Ambulatory anaesthesia offers low cost and low infection rate

Dr J N Monteiro

An ambulatory anaesthesia is one administered for a non emergency or elective surgical procedure, performed on carefully selected patients, which is undertaken with all its constituent elements (admission, operation and discharge home) on the same day. It is also referred to as day case anaesthesia, day care anaesthesia, outpatient anaesthesia and more recently office-based anesthesia.

Ambulatory anaesthesia is a relatively young and rapidly growing sub-specialty. Although its history is as old as the history of general anaesthesia itself, it has emerged as a recognised concept and is evolving over the past couple of decades. In the US, it comprises 70 per cent of anaesthesia services provided.

In the UK it is referred to as "day case anesthesia" and the NHS plan, published recently predicts that 75 per cent of elective surgical procedures will soon be conducted as day cases. Back home, 70 per cent of elective surgeries that qualify the criteria are performed as day cases in Hinduja Hospital, Mumbai.

The advantages of lower cost, lower rate of infection, less patient anxiety and greater patient convenience have been demonstrated by this sub-specialty over a period of five decades. It was established that paediatric patients recovered better at home without separating from their mothers. Patients saved money by recovering at home and continued to be employed while recuperating, thus beds were free for the hospital for sicker patients.

Newer anaesthesia practice allowed patients to recover faster, permitting the number and the complexity of cases to include longer and more complex procedures permitting a safer operation theatre without flammable anaesthetics.

Technology has offered sophisticated monitors to monitor patients more carefully during anaesthesia thus permitting sicker patients with more challenging medical conditions to be considered for ambulatory anesthesia.

Great societal and economic pressures mounted over a period of time and hospitals struggled to meet the demand for inpatient beds as day case anesthesia provided relief. It was recommended by insurers and society as a quick solution to curb medical costs, which was a great force that drove the emergence and growth of this sub- specialty.

Preoperative evaluation

All patients listed for day surgeries attend a pre-assessment clinic ideally as soon as the decision to operate is made. This ensures that patients listed for the procedure fits into the agreed medical selection criteria. The consultation provides an opportunity for explanation and discussion, helping to keep the patient well informed.

Pre-operative testing should be performed only if an abnormal test would alter patient management. Those requiring further investigations, anaesthetic assessment or their treatment to be optimised are identified early and corrective action taken. Pre-operative fasting guidelines, factors that may improve the outcome of the procedure like stopping smoking or weight reduction may also be discussed.

Types of anaesthetic agents

Anaesthetic agents today have been designed and marketed to meet specific niche criteria for ambulatory anesthesia. Among the agents available in India, propofol and sevoflurane have increased the ability of the anesthesiology to provide a successful day case experience.

Because of the rapid onset and offset of these agents longer cases can be planned on an ambulatory basis and patients can recover quickly and can be discharged home safely. Side effects such as the "hang-over effect" can be minimised. Propofol has the additional effect of reducing PONV (post-operative nausea and vomiting). There are several intermediate acting muscle relaxants available due to advancements in muscle relaxant that are perfectly suited in majority of cases requiring muscle relaxation.

Devices for airway management have also progressed. The emergence of the LMA (laryngeal mask airway) and COPA (cuffed oropharyngeal airway) have significantly broadened the options in the airway management armamentarium. A patient suitable for LMA instead of endotracheal intubation is no longer exposed to muscle relaxants for the sake of maintaining the airway. Short acting drugs provide great advantages for speed of emergence and potential cost savings but they are expensive. Few studies have been done that actually examine the actual cost to society of the various choices in ambulatory anesthesia.

Techniques

The challenging objectives and the growing importance of ambulatory anaesthesia has led to the development of efficient and safe general anaesthetic technique TIVA (total intravenous anaesthesia) of which ultra-short acting intravenous agents have played an important role.

Though intravenous induction or inhalational induction is both suitable in the ambulatory setting maintenance of general anaesthesia, inhalational agents may be more cost effective. Newer available agents are expensive and older less expensive agents can also provide a comparable anesthetic in skilled hands .

Regional techniques offer significant advantages in the outpatient setting. They can avoid the side effects of nausea, vomiting and pain that frequently delay discharge. They can also provide prolonged analgesia and a pain-free preoperative period with the use of continuous catheter infusions.

The choice of drugs must be well adjusted with the neuraxial technique. Despite frequently requiring some additional time at the outset, regional techniques have consistently been shown to provide competitive discharge times and costs, when compared with general anesthesia. They deserve a prominent place in day case surgery.

Recovery

The recovery begins immediately at the end of anesthesia and can be divided into three definite phases.

Early phase: The patient emerges from the anaesthesia and is closely monitored.

Intermediate phase: The patient has emerged completely from the anaesthesia and is assessed for discharge.

Late recovery phase: The patient recovers completely from surgery and anaesthesia and resumes normal daily activities.

There are a number of scoring systems to assess readiness for discharge. These use a variety of parameters such as level of consciousness, breathing, circulation, activity level, complications and mobility. A set of guidelines has also been set for such an assessment. It is also important to consider the patient's mental state when discharge is considered. They should feel ready to go home. Discharging the patient against his/her wishes could have serious consequences.

Post-operative analgesia

The control of pain is crucial for the provision of good day-case anaesthesia. There must be good communication between the patient and anaesthetist to increase compliance with the prescribed medication and ensure that the patient's expectations are realistic. Good post-operative analgesia requires planning and a proactive approach.

Treatment can be started pre-operatively with the administration of paracetamol and NSAIDS (non- steroidal anti-inflammatory drugs). There is a trend away from opioid analgesics as they are associated with PONV (post operative nausea and vomiting) that results in patient dissatisfaction and delays discharge. A multimodal approach including regional anaesthetic techniques as well as oral / parenteral analgesics has a higher success.

Conclusion

New technology, surgical techniques and progress in anaesthesiology will be supported and financed by society as long as it reduces the cost of health care. Although new technology may increase the direct costs of providing care in the operating room, the overall costs to the patient should be decreased. It would be imperative to mention that the anaesthesiologist should remain committed to the safety and the comfort of the patient primarily, which will simultaneously help the subspecialty to grow.

The writer is consultant anaesthesiologist, P D Hinduja National hospital and Medical Research Centre
Email: joran@vsnl.com