The influence of clearance on friction, lubrication and squeaking in large diameter metal-on-metal hip replacements.

Large diameter metal-on-metal bearings (MOM) are becoming increasingly popular, addressing the needs of young and more active patients. Clinical data has shown excellent short-to-mid-term results, though incidences of transient squeaking have been noted between implantation and up to 2 years post-operative. Geometric design features, such as clearance, have been significant in influencing the performance of the bearings. Sets of MOM bearings with different clearances were investigated in this study using a hip friction simulator to examine the influence of clearance on friction, lubrication and squeaking. The friction factor was found to be highest in the largest clearance bearings under all test conditions. The incidence of squeaking was also highest in the large clearance bearings, with all bearings in this group squeaking throughout the study. A very low incidence of squeaking was observed in the other two clearance groups. The measured lubricating film was found to be lowest in the large clearance bearings. This study suggests that increasing the bearing clearance results in reduced lubricant film thickness, increased friction and an increased incidence of squeaking.

How military nurses rationalize their postoperative pain assessment decisions.

AIM: This paper is a report of a study to explore how military nurses rationalize their postoperative pain assessment decisions, particularly when these differ from patients' pain self-reports. BACKGROUND: Postoperative pain is a complex phenomenon influenced by many factors that make assessment difficult. Nurses are taught to believe what patients say about their pain. However, their attitudes to pain are influenced by their cultural background and they may disagree with patients' self-reports. Military nurses belong to a military culture with different pain attitudes that may also influence their postoperative pain assessment. METHOD: An ethnomethodological ethnography study was carried out in 2003. A purposive sample of 29 British military surgical/orthopaedic Registered Nurses were interviewed to identify their taken-for-granted assumptions and commonsense cultural knowledge surrounding postoperative pain assessment. The data were analysed using a systematic process of inductive reasoning aided by Non-numerical, Unstructured Data for Indexing, Searching and Theorizing (QSR N6, NUD*IST). FINDINGS: Participants told two distinct stories in their postoperative pain narratives. The first, the cultural story, described how military nurses normally assess postoperative pain and revealed taken-for-granted assumptions surrounding this assessment. However, when military nurses believe that patients over- or under-report their pain, the cultural story was challenged through a collective story in which nurses used their commonsense knowledge to account for these differences. CONCLUSION: Postoperative pain assessment within a military culture is complex, but all nurses need to be aware that their socialization into different nursing cultures may influence their attitudes to postoperative pain assessment.

No pain, no gain: pain behaviour in the armed forces.

Pain is a unique phenomenon that is difficult to express and is influenced by many different factors, including cultural expectations. A dichotomy exists within the British Armed Forces between pain being seen as necessary--the "no pain, no gain" view--and the opposite image of stoical service personnel who suppress their emotions--the "roughie-toughie" image. This dichotomy was explored through an ethnographic study of pain behaviour experienced during a training course. Pain behaviour was found to be consistent with cultural expectations and this supported the "no pain, no gain" perspective. Physical and psychological pain were expressed differently, reinforcing the western, scientific mind-body dichotomy. In addition, personnel frequently tried to suppress their pain and this supported the "roughie-toughie" philosophy. Thus, pain expression varies according to the context in which it occurs. Nurses need to be aware of this to ensure they interpret and manage their patients' pain appropriately.

Personal experience of aeromedical evacuation of patients in the Balkans.

Nurses in the Princess Mary's Royal Air Force Nursing Service (PMRAFNS) undertake a variety of different roles in providing nursing care to Armed Forces personnel wherever they may serve. One such role is the evacuation by air of sick or injured personnel. This article discusses the experience of a nurse lecturer in the PMRANS who undertook the role of aeromedical evacuation liaison officer in the Balkans for a 4-month period during winter. The role is described and details of how the aeromedical evacuation of patients was organized is presented. The benefits of evacuating patients by air are discussed along with some of the potential problems that were encountered in the Balkans, including logistical problems and the vagaries of the weather. Finally, several examples of the types of patients evacuated are presented.