As surgery is moving toward minimally-invasive procedures, making a clear shift toward more selective blockades and better tolerated techniques, the anesthesiologist is faced with a real and dramatic growth in the number and complexity of ambulatory surgery, and is challenged to find a good solution to provide optimal care for his patients in hospitals who are consistently faced with cost savings each year. Indeed, strategies based on efficiency, safety, feasibility and costs should all be implied.

Central and peripheral nerve blocks should be performed in an (adjacent and fully monitored, equipped and staffed) regional block room rather than in-between operations, in the operating theatre itself. As such RA hardly consumes any intra-operative time, which is essential, especially in a high volume – fast turn-over surgical unit with many short procedures.

The use of RA is spreading as advances in the understanding of pain physiology, better technical skills, the development of new devices and the wide-spread development of ultrasound nerve localization will increase the number of patients who can benefit from RA, improving its success rate. The question arises whether to use central neuraxial blockade or peripheral nerve block for patients undergoing surgical interventions on a day case basis. Central neuraxial blockades are associated with side-effects, not seen with peripheral blocks (e.g. hypotension, bladder retention). Spinal anesthesia is one of the options for outpatient surgery. Thanks to the introduction of non-traumatic pencil-point needles with small gauge a fast, reliable and deep surgical block with simple injection of very small doses of local anesthetics can be obtained. Of course it has its problems in the outpatient setting: recovery of motor blockade after the block, bladder function, postdural headaches and transient neurologic symptoms (a benign syndrome commonly seen following spinal lidocaine in outpatients who were operated in the lithotomy position). Reducing the dose of local anesthetic (lidocaine, ropivacaine or bupivacaine) and the addition of intrathecal opioids (e.g. 20 μg fentanyl or 2.5 μg sufentanil) produces good results. This method can even be used to restrict the local anesthetic to one side: unilateralization of spinal anesthesia.

However the major disadvantage of both single injection techniques of central neuraxial and peripheral nerve blockade is, that after resolution of the regional blocks, the patient feels excruciating pain, which is difficult to manage and is often inadequate in the outpatient setting.

Peripheral nerve blocks (PNB) with long-acting anesthetics are attractive alternatives for outpatient surgery. They are site-specific, have few side effects, provide better surgical conditions and superior analgesia than systemic opioids, reduce the stress response to surgery, enhance patient satisfaction and improve patient outcome. PNB are often not contra-indicated in patients receiving anticoagulation. Peripheral catheter placement further adds on the quality by prolonging intra- to long lasting postoperative analgesia.

Anatomy is the key of success for all RA techniques. Knowledge of the relevant plexus anatomy and its relations, as well as the distribution of its sensory and motor innervations of the upper and lower extremities, is crucial for understanding the resulting distribution of sensory and motor blockade in PNB. Correct identification of superficial bony, muscular and vascular landmarks and profound structures are fundamental to achieving consistent success and minimizing complications with peripheral nerve blocks. Since the application of ultrasound, it has become obvious that anatomical variations within the plexus are extremely common, and may be considered more the rule rather than the exception. Very few structures are strictly consistent in size and localization among individuals, and are even different on the opposite sides of the same individual.

Identification of nerves can be done by several methods: 1) the classic method, including palpation and searching for the nerves using paresthesia; 2) the nerve stimulation method, using the nerve stimulator to localize the target nerves; 3) the ultrasound guided nerve method, where needles are visualized during insertion and injection of the local anesthetic; and 4) a combination of the above, usually nerve stimulation and ultrasound methods.

Our goal with many regional blocks is to be able to inject sufficient (but not too much) volumes and concentrations of local anesthetic as near as possible to the target nerves to be blocked, without delays or complications. Probably personal experience with a particular technique is the single most important factor for the success of any RA technique. Urmey (1) described the percutaneous electronic guidance technique, a non-invasive technique for prelocation of peripheral nerves facilitating peripheral nerve blockade. For a long time peripheral nerve stimulation was the gold standard method of nerve identification, but with the introduction of the ultrasound a more precise injection of the local anesthetic is feasible.

Describing various techniques or approaches to blocking the brachial plexus, textbooks typically identify the author who first described the particular approach. And there are many approaches. Most authors recommend tracing a geometrical line connecting one landmark to another, although the significance in practice is doubtful. For the upper plexus block, the cutaneous landmarks used are identified and connected to form a straight line, from the apex of the scalene muscular triangle, and ending with the point of palpation of the axillary artery in the axilla. This line, denoted by Paolo Grossi (2) as the "anesthetic line" can be used to localize the brachial plexus at any point. Obviously, interscalene brachial plexus block is one of the most popular upper extremity blocks in use all over the world, since first described in 1970 by Alon P. Winnie. It is a simple, safe and effective anesthesia technique for all types of surgery on the shoulder and upper arm. Hemidiafragmatic paralysis occurres in virtually 100% of the patients and ventilatory insufficiency is one of the contraindications for this block. With the use of ultrasound, complications such as accidental intrathecal injection, systemic toxicity, spinal cord injury and hematoma formation clearly should develop less

frequently. Both supraclavicular and infraclavicular blocks are less frequently performed due to the fear of accidental pneumothorax, with reported incidences between 0.5% to 6%. Again with ultrasound the knowledgeable anesthesiologist can clearly avoid the region of the lung. Axillary brachial plexus block, described by Halstead 125 yrs ago, still is the PNB most used for upper limb surgery, due to its high rate of efficacy and its low incidence of complications compared to the other brachial plexus approaches. Again ultrasound has increased both efficacy and safety of this block, while the dose of local anesthetic injected can be decreased. If for whatever reason the result of the brachial plexus block is not sufficient, one can always locate the main terminal nerves (ulnar, medican, radial) of the brachial plexus (using peripheral nerve stimulation and/or ultrasound) to block them selectively at the forearm. Distal upper extremity blocks are useful for wrist and hand surgery, not only as a supplement of more proximal incomplete blocks, but as a technique in itself when an upper arm tourniquet is not necessary. Blockade of the musculocutaneous nerve allows the application of a tourniquet. This nerve is often not included into a brachial plexus block. Recently with using ultrasound it is a rather easy to block the musculocutaneous nerve selectively. For more than 100 years intravenous regional anesthesia (Bier’s block) is applied all over the world, often in the acute setting of a first aid department (3). Bier’s block still is widely applied all over the world for procedures which do not exceed the time of tourniquet tolerance, but with as shortest insufflation time at least 30 minutes.

The disadvantage of any single block technique is that it wears off at a particular time, depending on the choice and the dose of the local anesthetic given. This usually is the case when the patient is back at home, often after business hours. Patients can be given better long lasting pain relief if a continuous technique is applied instead of a single block. As such pain is less, making mobilization easier. For each of the approaches a catheter can be inserted to which a continuous or patient controlled on-demand analgesic technique can be applied. Portable electronic or elastomeric pumps can be applied, allowing self-administration of local anesthetic by the patients (4). Nevertheless several requirements have to be fulfilled before widespread use of home therapy will be possible: appropriate patient selection; follow-up routines; 24-hrs access to anesthesiology services and simple (disposable) local anesthetic delivery devices.

Even though central neuraxial blocks are the first choice for thoracic and abdominal surgery and epidural catheters play a cornerstone in good postoperative outcome, PNB for lower extremity surgery in an outpatient setting, are the first choice for prolonged postoperative analgesia superseding other types of analgesia. Many procedures, particularly orthopedic surgery, are associated with moderate to severe postoperative pain, often poorly controlled with opioids or other analgesics.

Central neuraxial opioid side effects are similar to those of parental therapy. PNB are more attractive than central neuraxial blocks as the latter frequently mandate the use of urinary catheterization. PNB can also provide high-quality anesthesia and analgesia for unilateral lower extremity surgery.

Again a good knowledge of anatomy is the key to a successful blockade without complications. Although upper extremity regional blocks are applied for many decades, many anesthesiologist are still reluctant to provide lower extremity blocks for their patients, often due to lack of knowledge of the anatomy.

 The lumbar plexus (formed by the anterior divisions of the first four lumbar nerves) and the sacral plexus (formed by the lumbosacral trunk and first three sacral nerves) are the targets of peripheral nerve blocks of the lower extremities. The first lumbar nerve receives a branch from the XIInd thoracic nerve and splits into an upper and a lower branch. The upper branch divides into the iliohypogastric and ilioinguinal nerves, while the second lumbar nerve receives the lower branch from the first lumbar nerve and gives origin to the genitofemoral and the femoral cutaneous nerve. The remainder of the second nerve and the third and fourth lumbar nerves divide into a ventral and a dorsal division. The ventral division of the second, third and fourth lumbar nerves unite to form the obturator nerve, while the dorsal division of the same lumbar nerves join to form the femoral nerve. The great sciatic nerve is the continuation of the vertex of the sacral plexus. It is the largest nerve in the body, measuring 1 to 2 cm in diameter. It leaves the pelvis through the greater sciatic foramen below the piriformis muscle and descends along the back of the thigh to the popliteal fossa, where it divides into the common peroneal nerve and the tibial nerve. The common peroneal nerve is the most laterally situated terminal branch and supplies the muscles and skin of the anterolateral aspect of the leg and the dorsum of the foot. It descends obliquely on the lateral side of the popliteal fossa toward the fibula head, winds around the neck of the fibula and divides into the superficial and deep peroneal nerves. The latter gives muscular branches to the anterior muscle group of the lower leg and articular branches to the anterior face of the lateral ankle joint. The tibial nerve passes between both heads of the calf muscles, supplying the muscles on the posterior aspect of the lower leg and plantar aspect of the foot. The foot itself is innervated by five nerves, four of them are terminal branches of the sciatic nerve and the other one is a branch of the femoral nerve, i.e. the saphenous nerve, which runs next to the femoral artery in the mid femoral area, and becomes subcutaneous in the medial face of the knee, running parallel to the internal saphenous vein, downwards passing the medial malleolus, innervating the latter and part of the heel. The sural nerve is formed by branches of the tibial and common peroneal nerve and provides sensory innervation to the lateral aspect of the lateral ankle and the foot. The sural nerve passes behind and below the lateral malleolus.

With PNB of the lower extremity, total unilateral anesthesia is easy to perform, avoiding all disadvantages of central neuraxial blocks. Surgical procedures of the hip, thigh, knee, lower leg and foot are all possible. Successful blockade however is based on careful blockade of the surgical area, including all motor branches, and sensory branches of skin and bones, which are not necessarily identical in origin. Anesthesiologists have a wide choice of techniques available. Often combination of blocks on different nerves are applied, e.g. the psoas compartment block combined with a sciatic nerve block provides excellent surgical anesthesia to the entire lower extremity and is a good alternative to spinal blocks for hip surgery. To identify the exact spot of needle insertion and injection of local anesthetic, neurostimulation and echography using ultrasound certainly are valuable adjuncts. Depending on the situation other techniques such as the loss-of resistance, can be used to identify the correct anatomic localization of the needle tip. Especially the old fragile, ill-defined patient, can benefit from unilateral PNB, so that mobilization can be achieved as fast as possible.

A femoral nerve block can be used to provide anesthesia and analgesia for most surgeries involving the femur, the knee, anterior, lateral and medial thigh and the distal medial leg. The femoral artery is the most important landmark with the femoral nerve in the lateral (i.e. one finger or 2 cm) position. However it is important to highlight that the femoral nerve is located in a different aponeurosis compartment, which is deeper than that of the crural vessels. The femoral artery and vein are located between the fascia lata and fascia iliaca, whereas the nerve is below the fascia lata. As the femoral nerve is mainly motor (80%) its localization is easy to perform using a nerve stimulator, although ultrasound is also applicable. With the patient in the supine position, anatomical landmarks are identified: inguinal ligament (anterior superior iliac spine to lateral border of the pubic tubercle), inguinal crest by lifting the leg, and femoral artery. In the classic approach, a wheal is performed in a point immediately below the inguinal ligament and next to the lateral wall of the femoral artery pulse (1-2 cm). It is common to feel two "pops" as the needle goes through the fascia lata and the fascia iliaca and a loss-of-resistance once is felt once the latter is crossed. Another approach is to insert the needle immediately on the femoral crease (ask patient to flex the thigh on the hip). Correct stimulation results in up and down movements of the patella and/or twitch of the entire quadriceps muscle. The saphenous nerve can be blocked in the inguinal crease, mid femoral area, at the level of the tibial tuberocities or at the level of the internal malleolus. As it is a 100% sensory nerve, nerve stimulation is useless, although ultrasound may help to find the saphenous nerve.

Contrary to common belief, sciatic nerve blocks are relatively simple to master and perform. They are among the least frequently practiced nerve block procedures. The deep location of the sciatic nerve mandates proper training and thorough knowledge of anatomy. The use of a nerve stimulator is essential to optimize the success rate of sciatic nerve block, even when ultrasound is used. Longer (100 to 150 mm 21-22 gauge) insulated needles are needed. Irrespective of the approach, stimulation of the sciatic nerve produces either a dorsiflexion of the foot with an extension of the toes or an eversion (stimulation of the common peroneal nerve), or a plantar flexion of the foot and toes or an inversion (stimulation of the tibial nerve). Patients can be given a sciatic block (e.g. anterior, lateral, parasacral, posterior, gluteal, subgluteal approaches) irrespective of their position (supine, lateral, prone, lithotomy) on the operating table. The gluteal approach of the sciatic nerve often is more difficult than the subgluteal or mid femoral blocks, which are more easier to perform.

Operations performed on the forefoot, ankle and foot can easily be done by blockade of the sciatic nerve at the popliteal fossa, eliciting inversion or combined inversion/plantar flexion on nerve stimulation and injecting of e.g. 30 ml of the selected local anesthetic. The popliteal fossa is a triangular area located in the posterior part of the knee, defined medially by the semimembranosus and semitendinosus muscles and laterally by the femora biceps muscle. In fact the sciatic nerve is in its itinerary along the posterior thigh already divided into two branches (tibial and common peroneal nerves). Posterior and lateral approaches of the popliteal areas are both possible depending on the local situation of the patient.

Cutaneous nerve blocks of the lower extremity and blocks of the distal nerves (e.g. lateral femoral cutaneous, posterior femoral cutaneous, saphenous, sural and superficial peroneal nerves) are useful anesthetic techniques as an adjunct to the major conduction blocks of the lower extremity, although they might be applied as a sole anesthetic technique in specific indications.

New stimulating catheters to provide continuous peripheral nerve blockade, the use of disposable infusion pumps with large elastomeric and electronic pump volume reservoirs, allowing a combination of a background infusion with PCA boluses, all increase the magnitude of surgeries safely performed in the ambulatory setting while enhancing the quality of postoperative analgesia and patient satisfaction. One always should calculate the total dose given if a combination of PNB is applied, especially in lower extremity blocks where large volumes of local anesthetics of single-shot injections at different locations are given. Here too is the use of a catheter beneficial as lower volumes can be given, providing top-ups as indicated during the surgical procedure.

Although RA in children was reported over a century ago with the introduction of spinal anesthesia, the advent of safer methods for general anesthesia decreased its use till recently. However, both central neuraxial and PNB can be applied successfully in children and many anesthesiologists involved in pediatrics provide RA in anesthetized children. Similar indications, but adjusted equipment (including catheters) and doses of local anesthetics should be applied, so that this patient population can benefit from the application of RA to the maximum extent. Although caudal analgesia is the most common analgesic technique performed in children, other peripheral nerve blocks should not be forgotten. Childhood experiences of pain can result in short- and long-term negative sequelae, and improperly treated pain causes behavioral and biological consequences. Children too have the right to obtain the best care there is to take away any postoperative pain.

With better knowledge of the pathophysiological mechanisms of organ dysfunction associated with surgery, interventions aimed at attenuating the surgical pain and stress response, facilitating the immediate recovery process, the today anesthesiologist should practice RA wherever possible. RA is the ideal technique for ambulatory surgery, but certainly is still underutilized. We know that RA has advantages in the ambulatory setting. Upper and lower extremity nerve blocks have many advantages, such as simplicity, high efficiency, low cost, and are good alternatives to central neuraxial techniques when contra-indicated. Now we have to bring pain relief from the ambulatory surgery setting into the patient’s home postoperatively, so that he no longer is awake and full in pain in the midst of the night. The establishment of acute pain services in many institutions have a major impact on postoperative comfort and patient satisfaction. We can almost guarantee good pain relief during an operation. But our duty does not stop here. We have the tools to provide postoperative long-lasting pain relief. We now have to step into the next phase and control pain relief also in the days following surgery when the patient is at home. This requires extra equipment to guarantee continuous pain relief, but also manpower and a system whereby patients can contact the acute pain service on a 24-hr basis.

Patients should be informed about the benefits of RA. They should be given time to explain the procedure, taking away the frightening ideas of needles pricking through their skins. Resident training is extremely important. Junior and senior faculty anesthesiologists should practice on a regular base, but also should use skillslabs to improve their confidence in RA. Thorough knowledge of the pertinent anatomy is required to consistently perform RA blocks successfully. Surgeons should use infiltration blocks wherever feasible. This simple item already helps reducing the pain in the first hours postoperatively.

Continuing medical education is of paramount importance. Anesthesiologists, both staff and trainees, should have access to texts, photos, videos, and hopefully

Belgium is not the first country where surgery was done in "one day setting", but, we must say that the enthusiasm of Dr. Claude Delathouwer, from the Brussels One Day Clinic, was the start of international contacts, and finally, to the foundation of the International Association for Ambulatory Surgery (I.A.A.S.).

The I.A.A.S. is an International Non-profit Association with its registered office in Belgium.

Belgium and Day Surgery

About the Belgian situation, in terms of Day Surgery, I wanted to start as early as 1963. But, a law on hospital organisation, described below, prevented us from doing so.

A hospital was defined as an institution where one was accepted for surgery or for another treatment and where everything was organised to give the patient a good stay or journey. Even the mentality amongst the patients and the people was "you better stay 2 or 3 more days in the hospital because of the good after-care, the good food, the warmth in winter, because of the visits of your family and friends…..".

The functioning of the hospital was based on "charity" and the nurses did the after-care during the hospital-stay.  The bill had to be paid when leaving the hospital and patient got refund by the National Insurance under condition of overnight stay.

Few years later, there was some change in the refund system, and we had to wait until 1985 for a law, changing the definition of "hospital" and allowing refund of surgeon’s fee and hospital cost even without overnight stay.

Finally, in 1997, the Government formulates the rules, terms and conditions for the organisation of Day Case Surgery. However, in the mean time, most hospitals in Belgium already had their Day Surgery Centre and some specialists, like, Ophthalmologist, Plastic Surgeons, started practice in free-standing centres.

From then on, different initiatives were taken by the Government to stimulate the implementation of the day surgery concept. The financing system for the hospital changed in favour of the day surgery concept for a certain category; and also the surgeons were stimulated to treat their patients on an out-patient base, by paying them a bonus (but a very little one!) when using the day surgery facilities.

Day Surgery evolution:

The situation in the countries around Belgium is different because of the lack of hospitals and hospital beds. Long waiting lists were created. And this is then the story of Dr. J. Nicoll , paediatric surgeon at the Sick Children’s Hospital, Glasgow, Scotland and called "the founder of the modern day surgery" (Prof. P. Jarrett, UK).

At that time (1880) in Glasgow, poverty was widespread and child mortality was high. At the Sick Children’s Hospital, they could treat only 500 children a year and there were always cases waiting for admission. Therefore, the hospital opened a dispensary as an out-patient department. Initially with two trained nurses, working independently from the inpatient hospital: in the morning working in the dispensary and in the afternoon visiting the patients at their homes.

From 1889 on, Nicoll started to follow up the results of the outpatient treatment and gave a presentation at a meeting of the British Medical Association with his successfully results.

In Belgium, it was Dr. Delathouwer, who was the man after the initiative to establish ambulatory surgery in the national forum. As stomatologist and director of the Brussels One Day Clinic, he organised the first Belgian and European Congress on Ambulatory Surgery (Brussels, 1991). This congress was very successful with 600 delegates from 25 countries, all interested in the concept of ambulatory surgery.

Also, it was decided to create an organisation called "Belgian Association of Ambulatory Surgery (BAAS)" to stimulate the organisation of ambulatory surgery and research in this field, to organise congresses and to give support to all kind of activities promoting ambulatory surgery. Anyone, interested in the concept could become a member.

The IAAS was founded on the 15th of March, 1995 and Dr. Delathouwer, was elected as the first President. In 1996, IAAS was officially constituted.

In 1999, during a Nicoll Memorial Lecture, at the 3rd International Congress of Ambulatory Surgery in Venice, Italy, Dr. Claude Delathouwer observed: "How it is possible that the following 50 – 60 years no reports are available relating to ambulatory practice,……it seems that modern ambulatory surgery was reinvented approximately 30 years ago….", commenting on the lack of publications or presentations on Ambulatory surgery.

In the mean time he organised the 2nd European Congress (Brussels, 1993), 3rd European and 1st International Congress (Brussels, 1995).

Belgian Congresses organised were: 2nd Belgian Congress, Brussels 1997, 3rd Belgian Congress, Brussels 1998, 4th Belgian Congress, Brussels 2000, 5th Belgian Congress, Leuven 2003, (Joint Congress with the Department of Anaesthesiology, University Hospitals, Catholic University of Leuven, International Winter Symposium on "Anaesthesia for Day Case Surgery".

From 2005 on, the B.A.A.S. vzw-asbl participates in the new structure of the Royal Belgian Society of Surgery (RBSS) and the Board decided to organise his own Congress every second year.

So the next Congresses were organised as follows:

6th Belgian Congress, 2005 Gent, 7th Belgian Congress, 2007 Neder-over-Heembeek, and 8th Belgian Congress, 2009 Neder-over-Heembeek.

In 2002, 2004, 2006 and 2008 the BAAS participated in the Belgian Surgical Week (BSW) , organised by the Royal Belgian Society of Surgery (RBSS), with a session, dedicated to the ambulatory concept.

Since the beginning the BAAS organised different surveys amongst the Ambulatory Surgery Centres in Belgium: one about "Patient’s satisfaction" (1998) and another about "Nurse’s satisfaction" (1999). A register of the existing Ambulatory Centres was published in 1998 and a new volume is foreseen in 2009.

Many things are changing in the acceptation of the ambulatory surgery concept. Government, hospitals, surgeons, anaesthetists, nursing staff and administrators are convinced that this concept is a good one. The hot topic on our last Congress (2009) was the shift to office based surgery. This means that more surgery will be done in outpatient setting and in these, we all will have to take up our responsibility to take care of the safety of our patient.