The post-anaesthetic care unit as a special procedures unit

10

The post-anaesthetic care unit as a special procedures unit

E L I Z A B E T H A. M. FROST

It is often difficult to predict operating time and hence the need for post- anaesthetic care unit (PACU) time on a daily basis. Therefore, periods may develop when, although staff and space are available there are few or no patients. These times tend to occur in the early mornings or at the weekend. Not infrequently, hospital and nursing administrators have used these slack times to schedule certain procedures that are predictably short, require careful observation, but may not need all the resources of an operating room.

The advantages of using the PACU as a special procedures unit are: (i) operating room proximity; (ii)improved PACU utilization; (iii) availability of intensive care nursing staff, (iv) sterile environment; (v) accessibility to anaesthesiology and surgical departments. Procedures commonly scheduled for the PACU include:

�9 Electroconvulsive therapy; �9 Cardioversion; �9 Diagnostic nerve blocks; �9 Blood patches; �9 Blood transfusions; �9 Monitoring device placement.

Staffing should be on a one-to-one basis. Most therapies, which usually require 15-30 minutes, are performed by an anaesthetist, assisted by a PACU nurse. During electroconvulsive therapy, a psychiatrist is present; during cardioversion, a cardiologist is usually in attendance.

Although epidural saline and blood patches can be completed in about 15 minutes, frequently a catheter is left in place in case further administration should be necessary. Patients should be observed for 1 to 2 hours. Blood transfusions are administered slowly, and the patient's stay in the PACU may last several hours. After an initial observation period of about 15 minutes, critical nursing care is no longer essential and vital sign monitoring every 15 minutes is adequate. Both of these patient groups may have to be moved out of the acute PACU area to make room for in-coming surgical patients. Then, an area should be designated where they may be watched until they can be safely discharged home (at this point a ratio of one nurse to

Baillibre's Clinical Anaesthesiology-- 897 Vol. 8, No. 4, December 1994 Copyright �9 1994, by Bailli6re Tindall ISBN 0--7020-1947-X All rights of reproduction in any form reserved

898 ~. A. M. FROST

Table 1. Minimal requirements of a step-down area.

�9 Stretchers �9 Basic monitoring equipment: electrocardiogram (ECG); blood pressure �9 O2 supply, suctioning apparatus �9 Lounge chairs �9 Closets for storage of clothes �9 Kitchen facilities to prepare light foods and beverages (for example,

warm milk, tea, soda and ice) �9 Drug cabinets �9 Bathroom facilities �9 Nearby waiting room for parents and relatives �9 Reading materials, television, radio

three patients suffices). Equipment required for such a step-down unit is listed in Table 1. Alternatively, if there is a separated designated, step-down ambulatory unit, they may be observed in that area.

Emotional support of all these patients before, during, and after these procedures is a major aspect of their care. Although infection control is the responsibility of all medical personnel, the PACU nurse is often the main overseer of this essential aspect of patient care. Ideally, a section of the PACU that can be physically isolated should be used for all special procedures. Wearing of sterile gown, cap and mask should be required before the performance of invasive cannulations or nerve blocks. Use of disposable equipment and frequent hand-washing are strongly recommended.

ELECTROCONVULSIVE THERAPY

Electroconvulsive therapy (ECT) was introduced in 1937 as an alternative to pharmacologically-induced seizures in the treatment of several major affective disorders, including severe depression (Gaines and Rees, 1986; Selvin, 1987). Factors to be considered in the psychiatric patient coming for EC T are discussed below.

Drug therapy

Patients coming for ECT have usually failed a course of drug therapy. However , patients are often still maintained on those agents and knowledge of the medications, their classification, action and interaction with anaesthetic agents is important to the anaesthetist (Table 2).

Type and actions of antipsychotic drugs

The 'amine hypothesis' of depression suggests that deficiencies of amines (i.e., noradrenaline (norepinephrine) and serotonin), contribute to the aetiology of depression. Pharmacological correction of this deficiency should therefore effectively treat depression. Increased availability may be achieved by inhibition of re-uptake of exogenously or endogenously

THE POST-ANAESTHETIC CARE UNIT AS A SPECIAL PROCEDURES UNIT

Table 2. Classification of antidepressants.

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Non proprietary names Trade names Dose (rag)

Tricyclics Amitriptyline HC1 Imipramine HCI Desipramine HC1 Nortriptyline HC1 Doxepin HCI Trimipramine malleate Protriptyline HC1

Atypical Fluoxentin HCI Trazadon HCI

Monoamine oxidase inhibitors Isocarboxozide Phenelzine sulfate Tranylcypromine sulfate

Lithium carbonate (LiCOs)

Elavil 50-100 Tofranil 50-200 Norpramine 75-200 Palmelor 75-100 Sinequan, Adapin 75-150 SurmontiI 50.150 Vivactil 15-40

Prozac 20-60 Desyrel 150-200

Marplan 10-30 Nardil 15-30 Parnate 20-30 Lithane 300-600

released biogenic amines (Axelrod, 1971). Antidepressants have varying degrees of affinity at membrane sites, including pre-synaptic and post- synaptic receptors (e.g., amitriptyline HC1, imipramine HC1) (Iverson, 1974).

Monoamine oxidase inhibitors prevent the breakdown of noradrenaline to non-active metabolites, thus increasing available noradrenaline at receptor sites (e.g., phenelzine sutfate--Nardil | isocarboxazid--Marplan| tranylcypromine sulfate--Parnate | (Baldessarine, 1984).

Lithium carbonate (LiCO3) mimics the action of sodium by entering the excitable cell during depolarization, but lithium requires longer to be extracted by the cell. Excitability of the nerve cell is diminished by the accumulation of intracellular lithium. Clinically, lithium prolongs the neuromuscular action of both non-depolarizing muscle relaxants (e.g., pancuronium bromide) and depolarizing muscle relaxant (e.g., succinylcholine) (Borden et al, 1974; Nill et al, 1976).

Drug actions and interactions

Several side-effects of antidepressant agents, particularly the tricyclic antidepressant drugs have been described (Table 3).

Atropine as an antisialagogue is contraindicated in the presence of tricyclic antidepressants as it increases the likelihood of delirium and confusion. It necessary, glycopyrrolate is preferable, at a dose of 0.2-0.3 mg i.rn.

Patients maintained on monoamine oxidase inhibitors should not be given meperidine (Demerol| Such a combination may trigger a hypertensive crisis followed by severe hypotension. Narcotic analgesics like morphine HC1 should be used carefully in patients receiving tricyclics because of the possibility of uncontrollable hypotension. Narcotic analgesics also may

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Table 3. Side-effects of tricyclic antidepressants.

Type Minor (early) Major

Sedative Lassitude Sleepiness Fatigue Impaired consciousness with alcohol and

other drugs

Sympathomimetie Tachycardia Agitation Tremor Insomnia Sweating Aggravation of psychosis

Anticholinergic Blurred vision Aggravation of glaucoma Constipation Panalegic ileus Urinary hesitancy Urinary retention Fuzzy thinking Delirium

Cardiovascular Orthostatic hypotension Delayed cardiac conduction ECG abnormality Prolongation of P-R interval

Widening of the QRS complex Flattening or inversion of the T wave Dysrhythmias Sudden death

Neuropsychiatric Confusion Central anticholinergic syndrome Delirium Withdrawal

Allergic/toxic Cholestalic jaundice Agranulocytosis

Metabolic/endocrine Weight gain Gynaecomastia Sexual disturbance Amenorrhoea

Neurogenic Tremor Seizures Paraesthesia Neuropathy EEG alteration

induce delirium and hallucinations and complicate post-operative management.

Amitriptyline has a powerful anticholinergic action and decreases the availability of catecholamines in cardiac muscle. The incidence of cardiac dysrhythmias, orthostatic hypotension, and tachycardia is increased (William and Shorter, 1971). A quinidine-like cardiac depressant effect on the heart may occur. Despite these undesirable side-effects, discontinuation of therapeutic doses of tricyclic antidepressants is not warranted. Standard monitoring is adequate. Induction may be safely achieved with small doses of sodium pentothal and succinylcholine. Droperidol and ketamine should be avoided, as dysphoria may result. Also, droperidol is a potent hypotensive agent.

Safe ancillary drugs include antidysrhythmics (lidocaine), hypotensive drugs (nitroprusside), and vasopressors (phenylephrine and isoproterenol) (Barkai, 1985).

Cardiovascular system

Patients with pre-existing cardiovascular disease may require prior consultation. Hypertension and bradycardia may result from electrically-

T H E P O S T - A N A E S T H E T I C CARE UNIT AS A SPECIAL P R O C E D U R E S UNIT 901

induced convulsions. Before therapy, medical consultation should indicate that any hypertensive state or dysrhythmia is under the best possible control (McPherson and Lipsey, 1992). Monitoring through an extended post-ECT period is recommended. Patients with pheochromocytoma should not undergo ECT because of the risk of hypertensive crisis. Pacemaker function has not been shown to be affected.

Musculoskeletal disease

A history of osteoporosis, frequent fractures, back pain, or disc disease should be noted, because one of the complications of ECT is bony injury caused by muscle. Particularly careful monitoring of neuromuscular transmission is indicated, and the shock should not be administered prior to loss of train-of-four response.

Emotional support

A course of ECT involves usually 5-10 applications over a 3-5-week period. Moreover, by the nature of the illness, patients are frequently depressed or withdrawn. Special efforts should be made to communicate with the patients and to reassure them. If at all possible, the same team (nurse and anaesthesiologist) should care for the patients at each treatment. Informed consent may be difficult to obtain because of the underlying disease. It is best sought in the presence of other family members.

Fasting status

Two problematic situations may exist in this area. Frequently patients are extremely dehydrated because of disinclination to eat. Pre-anaesthetic preparation may require intravenous infusion of 11 or more of dextrose and lactated Ringer's solution. Because patients on the psychiatric service are frequently unreliable, a careful check must be made that a fasting state has been maintained for 6 hours before induction of general anaesthesia. Also, patients are not uncommonly transferred from another location where health care workers are less familiar with the concept of aspiration and 'NPO' (fasting) requirements. Careful education is often required-- especially of the helpful attendant who wants, in a well-meaning fashion, to relieve the stress of the patient by sharing food or drink with him.

Dentition

Poor attention to physical well-being is often manifest by oral sepsis. Loose teeth should be identified and, if necessary, removed because the induced seizure may cause them to break loose under anaesthesia.

Preparation for ECT

These patients are often treated as outpatients either from home or during a

902 E .A.M. FROST

short transfer from a nearby psychiatric hospital. The usual pre-anaesthetic checklist prevails and includes the following:

1. Identification. 2. Consent. 3. Nothing orally during the preceding 6 hours. 4. Securing of personal items (jewellery, other valuables). Removal of

dentures may not be necessary if these are tightly secured within the mouth. Also it may not be necessary and may even be therapeutically detrimental to insist on undressing the patient.

5. History and physical, including notation of maintenance medications. 6. Basic laboratory tests: serum chemistries, Hb, white cell count,

urinalysis, ECG, and chest X-ray. These tests need not be repeated before every treatment if no new disease processes have developed.

ECT should be administered in a section of the PACU that can be curtained off to provide privacy and space for treatment and recovery. The necessary medications and equipment are listed in Table 4.

Table 4. Equipment and medication necessary for ECT.

Medication Equipment

Atropine 0.2 mg Thiopental 2-4 mg kg -1 Propofol 1-2 mg kg -1 Succinylcholine 1 mg kg 1 Lidocaine 1-2 mg kg -1 O2 supply Intravenous solutions Labetalol 5-10 mg kg -1

Anaesthetic machine or Ambu bag ECG Suction apparatus Sphygmomanometer Electrodes delivering shock Conductive paste Artificial airways Equipment for endotracheal intubation Intravenous cannulation equipment Pulse oximeter Quiet area

The patient is prepared in bed by monitoring blood pressure, electrocardiogram, and oxygen saturation. A peripheral vein is cannulated. After pre-oxygenation, a small dose of atropine (0.2mg) is given if it is not contraindicated by other medications. Thiopental (2-4 mg kg -1) or propofol (1-2mgkg -1) are given. Methohexital, reported to have a decreased incidence of dysrhythmias when compared to other induction agents may be used (Orko, 1976). Alternatively, etomidate has been associated with a longer duration of seizure which has been considered preferable by some psychiatrists (Gaines and Rees, 1986). Before injection of the short-acting muscle relaxant (usually succinylcholine) the blood pressure cuff is inflated to prevent flow of blood to one arm. Should frequent premature ventricular contractions develop, and in any case before propofol, lidocaine 1-2 mg kg- 1 is given. As soon as the patient loses consciousness, ventilation must be supported. A bite block is inserted in the mouth; electrodes coated with sufficient paste are applied bilaterally or unilaterally to the head and a single shock is administered. An attenuated seizure or downward toe movement

T H E P O S T - A N A E S T H E T I C CARE UNIT AS A SPECIAL P R O C E D U R E S UNIT 903

may be observed, which lasts 1 to 2 minutes. The seizure can usually be followed more accurately by observing the non-paralysed arm.

Hypertension and either bradycardia or tachycardia occur almost immediately after the treatment. These effects are usually transient (lasting 1-15 minutes) and rarely require treatment. The patient should be responsive and awake within 10 minutes.

Record keeping of the vital signs, amounts of medication given, and the shock strength is very important as individual variation is common. Appro- priate modification of drug dose can then be made during subsequent treatments. In particular, a severe hypertensive response may be modified by prior injection of labetalol 5 rag.

CARDIOVERSION

Cardioversion is a simple, safe, and usually effective means of converting cardiac dysrhythmias to sinus rhythm. The main indications, atrial flutter and fibrillation, are usually not life-threatening situations and may be treated electively. Other dysrhythmias that respond to cardioversion include ventricular tachycardia and ventricular fibrillation. These are emergency situations, usually caused by haemodynamic instability and adherence to basic advanced cardiac life support (ACLS) protocols usually suffices. Elective cardioversion is not infrequently performed in the PACU.

Because elective cardioversion is usually preceded by a trial of drug therapy, these patients are generally already in the hospital. The most frequent cause of the dysrhythmia is prior coronary artery bypass. Other cardiac diseases are common and a careful history must be obtained.

Patients with atrial fibrillation are frequently receiving anticoagulant medication both before and after cardioversion to avoid post-conversion embolization. Quinidine is often given to patients for at least 24 hours before therapy because approximately 10% of cases may be converted by this drug alone. Digitalis and [3-adrenergic blocking agents are generally discontinued on the day before cardioversion because overdose of these medications may make the procedure ineffective. Hypokalaemia must also be corrected.

Monitoring, supportive and resuscitative equipment should be available as described for ECT. Sedation for cardioversion is recommended as a means to attenuate anxiety and pain associated with the electric shock. Thiopental (2-3 mg kg -1) and methohexital (1-1.5 mg kg -1) are preferred over benzodiazepines because of the more intense effect and shorter duration of action (Orko, 1976). Etomidate myoclonus may preclude its use in cardioversion (Shulman and Edelman, 1988).

Before application, the paddles must be checked for formation of oxide on the surface, which may impede the delivery of adequate energy. Muscular contractions may be caused by cardioversion but are much less severe than during ECT. However, cases have been reported of torn spinous processes, and it is routine to use small doses (0.3-0.5 mg kg -1) of succinylcholine chloride and support ventilation. Deep general anaesthesia is not required if energies of 100 Ws -1 or less are employed. The duration of shock

904 E.A.M. FROST

is 2.5 ms, and pain is not generally severe. The unanaesthetized patient may complain of a sensation of touching an exposed electrical outlet. However , repeated conversion at higher output levels in apprehensive, elderly patients requires more sedation.

The paddles of the cardiovertor are applied over the precordium and on the patient's back (anterolateral positions require slightly higher energy outputs). Cardioversion can be successful only when adequate amounts of conductive paste are used, the paddles are far enough apart with no bridge of gel or sweat between them, and firm contact is applied.

Initial t reatment for dysrhythmias of recent onset should start with low- energy current (about 20 to 40 J). If the first discharge is not successful, successive shocks of 50-100 J, followed by increments of 100 Ws-1 are given until the dysrhythmia converts. Final discharge is 400 Ws -1.

Although slight, there is a risk of electrocution, and therefore the patient should not be touched when the shock is delivered. Complications and treatment of problems that may be related to cardioversion are listed in Table 5.

Table 5. Complications and treatment of problems related to or caused by cardioversion.

Precipitating f a c to r s Complication Therapy

Cardioversion A-V nodal dysrhythmias None--usually resolves spontaneously

Ventricular dysrhythmias Lidocaine 1-2mgkg-1; correct cause

Digitalis, quinidine, hypokalaemia, hypoventi- lation, metabolic acidosis

Multiple shocks

High energy levels Myocardial damage Inadequate gel application (Any of above)

Hypotension

Pulmonary oedema Burn injuries Cardiac arrest

Vasopressors, (norepinephrine, dopamine), cardiac pacing

Sedation, digitalis, diuretics Local treatment Closed chest massage; cardiac

pacing

DIAGNOSTIC NERVE BLOCKS

The PACU, because of the availability of a sterile environment and skilled monitoring, is a suitable area for performing many types of blocks. Some of the more common ones are listed in Table 6.

Epidural injection, either as a single shot or as a continuous technique through a catheter, affords excellent post-operative pain relief. It may also be used as a diagnostic tool to assess the effect of pharmacological (and therefore temporary) interruption of pain pathways before permanent surgical or chemical section. A marked sympatholytic effect, as evidenced by increase in temperature of the lower extremities, not only indicates the benefits of surgical sympathectomy in the ischaemic limb but ensures

THE POST-ANAESTHETIC CARE UNIT AS A SPECIAL PROCEDURES UNIT

Table 6. Blocks administered in the PACU.

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Block Indication

Epidural

Subarachnoid Intercostal nerves Brachial plexus

Stellate ganglion Coeliac plexus

Post-operative pain relief; sympatholytic effect; relief of reflex sympathetic dystrophy pain

Intractable pain; anaesthetic technique Post-operative pain relief; Herpes zoster Pre-operative--anaesthetic technique; severe

angina Sympatholytic effect; Raynaud's disease Chronic pain

maximal blood flow to reattached tissue. An epidural catheter may be placed pre-operatively and local anaesthesia infused both to reduce the amount of general anaesthesia required and establish a state of pre-emptive analgesia.

Subarachnoid block may be performed to relieve post-operative pain, as the anaesthetic technique or in the treatment of chronic cancer pain when alcohol in the subarachnoid space may be used to cause a chemical posterior rhizotomy.

Other techniques to relieve chronic pain include the use of cold, hypertonic saline injections into the subarachnoid space. Pain relief has also been reported after b arbotage of cerebrospinal fluid. Injection of local anaesthetic agent combined with steroids, such as methylprednisolone or dexa- methasone, may be effective in decreasing pain by an anti-inflammatory effect. Injection is made adjacent to the suspected site of the lesion.

Intercostal nerve blocks relieve the pain of rib fractures and provide analgesia after abdominal surgery and thus facilitate deep breathing and coughing. Because of overlapping of the distribution of nerves, three nerves must be injected to provide complete anaesthesia for one dermatome.

Upper extremity block may be achieved by injection to the brachial plexus by either the supraclavicular or axillary approach. Because this anaesthetic technique has a relatively slow onset of action (about 20 to 30 minutes until total blockade), the procedure may be performed in holding areas or in the PACU. Brachial plexus block has also been used successfully in the therapy of angina pectoris involving pain in the left arm.

Stellate ganglion block is used in the treatment of peripheral vascular disease. By abolishing sympathetic supply to the upper extremity, maximal vasodilation is achieved, which is advantageous for preserving blood supply in newly anastomosed vessels or in the treatment of Raynaud's disease.

Coeliac plexus block is used in the management of chronic pain from upper abdominal viscera (usually cancer pain). If control blocks indicate good effect, the plexus may be destroyed by injection of 25 ml of 50% alcohol. Many anaesthetists prefer to use fluoroscopy to facilitate accurate needle placement in this block.

Performing a nerve block must be considered an anaesthetic technique. Thus an intravenous route should be secure and standard monitoring applied. Other requirements include a well lit area, sterile field, block sets as indicated, and local anaesthetic solutions (usually lidocaine 0.5%;

906 E. A. M. FROST

Table 7. Reactions and complications after nerve blocks.

Local effects in the immediate area of the block

Systemic reaction affecting the body as a whole

Immediate Pain Haematoma Paraesthesia

Late Infection

Local anaesthetic action Cardiovascular collapse Seizures Allergic phenomenon Vasopressor action Hypertension Sweating Apprehension

tetracaine 1% or chloroprocaine 0.5%). Reactions and complications after blocks are rare and are listed in Table 7. As for other procedures, emergency and resuscitative equipment should be available.

True allergy is extremely rare and limited mainly to ester type of drugs, such as procaine. Cardiovascular collapse and respiratory dysfunction (especially bronchospasm) may occur. Therapy includes cardiorespiratory support, sedation, and vasopressor infusions (for example, neosynephrine 0.02% infusion, ephedrine 12.5mg) as indicated. More commonly, reactions result from overdose of added vasoconstrictor substances. Treatment includes administration of o~- and [3-adrenergic blocking drugs (such as phentolamine and propranolol), sedation, and reassurance.

BLOOD PATCHES

A complication of subarachnoid puncture, usually during labour analgesia, is headache. Although this symptom generally resolves with bed rest, analgesics, and adequate hydration, occasionally the pain is incapacitating. An epidural injection of normal saline (30-50 ml) or of the patient's own blood is often curative. A catheter is inserted in to the epidural at the point at which the subarachnoid puncture was performed, and fluid is injected s lowly until headache abates.

BLOOD TRANSFUSION

The PACU may be used as a convenient location to treat patients who require frequent and repeated blood transfusions. These patients are often debilitated with other severe medical problems, such as renal failure, metastatic carcinoma, leukaemia, and haemophilia. Requirements for blood transfusion include a warm, quiet area, basic monitoring equipmment, facilities for hand-washing, intravenous trays and blood

THE POST-ANAESTHETIC CARE UNIT AS A SPECIAL PROCEDURES UNIT 907

Table 8. Complications of blood transfusions.

Mechanical Disease transmission

Haemolytic transfusion reaction

Cardiac failure

B acteraemia

Allergic reactions

Hypothermia Hepatitis (serum, infectious) Malaria AIDS Syphilis Brucellosis Shivering Apprehension Hypotension Haemoglohinuria DIC Hypotension Tachycardia Pulmonary oedema Fever Chills Urticaria Flushing Tachycardia Fever Bronchospasm

warmers. A filtration set is required for blood administration but not for plasma.

Haemolytic reaction, an immediate complication of blood transfusiort, is caused by incompatibility between antibodies in the recipient's plasma and antigen contained in the donor erythrocytes (Table 8). The commonest causes include mistakes in typing, cross-matching, initial sampling, or unit administration. The haemolytic process may progress to disseminated intravascular coagulopathy (DIC). Signs and symptoms include fever, shivering, chills, apprehension, hypotension, tachycardia, and haemo- globinuria. Treatment is as follows?

1. Stop the transfusion; return the blood to the bank. 2. Document the symptoms. 3. Support the cardiovascular system; give fluids including protein and

hetastarch until compatible blood is available; administer vasopressors as necessary.

4. Monitor the blood and urine for free haemoglobin. 5. Give mannitol (0.5 mg kg -1 intravenously) and follow with furosemide

0.5 mg kg-1). 6. Monitor arterial blood gases. 7. Correct acidosis and hyperkalaemia. 8. Give steroids to modify the antigen-antibody reaction. 9. Give diphenhydramine (1 mg kg-1).

10. Perform a coagulation profile and follow hourly as indicated. Call for haematology consultation early.

9 0 8 2. A. M. FROST

If the blood is transfused too rapidly, especially if there is pre-existent cardiac disease, circulatory overload may develop. Drugs that improve cardiac function and allow the vascular system to better tolerate expansion include calcium chloride, dopamine, and digitalis preparations. Diuretics, such as furosemide may be necessary; occasionally ventilatory support is indicated.

Use of disposable equipment has essentially eliminated pyrogens. However, errors in technique of blood collection may result in contami- nation, especially with Gram-negative bacteria and their endotoxins. If septicaemia develops, the outcome is usually fatal despite vigorous therapy. Prevention includes adequate refrigeration, dating procedures, careful biological control, and discarding of opened bags.

PRE-OPERATIVE PLACEMENT OF INVASIVE MONITORING DEVICES

To improve efficient use of operating room time and space, pulmonary artery catheters and arterial cannulae may be placed in the PACU. Emotional support is necessary but general anaesthesia is usually not indicated. Requirements prior to placement include use of sterile techniques, cardiovascular monitoring, suitable transducers and other recording apparatus.

OTHER ISSUES

Procedures carried out in a PACU should be described and documented in the Policy and Procedure Manual for the area. As the PACU is usually under the jurisdiction of the Department of Anaesthesiology, cases should be scheduled with the anaesthesiologist.

All procedures require a signed and witnessed consent. While it is the responsibility of the surgeon and/or anaesthetist to obtain the consent, verification of this legal requirement is usually the responsibility of the PACU nurse.

SUMMARY

Scheduling of short, relatively non-sterile and minimally invasive procedures in the post-anaesthetic care unit is not only feasible but greatly increases the efficient use of the facility. Therapeutic manoeuvres that lend themselves to management in the PACU range from simple blood transfusion, to electroconvulsive therapy, placement of nerve blocks and invasive monitoring.

The equipment and staffing required and the mechanics of undertaking the different procedures are outlined in this chapter, together with complications, how to avoid them and how to treat them.

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R E F E R E N C E S

Axelrod J (1971) Noradrenaline: Fate and control of its biosynthesis. Science 173: 598-606. Baldessarine RJ (1984) Treatment of depression by altering monoamine metabolism:

precursors and metabolic inhibitors. Psychopharmacology Bulletin 20: 224-239. Barkai AI (1985) Combined electroconvulsive therapy and drug therapy. Comprehensive

Therapeutics 11: 48-53. Borden H, Clark M & Katz H (1974) Use of pancuronium bromide in patients on lithium

carbonate. Canadian Anaesthesia Society Journal 21: 79-82. Gaines GY & Rees DI (1986) Electroconvulsive therapy and anesthetic considerations.

Anesthesia and Analgesia 65: 1345-1356. Iversen LL (1974) Uptake mechanism forncurotransmitter amines. Biochemistry Pharmacology

23: 1927-1935. McPherson R & Lipsey J (1992) Electroconvulsive therapy. In Rodgers M (ed.) Current

Practice in Anesthesiology, 2nd edn, pp 180-185. Philadelphia: BC Decker. Nill GE, Wong RC & Hoges MR (1976) Potentiation of succinylcholine neuromuscular

blockade by lithium. Anesthesiology 44: 439-442. Orko R (1976) Anaesthesia for cardioversion; a comparison of diazepam, thiopentone and

propranidid. British Journal of Anaesthesia 48: 257-262. Selvin BL (1987) Electroconvulsive therapy--1987. Anesthesiology 67: 367-385. Shulman MS & Edelmann R (1988) Use of etomidate for elective cardioversion. Anesthesiology

68: 656. William RB & Shorter C (1971) Cardiac complications of tricyclic antidepressant therapy.

Annals of Internal Medicine 74: 395-398.

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The post-anaesthetic care unit as a special procedures unit