We thank Dr Champion for his thoughtful comments on our publication titled: “Sedation After Cardiac Surgery: Is One Drug Better Than Another?” His letter highlights the importance of a multimodal, patient-centered approach to postoperative management. He reminds us of the potential utility of gabapentin/pregabalin, ketamine, and clonidine. Dr Champion also suggests that patients in fast-track recovery protocols after cardiac surgery have fewer postoperative complications, including delirium. Furthermore, he argues that for most patients under fast-track cardiac anesthesia protocols, their primary need is for analgesia and no sedation is necessary and a discussion comparing dexmedetomidine and propofol may be an artificial, forced choice between 2 bad options.
We agree with Dr Champion that post–cardiac surgery management should be individualized and patient centered. Multimodal approaches to postoperative patient management have been demonstrated to have benefits in many patient settings; however, our review was focused on sedation after cardiac surgery that presents some specific clinical requirements. Studies that evaluate the use of perioperative adjuncts in this setting are not as consistent. Further studies of their utility are still needed. Maitra et al1 recently reviewed the utility of gabapentin and pregabalin in the cardiac surgical setting, and their conclusion is that, although there may be some decrease in postoperative pain scores, their routine use cannot currently be recommended. Similarly, ketamine can be used as an analgesic adjunct after cardiac surgery and has been shown to decrease opioid use compared to patients who did not receive ketamine. However, ketamine caused hallucinations in a significant number of patients, and a more recent review by Mazzeffi et al2 highlights the paucity of data regarding the use of ketamine in this setting; however, recent reviews of ketamine use in other patient populations suggest that theoretical benefits may not be realized in clinical evaluations.2
Clonidine is another α2 agonist and it has also been used as a sedative medication in intensive care units (ICUs). However, evidence supporting the use of clonidine as a sedative in the critically ill requiring mechanical ventilation remains scarce. Until further randomized controlled trials are performed, the current data remain insufficient to support the routine use of clonidine as a sedative in the mechanically ventilated population of ICU patients.
In comparison to clonidine, dexmedetomidine has the advantages of increased α2 selectivity, greater titratability, and US Food and Drug Administration approval for use as a sedative in the ICU. In addition, dexmedetomidine has been shown to be beneficial in cardiac surgery, reducing the risk of postoperative ventricular tachycardia, decreasing postoperative delirium, decreasing risk of atrial fibrillation, and shortening the length of ICU stay and hospitalization. The benefits of dexmedetomidine are also catalogued in Table 3 of this review which contains the majority of prospective, retrospective, and meta-analysis of prospective studies. Even the study by Lin et al as referenced by Dr Champion demonstrated that dexmedetomidine was associated with shorter lengths of mechanical ventilation, a lower risk of delirium after cardiac surgery, and decreased incidence of ventricular tachycardia and hyperglycemia. The authors concluded that dexmedetomidine could be a safe and efficacious sedative agent in cardiac surgical patients.
The limitations of these adjuncts in this setting are why we included our reference to the potential use of inhalational anesthetic agents in place of intravenous agents to provide sedation in some ICUs, especially for patients after cardiac surgery. A recent meta-analysis of randomized controlled trials demonstrated a reduction in time to extubation with no increase in short-term adverse outcomes. Larger clinical trials are still needed to further evaluate the role of these agents as sedatives for critically ill patients.
We disagree with the suggestion that fast-track cardiac patients do not need sedation and are consequently free from significant postoperative complications (including delirium). Fast-track recovery as defined by the Society of Thoracic Surgeons is extubation within 6 hours. A recent report from a busy university hospital demonstrated that systems improvements led to almost 3/4 of cardiac surgical patients being extubated within 6 hours, but some form of sedation is clearly needed in a substantial number of those patients.3 Classic references have suggested that up to 53% of cardiac surgery patients experience postoperative neurocognitive decline, and more recent studies demonstrate that delirium still occurs in about 20% of cardiac surgery patients. There is still a substantial need for postoperative analgesia and sedation to facilitate fast-track recovery of cardiac surgical patients. Although it might be easy to compare propofol and dexmedetomidine to Scylla and Charybdis in the context that all drugs are poisons, for this patient population, we would emphasize the second component of that pharmacological tenet and stress that it is the dose that distinguishes.
Hong Liu, MD, FASEDepartment of Anesthesiology and Pain MedicineUniversity of California Davis HealthSacramento, Californiahualiu@ucdavis.edu
Fuhai Ji, MDDepartment of Anesthesiology and Pain MedicineUniversity of California Davis HealthSacramento, CaliforniaDepartment of AnesthesiologyThe First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
Ke Peng, MDDepartment of AnesthesiologyThe First Affiliated Hospital of Soochow UniversitySuzhou, Jiangsu, China
Richard L. Applegate II, MDNeal W. Fleming, MDDepartment of Anesthesiology and Pain MedicineUniversity of California Davis HealthSacramento, California
1. Maitra S, Baidya DK, Bhattacharjee S, Som A. [Perioperative gabapentin and pregabalin in cardiac surgery: a systematic review and meta-analysis]. Rev Bras Anestesiol. 2017;67:294–304.
2. Mazzeffi M, Johnson K, Paciullo C. Ketamine in adult cardiac surgery and the cardiac surgery intensive care unit: an evidence-based clinical review. Ann Card Anaesth. 2015;18:202–209.
3. Goldhammer JE, Dashiell JM, Davis S, Torjman MC, Hirose H. Use of provider debriefing to improve fast-track extubation rates following cardiac surgery at an academic medical center. Am J Med Qual. 2017 June 1 [Epub ahead of print].