Appendicular Skeletal Muscle Mass: Development and Validation of Anthropometric Prediction Equations

OBJECTIVES

Sarcopenia is the loss of muscle mass and function seen with increasing age. Central to making the diagnosis of sarcopenia is the assessment of appendicular skeletal muscle mass (ASM). The objective of this study was to develop and validate novel anthropometric prediction equations (PEs) for ASM that would be useful in primary or aged care.

DESIGN

PEs were developed using best subset regression analysis. Three best performing PEs (PE1, PE2, PE3) were selected and validated using the Bland-Altman and Sheiner and Beal methods.

SETTING

Community dwelling adults in South Australia.

PARTICIPANTS

188 healthy subjects were involved in the development study. 2275 older(age ≥ 50years) subjects were involved in the validation study.

MEASUREMENTS

ASM was assessed using dual x-ray abosrptiometry (DEXA). Weight and height was measured and body mass index (BMI) estimated.

RESULTS

A strong correlation between PE derived ASM and the DEXA derived ASM was seen for the three selected PEs. PE3: ASM= 10.047427 + 0.353307(weight) - 0.621112(BMI) - 0.022741(age) + 5.096201(if male) performed the best. PE3 over-estimated (P<0.001) ASM by 0.36 kg (95% CI 0.28-0.44 Kg) and the adjusted R2 was 0.869. The 95% limit of agreement was between -3.5 and 4.35 kg and the standard error of the estimate was 1.95. The root mean square error was 1.91(95% CI 1.80-2.01). PE3 also performed the best across the various age (50-65, 65-<80, 80+ years) and weight (BMI <18.5, 18.5-24.9, 25-29.9, ≥30 kg/m2) groups.

CONCLUSIONS

A new anthropometric PE for ASM has been developed for use in primary or aged care but is specific to Caucasian population groups.

Crisis management during anaesthesia: regurgitation, vomiting, and aspiration

BACKGROUND

Regurgitation, vomiting and aspiration may occur unexpectedly in association with anaesthesia. "Aspiration/regurgitation" was ranked fifth in a large collection of previously reported incidents that arose during general anaesthesia. These problems are encountered by all practising anaesthetists and require instant recognition and a rapid, appropriate response. However, the diagnosis may not be immediately apparent as the initial presentation may vary from laryngospasm, desaturation, bronchospasm or hypoventilation to cardiac arrest.

OBJECTIVES

To examine the role of a previously described core algorithm "COVER ABCD-A SWIFT CHECK", supplemented by a specific sub-algorithm for regurgitation, vomiting and aspiration, in the management of these complications occurring in association with anaesthesia.

METHODS

The potential performance of this structured approach for each of the relevant incidents among the first 4000 reported to the Australian Incident Monitoring Study (AIMS) was compared with the actual management as reported by the anaesthetists involved.

RESULTS

There were 183 relevant incidents of regurgitation, vomiting and aspiration among the first 4000 reports to the AIMS. Aspiration was documented in 96, was excluded in 69, and in 18 it could not be determined whether or not aspiration had occurred. It was considered that the correct use of an explicit algorithm would have led to earlier recognition and/or better management of the problem in 10% of all cases of regurgitation and vomiting and in 19% of those in which aspiration occurred.

CONCLUSION

Regurgitation and/or aspiration should always be considered immediately in any spontaneously breathing patient who suffers desaturation, laryngospasm, airway obstruction, bronchospasm, bradycardia, or cardiac arrest. Any patient in whom aspiration is suspected must be closely monitored in an appropriate perioperative facility, the acuity of which will depend on local staffing and workload. If clinical instability is likely to persist or if there are concerns by attending staff, the patient should be admitted to a high dependency unit or intensive care unit.

Crisis management during anaesthesia: obstruction of the natural airway

BACKGROUND

Obstruction of the natural airway, while usually easily recognised and managed, may present simply as desaturation, have an unexpected cause, be very difficult to manage, and have serious consequences for the patient.

OBJECTIVES

To examine the role of a previously described core algorithm "COVER ABCD-A SWIFT CHECK", supplemented by a specific sub-algorithm for obstruction of the natural airway, in the management of acute airway obstruction occurring in association with anaesthesia.

METHODS

The potential performance for this structured approach for each of the relevant incidents among the first 4000 reported to the Australian Incident Monitoring Study (AIMS) was compared with the actual management as reported by the anaesthetists involved.

RESULTS

There were 62 relevant incidents among the first 4000 reports to the AIMS. It was considered that the correct use of the structured approach would have led to earlier recognition of the problem and/or better management in 11% of cases.

CONCLUSION

Airway management is a fundamental anaesthetic responsibility and skill. Airway obstruction demands a rapid and organised approach to its diagnosis and management and undue delay usually results in desaturation and a potential threat to life. An uncomplicated pre-learned sequence of airway rescue instructions is an essential part of every anaesthetist's clinical practice requirements.

Crisis management during anaesthesia: laryngospasm

BACKGROUND

Laryngospasm is usually easily detected and managed, but may present atypically and/or be precipitated by factors which are not immediately recognised. If poorly managed, it has the potential to cause morbidity and mortality such as severe hypoxaemia, pulmonary aspiration, and post-obstructive pulmonary oedema.

OBJECTIVES

To examine the role of a previously described core algorithm "COVER ABCD-A SWIFT CHECK", supplemented by a specific sub-algorithm for laryngospasm, in the management of laryngospasm occurring in association with anaesthesia.

METHODS

The potential performance of this structured approach for the relevant incidents amongst the first 4000 reported to the Australian Incident Monitoring Study (AIMS) was compared with the actual management as reported by the anaesthetists involved.

RESULTS

There were 189 reports of laryngospasm among the first 4000 incidents reported to AIMS. These were extracted and analysed. In 77% of cases laryngospasm was clinically obvious, but 14% presented as airway obstruction, 5% as regurgitation or vomiting, and 4% as desaturation. Most were precipitated by direct airway stimulation (airway manipulation, regurgitation, vomiting, or blood or secretions in the pharynx), but patient movement, surgical stimulus, irritant volatile agents, and failure to deliver the anaesthetic were also precipitating factors. Desaturation occurred in over 60% of cases, bradycardia in 6% (23% in patients aged <1 year), pulmonary oedema in 4%, and pulmonary aspiration in 3%. It was considered that, correctly applied, the combined core algorithm and sub-algorithm recommended for the diagnosis and management of laryngospasm would have led to earlier recognition of the problem and/or better management in 16% of cases.

CONCLUSION

Laryngospasm may present atypically and, if not promptly managed effectively, may lead to morbidity and mortality. Although usually promptly recognised and appropriately managed, the use of a structured approach is recommended. If such an approach had been used in the 189 reported incidents, earlier recognition and/or better management may have occurred in 16% of cases.