**14. Postoperative respiratory complications**

The remaining effects of anesthesia could all meaningfully cause to respiratory complications [25]. Postoperative hypoxemia may happen in 20%-60% of geriatric surgical patients. As emphasized previously, geriatric patient has an increased alveolar-arterial gradient, decreased respiratory muscle strength, and diminished hypoxic and hypercarbic drives at baseline. Consequently, there is advanced loss of airway reflexes with age. Apnea and interrupted breathing after administration of narcotics are more common. Risk factors for respiratory complications include atelectasis, pneumonia, and pulmonary thromboembolism, advanced age, poor general health status, current infections, pre-existing cardiorespiratory diseases, hypoalbuminemia, and renal impairment. Supine position during recovery increases transpulmonary shunt [6]. Upper abdomen and intrathoracic procedures in geriatric patients have an independent factor in worsening postoperative hypoxemia and other respiratory complications.

Postoperative pulmonary aspiration in geriatric surgical patients is also an essential issue. Decreased respiratory muscle strength, together with reduced cough and swallowing reflexes may lessen clearance of secretions and increase the risk of pulmonary aspiration in the geriatric patients. This hazard is compounded by the effects of anesthetics, sedatives, and narcotics as well as by interventions such as tracheal intubation, nasogastric tube placement, and upper abdominal or head and neck surgery. An anesthesiologist should to be informed the geriatric patient and family members to this impending hazard and to adjust oral intake postoperatively. Geriatric patients also have a higher incidence of postoperative sleep apnea events. In some geriatric patients, intensive care management is neded.

#### **14.1 Hypothermia**

Geriatric patients are more at a higher risk of becoming hypothermic owing to anesthetic induced altered thermoregulatory mechanisms and their low basal metabolic rate. Adverse effects of postoperative hypothermia contain cardiac ischemia, arrhythmias, decreased drug metabolism, increased blood loss, wound infection, and prolonged hospital stay. In geriatric patients, every effort should be done to prevent heat losses. Numerous studies have been revealed that maintaining normothermia decreases cardiac morbidity. Several studies have been accomplished to evaluate the effects of many active or passive warming devices and methods including a forced-air warming blanket or heated humidifier circuit on perioperative hypothermia or shivering in geriatric patients [26, 27].

#### **15. Postoperative pain**

Geriatric patients are frequently undertreated for pain. Postoperative pain increases the risk of complications in the geriatric patients. However, pain

*Anesthetic Consideration for Geriatric Patients DOI: http://dx.doi.org/10.5772/intechopen.97003*

assessment in this population might be difficult due to cognitive impairment, dementia and aphasia. Insufficient postoperative analgesia may be associated with myocardial ischemia and respiratory failure [6]. However, the geriatric patient is enormously vulnerable to drug interactions and has an enhanced probability of undesirable effects. There is a correlation between postoperative pain and cognitive impairment. Postoperative pain might impair cognition and cognitive impairment could affect with the communication of postoperative pain. Multimodal drug therapy and perioperative regional analgesia could be very effective for perioperative pain management in geriatric patients. In addition, a balanced analgesic technique combining opioids, nonopioids and local anesthetic agents is also suggested.

#### **16. Postoperative cognitive impairment**

To identify postoperative cognitive impairment, clinician must be aware of the patient's habitual cognitive status to decide a reasonable assessment of alterations from their individual baseline status. Anesthesia had been concerned as a donating cause of postoperative cognitive impairment in the geriatric patients. Impairments are perceived in mood, memory, behavior, judgment, learning, language and motor function. The previous studies revealed that reduced brain functional reserve made the geriatric patients more likely to develop postoperative cognitive impairment [28]. The contributing factors might be narcotics, sedatives, anticholinergic, infection, anesthetic techniques, pain, sleep deprivation and hospitalization. Postoperative cognitive impairment could be categorized into two main groups: postoperative delirium (POD) and postoperative cognitive dysfunction (POCD). POD and or POCD affects 5-50% of geriatric patients.

Delirium is well-defined as an acute alteration in cognitive function that progresses over a brief period of time lasting for a few days to a few weeks. An incidence of POD is dependent on the type of surgery, patient's preoperative physical and cognitive status, and age of the patient. The overall prevalence of POD in geriatric patients after surgery has been appraised to be 10% [29]. The etiology of delirium is probably multifactorial and may include drug intoxication or withdrawal, drug interaction, anticholinergic agents, metabolic disturbances, hypoxia, abnormal carbon dioxide levels, sepsis, inadequate analgesia, and organic brain diseases. The incidence of POD may be less in outpatients than in hospitalized patients because of ambulatory patients return home postoperatively where suitable stimuli and support are obtainable. A previous systematic review for prevention of POD in geriatric patients scheduled for elective surgery presented that multicomponent interventions, antipsychotics, bispectral index-guidance, and dexmedetomidine treatment could successfully decrease an incidence of POD in geriatric patients undergoing elective non-cardiac surgery [30].

POCD is a syndrome well-defined by a deterioration from baseline in cognitive neuropsychological functioning which could last for months up to 1 year and possibly longer. POCD happens at rates as high as 79% at 7 days, 12.7% at 3 months in non-cardiac surgery patients [31]. The risk factors of POCD are multifactorial and may contain lower preoperative cognitive score, less educated, alcohol abuse, electrolyte abnormalities, type of surgical procedure, drug interactions, hypnotic or alcohol withdrawal, intraoperative events related to the surgical procedures as well as anesthetic agents and depth of anesthesia. Furthermore, physiological and sociological consequences of hospitalization and surgery might have a role. The only risk factor for late POCD was age. No differences between regional and general anesthesia in the incidence of postoperative cognitive impairment are noticed [32]. Interestingly, outpatients may have a superior cognitive outcome than inpatients.
