POST ANAESTHESIA CARE (RECOVERY).
Final Objective: On completion of this module you will be able to guarantee the safe recovery of your patient after anaesthesia.
Enabling Objective: To achieve this goal, you should know how to:
Reference Reading:
Recovery from anaesthesia is the time from the end of surgery to when the patient is alert and physiologically stable. The anaesthetist is ultimately responsible for the care of the patient during this period. For the majority of patients, recovery from anaesthesia is uneventful however when postoperative complications occur, they may be sudden and life threatening.
The post anaesthetic care unit (PACU) or recovery must be in close proximity to the operating rooms, have dedicated staff, appropriate monitoring and the drugs and equipment for routine and emergency care. All patients recovering from anaesthesia should be nursed in a PACU. All patients will benefit from supplemental oxygen. No patient should be left alone after anaesthesia.
The main functions of the PACU are:
PACU.
The recovery area must have a sufficient number of trolley spaces for the expected peak demand (at least 1.5 spaces/trolleys per operating room). Each space should be of adequate area with easy access to the patient’s head.
Each bed space should be provided with an oxygen outlet, oxygen flow meter and patient oxygen delivery systems, pulse oximeter, blood pressure monitor, stethoscope, medical suction, power outlets and lighting.
The PACU should have an emergency call system to contact anaesthetists. Within the recovery area there must be means for manual ventilation with oxygen (minimum of two devices), equipment and drugs for airway management and endotracheal intubation, emergency and other drugs, a range of intravenous equipment and fluids, drugs for acute pain management, needles and syringes, patient warming devices, temperature monitor and devices to measure expired carbon dioxide.
There should be easy access to a 12 lead electrocardiograph, defibrillator, chest drains, basic surgical tray, diagnostic imaging services and diagnostic blood testing and emergency management protocols.
The recovery trolley must have a firm base and mattress, tilt at least 15 degrees, be easy to manoeuvre, have brakes, provide for sitting a patient up and have secure side rails.
Staff specially trained in the care of patients recovering from anaesthesia must be present at all times. Trainee nurses and registered nurses who are not experienced in the care of patients recovering from anaesthesia must be supervised. There should be no less than one nurse to three patients, and one nurse to each patient who has not recovered protective airway reflexes or consciousness.
A written routine for checking the equipment and drugs must be established. When an anaesthetised patient is being transferred from one trolley to another, a minimum of three people must assist with lifting. An anaesthetist must be present to have prime responsibility for the patient’s head, neck and airway.
A designated anaesthetist should be contactable. Observations should be recorded at appropriate intervals and should include state of consciousness, oxygen saturation, respiratory rate, pulse rate, blood pressure and temperature.
The length of time any patient spends in recovery will depend upon a variety of factors including the duration and type of surgery, anaesthetic technique, pre-existing disease and the occurrence of any complications. Most units have a policy determining the minimum length of stay which is usually about 30 minutes. All patients should remain until they are considered safe to be discharged from the recovery area according to established discharge criteria.
The anaesthetist responsible for the patient should accompany the patient until transfer to the recovery area staff is completed, provide written and verbal instructions to the recovery area staff, specify the type of apparatus and the flow rate to be used for oxygen therapy, remain in the vicinity until the patient is safe to be left in the care of recovery area staff and supervise the recovery period and authorise the patient’s discharge from the recovery area.
Transport.
Patients should be transported from the operating theatre to recovery by the anaesthetist with the patient on their side to reduce the risk of aspiration. Oxygen delivered by facemask is indicated in most patients to prevent hypoxia due to hypoventilation or diffusion hypoxia.
Admission to PACU.
The anaesthetist must “hand over” the patient to the nurse who will care for the patient in the PACU. Patients must not be left without providing a full report. This report includes the patient identification, age, operation, diagnosis, a summary of previous medical and surgical history, allergies, preoperative vital signs, anaesthetic technique with emphasis on problems that may affect the immediate postoperative care, intraoperative medications (especially analgesia and anti-emetics) and PACU instructions (analgesia, anti-emetics, intravenous fluids and oxygen).
The anaesthetist should wait until the first set of vital signs is done before leaving the patient.
Monitoring.
Close observation of the patient’s respiratory, cardiovascular and conscious state is most important. Observations should be performed and recorded at least every five or ten minutes. Unconscious patients must have constant observation until awake. Standard monitoring includes respiratory rate, depth and character of respiration, oxygen saturation, pulse rate and rhythm, blood pressure, bleeding (drain tubes, drain bottles and dressings), conscious state, sedation score, pain score, urine output and temperature.
Discharge criteria.
Patients must not be returned to the ward until it is safe to do so. To decide when a patient has recovered enough, many PACU use a scoring system like the “Aldrete” scoring system that was first described in 1970. This system assigns a score of 0, 1, or 2 to activity, respiration, circulation, consciousness and colour or oxygen saturation, giving a maximal score of 10. A score of 9 or more indicates that the patient can be safely transferred to the ward.
Activity: able to move voluntarily or on command
4 limbs 2
2 limbs 1
0 limbs 0
Respiration
Able to deep breathe and cough freely 2
Shallow or limited breathing 1
Apnoea 0
Circulation
BP +/- 20 mmHg of pre-anaesthetic level 2
BP +/- 20-50 mmHg of pre-anaesthetic level 1
BP +/- 50 mmHg of pre-anaesthetic level 0
Consciousness
Fully awake 2
Wakes to voice 1
Unconscious 0
Oxygen saturation
> 92% on room air 2
Needs oxygen to maintain > 90% 1
Oxygen saturation < 90% even with oxygen 0
(Modified Aldrete Score)
Patients must also be warm, have adequate pain relief (pain score of 3 or less), nausea and vomiting must be treated and there must be no obvious surgical complication (e.g bleeding).
PACU Complications.
The incidence of PACU complications has been estimated to occur in 5% of all PACU admissions. Most PACU problems involve the respiratory system, cardiovascular system, delayed return of consciousness, inadequate analgesia and nausea and vomiting. All these problems should be anticipated.
The most important monitor is a well-trained person with immediate access to the help of an anaesthetist. With all complications first ensure that the patient has adequate oxygenation and ventilation.
Haemodynamic complications occur in 1% of all PACU admissions and include hypotension, hypertension, dysrhythmias and myocardial ischaemia and infarction.
Hypotension is the commonest cardiovascular complication occurring in the postoperative period. It can be due to a variety of factors, alone or in combination including hypovolaemia, reduced myocardial contractility, vasodilation and cardiac dysrhythmias.
Management includes administering 100% oxygen, elevating the legs to increase venous return, administering 10-20ml/kg boluses of intravenous fluid and controlling external surgical bleeding by direct pressure. Blood loss of greater than 30% of the circulating blood volume will usually require the administration of cross-matched blood.
Respiratory complications occur in 2% of all PACU admissions and include inadequate oxygenation and/or ventilation, upper airway obstruction, laryngospasm and aspiration. General anaesthesia has several physiological effects that continue into the recovery period. Hypoxaemia is traditionally recognized by the observation of cyanosis, but cyanosis is only detected when arterial pO2 is less than 55mmHg, an oxygen saturation of 85%. The pulse oximeter allows early detection and prevention of hypoxaemia and should always be used if available. All patients will benefit from oxygen by facemask. Oxygen will prevent diffusion hypoxia when nitrous oxide has been used, compensate for hypoventilation and V/Q mismatch and meet any increased oxygen demand post surgery (for example hypothermia and shivering).
Hypoxia must always be excluded before giving a sedative to calm a patient in PACU. Sedatives (e.g diazepam) are rarely needed in PACU.
Airway obstruction should be prevented by recovering all patients in the lateral position, especially those at increased risk (obese, obstructive sleep apnoea, oral surgery and at risk of regurgitation). If upper airway obstruction occurs it must be immediately treated. Patients will have inadequate air movement, intercostal and suprasternal retraction and abnormal abdominal movement and may have noisy breathing. Complete upper airway obstruction is silent.
While 100% oxygen is given, a simple chin lift with a jaw thrust may be all that is required to relieve the obstruction. An oropharyngeal or nasopharyngeal airway may be needed to maintain an unobstructed airway.
Central nervous system complications include delayed awakening, emergence delirium, awareness and central and peripheral neurological damage.
The most frequent cause of delayed awakening is persistent effects of anaesthetics. Less common but potentially life threatening causes includes hypoxia, decreased cerebral perfusion, hypothermia, hypoglycaemia, sepsis, hyponatraemia and other electrolyte, and acid base disturbances.
Patients with emergence delirium show periods of excitement alternating with lethargy, disorientation and inappropriate behaviour. Delirium is more common in the elderly and those with a history of drug dependency, dementia or other psychiatric disorders. Delirium may also be a symptom of hypoxaemia, hypoglycaemia, hyponatraemia, alcohol withdrawal or intracranial injury.
The management of pain and nausea begins in theatre and continues in PACU.
PROTOCOL FOR POSTOPERATIVE NAUSEA & VOMITING (PONV)
Remember:
4 mg of ondansetron (or a similar serotonin antagonist), 4 mg of dexamethasone (after induction of anaesthesia), 1.25 mg of droperidol and total intravenous anaesthesia all reduce the relative risk of PONV to a similar extent (approximately 26 percent). These interventions all act independently of one another. An antiemetic that has not been used prophylactically should be chosen for the treatment of PONV.
SELF-ASSESSMENT QUESTIONS
ASSIGNMENT
Discuss the management of pain and nausea and vomiting in the PACU.
PACU CASE STUDIES
Case No 8.1
Odgerel has severe vomiting in recovery after an appendicectomy.
What are the risk factors for postoperative nausea and vomiting?
What are the potential adverse effects of severe vomiting after surgery?
How could you treat the vomiting?
Case No 8.2
Your pre-eclamptic obstetric patient has had a general anaesthetic for a caesarean section. She now fails to awaken from the general anaesthetic.
What are the possible causes of her delayed awakening?
How would you manage her?
Case No 8.3
After a two-hour operation for an open cholecystectomy your patient’s blood pressure is 180/120 in the PACU.
What are the likely causes of hypertension in PACU?
After other causes for the hypertension are excluded, what drugs could be used to treat the hypertension?
Final Objective: On completion of this module you will be able to guarantee the safe recovery of your patient after anaesthesia.
Enabling Objective: To achieve this goal, you should know how to:
- Describe the changes of normal physiology that may occur in the immediate post-anaesthetic period (with special emphasis on the airway, respiration and circulation).
- Outline a plan of management for patients during the post-anaesthetic period.
- Outline the causes and management of common recovery room problems.
- Develop discharge criteria for patients in the recovery room.
Reference Reading:
- Developing Anaesthesia Chapters 39 & 40
- Oxford handbook of anaesthesia chapter 40
Recovery from anaesthesia is the time from the end of surgery to when the patient is alert and physiologically stable. The anaesthetist is ultimately responsible for the care of the patient during this period. For the majority of patients, recovery from anaesthesia is uneventful however when postoperative complications occur, they may be sudden and life threatening.
The post anaesthetic care unit (PACU) or recovery must be in close proximity to the operating rooms, have dedicated staff, appropriate monitoring and the drugs and equipment for routine and emergency care. All patients recovering from anaesthesia should be nursed in a PACU. All patients will benefit from supplemental oxygen. No patient should be left alone after anaesthesia.
The main functions of the PACU are:
- Monitor the patient’s vital signs more closely than is possible on the ward
- Optimise the patient’s analgesia and treat postoperative nausea and vomiting
- Quickly detect and treat early complications after surgery and anaesthesia.
PACU.
The recovery area must have a sufficient number of trolley spaces for the expected peak demand (at least 1.5 spaces/trolleys per operating room). Each space should be of adequate area with easy access to the patient’s head.
Each bed space should be provided with an oxygen outlet, oxygen flow meter and patient oxygen delivery systems, pulse oximeter, blood pressure monitor, stethoscope, medical suction, power outlets and lighting.
The PACU should have an emergency call system to contact anaesthetists. Within the recovery area there must be means for manual ventilation with oxygen (minimum of two devices), equipment and drugs for airway management and endotracheal intubation, emergency and other drugs, a range of intravenous equipment and fluids, drugs for acute pain management, needles and syringes, patient warming devices, temperature monitor and devices to measure expired carbon dioxide.
There should be easy access to a 12 lead electrocardiograph, defibrillator, chest drains, basic surgical tray, diagnostic imaging services and diagnostic blood testing and emergency management protocols.
The recovery trolley must have a firm base and mattress, tilt at least 15 degrees, be easy to manoeuvre, have brakes, provide for sitting a patient up and have secure side rails.
Staff specially trained in the care of patients recovering from anaesthesia must be present at all times. Trainee nurses and registered nurses who are not experienced in the care of patients recovering from anaesthesia must be supervised. There should be no less than one nurse to three patients, and one nurse to each patient who has not recovered protective airway reflexes or consciousness.
A written routine for checking the equipment and drugs must be established. When an anaesthetised patient is being transferred from one trolley to another, a minimum of three people must assist with lifting. An anaesthetist must be present to have prime responsibility for the patient’s head, neck and airway.
A designated anaesthetist should be contactable. Observations should be recorded at appropriate intervals and should include state of consciousness, oxygen saturation, respiratory rate, pulse rate, blood pressure and temperature.
The length of time any patient spends in recovery will depend upon a variety of factors including the duration and type of surgery, anaesthetic technique, pre-existing disease and the occurrence of any complications. Most units have a policy determining the minimum length of stay which is usually about 30 minutes. All patients should remain until they are considered safe to be discharged from the recovery area according to established discharge criteria.
The anaesthetist responsible for the patient should accompany the patient until transfer to the recovery area staff is completed, provide written and verbal instructions to the recovery area staff, specify the type of apparatus and the flow rate to be used for oxygen therapy, remain in the vicinity until the patient is safe to be left in the care of recovery area staff and supervise the recovery period and authorise the patient’s discharge from the recovery area.
Transport.
Patients should be transported from the operating theatre to recovery by the anaesthetist with the patient on their side to reduce the risk of aspiration. Oxygen delivered by facemask is indicated in most patients to prevent hypoxia due to hypoventilation or diffusion hypoxia.
Admission to PACU.
The anaesthetist must “hand over” the patient to the nurse who will care for the patient in the PACU. Patients must not be left without providing a full report. This report includes the patient identification, age, operation, diagnosis, a summary of previous medical and surgical history, allergies, preoperative vital signs, anaesthetic technique with emphasis on problems that may affect the immediate postoperative care, intraoperative medications (especially analgesia and anti-emetics) and PACU instructions (analgesia, anti-emetics, intravenous fluids and oxygen).
The anaesthetist should wait until the first set of vital signs is done before leaving the patient.
Monitoring.
Close observation of the patient’s respiratory, cardiovascular and conscious state is most important. Observations should be performed and recorded at least every five or ten minutes. Unconscious patients must have constant observation until awake. Standard monitoring includes respiratory rate, depth and character of respiration, oxygen saturation, pulse rate and rhythm, blood pressure, bleeding (drain tubes, drain bottles and dressings), conscious state, sedation score, pain score, urine output and temperature.
Discharge criteria.
Patients must not be returned to the ward until it is safe to do so. To decide when a patient has recovered enough, many PACU use a scoring system like the “Aldrete” scoring system that was first described in 1970. This system assigns a score of 0, 1, or 2 to activity, respiration, circulation, consciousness and colour or oxygen saturation, giving a maximal score of 10. A score of 9 or more indicates that the patient can be safely transferred to the ward.
Activity: able to move voluntarily or on command
4 limbs 2
2 limbs 1
0 limbs 0
Respiration
Able to deep breathe and cough freely 2
Shallow or limited breathing 1
Apnoea 0
Circulation
BP +/- 20 mmHg of pre-anaesthetic level 2
BP +/- 20-50 mmHg of pre-anaesthetic level 1
BP +/- 50 mmHg of pre-anaesthetic level 0
Consciousness
Fully awake 2
Wakes to voice 1
Unconscious 0
Oxygen saturation
> 92% on room air 2
Needs oxygen to maintain > 90% 1
Oxygen saturation < 90% even with oxygen 0
(Modified Aldrete Score)
Patients must also be warm, have adequate pain relief (pain score of 3 or less), nausea and vomiting must be treated and there must be no obvious surgical complication (e.g bleeding).
PACU Complications.
The incidence of PACU complications has been estimated to occur in 5% of all PACU admissions. Most PACU problems involve the respiratory system, cardiovascular system, delayed return of consciousness, inadequate analgesia and nausea and vomiting. All these problems should be anticipated.
The most important monitor is a well-trained person with immediate access to the help of an anaesthetist. With all complications first ensure that the patient has adequate oxygenation and ventilation.
Haemodynamic complications occur in 1% of all PACU admissions and include hypotension, hypertension, dysrhythmias and myocardial ischaemia and infarction.
Hypotension is the commonest cardiovascular complication occurring in the postoperative period. It can be due to a variety of factors, alone or in combination including hypovolaemia, reduced myocardial contractility, vasodilation and cardiac dysrhythmias.
Management includes administering 100% oxygen, elevating the legs to increase venous return, administering 10-20ml/kg boluses of intravenous fluid and controlling external surgical bleeding by direct pressure. Blood loss of greater than 30% of the circulating blood volume will usually require the administration of cross-matched blood.
Respiratory complications occur in 2% of all PACU admissions and include inadequate oxygenation and/or ventilation, upper airway obstruction, laryngospasm and aspiration. General anaesthesia has several physiological effects that continue into the recovery period. Hypoxaemia is traditionally recognized by the observation of cyanosis, but cyanosis is only detected when arterial pO2 is less than 55mmHg, an oxygen saturation of 85%. The pulse oximeter allows early detection and prevention of hypoxaemia and should always be used if available. All patients will benefit from oxygen by facemask. Oxygen will prevent diffusion hypoxia when nitrous oxide has been used, compensate for hypoventilation and V/Q mismatch and meet any increased oxygen demand post surgery (for example hypothermia and shivering).
Hypoxia must always be excluded before giving a sedative to calm a patient in PACU. Sedatives (e.g diazepam) are rarely needed in PACU.
Airway obstruction should be prevented by recovering all patients in the lateral position, especially those at increased risk (obese, obstructive sleep apnoea, oral surgery and at risk of regurgitation). If upper airway obstruction occurs it must be immediately treated. Patients will have inadequate air movement, intercostal and suprasternal retraction and abnormal abdominal movement and may have noisy breathing. Complete upper airway obstruction is silent.
While 100% oxygen is given, a simple chin lift with a jaw thrust may be all that is required to relieve the obstruction. An oropharyngeal or nasopharyngeal airway may be needed to maintain an unobstructed airway.
Central nervous system complications include delayed awakening, emergence delirium, awareness and central and peripheral neurological damage.
The most frequent cause of delayed awakening is persistent effects of anaesthetics. Less common but potentially life threatening causes includes hypoxia, decreased cerebral perfusion, hypothermia, hypoglycaemia, sepsis, hyponatraemia and other electrolyte, and acid base disturbances.
Patients with emergence delirium show periods of excitement alternating with lethargy, disorientation and inappropriate behaviour. Delirium is more common in the elderly and those with a history of drug dependency, dementia or other psychiatric disorders. Delirium may also be a symptom of hypoxaemia, hypoglycaemia, hyponatraemia, alcohol withdrawal or intracranial injury.
The management of pain and nausea begins in theatre and continues in PACU.
PROTOCOL FOR POSTOPERATIVE NAUSEA & VOMITING (PONV)
Remember:
- Volume
- Oxygen
- Medication (dexamethasone, droperidol, 5HT3 antagonist, metoclopramide)
- Iatrogenic (stop all drugs or procedures causing PONV)
- Treat pain
4 mg of ondansetron (or a similar serotonin antagonist), 4 mg of dexamethasone (after induction of anaesthesia), 1.25 mg of droperidol and total intravenous anaesthesia all reduce the relative risk of PONV to a similar extent (approximately 26 percent). These interventions all act independently of one another. An antiemetic that has not been used prophylactically should be chosen for the treatment of PONV.
SELF-ASSESSMENT QUESTIONS
- List the causes of hypotension in PACU. How would you decide the cause of the hypotension and how can the hypotension be treated?
- List the common dysrhythmias in PACU. How are they treated?
- What are the causes of hypoxaemia in recovery? What are the causes of hypoventilation?
- How do you manage upper airway obstruction?
ASSIGNMENT
Discuss the management of pain and nausea and vomiting in the PACU.
PACU CASE STUDIES
Case No 8.1
Odgerel has severe vomiting in recovery after an appendicectomy.
What are the risk factors for postoperative nausea and vomiting?
What are the potential adverse effects of severe vomiting after surgery?
How could you treat the vomiting?
Case No 8.2
Your pre-eclamptic obstetric patient has had a general anaesthetic for a caesarean section. She now fails to awaken from the general anaesthetic.
What are the possible causes of her delayed awakening?
How would you manage her?
Case No 8.3
After a two-hour operation for an open cholecystectomy your patient’s blood pressure is 180/120 in the PACU.
What are the likely causes of hypertension in PACU?
After other causes for the hypertension are excluded, what drugs could be used to treat the hypertension?