Clinical Problems in the Postanesthesia Recovery Room

(PACU)

Heidi Eriksson, MD, PhD

Helsinki University Central Hospital

Finland

Recovery room incidents: a review of 419 reports from the Anaesthetic Incident Monitoring Study (AIMS) Kluger and Bullock Anaesthesia 2002

• The Australian incident monitoring study (Anesthesia and Intensive Care 1993)

– incident reporting study

– voluntary, self-reporting audit of actua/potential incidents that occur during anesthesia

• 8372 reports , 478´(18%) in PACU

Recovery room incidents: a review of 419 reports from the Anaesthetic Incident Monitoring Study (AIMS)

• 92 % in adults

• 90 % during daytime hours

• 4 % at night

Kluger and Bullock. Anaesthesia 2002

Factors influencing stay in the postanesthesia care unit

• Patient history and age were not predictive!

• Postoperative pulmonary/airway problems

– desaturation, stridor, obstruction

• Postoperative cardiovascular problems

– hypo/hypertension, chest pain/ECG changes, pulmonary oedema/HF

• Length of surgery

• Unexplained - due to organizational factors ??

Seago J et al. J Clin Anaesth 1998

American Society of Anesthesiologists-Physical Status Classification(ASA-PS)

• is not an indicator of perioperative risk

– Perioperative risk

» preoperative medical status

» nature on the anesthetic technique

» nature of the surgical procedure

low risk- intermediate risk- high risk

• does not take into account

• age

• complexity of the operation

• is a measure of preoperative medical status

Preoperative assessment

General surgery 118 28 %Orthopedics 72 17 %Ear, nose and throat 42 10 %Opthalmology 33 8 %Gynecology 30 7 %Urology 28 7 %Vascular 25 6 %Dental and maxillofacial 14 3 %Plastic 12 3 %Cardiothoracic 12 3 %Obstetric 10 2 %Electroconvulsive 6 1 %Neurosurgery 5 1 %Pain block 2 0.5 %Radiology 1 0.2 %

Vascular access 1 0.2 %

Type of procedure & recovery room incidents reported to AIMS

Kluger and Bullock. Anaesthesia 2002

Cardiovascular 99 24 %Respiratory 97 25 %Airway 86 21 %Drug error 44 11 %CNS 32 8 %Equipment 27 6 %Communication problems 7 2 %Hypotermia 6 1 %Regional block problems 4 1 %Inadequate documentation 4 1 %Hyperthermia 3 1 %Trauma 3 1 %Dental problems 2 0.5 %Renal 1 0.2 %Skin 1 0.2 %Blood transfusion 1 0.2 %Facility limitations 1 0.2 %Gastrointestinal problems 1 0.2 %

Primary presenting problem & recovery room incidentsreported to AIMS

Kluger and Bullock. Anaesthesia 2002

Pulmonary oedema 29 7 %Hypotension 26 6 %Cardiac arrest 20 5 %Bradycardia 7 2 %Myocardial ischemia 7 2 %Tachycardia 4 1 %Bleeding 2 0.5 %Hypertension 2 0.5 %Allergy 1 0.2 %Radial artery ischemia 1 0.2 %

Presenting problem in 99 cardiovascular incidents out of 419 PACU incidents reported to AIMS

Kluger and Bullock. Anaesthesia 2002

Hypotension in PACUQuick assessment

• decreased ventricular preload

– hypovolaemia

– postoperative bleeding

• reduced myocardial contractility

– myocardial ischemia

– congestive heart failure

• reduction of systemic vascular resistance

– septicaemia

– regional anesthesia/analgesia

– anaphylaxis

Hypertension in PACUQuick assessment

• pain• hypoxia• hypercapnia• anxiety/agitation

• fluid overload– developing pulmonary oedema

• urinary retention

• untreated hypertension

Heart rhytm abnormalities in PACUQuick assessment

• pain

• hypoxia

• hypercapnia

• hypovolaemia/hypervolaemia

• electrolyte inbalance

• metabolic acidosis

• pre-existing heart disease

• myocardial ischemia

Respiratory failure: inadequate oxygenation/ventilation 74 18 %

Aspiraton 7 2 %

Respiratory arrest 6 1 %

Bronchospasm 5 1 %

Pneumothorax 5 1 %

Presenting problem in 97 respiratory incidents out of 419 PACU incidents reported to AIMS

Kluger and Bullock. Anaesthesia 2002

Airway obstruction 59 14 %

Laryngospasm 18 4 %

Jaw dislocation 2 0.5 %

Foreign body (throat pack) 2 0.5 %

Failed extubation 1 0.2 %

Endobronchial intubation 1 0.2 %

Presenting problem in 97 airway incidents out of 419 PACU incidents reported to AIMS

Kluger and Bullock. Anaesthesia 2002

Desaturation in PACUQuick assessment

• airway obstruction

• laryngeal spasm

• bronchospasm

• hypoventilation

• obesity

• perfusion-ventilation

– atelectasis

– pulmonary oedema

– pneumothorax

– pulmonary embolism

– aspiration

• pain

Hypoventilation in PACUQuick assessment

• oversedation

– residual anesthetic

• opioids

– parenteral

– epidural/intrathecal

Wheezing in PACUQuick assessment

• laryngeal spasm (stridor)

– after thyroid operation

• bleeding

• paresis of n recurrens

• bronchospasm

– asthma

– bronchial hyper-responsivess (smoking, postviral)

– pulmonary oedema

– aspiration

– anaphylaxis

But does residual neuromuscular block put our patients in danger?

• Muscle function and coordination of protective reflexes of the pharynx and upper esofagus recover late

– Eriksson L et al. Anesthesiology 1997

• Ventilatory response to hypoxia is reduced (direct inhibition of chemoreceptor activity in the carotic bodies)

– Eriksson L et al. Anesthesiology 1993, Wyon N et al Anesthesiology 1999

• Volunteers– Difficulty in maintaining airway – Desaturation and need for supplemental oxygen – Disability to swallow – Distress

• PACU time prolonged– Murphy et al. Anesth Analg 2004

Eikerman et al. Anestehsiology 2003Kopman A et al. Anesthesiology 1997Bissinger et al. Physiol Res 2000

Residual neuromuscular block is a risk factor for postoperative pulmonary complications: A prospective, randomised, and blinded study of postoperative pulmonary complications after atracurium, vecuronium and pancuroniumBerg et al. Acta Anaesthesiol Scand 1997

• Manual TOF during operation

• TOF 1-2/4

• Reversal when 2-4/4

• Extubation when 4/4

• Mechanomyographically postoperatively

• Follow-up up to 6 PODs

• Postoperative pulmonary complication : pneumonic infiltration/atelectasis in X-ray

TOF recordings at first postoperative mechanomyographic recording

Berg et al. Acta Anaesthesiol Scand 1997

Postoperative pulmonary complications

Berg et al. Acta Anaesthesiol Scand 1997

Type of surgery and the risk of pulmonary complications

Berg et al. Acta Anaesthesiol Scand 1997

Probability of postoperative pulmonary complications

Multiple logistic regression analysis relating the probability of POPC to various covariates

Berg et al. Acta Anaesthesiol Scand 1997

Residual paralysis in the PACU after single intubating dose of nondepolarizing muscle relaxant with an intermediate duration of action Debaene et al Anesthesiology 2003

• 526 patients

• 2ED95 dose of vecuronium, rocuronium, or atracurium

• No muscle relaxant thereafter

• Excluded, if reversal used

• Time delay between the injection of muscle relaxant and quantitative measurement of neuromuscular blockade assessed

Bedaene et al. Anesthesiology 2003

• Conclusion: A long duration between the administration of a single dose of an internediate-acting nondepolarizing muscle relaxant and the arrival to PACU does not guarantee the lack of residual paralysis

• Note! – hypothermia,– halogenated anesthesia agents

Residual neuromuscular block

Widely used tests to assess recovery from neuromuscular block

• Train-of-four ratio > 0.7 / 0.9 by peripheral nerve stimulation

• Reliable clinical tests of postoperative neuromuscular recovery• Sustained head lift fot 5s• Sustained leg lift fot 5 s• Sustained hand grip for 5 s• Sustained tongue depressor test• Maximun ispiratory presuure >-50 cm H20

However,

poor sensitivity

do not secure against residual block !Pedersen et al. Anesthesiology 1990Shorten et al. Can J Anaesth 1995Fruergaard et al. Acta Anaesthesiol Scand 1998Bedaene et al. Anesthesiology 2003

Residual neuromuscular block

• Significant residual block can be excluded only by objective, methods

• mechanomyography

• electromyography

• acceleromyography

• ”It is time to move from discussion to action and introduce objective neuromuscular monitoring to all ORs. I believe that objective neuromuscular monitoring is an evidence-based practice and should consequently be used whenever a nondepolarizing neuromuscular blocking agent is administered”

Eriksson L. Evidence-based practise and neuromuscularmonitoring. It,s time for routine quantitative assessment.Anesthesiology 2003

”The ideal world is one thing, and the real world another!”

Viby-Mogensen. Postoperative residual curarizationand evidence-based anaesthesia. BJA 2000

How to avoid residual neuromuscular block? (I)

• Long acting neuronuscular blocking agents should not be used

• Antagonize the block at the end of the procedure• Reversal initiated only when (2-)3-4/4 TOF stimulations present or when

spontaneous muscle activity is present• Prefer tactile evaluation of response to double-burst stimulation (DBS) to

TOF stimulation

• Consider clinical signs and symptoms in relation to the response to nerve stimulation

• Keep in mind the additive/prolonged effects caused by anesthetics and hypothermia

Viby-Mogensen. Postoperative residual curarization and evidence-based anaesthesia. BJA 2000

How to avoid residual neuromuscular block? (II)

• Every operating room and PACU should have an apparatus for assessing neoromuscular blockade ( and know how to use it !)

• TOF, preferably quantitative, monitoring of the neuromuscular block is mandatory if antagonists are not used!!

• TOF >0.9 the new ”gold standard” for full recovery

Viby-Mogensen. Postoperative residual curarizationand evidence-based anaesthesia. BJA 2000

Postoperative pain

• a complication itself ?

• aggressive pain prophylaxis in all patients

Note!

• pain must be in proportion to the operative procedure performed

– operative/postoperative complication in development

– tolerance to opioids

Postoperative pain

• discomfort• agitation• PONV• sympathetic activation

– cardiovascular complications• hypertension

– surgical bleeding

• immobilisation– deep vein thrombosis– pulmonary dysfunction

• chronic postsurgical pain

Opioid related side effects

• PONV

• drowsiness

• respiratory depression

• dysphoria/agitation

• gastrointestinal and bladder dysfunction

Balanced or multimodal analgesia

• Non-steroidal anti-inflammatory analgesics (NSAIDs)

• Paracetamol

• Local anesthetics

– wound infiltration /neural blockade

– liposome local anesthetics in the future?

• Combined with

– PCA

– Epidural

Cyclooxygenase-2 inhibitors in postoperative pain management. Currest evidence and future directionsGilron et al. Anesthesiology 2003

Efficacy of postoperative epidural analgesia. A meta analysisBlock et al JAMA 2003

• 1404 articles in PubMed reviewed of which 1304 rejected

– Inclusion criteria

• randomization

• epidural analgesia versus parenteral opioids in adults

• VAS/Numeric rating

Efficacy of postoperative epidural analgesia ; pain at rest

Block et al. JAMA 2003

Efficacy of postoperative epidural analgesia; incident pain

Block et al. JAMA 2003

Efficacy of postoperative epidural analgesia; VAS recordings

Block et al. JAMA 2003

Conclusion: Epidural analgesia (other than TEA with opioids only) provides better postoperative analgesia to parenteral opioid

Efficacy of postoperative epidural analgesia; complications

Block et al. JAMA 2003

The ”Little big problem of anesthesia”Postoperative nausea and vomiting (PONV)

• Patient-specific risk factors– Female sex IA

– Nonsmoking status IVA

– History of PONV/Motion sickness IVA

• Anesthetic risk factors– Use of volatile anesthetics IA

– Nitrous oxide IIA

– Use of intraoperative IIA and postoperative opioids IVA

• Surgical risk factors– Duration of surgery IVA

– Type of surgery (laparoscopy, ear-nose-throat, neurosurgery, breast, strabismus, laparotomy, plastic IVB

Consensus guidelines for managing postoperative nausea and vomitingGan et al. Anesth Analg 2003

Postoperative nausea and vomiting (PONV)Keep the baseline risk low !

• Regional anesthesia IIIA

• Propofol for induction and maintenence IA

• Intraoperative supplemental oxygen IIIB

• Adequate hydration IIIA

• Avoid nitrous oxide IIA

• Avoid volatile anesthetics IA

• Minimize intraoperative IIA and postoperative IVA opioids

• Minimization of neostigmine IIA

Gan et al. Anesth Analg 2003

Algorithm for prevention of PONV

Gan et al. Anesth Analg 2003

Multimodal or balancedantiemetic strategy

Prophylaxis of PONVAntiemetic doses and timing in adults

Gan et al. Anesth Analg 2003

Treatment of PONV in PACU

Gan et al. Anesth Analg 2003

Perioperative mild hypothermia (34-35C);Complications

Sessler.Perioperative hypothermia. NEJM 1997

Perioperative maintenance of normothermia reduces the incidence of morbid cardiac events: A randomized clinical trial. Frank et al. JAMA 1997

Perioperative hypothermia and PACU

• cardiovascular complications– symphathetic overactivity– norepinephrine

• coagulapathy– platelet function– clotting factor enzyme function– fibrinolytic activity

• shivering– increased total-body oxygen consumption– patient discomfort

• residual neuromuscular blockade– respiratory complications– aspiration

• prolongation of PACU stay

Perioperative hypothermia

First stage

• internal transfer of core heat to periphery i.e., internal redistribution

Second stage

• drop in core temperature as the result of heat losses

– cutaneous,

– exposure of viscera

– cold solutions

Third stage

• cutaneous vasocontriction

• core temperature remains almost stable but the heat content of the limbs continues to fall

• Mild hypothermia 34-35 C Sessler Anesthesiology 2001

Perioperative mild hypothermiaDelay in recovery

Lenhard et al.Mild intraoperative hypothermia prolongs postoperative recivery Anesthesiology 2001

Postanesthesia shivering

• Involuntary movement that may affect one/several muscle groups and generally occurs in the early recovery phase after general anesthesia

• Thermoregulatory shivering

– associated with cutaneous vasoconstriction

– physiological response to hypothermia

• Non-thermoregulatory shivering

• Overall incidence 6-66%

Risk factors for postanesthesia shivering

• Young adult

• Long surgery & anesthesia

• Drop in body temperature

• No active perioperative rewarming

• Anesthetic used

– Halogenated agents +

– Thiopental +

– Propofol -

• Little opioids perioperatively

• Postoperative pain

Hypothermia and shivering in PACU

• Use forced-air blankets and warmed iv solutions

• Consider rewarming the patient before extubation

– Temperature monitoring

• Beware of altered pharmacokinetics

– monitor (and antagonize) residual neuromuscular blockade

– extubate when awake ! Increased risk of aspiration

• Treat postoperative pain promptly!

Alfonsi. Postanesthetic shivering. Systematic review. Drugs 2001

Postanesthesia shivering: Medical treatment

Alfonsi. Postanesthetic shivering. Systematic review. Drugs 2001

Meperidine 0.4-0.85 mg/kg i.v.Tramadol 1-2 mg/kg i.v.Mg-sulphate 30 mg/kg i.v.(Clonidine 0.3g/kg i.v)

Postoperative agitation

• Hypoxia• Hypercapnia

• Pain

• Distension of the stomach• Urinary retention

• Apprehension about the findings at operation or fear of pain

• (Intraoperative awareness)

• (Neurological sequalae)

Inapproriate drug 17 4 %

Overdosage 14 3 %

Inadequate drug/dosage 6 1 %

Misconnection/wrong route 3 1 %

Side-effect 2 0.5 %

Withdrawal 1 0.2 %

Allergy 1 0.2 %

Drug error related incidents out of 419 PACU incidents reported to AIMS

Kluger and Bullock. Anaesthesia 2002

Discharge criteria from the PACUThe Association of Finnish Anaesthesiologists 1999

• conscious

• can secure his/her airway

– protective reflexes recovered

• ventilation and oxygen saturation adequate

• stable hemodynamics (heart rate, blood pressure)

• normothermia

• pain and PONV in adequate control

• motor block wearimg off (spinal, epidural)

• no surgical reasons requiring longer follow-up

• a plan for analgesics, antiemetics and intravenous fluids provided

Aldrete Score

Surgical ward

PACU

Operation RoomOR

Preoperative clinic

High Dependency Unit HD

Intensive Care Unit ICU

PACUSafetyComfort

PACUSafetyComfort