The patient is transferred from the operating theatre to the PACU by one or more of the anaesthetist, anaesthetic nurse, scrub nurse or operating department practitioners. It is the anaesthetist's responsibility to ensure the safe transfer of the patient. The patient should be assessed as stable prior to leaving the operating theatre and the anaesthetist will decide on the level of monitoring required, which will depend on the distance of the transfer, the patient's level of consciousness, and the patient's cardiovascular and respiratory status.

Oxygen is usually administered to the patient during the transfer unless they did not receive supplemental oxygen during the procedure. It is vital that the anaesthetist flushes the patient's intravenous lines to ensure that there are no residual anaesthetic drugs remaining (AAGBI [5]).

Post‐anaesthetic care can best be described and understood as a series of nursing procedures performed sequentially and simultaneously on patients immediately after anaesthesia or surgery. Such patients will display varying degrees of responsiveness and physical and emotional states.

The recovery period is potentially hazardous. Therefore, when the patient arrives in the PACU, individual nursing care is required until the nurse is satisfied that the patient can maintain their own airway and is sufficiently oxygenated (AAGBI [5], AfPP [9]).

Whereas in the past, post‐anaesthetic care meant a relatively brief period of observation in an area close to theatres, it has now evolved into a distinct critical care area where patients of varying dependencies receive specialist clinical care from trained staff using a variety of drugs, monitoring and equipment (AAGBI [5]). The following items are the minimum required in each bed space or recovery bay (Figure 16.37):

The equipment should be compatible between the operating theatres and the PACU. It must be arranged for ease of access and always be clean and in full working order.

Additionally, other equipment should be available centrally for respiratory and cardiovascular support:

The relevant resuscitation equipment, drugs, fluids and algorithms should be immediately available for the management of both surgical and anaesthetic complications. Ideally these items should be contained in dedicated trolleys (AAGBI [5], AfPP [9]).

No fewer than two staff (at least one must be a registered practitioner) should be present when there is a patient in the PACU who does not fulfil the discharge criteria. The staffing level should allow one‐to‐one observation of every patient by an anaesthetist or registered PACU practitioner until patients have regained control of their airway, are haemodynamically and respiratorily stable, and are able to communicate. One member of staff present should be a certified acute life support (ALS) provider. Life‐threatening complications can occur during the immediate post‐operative and post‐anaesthesia phase. Any failure to provide adequate care can have devastating consequences for patients, their families and staff. Patients must be kept under clinical observation at all times. The frequency of the observations is dependent on the procedure performed, the physical status of the patient and the stage of recovery. Box 16.10 outlines the minimum information that should be routinely monitored and recorded for patients in the PACU.

Discharge from the PACU is ultimately the responsibility of the anaesthetist but is usually delegated to PACU practitioners, who use discharge criteria to assess whether the patient has achieved the optimum recovery, enabling them to return to the ward safely. In the event of complications or deterioration, the anaesthetist must be informed and should assess the patient before their return to the ward (AAGBI [5], AfPP [9]).

The PACU must adhere to minimum criteria that patients must meet prior to their discharge to the general ward or other clinical areas (Box 16.11).

Pain is the most common adverse effect of surgery for the majority of patients (Chou et al. [43]). Pain is a subjective experience and patients in the PACU should receive both effective and empathetic care to relieve their pain (AfPP [9]). A patient should not be discharged from the PACU until satisfactory pain control has been achieved. PACU staff must be trained and competent in the use of intravenous analgesia, patient‐controlled analgesia, epidurals, spinals and peripheral nerve blocks (AAGBI [5]). It is important to recognize that pain may not only be caused by the surgery. Other reasons include pre‐existing medical conditions, poor positioning during surgery, headache as a result of anaesthetic drugs, and muscle aches from the use of depolarizing muscle relaxants (e.g. suxamethonium) (Chou et al. [43]).

Post‐operative nausea and vomiting may arise from many causes. These include hypotension, swallowing of blood (e.g. in oral surgery), abdominal surgery and anxiety, but most commonly as a side‐effect of opioid administration. Nausea, vomiting and retching may exist independently and therefore require individual assessment (AfPP [9]). Patients should not be discharged from the PACU unless their post‐operative nausea and/or vomiting are controlled and suitable medication has been prescribed (AAGBI [3]).

Inadvertent perioperative hypothermia (below 36.0°C) is a common but preventable complication of surgery and is associated with poor outcomes for patients. Adult surgical patients may develop hypothermia at any stage of the perioperative journey, though the elderly, the malnourished and those who have undergone long surgery or where large amounts of blood or fluid replacement therapy have been used are especially at risk (Williams and El‐Houdiri [231]).

During the first 30–40 minutes of anaesthesia, a patient's temperature can fall to below 35.0°C. Reasons for this include:

On admission to the PACU, the patient's temperature must be measured and documented. If it is below 36.0°C, active warming should be commenced until the patient is warm. They should not be discharged until their temperature is 36.0°C or above (NICE [143]). Hypothermia produces symptoms that mimic those of other post‐operative complications, which may result in inappropriate treatment. Hypothermia interferes with the effective reversal of muscle relaxants, so patients who are shivering, restless or confused, or who have respiratory depression, should be monitored. Shivering puts an increased demand on cardiopulmonary systems as oxygen consumption is increased (Feldmann [61], Frank et al. [65]). Cardiac complications such as arrhythmias or myocardial infarction are some of the principal causes of post‐operative morbidity (Warttig et al. [220]).

When emerging from the final stage of anaesthesia, some patients can behave in an emotional and disinhibited fashion, at variance with their normal behaviour (Eckenhoff et al. [55], Radtke et al. [169]). Therefore, it is important to establish a rapport with each individual to gain the patient's confidence and co‐operation and to aid assessment. These displays are always transient and fortunately patients seldom have any recollection of them. All actions must be accompanied by commentary and explanation regardless of the patient's apparent responsiveness, as the sense of hearing returns before the patient's ability to respond (Levinson [100], Starritt [197]).