Local Infiltration Analgesia: A Technique to Improve Outcomes after Hip, Knee or Lumbar Spine Surgery PDF

Preface

What is LIA? Strictly speaking, local infiltration analgesia (LIA) is a technique for management of the acute phase of postoperative pain, particularly after knee and hip surgery. The technique was developed by Dr. Dennis Kerr and Dr. Lawrence Kohan in Sydney, Australia, between 1998 and 2008, specifically to assist in improving postoperative outcomes; it was first published in Acta Orthopaedica April 2008 (1). Since then, development has continued, minor modifications have been adopted, and its use has been extended to other fields, particularly lumbar spine surgery.

The technique is based on systematic infiltration of a mixture of long-acting local anesthetic, a direct acting anti-inflammatory drug, and sometimes other drugs (such as steroids and clonidine) around all structures subject to surgical trauma. The intention is to target all elements involved in generation of pain signals at the site of injury, including nociceptors, nerve endings, nerves, and all active constituents of the biological soup responsible for the inflammatory response to injury. The technique also encompasses measures, based on first aid treatment of snakebite, to slow down the uptake of the drugs. The duration of the block is extended by the use of a pain catheter to top up and re-inject the joint by hand as the initial block recedes.

Many factors, including preparation, surgery, anesthesia, pain management, and postoperative care, influence short-term outcomes after surgery. Local Infiltration Analgesia is merely one piece of this jigsaw puzzle of important contributing elements. Specifically, it is the element designed to manage the Acute Postoperative Pain Phase lasting about 36 hours post operation, and should be regarded as a key enabling technique promoting rapid return to the normal activities of daily living and facilitating discharge from hospital.

Although LIA is a technique for acute postoperative pain control, the focus of our efforts has not been pain control per se, but rather to improve the overall rate and quality of recovery from surgery and anesthesia, and then to use this advantage as a platform to implement a cascading series of measures for improving overall outcomes. Rapid, high-quality recovery makes it possible to avoid, reduce, or rapidly terminate all invasive measures and to have people return to normal activity (including personal hygiene), with dramatic improvement in the incidence of infection and venous thromboembolism (VTE). Consequently, any assessment of this technique in comparison to other techniques for pain control must include measures of postoperative quality of recovery and global outcomes such as VTE and hospital-acquired infection rates since these were the concerns that this technique was designed to address.

Because this key technique has also triggered important changes to other aspects of pain management and perioperative care, the term LIA is also used in a much broader sense to denote (or be a proxy marker for) our whole approach originally known as the "Kohan/Kerr technique for pain management and perioperative care."

I believe that clinicians are more akin to engineers than scientists. It is the clinician's task to stay abreast of the developments in science, and also transduce the mixture of science and experience into practical results. In common with engineers, this involves a good deal of pragmatism and practical consideration of the constraints imposed by the circumstances of each practice. In the real world, ideal results may not be achievable or getting that last 5% may be too costly to implement, but often close approximations are achievable and affordable. Engineers accept these practical limitations and, having achieved a useful practical outcome, continue to polish the result with continuous quality improvement techniques; in the end, they are able to achieve the closest possible approach to the ideal outcome. This is exactly the process by which local infiltration analgesia was developed.

In private practice, there is no money, no staff, and very little time to devote to research, but there is an abundance of clinical material. Randomized controlled double-blind trials are also difficult to conduct from a private practice base. The time, money, and documentation required for approval by ethics committees and government agencies are a significant impediment to research. In addition, normal medical indemnity insurance does not cover clinical trials and obtaining private insurance to cover clinical trials is costly and difficult. The practical alternative for private clinicians is careful observation, documentation, and audit of outcomes with constant review to polish future practice.

The clinical trial approach is also not well adapted to the development of a new technique such as LIA. Each aspect of this multifaceted approach would need to be the subject of at least one separate trial, which would take an extraordinarily long time to conduct and correlate into a unified technique. We also consider it unethical to set up placebo control groups or control groups using techniques that we know to be inferior.

The LIA technique has been used for several different types of operations. Some of these operations have been of minor nature such as arthroscopy, unicompartmental knee surgery, and anterior cruciate ligament surgery in which pain control and satisfactory outcomes are much easier to achieve that is the case for total joint arthroplasty. Although the information to be gained from minor surgery cases is useful for toxicity and side-effect monitoring, the main focus of this book has been the use of the LIA technique for total joint arthroplasty. The outcomes reported therefore reflect this bias.

Some of the work in this book has appeared in part in other publications, notably, from our original paper about the LIA technique (1) and from Chapter 30 in the book "Modern Hip Resurfacing" (2). Although I have reworked the material to ensure its relevance in this context, I have self-plagiarized some of the sentences and, occasionally, whole paragraphs from these previous publications because I could not find a better way to say the same things.

I particularly wish to acknowledge the contribution of Prof. Lawrence Kohan, orthopedic surgeon and our team leader. Prof. Kohan and I have been working together for more than 15 years, and we have developed the LIA technique together. Many of his ideas have been incorporated in the overall technique and he is responsible for developing the systematic injection sequence. His support and encouragement have been invaluable and, without access to his private patients, the technique would never have been developed. I also work closely with two other orthopedic surgeons who have contributed significantly. Assoc. Prof. Peter Papantoniou has especially contributed to the development of LIA for lumbar spine surgery and Dr. Sami Farah has assisted in reviewing the manuscript. Two of our orthopedic fellows, Dr. Ikram Nizam and Dr Sandeep Biswall, have contributed by investigating and documenting some of the outcomes associated with the LIA technique. Finally, two Swedish medical students, Joakim Rostlund and Jesper Benck, visiting during their elective term, provided valuable assistance in conducting studies on ketorolac .

The purpose of this book is to document aspects of the LIA technique and its modifications for use in different circumstances. I also hope to provide an appreciation of how we have polished our practical outcomes to fi t it into the overall context of pain management and perioperative care. Finally, clinical outcomes and experience over the last 13 years will be presented.