Regional anesthesia in the form of peripheral nerve blocks has been used to decrease postoperative pain in the ICU. Peripheral nerve blocks have the benefit of having less strict anticoagulant guidelines prior to performing the block and less side effects and provide safe effective analgesia. These blocks can be performed via a single injection or via a continuous catheterbased technique.²

Fascial plane blocks such as the pectoral 1 and 2 blocks, the erector spinae plane block, as well as the serratus anterior plane blocks have been used for rescue analgesia for cardiac surgical patients who have had severe postsurgical pain and can also improve lung function by reducing splinting from severe thoracic pain.

Patients who have had sternal fractures, sternotomies, and rib fractures have also benefited from ultrasound-guided transversus thoracis plane blocks, which can also decrease pain scores and ultimately improve lung function by reducing splinting secondary to severe pain.

Patients who have suffered rib fractures, as well as those undergoing thoracic and upper and mid abdominal surgeries, can benefit from neuraxial analgesia, in particular, thoracic epidural analgesia.³,⁴

Benefits include reduced pain scores, improved pulmonary function, increased gastric motility, decreased risk of deep vein thrombosis that may assist in early extubation in patients who are intubated, reduced time to initial bowel movement, and reduced morbidity and mortality.

Side effects of neuraxial anesthesia include but not limited to nausea, vomiting, urinary retention, and lower extremity weakness (especially in the case of lumbar epidural). If opiates are added to the local anesthesia administered via these routes, opioid-induced pruritis
can also occur. In addition, the choice of using these techniques must be weighed against their possible side effects.

Contraindications to neuraxial interventional techniques include patient refusal, hemodynamic instability, true allergy to local anesthetic drugs, and active anticoagulation (guided by the anticoagulation guidelines from the American Society of Regional Anesthesia).

Opiates used for acute perioperative pain management include morphine, hydromorphone, fentanyl, buprenorphine, methadone, remifentanil, sufentanil, alfentanil, and ketamine. These medications can be administered via oral, intravenous, sublingual, intramuscular, and rectal administration. All of these medications provide excellent analgesia, however, they have numerous unwanted side effects and significant abuse potential. Adverse side effects include nausea, vomiting, sedation, opioid-induced respiratory depression, opioid-induced constipation, opioid-induced pruritis, and urinary retention. In addition, they can result in hypoventilation and hypercarbia and can lead to cardiopulmonary compromise in critically ill patients. This may result in these patients requiring respiratory support or may result in prolonged intubation.⁵

Methadone is generally administered to patients who have a history of opiate abuse and are attempting to overcome their addiction. In addition, it can also be used as part of an anesthetic plan to reduce perioperative pain. This drug is generally administered orally or intravenously. Administration of methadone in particular can prolong the QTc interval and can lead to torsade de pointes, which may result in ventricular tachycardia and fibrillation in patients with a history of prolonged QT. A careful review of medications must be performed prior to reduce the risk of increasing the QTc.

Remifentanil may be used as a continuous intravenous infusion at a low rate with a patient controlled bolus as part of patient-controlled analgesia for acute pain management. Remifentanil is unique of all the opiates in that it has a very short half-life and context sensitive half time of ˜10 minutes resulting in complete clearance of the opiate from the blood. This is due to the fact that it is metabolized by red blood cell esterases, which rapidly break down the drug in the blood stream.⁶