nitrous oxide judiciously to avoid oxygen-enriched environments in proximity to ignition sources. Potential fuels include surgical drapes and PVC tracheal tubes. Heat and ignition sources include surgical diathermy, lasers, defibrillators and static electricity. Small fires can be patted out or extinguished with sterile saline or water. With larger fires, burning material must be removed and extinguished and oxygen must be stopped, after which ventilation should be re-established with air until the fire risk is removed. The acronym RACE is helpful if evacuation becomes necessary: Rescue patient, Alert other theatres, Confine smoke and fire and Evacuate theatre.     

Fires and explosions

Fires and explosions require three elements in order to occur (the ‘fire triangle’): oxygen, fuel and heat. In the operating theatres, different team members have control over each limb of the fire triangle hence good teamwork is paramount to prevent and restrain a fire. Managing a fire involves recognizing early signs and separating the three elements of the fire triangle, extinguishing the fire immediately, evacuating when appropriate and delivering post-fire care. Airway fires are a particular challenge and establishing a patent airway and ensuring ventilation in these cases can be very difficult and require surgical input. This article reviews the physics and aetiology of surgical fires and explosions. It summarizes international guidelines for the prevention and treatment of fires.     

Damage to cobalt-chromium surfaces during arthroscopy of total knee replacements

BACKGROUND: It has been stated that care must be taken not to scratch the metal components during total knee arthroscopy; however, this concern has not been studied. Clinical observation during arthroscopy of total knee replacements suggested the possibility of damage to the femoral component by the arthroscopic cannula; therefore, a bench test was performed to study this potential risk. METHODS: Cobalt-chromium femoral components were tested to determine the surface damage that resulted from moving a stainless-steel arthroscopic cannula and a plastic arthroscopic cannula across the components under a variety of applied loads. Scanning electron microscopy and surface-roughness measurements of the prosthetic surface were used to evaluate the damage. RESULTS: The stainless-steel cannula produced observable alterations to the surface of the femoral component at loads as small as 8 N. The majority of these alterations were deposits of stainless steel from the cannula onto the component. The plastic cannula did not appear to produce alterations on the component surface. Surface roughness increased with increasing loading of the stainless-steel cannula, but there was no noticeable change with increasing loading of the plastic cannula. These forces did, however, severely damage some parts of the plastic cannula. CONCLUSIONS: Alterations to the surface of cobalt-chromium femoral components can occur during arthroscopy with stainless-steel cannulae but not with plastic cannulae. The results of this study support a recommendation to use plastic cannulae during arthroscopy of total knee replacements. Clinical Relevance: Arthroscopy of total knee replacements is increasing in the clinical setting, and damage to the prosthesis should be avoided whenever possible. This study provides evidence that damage to the femoral component is possible with a stainless-steel cannula and that use of a plastic cannula may reduce this risk.     

Surgical fires,a clear and present danger

BackgroundA surgical fire is potentially devastating for a patient. Fire has been recognised as a potential complication of surgery for many years. Surgical fires continue to happen with alarming frequency. We present a review of the literature and an examination of possible solutions to this problem.MethodsThe PubMed and Medline databases from 1948 onwards were searched using the subject headings “operating rooms”, “fire”, “safety” and “safety management”. “Surgical fire” was also searched as a keyword. Relevant references from articles were obtained.ResultsFire occurs when the three elements of the fire triad, fuel, oxidiser and ignition coincide. Surgical fires are unusual in the absence of an oxygen-enriched atmosphere. The ignition source is most commonly diathermy but lasers carry a relatively greater risk. The majority of fires occur during head and neck surgery. This is due to the presence of oxygen and the extensive use of lasers.The risk of fire can be reduced with an awareness of the risk and good communication.ConclusionsSurgery will always carry a risk of fire. Reducing this risk requires a concerted effort from all team members.     

Inherent laxity in total knee prostheses

The anterior-posterior and rotatory laxities of 14 total knee prosthesis designs were measured in a loading rig with compressive, shear, and torque loads representative of physiologic loads. The measured laxities covered a wide range, both greater and smaller than that of the anatomic knee. This range was mainly due to the curvature or flatness of the plastic tibial surface and conformity with the femoral component. Pressure patterns showed the corresponding contact track and area on the tibial surfaces. It is proposed that for normal function, the laxity of the device should complement the remaining anatomic structures to produce a combined laxity resembling that of the normal knee. Excessive prosthetic laxity will lead to the risk of instability, soft tissue attenuation, edge-loading on components, and high contact stresses on the plastic. Inadequate prosthetic laxity may lead to altered kinematics and excessive stresses at the interface, running the risk of long-term loosening. The authors show the laxities of many currently used devices, providing important background information for assessing the role intrinsic prosthetic constraint might play in total joint performance in clinical analyses.     

Risks and prevention of surgical fires

Surgically induced fire is a life-threatening hazard; this topic has received little attention, although only 3 factors, the so-called fire triad, are needed for surgical fires to occur: an oxidizer, fuel and an ignition source. This systematic review aims to determine the impact of each component and to delegate every staff member an area of responsibility, thus ensuring patient health through prevention or protection. The trial was registered in Prospero CRD42018082656. A database search of eligible, preferably evidence-based studies was conducted. The Robins-I tool for assessing the risk of bias revealed a moderate risk of bias. Due to insufficient data, the main findings of these studies could not be summarized through a quantitative synthesis; therefore, a qualitative synthesis is outlined. The results are summarized according to the roles of the fire triad and discussed. (1) Role of the oxidizer: oxygen is the key component of the triad. Safe oxygen delivery is important. An oxygen-enriched environment (ORE) is caused by draping and is preferably prevented by suctioning. Fuel characteristics are affected by varying oxygen concentrations. (2) Role of the ignition source: electrocauterization is the most common ignition source, followed by lasers. Less common ignition sources include fiberoptic cables and preparative solutions, petrol or acetone. (3) Role of the fuel: surgical drapes are one of the most common fuels for surgical fires followed by the patient’s hair and skin. Skin preparation solutions are among the less common fuels. Many fire-resistant materials have been tested that do not remain fire resistant in ORE. It was concluded that the main problem is defining the real extent of this hazard. Exact numbers and exact condition protocols are needed; therefore, standardized registration of every fire and future studies with much evidence are needed. Immediate prevention consists of close attention to patient safety to prevent surgical fires from happening.     

Fire tests and hazards: an Australian approach

The use of fire tests in assessing fire hazards is described against a general discussion of the uses of fire tests, the concepts of fire hazard and fire risk and the methods of test classification. Four approaches to fire hazard assessment are explored: analysis of fire risk data, simulation experiments, ‘direct data’^† tests and fire hazard specifications using direct data or ‘supportive data’ tests. It is concluded that users of these tests need to be aware of their significance and the manner in which they should be used.     

The clinical anatomy of the triangle of Petit

INTRODUCTION: Hernias through the triangle of Petit (TP) are uncommon. The anatomy of the TP is known to be variable, yet quantitative data are scant. MATERIALS AND METHODS: The triangle was observed in 80 adult cadavers and its dimensions and surface area were measured. RESULTS: On the basis of surface area we classified the triangles into four types. Type I or small TP, with a surface area of <8 cm2, accounted for 43.7% of our specimens. Type II (26.2%) were intermediate in size, with a surface areas of 8-12 cm2. Type III (12.5%) were large triangles with surface areas >12 cm2. Finally, Type IV (17.5%) were not triangles. In these, the latissimus dorsi was covered by the external abdominal oblique muscle. CONCLUSIONS: We hope these data will help prediction of which patients are at greater risk of herniation through the TP.     

Protection of femoral neck taper in revision of acetabular component

In hip revision restricted to the acetabular component, the taper of a modular stem is in constant danger of scratching. We used a plastic syringe to protect the taper of the femoral component. A plastic syringe of appropriate size remains well in place and offers a novel and inexpensive protective device for the taper of the femoral component available in every operation room.     

足第二趾再造手指的重塑整形

目的 探索足第二趾再造手指一期重塑整形的方法.方法 对6例6指Ⅲ～Ⅳ度缺损,行足第二趾移植再造手指,术中同时行足第二趾"指腹"和"颈部"部位的三角皮瓣转换整形术来重塑外形. 结果 6例6指再造手指和局部改形三角皮瓣均成活.5例经8～15个月随访,再造手指外形得到明显改善.指腹感觉恢复良好,两点辨别觉为8～10 mm.患者比较满意. 结论 一期行局部三角皮瓣转移重塑再造手指外形,解决了再造指"指腹"膨大和掌侧"颈部"狭窄的外形缺陷,临床疗效较好.     

Failure mechanisms of metal-backed patellar components

A specific type of failure of a metal-backed patella occurred, consisting of a separation of the polyethylene from the metal backing. This dissociation is followed by wearing of the metal backing against the femoral component. This produces clinical signs and symptoms that usually require revision. This failure occurred in 16 knees of 14 patients. Average time to failure was 14 months. Failure was associated with patellar implant design, surgical technique, patient characteristics, and femoral component design. The plastic of the metal-backed patellae was thin at the periphery. The metal plate did not extend to the edge of the plastic and acted like a sharp edge that cut the thin plastic. The plastic dome was not bonded to the plate and became separated from the plate once the plastic tore. The plate became deformed. Failure was more likely with a subluxated, tilted, or excessively thick patella or flexed femoral component. The typical patient was a large, active male who had achieved more than 115 degrees of flexion. A prominent edge on the lateral intercondylar ridge of the femoral component resulted in a concentrated load being applied to the plastic dome and favored rapid wear of the patella. Until a greater understanding of patello-femoral loading is acquired, caution in the use of metal-backed patellae is recommended.     

Infections After Plastic Procedures: Incidences,Etiologies, Risk Factors,and Antibiotic Prophylaxis

Background Through a review of the English literature, this study aimed to assess the incidence, etiology, risk factors, and preventive measures for postoperative infections occurring after plastic surgery operations. Methods All studies describing the occurrence of infections after plastic surgery procedures including case reports, prospective trials, and retrospective series were selected. Results The 85 articles analyzed showed that incidences differ greatly among procedures and seem to be influenced by different and specific risk factors for each operation. Etiologic agents are primarily bacteria, although mycobacteria, virus, and fungi also have been described. No agreement exists on the use of antibiotic prophylaxis, except for abdominoplasties, because few specific prospective trials are present in the literature. Conclusions Infections remain an important problem in plastic surgery with different points that still need to be clarified. Hopefully, in the future prospective randomized trials will definitively address this issue in order to provide plastic surgeons with clear and unbiased guidelines on its prevention and management.     

急症腹腔镜胆囊切除术中转开腹危险因素的分析

目的:分析术前预测急症腹腔镜胆囊切除术(laparoscopic cholecystectomy,LC)中转开腹的可能性,以期找到客观、实用、准确率高的预测LC手术难易度的方法,并选择适当的手术方式.方法:回顾分析2005～2009年120例急症LC中38例中转开腹患者的临床资料.从胆囊炎、胆囊结石疾病病理方面提取胆囊...     

“Triangle of safety”: anatomic considerations in transvaginal natural orifice surgery

Background

The introduction of transvaginal (TV) natural orifice transluminal endoscopic surgery (NOTES) brings the loss of traditionally used cutaneous landmarks for safe peritoneal access. This video describes the use of landmarks within the posterior vaginal fornix to define a “triangle of safety” wherein the peritoneal cavity can be accessed while minimizing the risk of injury to surrounding structures.

Methods

The triangle of safety is best identified in the following way. The cervix and posterior fornix are visualized. Then an imaginary clock located at the base of the cervix is envisioned. The superior two corners of the triangle are represented by the 4 and 8 o’clock positions on this imaginary clock. Sometimes the cervix needs to be grasped and elevated anteriorly so that the inferior apex of the triangle delineated by the center of the rectovaginal fold is better visualized.

Results

During hybrid TV NOTES, the rectovaginal pouch of Douglas is visualized from the umbilicus, and the vaginal port can then be safely passed through the center of the triangle. It is important that the vaginal port should be angled upward, aiming toward the umbilicus to avoid injury to the rectum. During pure TV NOTES, the incision is made with electrocautery from the 5 o’clock position to the 7 o’clock position within the triangle. The peritoneum is sharply entered, and the colpotomy is dilated with the surgeons’ fingers.

Conclusions

The triangle of safety defines a set of landmarks between the base of the cervix and the rectovaginal fold. It allows for a safe TV access for hybrid and pure TV NOTES while minimizing the risk of injury to surrounding structures.     

Bandage burns: the fire risk of cottonwool: two case reports

A potential fire hazard of conventional dressings is reported. The danger is illustrated by the two following case reports of patients who sustained burns when the cottonwool component of their dressings caught fire.     

LC 术胆管损伤的危险因素及术后分析

目的 分析LC 术胆管损伤的危险因素,并对胆管损伤术后进行分析.方法 回顾性分析本院1999 年10 月至2010 年12 月行LC 术的4 531 例患者所出现的41 例胆管损伤,对胆管损伤的各影响因素进行χ2检验,分析胆管损伤的独立危险因素;同时分析胆管损伤是否能在术中及时发现.结果 单因素分析显示:患者性别、炎症分期、B 超示胆囊壁厚度、胆囊三角解剖和手术经验与胆总管损伤有关联(P<0.05).多因素非条件Lo-gistic 回归分析结果显示:胆囊三角解剖和手术经验是胆管损伤的独立危险因素(P<0.05).胆管损伤术中发现例数明显多于术后发现例数(χ2=12.868,P<0.05).结论 患者性别、炎症分期、B 超示胆囊壁厚度、胆囊三角解剖和手术经验与胆总管损伤密切相关.胆囊三角解剖和手术经验是胆管损伤的独立危险因素.胆管损伤一般能在术中及时发现及处理.     

腹腔镜胆囊切除术严重并发症的危险因素及预防措施分析

目的:观察腹腔镜胆囊切除术(laparoscopic cholecystectomy,LC)的严重并发症,分析其相关危险因素及预防措施。方法:回顾分析近年行LC患者的临床资料,共纳入2 584例研究对象,统计严重并发症发生率,对可能引起并发症的临床因素进行单因素及logistic多因素回归分析。结果:单因素分析结果提示急性期、胆囊壁厚度、胆囊三角电灼、Calot三角粘连、解剖变异与并发症发生率有关(P<0.05)。将有意义的因素纳入多因素logistic回归分析,按照OR值由高至低依次排列,Calot三角粘连、解剖变异、急性期、胆囊三角电灼是LC严重并发症的独立危险因素(P<0.05),而胆囊壁厚度超过5 mm不是独立危险因素。结论:正确认识危险因素,严格掌握手术适应证,规范术中操作,可降低严重并发症的发生。     

Response and legislative changes after the Kiss nightclub tragedy in Santa Maria/RS/Brazil: Learning from a large-scale burn disaster

Purpose

A major fire occurred on January 27, 2013, at 02:30 at Kiss nightclub in the city of Santa Maria, State of Rio Grande do Sul, in Southern Brazil. In this retrospective report, we aimed to describe the nightclub fire event, its immediate consequences, and evaluated its impact on legislation. Our objective was to disseminate the lessons we learned from this large-scale nightclub fire disaster.

腹腔镜胆囊切除术Calot三角扩大法预防胆道损伤体会

目的 探讨Calot三角扩大分离法在腹腔镜胆囊切除术（LC）中预防胆道损伤的作用.方法 回顾性分析我院2010年8月至2013年8月接受腹腔镜胆囊切除术（LC）的846例患者的临床资料.其中应用Calot三角扩大法LC病例534例,未采用Calot三角扩大法LC312例.结果 因急性结石性胆囊炎中转开腹手术6例,萎缩性结石性胆囊炎中转开腹手术3例,其余的均成功施行LC.采用Calot三角扩大法LC的病例无胆道损伤发生,未采用Calot三角扩大法LC发生胆道损伤2例.结论 采用Calot三角扩大分离法对于胆囊三角的暴露更清晰,减少了LC胆道损伤的风险.     

老年患者腹腔镜胆囊切除术并发症发生的相关危险因素分析

目的:探讨老年患者腹腔镜胆囊切除术(laparoscopic cholecystectomy,LC)并发症发生情况及其相关危险因素,为LC并发症的防治提供可借鉴依据。方法:收集2013年4月至2016年4月783例行LC的老年患者的临床资料,分析并发症情况,并采用单因素及多因素分析的方法筛选并发症发生的相关危险因素。结果:并发症总发生率为4.47%(35/783),单因素回归分析结果显示,病程、专科手术经验、手术时间、胆囊壁厚度、胆囊与周围粘连、Calot三角粘连、胆囊颈结石、解剖变异、放置引流、合并基础疾病等10个因素与并发症密切相关。多因素分析表明,影响并发症发生的因素包括专科手术经验(OR=2.954)、胆囊壁厚度(OR=2.496)、胆囊与周围粘连(OR=3.286)、Calot三角粘连(OR=4.212)、放置引流(OR=0.321)、合并基础疾病(OR=4.532)。结论:老年患者行LC的并发症发生率仍较高,手术并发症发生的影响因素较多,临床应提高防范意识,采取针对性的预防措施,以降低并发症发生率,改善患者预后。