Institutional organization

In an effort to move the subspecialty forward in this regard, the American Society of Regional Anesthesia has endorsed a set of guidelines for regional anesthesia fellowship training.⁵ These guidelines have been developed by a group of regional anesthesiology fellowship directors and other interested parties from across the United States over a number of years. They suggest a method for addressing:

Some of the ‘critical determinants of learning’ have been identified and include:

Programs such as that endorsed by ASRA are required to ensure residents obtain such formal structured training and to minimize factors such as in points (2), (3) and (4). It sets out a template that any institution may adopt and adapt in developing a comprehensive fellowship program (Box 10.1). The remainder of this chapter will, for the most part, deal with the practicalities of imparting skills and the assessment of competencies in these skills.

Skills and competencies

For many years, training programs have tended to concentrate on exposing their residents to a subspecialty for a predetermined period of time in order for them to attain competence. While this method has worked in the imparting of certain skills, it is clearly flawed. Therefore, efforts have been directed towards a variety of alternative techniques.

Recommended case numbers

There is broad agreement as to the minimum recommended number of times a resident should perform a procedure in order to reach the requisite standard.^7–9 The learning curves for a variety of procedures show a marked improvement of skill after the initial 20 attempts and inter-individual scattering decreases over time (Figs 10.1–10.6).

Figure 10.1 A summary of mean learning curves.

(Konrad C, Schüpfer G, Wietlisbach, Gerber H. Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures? Anesth Analg 1998; 86: 635–639.)

Figure 10.2 The intubation learning curve.

(Konrad C, Schüpfer G, Wietlisbach, Gerber H. Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures? Anesth Analg 1998; 86: 635–639.)

Figure 10.3 The spinal anesthesia learning curve.

(Konrad C, Schüpfer G, Wietlisbach, Gerber H. Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures? Anesth Analg 1998; 86: 635–639.)

Figure 10.4 The epidural anesthesia learning curve.

(Konrad C, Schüpfer G, Wietlisbach, Gerber H. Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures? Anesth Analg 1998; 86: 635–639.)

Figure 10.5 The brachial plexus anesthesia learning curve.

(Konrad C, Schüpfer G, Wietlisbach, Gerber H. Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures? Anesth Analg 1998; 86: 635–639.)

Figure 10.6 The arterial line learning curve.

(Konrad C, Schüpfer G, Wietlisbach, Gerber H. Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures? Anesth Analg 1998; 86: 635–639.)

This method of prescribing a minimum case load for trainees can be limited by the case mix, staff to resident ratios in teaching manual skills, and physician preferences for special procedures. These factors in turn may contribute to the variation amongst institutions which has led to the lamentable situation as outlined in the opening paragraph of this chapter. In addition, recommending minimum numbers is likely to do both the resident who quickly reaches competence and whose further efforts would be better expended elsewhere, and the poorly performing resident who requires further exposure to the procedure, a disservice.

Cusum method

Cumulative sum (cusum) analysis is a statistical method of distinguishing deviations from an acceptable failure rate. It has been used in industry as a method of quality control and more latterly in healthcare, where it has the potential to determine when a resident is proficient in a new technique and as a continuous audit of quality of practice for more experienced clinicians.^13–15

Prior to commencement, suitable acceptable and unacceptable failure rates for the procedure must be chosen (p₀ and p₁), examples of which are given in Table 10.3. The desired magnitude of the type 1 and type 2 errors (α andβ) must also be chosen and the two boundary limits to the cusum, h₀ and h₁ are calculated, as is the variable s (Fig. 10.7). The cusum increases by 1−s for a failure and decreases by s for a success. When the cusum breaks through the lower boundary limit (h₀) from above then the true failure rate does not differ significantly from the acceptable failure rate (the null hypothesis) with the probability of a type II error equal to β. If the cusum breaks through the upper boundary limit (h₁) from below then the true failure rate is significantly greater than the acceptable failure rate with a probability of a type I error equal to α. Further lines are drawn on the graph at 2h₁, 3h₁ and 4h₁ as required, allowing the null hypothesis to be accepted or rejected on further attempts. If the cusum stays between h₀ and h₁ the observations must be continued, as no statistical inference can be made. A sample cusum chart for obstetric extradural from two anesthesiology residents is shown in Figure 10.8.

Table 10.3 Acceptable and unacceptable failure rates for four procedures (as defined by a consensus of consultants), the values of s and the boundary limits for the cusum

Figure 10.7 The formulae to calculate the variables for the cusum.

(Kestin I. A statistical approach to measuring the competence of anaesthetic trainees at practical procedures. Br J Anaesth 1995; 75: 805–809.)

Figure 10.8 The cusum for obstetric extradurals from two anesthetic registrars. For registrar A, the cusum increases through six successive boundary lines in the first 99 attempts; the true failure rate for this series is 27%. From attempt 100 onwards, the cusum is stable and then declines through two boundary lines; the failure rate for this series (6.7%) is not significantly different from the acceptable failure rate (5%). For registrar B, a lower boundary line is crossed after 47 attempts; the true failure rate is not significantly different from the acceptable rate.

(Kestin I. A statistical approach to measuring the competence of anaesthetic trainees at practical procedures. Br J Anaesth 1995; 75: 805–809.)

The advantages of this method are that poor performance can be detected early, i.e. as soon as an upper boundary line is crossed, and remedial action taken. It also allows practitioners to continually audit their own practice. The data are easy to obtain and comparisons are made with reference to minimum acceptable standards. The disadvantages are that the standards of success and failure need to be defined; the system relies on the honesty of the individual and their consistent interpretations of success and failure. The method doesn’t allow weighting of the score according to expected difficulty and doesn’t assess other important components of the learning process or personal characteristics seen to be important to the practice of anesthesiology.

‘A specialty in transition?’

Peripheral nerve blockade is now a well-accepted method for realizing the clinical and economic benefits of better pain control, ‘fast-tracking’ of patients, improved discharge times, improved physical therapy and improved postoperative cognitive dysfunction scores. Unfortunately, the inherent failure rate it has carried to date, combined with other impediments to its performance in theater, has meant it has been held in lower esteem than generally simple, safe and efficacious general anesthesia.¹⁶ The traditional methods used to perform peripheral nerve blockade (transarterial and paresthesia techniques, nerve stimulation) have relied on a sound knowledge of anatomy and surface anatomy. Inherent weaknesses in these approaches are obvious when one considers the range of anatomical variation present in the human population and the limitations in the sensitivity and specificity of nerve stimulation.

The advent of ultrasound has been described as a significant step-change in regional anesthesia.¹⁷ As ultrasound-guided regional anesthesia (USGRA) has the potential to produce successful nerve block in all cases, failures will be due to poor operator technique rather than inherent deficiencies of the technique per se. This is an important point to consider, as the requirement to deliver suitably trained practitioners will come with the realization of regional anesthesia’s potential.

While experienced practitioners will learn the techniques from their peers, it behoves the profession as a whole to ensure training in USGRA becomes a core part of all future anesthesiology training. The teaching of these new, yet essential, skills should be included as part of residency training. The proverb ‘see one, do one, teach one’ should not be applied to a core competency such as USGRA, and a number of quality-compromising patterns of behavior can be identified when novices undertake to learn these techniques.¹⁸ The incorporation of transesophageal echo (TEE) into mainstream clinical practice has led to a formal process of accreditation and documentation, and so it may be with USGRA.

The American Society of Regional Anesthesia and Pain Medicine and the European Society of Regional Anesthesia and Pain Therapy Joint Committee has now issued recommendations for education and training in USGRA (Box 10.2).¹⁹ The document aims to define the scope of practice of USGRA under the following headings:

Acquiring and maintaining expertise

The practical implications of training large numbers of anesthesiology residents and their seniors in USGRA is formidable and it will likely be a number of years before every residency program has the in-house expertise to be able to do this. Advice on training is available from a number of sources (Table 10.4) and there are many workshops that can be currently availed of. However, there is usually no formal accreditation of attained skills.

Table 10.4 Websites for information

Reproduced from Bodenham A. Ultrasound imaging by anaesthetists: training and accreditation issues. Br J Anesth 2006; 96: 414–417.

As the range of procedures likely to be performed by anesthesiologists using ultrasound increases (Table 10.5), it is likely that so too will there be a demand for more comprehensive training to a high standard. Such training will have to enable the practitioner to recognize common pathology and when a referral for further investigation is required (Table 10.6).²⁰

Table 10.5 Ultrasound procedures likely to be conducted by anesthetists

Reproduced from Bodenham A. Ultrasound imaging by anaesthetists: training and accreditation issues. Br J Anesth 2006; 96: 414–417.

Table 10.6 Levels of competence for ultrasound, shortened from Royal College of Radiologists’ guidelines

Note: The boundaries between levels should only be regarded as a guide.

Reproduced from Bodenham A. Ultrasound imaging by anaesthetists: training and accreditation issues. Br J Anaesth 2006; 96: 414–417

Reproduced from Hargett M, Beckman J, Liguori G, Neal J. Guidelines for regional anesthesia fellowship training. Reg Anesth Pain Med 2005; 30: 218–225.

Motivation to improve, focus on clearly defined tasks, immediate useful feedback and repetitive deliberate practice strategically guided by an expert instructor are the keys to forming and maintaining expertise.²¹ Simulation-based training may form an important component in this and USGRA may be particularly suited to this type of training and the on going assessment of expertise.²² It is also likely that the public, government and other regulators will insist on some form of assessment and accreditation. Anesthesiologists have been to the forefront in this type of training and are well placed to affect both the pace and direction of the changes that are required. Funding of simulator-based research to establish valid training content, structure, and scoring metrics is required. Collaboration is necessary with educators, psychometricians, and other specialties. Training of a large cadre of skilled instructors/evaluators and a commitment to large-scale standardized training and assessment of medical students, residents, and experienced anesthesiologists is also necessary.¹¹