J. M. Davies

3 Human factors in the operating room: interpersonal determinants of safety, efficiency and morale

Summary The majority of accidents in technical professions have human error as a causal element. More critically, these errors tend to involve interpersonal issues: communications, leadership, conflict, flawed decision-making, etc. Aviation has responded by initiating formal instructions in the interpersonal aspects of human factors through programmes that are known as Crew Resource Management (CRM) training. Research into the interpersonal activities in the operating room has demonstrated similar problems in communication, conflict and situational awareness. To define the issues more sharply, an input-process-outcome model of operating room team performance was adapted from one developed in aviation. The model defines areas such as attitudes, organizational culture and group processes that are amenable to improvement through training and organizational interventions. It has also led to the development of formal human factors training programmes that, like that in aviation, involve simulation. Team-Oriented Medical Simulation (TOMS) at the University of Basel/Kantonsspital is a training programme that includes a full operating room simulator. Anaesthetists, surgeons, nurses and orderlies conduct scheduled surgery on an instrumented mannequin that allows both anaesthetic and laparoscopic simulation. Initial results from simulations show highly favourable reactions from participants. Human factors and quality assurance programmes need to be data-driven to have a positive impact. Survey and systematic observational methodologies have been used to define areas that may benefit from training. Results from three hospitals showed highly significant differences in attitudes regarding the interpersonal aspects of surgery between organizations and among subgroups (anaesthetists, surgeons, nurses) within organizations. We conclude that integrated quality assurance and human factors programmes have the potential to increase safety, efficiency and job satisfaction among medical personnel.

Accident analysis of large-scale technological disasters applied to an anaesthetic complication

The occurrence of serious accidents in complex industrial systems such as at Three Mile Island and Bhopal has prompted development of new models of causation and investigation of disasters. These analytical models have potential relevance in anaesthesia. We therefore applied one of the previously described systems to the investigation of an anaesthetic accident. The model chosen describes two kinds of failures, both of which must be sought. The first group, active failures, consists of mistakes made by practitioners in the provision of care. The second group, latent failures, represents flaws in the administrative and productive system. The model emphasizes the search for latent failures and shows that prevention of active failures alone is insufficient to avoid further accidents if latent failures persist unchanged. These key features and the utility of this model are illustrated by application to a case of aspiration of gastric contents. While four active failures were recognized, an equal number of latent failures also became apparent. The identification of both types of failures permitted the formulation of recommendations to avoid further occurrences. Thus this model of accident causation can provide a useful mechanism to investigate and possibly prevent anaesthetic accidents.RésuméLa survenue d’une série d’accidents dans des complexes industriels tels que Three Mile Island et Bhopal ont déclenché le développement de nouvelles méthodes de causalité et d’investigation de désastres. Ces modèles analytiques sont potentiellement intéressants en anesthésie. Ainsi, on a appliqué un des systèmes préalablement décrits afin d’étudier les accidents anesthésiques. Le modèle choisi décrit deux sortes d’échecs qui doivent tous les deux être recherchés. Le premier groupe, des échecs actifs, consiste en des erreurs que le practicien commet dans la pratique de sa profession. Le deuxième groupe, des échecs latents, représente des défauts dans les sytèmes administratifs et productifs. Le modèle met l’emphase sur la recherche des échecs latents et démontre que la prévention des échecs actifs seul n’est pas suffisant afin d’éviter des accidents futurs si les échecs latents demeurent inchangés. Ces critères de base et l’utilité de ce modèle sont illustrés par l’application dans un cas d’aspiration du contenu gastrique. Alors que quatre échecs actives furent reconnus, un nombre égal d’échecs latents est devenu apparent. L’identification des deux types d’échecs permet la formulation de recommandations afin d’éviter la répétition de ces échecs. Ainsi, ce modèle d’investigation des causalités d’accidents peut fournir un mécanisme utile d’investigation et possiblement de prévention des accidents anesthésiques.

Difficult intubation in the parturient.

Difficult or failed tracheal intubation is an important cause of anaesthetic-related maternal morbidity and mortality. The incidence of failed intubation in parturients is estimated to be as frequent as 1 in 500; that of mortality is unknown, although some 10–13 pregnant women in England, Scotland and Wales die each year because of anaesthetic-related complications. To prevent such catastrophes, all necessary monitors and equipment should be available, including that needed to deal with a failed intubation. Assessment of the patient may lead to preoperative recognition of a difficult airway; altered positioning may be of help both in recognition and management. Furthermore, adequate assistance, correct use of cricoid pressure, and confirmation of tracheal intubation are fundamental to safe practice. Lastly, should the anaesthetist fail to intubate the patient’s trachea, a management protocol is suggested.RésuméUne intubation trachéale difficile peut être lourde de conséquence chez la femme enceinte et on estime qu’elle échoue une fois sur cinq cent dans cette population. On ignore le nombre de décès qui lui sont attribuables mais, bon an, mal an, de 10 à 13 femmes enceintes meurent de complications anesthésiques en Angleterre, en Ecosse et au Pays de Galles. Pour prévenir ces tragédies, il faut avoir sous la main tous les moniteurs et instruments permettant de pallier à une intubation difficile ou ratée. L’examen pré-opératoire de la patiente révélera souvent les difficultés à venir et la meilleure position pour les contourner. Une assistance éclairé pourra exercer à bon escient une pression sur le cricoïde et aider à confirmer le succès de l’intubation. Enfin, nous vous proposons un plan d’action lorsque l’intubation s’avère impossible.

Fatal air embolism during dental implant surgery: a report of three cases

Between October 6, 1986 and September 17, 1987, 11 patients underwent insertion of mandibular dental prostheses by the same oral surgeon. Three patients suffered cardiac arrest during surgery and subsequently died. Two of the patients who died had received general anaesthetics and the other had intravenous sedation given by three different anaesthetists. All three patients arrested suddenly, developing profound cyanosis and electrical mechanical dissociation, underwent prolonged resuscitative efforts, and had marked hypoxaemia and hypercapnia, despite cardiopulmonary resuscitation. Two other patients had signs of injection of air but survived, one suffering cardiac collapse and the other sustaining massive subcutaneous emphysema. Air embolism was produced by inadvertent injection of a mixture of air and water, passing through the hollow dental drill, directly into the mandible to the facial and pterygoid plexus veins and thence to the superior vena cava and right atrium.RésuméDu 6 octobre 1986 au 17 septembre 1987, le mme chirurgien-dentiste procéda à l’insertion intramandibulaire de prothèses chez 11 patients. Trois d’entre eux succombèrent à un arrêt cardiaque pendant l’intervention. Trois anesthésistes différents avaient utilisé dans deux cas, une anesthésie génerale et dans l’autre, de la sédation par voie intraveineuse. La dissociation électromécanique doublée de cyanose survenait brutalement et demeurait réfractaire aux efforts prolongés de réanimation avec hypoxémie et hypercarbie marqués. Une emphysème souscutané spectaculaire chez l’un et un épisode de collapsus cardiovasculaire chez l’autre, fit suspecter une injection d’air chez deux survivants. Il s’avéra qu’un mélange accidentel d’air et d’eau irriguant la fraise dentaire se trouvait injecté directement dans le maxillaire inférieur, et de là, par les plexus veineux faciaux et ptérygoïdiens allait jusqu’ à la veine cave et à l’oreillette droite, créant une embolie aérienne massive.

Current models of quality : an introduction for anaesthetists

The purpose of this review is to provide the practicing anaesthetist with an historical perspective of quality, a summary of current models, and an introduction to the expectations ofaccreditors. Articles were obtained from an electronic literature search on Silver Platter® using the search terms Quality, Quality assurance, Anes*, and Anaes*. In addition, textbooks on quality assurance in health care, quality improvement texts from business management, and accreditation documents were reviewed. Quality systems in health care are derived from business or industrial models. Study of this field is hampered by poorly defined terminology and jargon. Over the years, many different models have been used in health care, but recent studies have investigated the effectiveness of methods such as Quality Improvement. Many of the systems used by hospitals appear to have been prompted by requirements of accreditation standards. Recently, systems of hospital organization have appeared which link Quality Assurance, Quality Improvement, risk management and utilization management. Despite the confusion created by illdefined terminology and rapid change in some definitions, anaesthetists need to be aware of the basic models of accreditation requirements.RésuméL’objet de cette revue consiste à fournir à l’anesthésiste une perspective historique de la gestion de la qualité, un résumé des modèles courants et un aperçu des exigences des accréditeurs. Les documents ont été obtenus à partir d’une recherche électronique sur Silver Platter® en utilisant les termes Quality, Quality assurance, Anes* et Anaes*. De plus des manuels traitant de la gestion de la qualité dans les services de santé, des textes sur l’amélioration de la qualite dans l’administration des affaires et les documents d’accréditation ont été consultés. Les systèmes de gestion de la qualité sont dérivés de modèles financiers et industriels. Les études dans ce domaine sont entravées par une terminologie et un jargon mal définis. Depuis plusieurs années, en soins de santé, on utilise plusieurs modèles, mais des études récentes ont examine l’efficacité de méthodes telles que l’amélioration de la qualité. Plusieurs des systèmes hospitaliers sont déterminés par les standards d’accréditation. Des systèmes d’organisation hospitalière d’origine récente relient ensemble la gestion de la qualité, l’amélioration de la qualité, et la gestion du risque. Malgré la confusion causée par une terminologie mal définie et les variation rapides de définition, les anesthésistes doivent connaître les modèles de base et les exigences des accréditeurs.

The liver and anaesthesia

Normal anatomy and physiology The liver is the largest single organ and is concerned through its storage, synthetic and excretory functions with nearly all the fundamental processes of the body. The liver contains only two types of cells, the hepatoeyte and the Kupffer cell, but has a complex vascular supply and excretory system. Histological examination of the liver in man reveals a Iobular structure with central veins. The portal vein, hepatic artery and bile duct have an intricate pattern of branching, such that, at each division they are bound together in a fibre sheath to form the portal tract. This ends as a network of sinusoids which connects the terminal branches of the hepatic venous and portal systems together. The total unit is usually described as a lobule or acinus. The livers excretory functions occur in two ways, by secretion of bile and directly into the hepatic veins. The biliary cannuliculi begin at the level of the hepatocytes and form the biliary tract which empties into the duodenum. The liver secretes about one litre of bile per day, which is produced continuously, but is only released into the duodenum during digestion. Normally, bile is stored in the gall bladder where it is concentrated to about one-fifth of its volume. Bile is made up of electrolytes, proteins, some carbohydrate, bilirubin, bile salts and lipids (cholesterol, phospholipids, and fatty acids). The cholesterol and fatty acids are held in solution by the detergent action of the bile salts and phospholipids, forming soluble molecular aggregates called micelles. The main function of bile salts is the emulsification of dietary fat, an essential part of fat absorption. In addition, the absorption of fat soluble vitamins, in particular, vitamins A and K, is related to bile salts. The livers central role in carbohydrate, protein and fat metabolism is well recognised. Albumin is a major synthetic product and free fatty acids (FFA) generated by the liver provide 80-90 per cent of normal body energy consumption. Drug, cholesterol, and steroid metabolism, both oxidative and reduetive, is carried out within the hepatoeytes. Water soluble metabolites are excreted into the plasma and bile. The liver is also a major storage site for such substances as vitamin B12, iron, copper, and glycogen.

A USABILITY EVALUATION OF AN INFUSION PUMP BY NURSES USING A PATIENT SIMULATOR

Using a high-fidelity patient simulator, this study had nurses evaluate the advanced features of an intravenous (IV) infusion pump being considered for purchase by a large Canadian health region. Three use cases or scenarios were developed, based on known difficulties administering multiple drugs through separate IV lines and the potential for certain drugs (e.g., heparin) to contribute to adverse outcomes in patients if the drug dosage was incorrectly calculated. After an in-service training session with the pump, thirteen nurses performed the use cases on an Emergency Care Simulator, which displayed a range of vital signs. During the sessions, nurses were required to use a think-aloud protocol, verbalizing all steps they were performing. The most common problems found were with the “Change Mode”and the “Select New Patient”features. Use of the On/Off switch was identified as a common strategy to clear pump information and to escape incorrect navigation paths. The consequential contribution to patient safety of these problems ranged from non-hazardous to potentially very hazardous. A number of design recommendations were made to address problems that were identified with the pumps hardware and software configurations, as well as to any in-service provided to new pump users.

A User-Centered Evaluation of three Intravenous Infusion Pumps

Considerable research has focused on whether medical equipment can be made safer/more effective using user-centered design principles. Medication errors may result from improper operation, mechanical failure, and tampering. The present study evaluated the effectiveness and advantages of three intravenous infusion pumps. Five evaluators used heuristic evaluation to identify, categorize, and prioritize usability problems. Positive and negative features were classified according to usability and design principles. The most common negative feature was difficulty setting up an infusion. The most common positive feature was visual feedback regarding pump status. The methodology was effective at identifying a number of problems. Ongoing research involves testing domain-experts to validate the severity of the usability problems identified and discover other safety-relevant errors.

Identification of Intensive Care Unit (ICU) System Integration Conflicts: Evaluation of Two Mock-up Rooms Using Patient Simulation

To address increasing patient demands and acuity, the Calgary Health Region is renovating the intensive care units (ICU) at three of their adult acute care sites. Before finalizing the design plans, mock-up rooms were created at two of the sites according to several proposed room designs in order to identify potential issues during the design phase of the project. All necessary equipment was included within each of the two mock-up rooms so as to nearly replicate a functioning ICU. Evaluations of equipment, room layout and conflicts were accomplished using patient simulation of a cardiac arrest, an acutely ill patient, a palliative care patient and the admission of a new patient. Digital videos, think aloud audio tracks and extensive debriefing sessions were combined and analyzed. Specific category issues were identified including the articulating arms, visibility of the patient monitors, equipment usability, collisions with equipment, and communication issues. Elaboration of each issue and presentation of design recommendations is given.

The cost of an established quality assurance programme: is it worth it?

Although the literature concerning quality assurance (QA) is voluminous, little information exists about the costs or benefits of departmentally based QA programmes. We measured the direct costs and then investigated the financial and non-financial benefits derived from a well-funded QA programme over a period of five years. Data were obtained from departmental budgets, annual reports of the QA programme, and several databases used by the programme. The average annual cost was