It is not uncommon, in small country hospitals, to have a recess or small room leading from the operating theatre in which the patients remain until they have recovered from the immediate effects of the operation.
The definition of levels of postoperative care needed should be established on the predicted odds of perioperative mortality. In accordance with the AAGBI Guidelines (2014), patients with predicted perioperative mortality of more than 10% should be admitted to a level 2 (recovery room) or 3 (intensive care unit) critical care facility.
Postoperative care begins at the end of the surgical procedure and continues throughout the hospitalization from discontinuation of anesthesia to recovery of protective reflexes and motor function (Phase 1), then from discharge out of the operating theater to admission into the surgical ward (Phase 2) and, finally, from the ward to hospital discharge (Phase 3).
Phase 1 recovery coincides with the period during which patients pass from a drug-induced state of coma to a state of recovery of vital functions, allowing them to be moved to an intermediate- or low-intensity care location. This usually takes place in the recovery room (RR) or postanesthesia care unit (PACU), where adequate instrumental and clinical monitoring are ensured. These areas were developed with the aim of minimizing early perioperative complications (EPCs), providing high safety standards and improving quality of care, and are pivotal elements in perioperative medicine.
In the elderly, a number of risk factors for EPCs are often present, such as changes in both pharmacokinetics and pharmacodynamics prolonging the effects of anesthetic drugs, associated conditions reducing functional reserves, aging processes modifying the physiologic response to hypoxia and hypercapnia, reduced capability to maintain normothermia and swallowing alterations facilitating aspiration. EPCs can be fatal when occurring out of the operating theater or the RR. Respiratory depression, cardiovascular alterations, hypothermia and postoperative delirium (POD) are the most common. RRs are essential in the prevention of EPCs; a dedicated area for Phase 1 recovery should always be present where surgical patients are treated, and especially in hospitals where geriatric surgery is performed.
EPCs in the Elderly
Studies analyzing EPCs in the elderly are few, however those on the general population have shown that complications occurring in the RR are related to respiratory, cardiovascular and central nervous system disorders and are accompanied by hypoxia, hypothermia, pain, nausea and vomiting, urinary retention and anxiety.
Respiratory depression is followed by 70% mortality when occurring in the ward, vs. 29% when occurring in the operating theater or the RR (Tiret et al. 1986). It is usually due to residual centrally acting anesthetic or neuro-muscular blockade (NMB). Aspiration may occur as a consequence of residual drug action or swallowing difficulties, or both. Early postoperative reintubation is associated with significantly increased mortality and increased hospital stay.
Drugs used during anesthesia may have prolonged effects in the elderly, as aging modifies distribution volume, renal clearance and sensitivity to drugs (see Chapter 19). No data support the use of one anesthetic over another, but the choice of anesthetic agent should favor those with fast clearance and reduced side effects. Intraoperative use of target controlled infusion (TCI) techniques, and cerebral and NMB monitoring helps in avoiding overdosing and obtaining fast recovery. Postoperative residual curarization (PORC) is likely to occur in the elderly. NMB monitoring is fundamental in identifying the right time for safe extubation, which coincides with a TOF ratio of 0.9. Sugammadex hastens recovery after NMB induced by vecuronium or rocuronium; studies showed that it can be safely and effectively used in the elderly (McDonagh et al. 2011), even though higher dosages may be required (Shin et al. 2016). The use of atropine and neostigmine for NMB reversal should be avoided, due to their cardiovascular and cognitive side effects, to which the elderly are highly sensitive.
Adequate sedation should be maintained till tracheal intubation can be safety removed; when sedation is not appropriate, patients should be reassured and kept calm, in order to avoid damage to the airway or cardiac alterations. The goal is avoiding agitation and discomfort, at the same time ensuring adequate gas exchange, in a patient supposed to be under major physical and psychological stress, who might even be believed to be at the point of death. Considering the frequent psychological frailty presented by elderly patients, the role of nurses and a sensitive professional attitude are valuable in this phase.
Measures to avoid respiratory depression in the RR include:
intraoperative use of drugs with fast clearance
intraoperative use of cerebral and NMB monitoring
postoperative maintenance of pulse oximetry and adequate ventilatory support as needed
careful clinical observation.
Even though long-lasting procedures – especially those requiring deep anesthesia and prolonged NMB – are usually accompanied by a higher risk of delayed recovery and respiratory depression in patients of any age, this problem is also likely to occur in the elderly after short or minor procedures, during which opioids were used. Patients may look awake and well oxygenated, have only a short stay in the RR (or bypass it) and – once on the ward – develop respiratory depression; this is typically due to the camel-hump (biphasic) decay curve of fentanyl that, with the increased muscular blood flow caused by restoration of motor activity, causes a redistribution of opioid metabolites and respiratory depression in an unprotected area.
Risk factors for hypoxia are age >55 years, reduced preoperative pulmonary function, residual effects of anesthetics, the surgical field involved in the procedure, the duration of anesthesia and ASA class II or III (Nascimento et al. 2015).
Hypoxemic episodes (SpO2 <90%) have been recorded in the past in up to 55% of patients admitted to RR. The extensive use of pulse oximetry has significantly reduced its incidence; whether this is due to oximetry as a means to identify, prevent and intervene in complications related to hypoxia or as a protective measure against human negligence, is questionable.
When not promptly detected and treated, hypoxia can be responsible for major adverse events in any patients, but mostly in the elderly where aging processes and associated conditions create a vulnerability.
Acute changes in blood pressure, heart rate and rhythm are common events among elderly patients in the RR and are the third most common problem requiring treatment in the early postoperative period (Kluger and Bullock 2002). Myocardial infarction in the RR is rare in the general population, however ischemic events are not exceptional in older patients presenting with cardiac risk factors and/or undergoing stressful surgery. Recently, a new perioperative clinical entity (MINS: myocardiac injury after non-cardiac surgery) has been defined (Botto et al. 2014). Identification of patients at risk, adequate intraoperative hemodynamic balance by use of goal-directed therapy (GDT) and ECG monitoring are fundamental in reducing the number of cardiac events in the RR. The likelihood of cardiovascular problems is related to:
severity of pre-existing cardiovascular conditions (coronary insufficiency, hypertension, heart failure)
invasiveness of the surgical procedure (major vascular, thoracic, abdominal)
severity of perioperative stress (blood loss, fluid shifts, sepsis, pain, hypothermia).
Together with these factors, respiratory distress, agitation or PONV have been shown to be related to cardiac events in the RR.
Hypotension in the RR can be caused by decreased ventricular preload, reduced myocardial contractility or profound reduction in peripheral vascular resistance. Decreased right ventricular preload is usually related to hypovolemia, whereas decreased left ventricular preload is usually a consequence of acute massive pulmonary embolism, rarely occurring in the RR. Decreased myocardial contractility can be related to the depressant effects of volatile anesthetics; however, it may also be caused by pre-existing ventricular dysfunction or perioperative myocardial infarction, which are often present in the elderly.
Intraoperative implementation of GDT as a guide to fluid administration and optimal cardiac preload has been shown to improve hemodynamic balance, especially in high-risk patients, avoiding excessive fluid infusion and hypovolemia, and ensuring that the circulating volume and global oxygen delivery are optimal. Current flow monitoring techniques include Doppler technologies or arterial pressure waveform analysis. Both are well tolerated, have limited bias and can be used throughout the RR stay. Once the optimal circulating volume has been restored, the persistence of hypotension suggests searching for – and treating – ischemic events (ECG, echocardiography, troponin dosage) and, when indicated, inotropic support.
Hypertension in the RR has multifactorial etiology and can be related to pain, hypercapnia, hypoxia, urinary retention or excessive fluid load. Pre-existing hypertension is present in 50% of the patients who develop hypertension in the RR.
Severe hypertension can lead to major cardiovascular morbidity, such as left ventricular failure, myocardial infarction, dysrhythmia or pulmonary edema. Discriminating between hypertensive urgency and emergency addresses adequate treatment. Whereas hypertensive urgency (i.e. hypertensive crisis not accompanied by progressive end-organ dysfunction) usually responds to non-pharmacological measures (such as pain treatment, correction of hypoxia or hypercapnia, bladder draining or diuretics), patients with hypertensive emergency (BP >180–120 mmHg, neurological signs suggesting cerebral infarction or hemorrhage) are best treated in the ICU with intravenous hypotensive agents, such as β-blockers, nicardipine or sodium nitroprusside.
Most ischemic episodes tend to start at the end of surgery and during emergence from anesthesia, due to increased sympathetic tone and procoagulant activity, with consequent increased myocardial oxygen consumption, sub-endocardial ischemia and thrombosis.
Postoperative myocardial infarction (MI) after non-cardiac surgery is one of the most serious complications of surgery and anesthesia. While its incidence in the general non-cardiac surgical population is less than 1%, in sub-groups of patients with cardiac risk factors and older age this incidence is substantially higher. Chest pain may not be present, especially in diabetic patients. ST-elevation and increased troponin are the classical markers of acute coronary occlusion and MI. This event is usually reported on the second or third postoperative day; however, in some patients myocardial ischemia manifests during surgery or in the RR (Obal et al. 2005, Wada 2007, Lee et al. 2010).
Recent investigations have substantially improved the understanding of MINS. MINS is defined as a prognostically relevant myocardial injury due to ischemia occurring within 30 days after non-cardiac surgery. Its occurrence in the RR is unknown, mostly because MINS occurs asymptomatically in the majority of cases. ST-depression and positivity to troponin T (TnT) are specific markers.
The most common arrhythmic manifestations occurring in the RR include sinus tachycardia/bradycardia, ventricular premature beats, ventricular tachycardia and supraventricular tachyarrhythmias. They are often a sign of metabolic or perfusion problems and rarely require pharmacological treatment once the cause has been removed. Hypokalemia or other electrolyte imbalances, metabolic alkalosis and acidosis, together with pre-existing arrhythmic disorders, are the most frequent causes. The occurrence of sudden left bundle block requires further examination to exclude ischemic events; however, it may be transient in the absence of cardiac ischemia.
POD is a severe postoperative complication that can be observed especially in the elderly (ESA 2017). Clear evidence indicates that its detection should start in the RR, in order to allow early diagnosis and prompt treatment with the aim of reducing short- and long-term consequences. POD in its hypoactive form is very difficult to detect and its identification is strictly linked to the awareness professionals have of its possible onset after surgery.
Detection of POD in the RR first requires that residual actions of anesthetic drugs are excluded as causative factors of the mental state. The Richmond Agitation Sedation Score (RASS) is the recommended tool for this differential diagnosis. Pupillary measures have been found to help in identifying delirious patients in the PACU (Yang et al. 2017).
The risk of POD is higher in elderly, comorbid, functionally and sensory impaired, frail, dehydrated and malnourished patients. Other risk factors are alcohol addiction and use of anticholinergic drugs. This risk should be evaluated preoperatively, and patients at risk should be identified and assigned to targeted preventive measures. Invasive, high-stress and long-lasting surgery is likely to precipitate this risk (see Chapter 14). In the RR, pain, urinary retention and anxiety can favor its development.
Once evaluated using RASS, POD detection should be made by validated scales such as Nu-DESC or CAM. Treatment aims to remove causative factors and alleviate symptoms by both non-pharmacologic and pharmacologic measures (see Chapter 38).