**2. Postoperative pain control**

There has been a little systematic study of pain associated with CIED implantation even though, such procedures are increasingly prevalent. Further complicating the subject of postoperative pain control are differences between subcutaneous and transvenous devices and the fact that some implantation procedures are done on an outpatient basis.

## **2.1 Risk factors for postoperative pain**

The BRUISE-CONTROL studies 1 and 2 used a visual analog scale to assess pain in 1308 patients who had a CIED implanted. Using multivariable regression analysis, the following were associated with clinically important postsurgical pain: clinically significant hematoma (odds ratio [OR] 3.8), *de novo* CIED implantation (OR 1.9), female sex (OR 1.6), age < 65 years (OR 1.5), and body mass index <20 (OR 2.1) [5].

In a study of 21 consecutive adult CIED patients (mean age 61 ± 11 years), patients were asked to rate their pain on a 0 to 100 visual analog scale, where 0 was no pain at all and 100 was the worst possible pain imaginable. Patients rate their pain 24 hours after surgery and again at one month postoperatively. At 24 hours postimplant, the mean VAS score was 34 ± 20. Only one patient in the study experienced severe pain, with the rest rating pain as moderate (48%) or mild (48%). Using regression analysis, it was found that the use of intraoperative fentanyl and a longer time spent in the procedure were significant predictors of more intense postoperative pain. The mean VAS score for pain at one month was 19 ± 18 and 17 out of 21 patients rated this pain as "mild" [6].

#### **2.2 Inpatient versus outpatient pain control**

Device implantation may be done on an inpatient or outpatient basis, depending on a variety of factors, including patient characteristics, comorbidities, physician preference, geography, patient frailty, and other factors. A retrospective chart review of 415 consecutive primary-prevention ICD patients found that same-day discharge was safe and feasible [7]. However, in real-world clinical practice, many such procedures are performed on inpatients. In a prospective study of 327 *de novo* ICD patients, 40.3% were implanted during acute hospitalization [8]. Of these inpatients, 57.6% were secondary-prevention patients [8]. Predictors of hospitalization include, a more complex device (non-single-chamber device), New York Heart Association (NYHA) class IV symptoms, low diastolic blood pressure, higher blood urea nitrogen levels, and lower hemoglobin [8].

### **2.3 Subcutaneous ICDs**

Subcutaneous ICDs are often implanted under general anesthesia and postoperative pain may be managed with opioid analgesia. However, there is a trend toward moving away from general anesthesia and postoperative opioids to a different type of pain control [9]. Monitored anesthesia care (MAC) has been reported in the literature to be a safe and effective method for subcutaneous ICD implantation [10, 11]. The

#### *Postoperative Pain Control Following Cardiac Implantable Electronic Device Implantation DOI: http://dx.doi.org/10.5772/intechopen.101517*

truncal plane block along with perioperative nonopioid analgesics is being considered and appears feasible and effective [12]. A study of 91 consecutive patients undergoing subcutaneous ICD implantation at 10 centers found ultrasound-guided serratus anterior plane block was effective for anesthesia during the procedure and postoperative analgesia [13].

The Subcutaneous Defibrillator and Send Home (DASH) study investigated the feasibility and safety of subcutaneous ICD implant in patients (mean age 47 ± 14 years) discharged on the same day [14]. In total, 49 patients were enrolled and all were discharged following the surgery without staying overnight at the hospital. The protocol called for preoperative acetaminophen 975 mg and oxycodone 10 mg, local bupivacaine during the surgery, and limited fixed-dose combination oral analgesic of oxycodone plus acetaminophen (5/325 mg) after surgery, every 6 hours as needed. Using a 0 to 10 numerical pain rating scale, severe pain (defined as a score ≥ 8) occurred in 14.3% of patients on the day of surgery, 14.3% on postoperative day 1, and 8.2% of patients on a postoperative day 3 [14].

In a study of 104 adult patients undergoing subcutaneous ICD implantation, 69% were administered intraprocedural liposomal bupivacaine but there were no statistically significant differences between those who received bupivacaine and those who did not in terms of inpatient opioid consumption, outpatient opioid prescriptions, or overall opioid consumption in the postoperative period [15]. Similar findings were observed in a study of liposomal bupivacaine in knee arthroplasty [16].

In a study of opioid use following CIED implantations, patients who underwent subcutaneous ICD implantation were more likely to be prescribed opioids than those implanted with transvenous devices (25% vs. 20%) [17]. In a retrospective single-center study of structured interviews with female patients who were implanted with a subcutaneous ICD (mean time since implant 4.6 ± 3.1 years) 54% said their postsurgical pain was worse than they expected [18]. About half (44%) said that they experienced daily discomfort with their bra and the implanted device [18]. Thus, while postoperative pain can be managed following subcutaneous ICD implant, there are important gaps to be recognized in how pain is treated. In particular, patients should be advised about the nature, duration, and intensity of pain anticipated and provided with an analgesic regimen with specific instructions.

### **2.4 Device revision**

ICDs and other CIEDs require replacement upon battery depletion, and the incidence of any type of complication within 45 days of device revision is 4.3% [19]. Device infections are more common for ICD and CRT-D system revisions than initial implants (2.9% and 3.9% for revisions, respectively, and 1.6% for both ICD and CRT-D *de novo* systems) [20]. It should be noted in this context that a CRT-D system is a more complicated device than a transvenous ICD, even a dual-chamber ICD, and requires a left-ventricular lead. This risk for infection may be cumulative with subsequent device revisions; in fact, each intervention at the same implant site appears to double the risk for infection [21]. There are no studies, comparing postoperative pain intensity or characteristics of initial and revised procedures. Since up to 40% of ICD procedures involve a generator replacement [22], this represents a significant knowledge gap.

In an analysis of opioid prescribing for CIED implantation, patients undergoing device upgrades and generator change-outs were less likely to receive opioids than those getting a *de novo* implant (18.3%, 11.6%, and 20%, respectively) [17].

### **2.5 Special populations**
