Old Blocks, New Tricks.

 Glenda Rudkin

Local and regional anaesthesia avoids many of the risks involved in general anaesthesia.  Providing complete anaesthesia ensures the patient has a pain free recovery period, allowing early discharge.  There are direct cost benefits, with drug and equipment costs being consistently lower for local and regional anaesthesia. Indirect cost advantages are also significant, where costs are not incurred for analgesics or anti-emetics.  It is for these reasons and the new wave of technology and expertise in local and regional anaesthesia that we are seeing a growing trend towards regional anaesthesia and peripheral nerve blocks in both inpatient management and day surgery.  Many of the blocks performed have been techniques used by anaesthetists for many years, however new approaches, modified block technology and new adjuvants have modified our practices.

“Old blocks” such as spinals, have been improved recently by fine pencil point needles and opioid adjuvants.  There have also been “new blocks” introduced  such as suprascapular nerve blocks for shoulder arthroscopy and the lateral approach to the sciatic nerve at the knee for major foot and ankle surgery.  Chung has shown in a review of over 10,000 ambulatory procedures that orthopaedic patients have the highest incidence of pain.¹ Peripheral nerve blocks are therefore an excellent choice for day case orthopaedic surgery.

Equally, interscalene (ISB) block is also an outstanding choice for shoulder surgery.  Several studies have shown ISB to be a time efficient technique with less nausea and vomiting and narcotic related side effects.²  Knee arthroscopy is the commonest orthopaedic day surgery procedure performed.  Choices for anaesthesia are many and varied, however Goranson et al have suggested that intra-articular local anaesthesia alone is satisfactory for most routine arthroscopies³ with significant cost savings when intra-articular techniques are used.

The placement of catheters into wounds or peripheral nerve catheters may be the next exciting phase where patients can be discharged home to self-administer local anaesthetic through an appropriately placed catheter.⁴  There is then potential for performing more painful procedures comfortably on a day basis such as knee anterior cruciate ligament repairs.  However, a cautionary note: although there may be cost advantages with these new techniques, patient safety is of paramount importance and patient outcomes need to be monitored closely.

References.

1.                  Chung F, Ritchie E, Su J.  Postoperative pain in ambulatory surgery.  Anesth Analg 1997; 85:808-16.

2.                  Tetzlaff JE, Yoon HJ, Brems J.  Interscalene brachial plexus block for shoulder surgery. Reg Anesth 1994 ;19:339-43.

3.                  Goranson BD,et al. A comparison of three regional anaesthesia techniques for outpatient knee arthroscopy. Can J Anaesth 1997; 44:822-26.

4.                  Rawal N et al. Postoperative patient-controlled local anesthetic administration at home. Anesth Analg 1998; 86:86-89.