Dear Editor,

We read with interest the article by MJ Reed et al. As they have mentioned there have been numerous attempts to devise scoring systems for airway assessment, however these scores have been undermined by low sensitivity and specificity. Furthermore Positive predictive values for these tests range from 4 – 60% [1], we believe that such a low predictive value has significant implications for airway management particularly in the Emergency Department. With a positive predictive value of 50% at least half of difficult intubations are likely to be unexpected. Whilst the morbidity associated with a difficult intubation is clear to all, some patients may be subjected to unnecessarily invasive techniques that may not be required.

In the words of Levintine “Direct Laryngoscopy with pharmacological adjuncts is very successful, very fast and has low complication rates” [2]. The authors of the study do not state at which LEMON score a patient’s airway is anticipated to be difficult. Assuming a score of >3 the positive predictive value would be 47%. The study quotes a rate of 2% difficult intubations in the Emergency Department; the study rate of 42 difficult intubations in 156 patients therefore seems to be abnormally high, possibly due to the inclusion of grade II laryngoscopic view as difficult. We would question the classification of Cormack and Lehane grade II laryngoscopy as “difficult”, most Emergency Departments are equipped with bougies making it possible to easily intubate with this view [3].

Although the LEMON score is referred to as an “airway assessment” it is in fact an intubation assessment. No patient dies from failure to intubate, rather it is failed oxygenation. In the absence of an airway assessment with 100% accuracy then airway assessment needs to be holistic. The American Society of Anaesthesiologists published guidelines suggesting airway assessment must also take into account difficulty in ventilation, patient co-operation, potential surgical airway access and maintaining oxygenation throughout airway management procedures as these problems may occur alone or in combination [4]. Whilst anaesthestists have the luxury of time when assessing an airway we feel the limited time in the Emergency department would be better spent considering these issues rather than calculating a LEMON score.

The harsh reality is that there will be no test that has 100% specificity and sensitivity. The only way to deal with the airway in the Emergency department is to be prepared for the unanticipated difficulties: with experienced assistants, difficult airway trolleys and a plan B, all of which should be standard practice. There is little margin for error in airway management. We believe that a test that makes airway management “more likely” to be difficult is of limited value in the emergency department.

Dr S. Dorrian
SHO Critical Care New Cross hospital
Wolverhampton

Dr S. Nagaiyan
SpR Anaesthetics New Cross hospital
Wolverhampton

References

1. Das S, Pearce A. Pre-operative airway evaluation Anaesthesia 2002 Aug; 57(8):824.

2. Levitan RM, Kush S, Hollander JE Devices for difficult airway management in academic emergency departments: results of a national survey Annals of Emergency Medicine 1999 Jun; 33(6): 694-8.

3. Morton T, Brady S, Clancy M Difficult airway equipment in English Emergency Departments Anaesthesia 2000 May; 55(5):485-8.

4. American Society of Anaesthesiologists Practice guidelines for management of the difficult airway Anaesthesiology 2003 May; 98(5); 1269–77.

Dear editor,

With interest we read the paper by van der Wulp et al.(1) It is important that the system is evaluated since it is consensus based and applied very commonly in emergency care.

The study evaluated the reliability and validity of the Manchester Triage System (MTS). Validity was assessed by comparing the triage results (vignettes) of 55 nurses with the triage results of two MTS experts who applied the MTS to the same vignettes.

This approach represents a reliability study that determined agreement of the MTS application in practice between nurses and experts. To assess validity of a triage system which can be considered as a diagnostic test, criteria for diagnostic research has to be applied. The gold standard has to be assessed independent of the triage result and has to be predictive for patient outcome such as disease severity.(2) Furthermore, a gold standard for urgency aims to discriminate between those patients whose condition will worsen if no immediate care is delivered and patients who can safely wait. Several standards are described: urgencies attributed by experts independent of the triage outcome, admission rate, resource use, or the reference standard for urgency.(3, 4)

The conclusion of this study should be that the participating nurses correctly applied the MTS in 67% compared to experts.(1) Sensitivity and specificity can be used to quantify the performance of a triage system, if it is evaluated as a diagnostic test. When reliability is studied, a kappa is more appropriate. Therefore, it cannot be concluded that sensitivity of the MTS is higher in children and the results cannot be compared to the results described in the paper by Roukema et al.(3)

We realize that it is difficult to validate triage systems due to a lack of agreement on how to judge the appropriateness of a visit to the emergency department.

References

1.Van der Wulp I, van Baar ME, Schrijvers AJ. Reliability and validity of the Manchester Triage System in a general emergency department patient population in the Netherlands: results of a simulation study. Emerg Med J 2008;25(7):431-4.

2.Hardern RD. Critical appraisal of papers describing triage systems. Acad Emerg Med 1999;6(11):1166-71.

3.Roukema J, Steyerberg EW, van Meurs A, Ruige M, van der Lei J, Moll HA. Validity of the Manchester Triage System in paediatric emergency care. Emerg Med J 2006;23(12):906-10.

4.Van Veen M, Steyerberg E, Ruige M, Van Meurs A, Roukema J, Van der Lei J, et al. The Manchester Triage System in paediatric emergency care: validity and pitfalls. BMJ, in press 2008.

Dear Editor

We read with interest the article and accompanying editorial by Lecky et al. in this month's Emergency Medicine Journal.[1] Of note, between 1989 and 1994 there was an increase in the proportion of trauma patients (ISS>15) in whom a consultant was involved in their care: at the same time, trauma related mortality fell. Since then, both the level of documented consultant involvement and the mortality have plateaued. Documented middle grade involvement is unchanged from 1989.

This lack of improvement in the involvement of consultants and middle grades is of concern, and there is great pressure from many sides to increase senior cover on the shop floor. This includes BAEM's 1995 recommendations for increasing the levels of senior staff in A&E departments.[2] Many of these recommendations were repeated in the Workforce Planning Document from BAEM and FAEM[3]: one of the main recommendations of this paper is that shop floor consultant cover should be available 12 hours a day, 7 days a week. This is to achieve the objective of allowing all patients to have an experienced clinician (Specialist Registrar, Non consultant career grade, consultant) either care for them directly, or supervise their care closely. In addition, the recently published NHS Plan made plain the government's intention to have more consultants involved in patient care.[4]

To investigate the current level of availability and involvement of senior and middle grade doctors in patient care in A&E departments, we undertook a survey of the 12 A&E departments in the South West deanery. These departments see between 24,500 and 85,000 new patients each year, and are staffed by between one and five consultants. We looked at the level of medical staff actually available to see new patients throughout two days in April 2001, and obtained information on all patients presenting on those two days, including triage category and level of seniority of doctor involved in their care.

Nine departments responded. No department provided 12-hour consultant cover. Most had at least 12-hour cover from a middle grade doctor, and 3 departments provided 24-hour middle grade cover. Consultant cover was poor: at the maximum, only 5 departments had a consultant on the shop floor at 1200 on Wednesday - other times had lower levels of cover. The level of middle grade and senior cover in these departments was worse at night and at the weekend.

The proportions of patients in each triage category seen by more experienced doctors or with more experienced doctors involved in their care is shown in the table.

Table

("experienced doctor" = consultant, SpR or NCCG)

Following comments from some hospitals that not all the senior involvement might have been documented, we undertook a one-day audit of our own department, looking at whether the involvement of more senior medical staff is actually recorded in patient's notes. On the day studied, 218 patients were seen, of which 61 (28%) were seen initially by a senior or middle grade doctor. Of the 157 seen initially by a SHO, 39 had a senior or middle grade involved in their care at some stage (either seeing the patient, or giving advice on their care). Thus 100 patients (46%) had senior or middle grade involvement. Unfortunately, of the 39 patients for whom SHOs asked advice, this involvement of the more experienced doctor was only documented in seven (18%).

Whilst we acknowledge that our study was too small to draw statistical conclusions from, there is documented experienced staff involved in the care of 36% of patients. In many ways this is better than the impression given in many documents that A&E is still a service provided primarily by SHOs,[5,6] but it is concerning that the proportion of patients seen solely by a SHO (54%) appears to be little improved, despite increasing numbers of consultants and middle grade staff, since the Platt report in 1967, which found that 66% of patients were seen by a SHO only.

We have approached BAEM to raise the possibility of this study being expanded across the country. In the meantime, even if senior and middle grade doctors involved in the care of patients, this involvement may not be getting documented.

References

(1) Lecky FE, Woodford M, Bouamra O, et al. Lack of change in trauma care. Emerg Med J 2002;19:520-3

(2) BAEM. Planning for increased senior staff cover in Accident and Emergency departments. London: BAEM, 1995.

(3) Department of Health. Workforce planning in A&E medicine 2001-2010. BAEM, London 2001. The NHS Plan. London: Department of Health, 2000.

(4) Department of Health The NHS Plan. London: Department of Health, 2000.

(5) Audit Commission By Accident or Design London: Audit Commission, 1996.

(6) National Audit Office NHS Accident and Emergency Departments in England. London: National Audit Office, 1992.

(7) Accident and Emergency Services The Standing Medical Advisory Committee. London: HMSO, 1962.

Milligan, et al. (1) provides valuable insight into the varied management of massive haemorrhage post trauma. However, the conclusions that emergency physicians lacked core knowledge and were unaware of how to prevent and treat early coagulopathy appear unfounded. It would be more prudent to conclude that a paucity of high level of evidence guiding trauma resuscitation was responsible for this varied practice.

The definition of massive transfusion has little clinical significance during trauma resuscitation and even so, remains debated with an acute definition likely to be more effective than the traditional definition. (2) Massive blood transfusion during trauma resuscitation is rarely based on a target haemoglobin and current experience with thromboelastography suggests that platelet function rather than absolute platelet counts should direct platelet transfusion. The ideal ratio of packed red blood cells to fresh frozen plasma similarly has been gleaned from retrospective associations only, confounded by multiple biases. Recent randomised controlled trials have failed to show any outcome benefit from the stated indication for recombinant factor VIIa.

Attempts to develop massive transfusion protocols supported by inadequate evidence have previously resulted in marked variability in practice.(3) A massively haemorrhaging trauma patient presents a challenging scenario to most emergency physicians and in the face of poor level of evidence to guide practice, it is not surprising that most use clinical gestalt (referred by the authors as "guess"). Rather than criticising the knowledge of emergency physicians or imposing non-evidence based "protocols", research efforts should be directed at multicentre, outcome focused randomised controlled trials comparing different but valid strategies in managing massive haemorrhage. Only then can we embark on developing effective massive transfusion guidelines.

References

1. Milligan C, Higginson I, Smith JE. Emergency department staff knowledge of massive transfusion for trauma: the need for an evidence based protocol. Emerg Med J. 2010 (In Press). doi:10.1136/emj.2009.088138.

2. Mitra B, Cameron PA, Gruen R, et al. The definition of massive transfusion in trauma: a critical variable in examining evidence for resuscitation. Eur J Emerg Med. 2010 (In Press). doi: 10.1097/MEJ.0b013e328342310e

3. Schuster KM, Davis KA, Lui FY, et al. The status of massive transfusion protocols in United States trauma centers: massive transfusion or massive confusion? Transfusion 2010; 50(7): 1545-1551.

Conflict of Interest:

None declared