**4. Postoperative care**

Obesity is associated with some problems also during postoperative period. The steps of postoperative care of an obese patient should be carefully assessed before the surgery. Postoperative care should aim to prevent from respiratory dysfunction, hypothermia, hemodynamic instability, thromboembolism, nausea, vomiting, and pain [95, 96].

Monitoring should be continued in the recovery unit, while the patient is in sitting position or the head is upward at 45°. Oxygen support should be maintained until arterial oxygen saturation values return to preoperative levels or the patient becomes completely mobilized. In order to be discharged into the ward, the patient should meet routine criteria for leaving wakening room, no hypopnea or apnea period should occur, and preoperative arterial oxygen saturation values should be reached [96].

The prevalence of myocardial infarction is higher in this group compared to nonobese population. In addition, a new onset of atrial fibrillation may be seen during postoperative period. Close monitoring of these patients should be continued also after the surgery [97, 98].

Although being rare, rhabdomyolysis is a fatal complication in this patient population. Predisposing factors include hypotension, dehydration, immobility, and prolonged surgical interventions. In particular, pain in deep tissues of gluteal region should signal rhabdomyolysis. Creatine kinase levels are elevated in such patients [99].

Obesity is a risk factor for thromboembolism, where prophylaxis is recommended in all surgical interventions, except minor surgery. While oral agents such as rivaroxaban and dabigatran are not recommended for obese patients, low-molecular-weight heparin is recommended for prophylactic purposes [96, 100].

The incidence of postoperative nausea-vomiting is not increased in obese patients, albeit a contradictory issue [101].

An effective postoperative pain management is important to prevent pulmonary complications and provides sufficient respiratory depth. Pain management through intramuscular route is not recommended in obese patients. Opioid-induced upper airway obstruction and respiratory depression are more likely to be seen in obese patients with obstructive sleep apnea. When deciding postoperative analgesia in obese patients, selecting a multimodal analgesia method rather than a unimodal method will provide more effective pain control and avoidance of potential complications [95, 96, 102].

#### **4.1. Intensive care**

nerve blocks is especially very compelling in morbidly obese patients. Seventh cervical vertebra or gluteal fissure may be used to identify midline for central blocks. Distribution of the local anesthetics is hard to estimate due to lipid infiltration into epidural space and increased intraabdominal pressure, in which case 75–80% of normal local anesthetic dose may suffice. Regional block practices are regarded as more difficult in obese patients. In a study of 2020 supraclavicular block applications, success rate in obese patients was 94.3% compared with 97.3% in nonobese patients, which was significantly different [92]. The prospective study by Nielsen et al. [93] with over 9000 regional block procedures showed that the failure rate was 1.62 times higher in obese patients than in nonobese patients. Block procedures may be

safely performed under the guidance of ultrasonography in obese patients [93, 94].

dynamic instability, thromboembolism, nausea, vomiting, and pain [95, 96].

Obesity is associated with some problems also during postoperative period. The steps of postoperative care of an obese patient should be carefully assessed before the surgery. Postoperative care should aim to prevent from respiratory dysfunction, hypothermia, hemo-

Monitoring should be continued in the recovery unit, while the patient is in sitting position or the head is upward at 45°. Oxygen support should be maintained until arterial oxygen saturation values return to preoperative levels or the patient becomes completely mobilized. In order to be discharged into the ward, the patient should meet routine criteria for leaving wakening room, no hypopnea or apnea period should occur, and preoperative arterial oxy-

The prevalence of myocardial infarction is higher in this group compared to nonobese population. In addition, a new onset of atrial fibrillation may be seen during postoperative period.

Although being rare, rhabdomyolysis is a fatal complication in this patient population. Predisposing factors include hypotension, dehydration, immobility, and prolonged surgical interventions. In particular, pain in deep tissues of gluteal region should signal rhabdomyoly-

Obesity is a risk factor for thromboembolism, where prophylaxis is recommended in all surgical interventions, except minor surgery. While oral agents such as rivaroxaban and dabigatran are not recommended for obese patients, low-molecular-weight heparin is recommended

The incidence of postoperative nausea-vomiting is not increased in obese patients, albeit a

An effective postoperative pain management is important to prevent pulmonary complications and provides sufficient respiratory depth. Pain management through intramuscular route is not recommended in obese patients. Opioid-induced upper airway obstruction and

Close monitoring of these patients should be continued also after the surgery [97, 98].

**4. Postoperative care**

90 Current Topics in Anesthesiology

gen saturation values should be reached [96].

for prophylactic purposes [96, 100].

contradictory issue [101].

sis. Creatine kinase levels are elevated in such patients [99].

Obesity was found to be associated with increased need for mechanical ventilation and longer duration of stay with tracheostomy and at intensive care unit. No increase in mortality was shown.

For mechanical ventilation, 5–7 ml/kg of tidal volume calculated according to the ideal body weight is recommended as well as maintaining a peak inspiratory pressure below 35 cm/H<sup>2</sup> O [76, 103].

If the obese patient is hemodynamically stable and gastrointestinal system is functional, enteral route is preferred over parenteral route for nutrition. Guideline of Society of Critical Care Medicine and American Society for Parental and Enteral Nutrition reports that hypocaloric nutrition support preserves nitrogen balance and decreases morbidity in obese patients [104].

"Obesity paradox" is defined as the better prognosis of obese patients after acute cardiovascular decompensation despite the established role of the obesity for developing of cardiovascular diseases. Nevertheless, the effects of obesity on critical illness, death, or long-term outcomes are conflicting [105].
