Quality Improvement Initiative to Improve Postoperative Pain with a Clinical Pathway and Nursing Education Program.

BACKGROUND AND AIMS: We created a multicomponent intervention to improve pain management in the immediate postoperative period with the goal of improving the quality of patient recovery. DESIGN: A multicomponent intervention to improve pain management in the immediate postoperative period with the goal of improving the quality of patient recovery. SETTINGS: Pain management education of postanesthesia recovery room nurses through a practical intervention has the potential to improve patient pain experience, especially in those with a history of opioid tolerance. PARTICIPANTS/SUBJECTS: Postanesthesia recovery nurses/postanesthesia patients. METHODS: The intervention included two components: a clinical pain pathway on multimodal analgesia for both opioid-naïve and opioid-tolerant patients undergoing surgery and an educational program on pain management for frontline clinical nurses in the postanesthesia care unit (PACU). We measured the intervention's impact on time to pain relief, PACU length of stay, and patient satisfaction with pain management, as measured by self-report. RESULTS: Patient PACU surveys indicated a decrease in the percent of patients with opioid tolerance who required more than 60 minutes to achieve adequate pain relief (from 32.7% preintervention to 21.3% postintervention). Additionally, after the intervention, the average time from a patient's PACU arrival to his or her discharge criteria being met decreased by 53 minutes and PACU stay prolongation as a result of uncontrolled pain for opioid-tolerant patients decreased from 45.2% to 25.7%. The sample size was underpowered to perform statistical analysis of this improvement. CONCLUSIONS: After the combined intervention of a clinical pain pathway and interactive teaching workshop, we noted shortened PACU length of stay, reduced time to reach pain control, and improved overall patient satisfaction. Although we could not determine statistical significance, our findings suggest improved management of acute postoperative pain, especially for patients who are opioid tolerant. Because of the paucity of data, we were not able to conduct the analysis needed to evaluate quality improvement projects, as per SQUIRE 2.0. could be adopted by any institution.

The efficacy and safety of epidural-based analgesia in a case series of patients undergoing lung transplantation.

OBJECTIVE: Successful pain management after lung transplantation is critical to ensure adequate respiratory effort and graft expansion. The authors investigated whether thoracic epidural analgesia (TEA) provided adequate pain control after lung transplantation without added morbidity. DESIGN: Retrospective review. SETTING: University teaching hospital. PARTICIPANTS: One hundred twenty-three patients who presented to this institution for lung transplantation from January 2008 to June 2013. INTERVENTIONS: Patient demographics, postoperative pain scores, and epidural-related complications were abstracted from the institutional electronic database. The authors used the previously validated Quality of Recovery (QoR) score and Visual Analog Scale (VAS) as measures of recovery. MEASUREMENTS AND MAIN RESULTS: Of the 123 patients who underwent lung transplantation in this time frame, 119 patients had thoracic epidurals placed for postoperative analgesia. The mean age was 49.4 years (range, 18-73), and 60 (50.4%) were male. The most common indications for transplant were pulmonary fibrosis (33.6%), cystic fibrosis (26.1%), and chronic obstructive pulmonary disease (20.2%). The median length of stay in the intensive care unit and duration of mechanical ventilation were 21 and 1.2 days, respectively. Eight (6.7%) patients experienced postoperative pulmonary compromise (eg, pneumonia, prolonged intubation). No serious complications were associated with TEA placement. On days 1, 3, and 7 after TEA placement, the mean QoR was 7.6, 9.4, and 9.7, and the mean VAS was 2.5, 2.1, and 2.0, respectively. CONCLUSIONS: In this case series, the authors observed excellent analgesia and no serious complications associated with TEA. Therefore, an epidural-centric approach to pain control after lung transplantation should be considered in appropriate patients.

Curriculum development for an advanced regional anesthesia education program: one institution's experience from apprenticeship to comprehensive teaching.

Results of recent attitude survey studies suggest that most practicing physicians are inadequately treating postoperative pain. Residents in anesthesia are confident in performing lumbar epidural and spinal anesthesia, but many are not confident in performing the blocks with which they have the least exposure. Changes need to be made in the training processes to a comprehensive model that prepares residents to perform a wider array of blocks in postgraduate practice. Here, we describe one institution's approach to creating a standardized, advanced regional anesthesia curriculum for residents that follows the six core competencies of the ACGME. Residents received training in anatomy dissection, ultrasound-guided regional anesthesia, traditional nerve stimulation techniques, problem-based learning and simulation sessions, oral board presentation sessions, and journal club sessions. Residents kept a detailed log for their use of peripheral nerve block procedures. We have now redesigned and implemented an advanced regional anesthesia program within our institution to provide residents with experience in regional anesthesia at a competent level. Resident's knowledge in regional anesthesia did improve after the first year of implementation as reflected in improvements between the pre- and post-tests. As the advanced regional anesthesia education program continues to improve, we hope to demonstrate levels of validity, reliability, and usability by other programs.

Improved residents' knowledge after an advanced regional anesthesia education program.

BACKGROUND: Although residents in anesthesia are confident in performing neuraxial anesthesia, many are not confident in performing peripheral nerve blocks. The purpose of this study was to evaluate the effectiveness of a structured regional anesthesia teaching program in a large academic medical center. METHODS: Residents participated in regional anesthesia didactics that took place in a unique resident education program scheduled during two fully protected teaching days a month. The curriculum included hands-on cadaver workshops in the anatomy lab, hands-on ultrasound workshops, hands-on nerve stimulator and surface anatomy workshops, and simulator sessions related to complications of regional anesthesia. Before beginning the formal regional anesthesia teaching program, residents completed a pretest composed of 25 multiple choice questions (MCQ) and a three-section observed standardized clinical examination (OSCE). Seven months later, approximately 1 month after completion of the regional anesthesia curriculum, the residents were evaluated again with the exact same tests. Pretest and post-test results for both the MCQ and the OSCE were compared by using a paired t-test for statistical means. RESULTS: Post-test results were significantly improved (P < 0.05) across all clinical anesthesia (CA) years and for both the MCQ and OSCE examinations. Post-test results were also significantly improved (P < 0.05) across all CA years for each of the three sections of the OSCE. CONCLUSION: The formal regional anesthesia teaching program developed by the departmental faculty was effective in improving resident knowledge.

Patient engagement and prescription opioid use in perioperative pain management.

OBJECTIVE: To examine (1) patient perceptions regarding their engagement and the engagement of their families in perioperative pain management, (2) demographic and clinical characteristics associated with perceived patient and family engagement, and (3) the association between perceived patient and family engagement and patient outcomes. DESIGN: A prospective, observational study. SETTING: The Personalized Pain Program (PPP) at the Johns Hopkins Hospital in Baltimore, Maryland. PARTICIPANTS: Patients having more than one visit to the PPP. INTERVENTIONS: n/a. MAIN OUTCOME MEASURES: Since the inception of the PPP, patients were surveyed prior to each clinic visit to assess their pain severity and interference using the Brief Pain Inventory. Starting August 22, 2018, two additional questions were added to the survey to assess patient perceptions of their engagement and the engagement of their families in perioperative pain management. In addition, electronic medical records were reviewed to collect data on daily opioid consumption during the first and last PPP visits presurgery and post-surgery. RESULTS: The final analysis included 511 survey responses from 155 patients. Perceived engagement of the patient in perioperative pain management improved over time (p < .001) and was significantly associated with reduction in prescription opioid consumption after surgery (coef = 12.7, SE = 5.8, p = .031). CONCLUSIONS: Surgical patients and their family members should be actively engaged in perioperative pain management to improve prescription opioid use and the quality and safety of perioperative care.

Addressing the Opioid Crisis One Surgical Patient at a Time: Outcomes of a Novel Perioperative Pain Program.

Opioid prescriptions in the surgical setting have been implicated as contributors to the opioid epidemic. The authors hypothesized that a multidisciplinary approach to perioperative pain management for patients on chronic opioid therapy could decrease postoperative opioid requirements while reducing postoperative pain scores and improving functional outcomes. Therefore, a Perioperative Pain Program (PPP) for chronic opioid users was implemented. This study presents outcomes from the first 9 months of the PPP. Sixty-one patients met the inclusion criteria. Opioid consumption in morphine milligram equivalent (MME) was calculated and physical and health status of patients was assessed with the Brief Pain Inventory, Short-Form McGill Pain Questionnaire, and Short Form-12. Preliminary results showed significant reduction in MME, improved pain scores, and improved function for surgical patients on chronic opioids. PPP effectively reduced opioid usage without negatively influencing patient-reported outcomes, such as physical pain score assessment and health-related quality of life.

Experience with an Enhanced Recovery After Spine Surgery protocol at an academic community hospital.

OBJECTIVE: Enhanced Recovery After Surgery (ERAS) protocols have rapidly gained popularity in multiple surgical specialties and are recognized for their potential to improve patient outcomes and decrease hospitalization costs. However, they have only recently been applied to spinal surgery. The goal in the present work was to describe the development, implementation, and impact of an Enhanced Recovery After Spine Surgery (ERASS) protocol for patients undergoing elective spine procedures at an academic community hospital. METHODS: A multidisciplinary team, drawing on prior publications and spine surgery best practices, collaborated to develop an ERASS protocol. Patients undergoing elective cervical or lumbar procedures were prospectively enrolled at a single tertiary care center; interventions were standardized across the cohort for pre-, intra-, and postoperative care using standardized order sets in the electronic medical record. Protocol efficacy was evaluated by comparing enrolled patients to a historic cohort of age- and procedure-matched controls. The primary study outcomes were quantity of opiate use in morphine milligram equivalents (MMEs) on postoperative day (POD) 1 and length of stay. Secondary outcomes included frequency and duration of indwelling urinary catheter use, discharge disposition, 30-day readmission and reoperation rates, and complication rates. Multivariable linear regression was used to determine whether ERASS protocol use was independently predictive of opiate use on POD 1. RESULTS: In total, 97 patients were included in the study cohort and were compared with a historic cohort of 146 patients. The patients in the ERASS group had lower POD 1 opiate use than the control group (26 ± 33 vs 42 ± 40 MMEs, p < 0.001), driven largely by differences in opiate-naive patients (16 ± 21 vs 38 ± 36 MMEs, p < 0.001). Additionally, patients in the ERASS group had shorter hospitalizations than patients in the control group (51 ± 30 vs 62 ± 49 hours, p = 0.047). On multivariable regression, implementation of the ERASS protocol was independently predictive of lower POD 1 opiate consumption (ß = -7.32, p < 0.001). There were no significant differences in any of the secondary outcomes. CONCLUSIONS: The authors found that the development and implementation of a comprehensive ERASS protocol led to a modest reduction in postoperative opiate consumption and hospital length of stay in patients undergoing elective cervical or lumbar procedures. As suggested by these results and those of other groups, the implementation of ERASS protocols may reduce care costs and improve patient outcomes after spine surgery.

Postoperative pain management in the elderly undergoing thoracic surgery.

The management of postoperative pain in the elderly represents a considerable challenge because these patients are generally at higher risk for postoperative complications. There are several analgesic options, some of which may influence perioperative morbidity in this high-risk group of patients. Although use of regional analgesia, particularly epidural analgesia is associated with some benefits, including a decrease in perioperative morbidity, there are side effects and complications (eg, medication-related side effects, epidural hematoma, infection) from these and other techniques, and the clinician should evaluate the benefits and risks of each technique on an individual basis. Nevertheless, the available data suggest that use of regional analgesic techniques (ie, epidural and paravertebral catheters) is associated with a decrease in perioperative pulmonary complications.

Regional techniques and outcome: what is the evidence?

PURPOSE OF REVIEW: Despite some controversy regarding the strength of the available data, the use of regional anesthesia and analgesia does provide improvement in patient outcomes. Although the majority of available data have examined the effect of epidural anesthesia and analgesia on patient outcomes, an increasing number of studies recently have investigated the effect of peripheral regional techniques on patient outcomes. RECENT FINDINGS: Data generally indicate that the perioperative use of regional anesthesia and analgesia may be associated with improvement in both major (e.g. mortality, major morbidity) outcomes and rehabilitation. The majority of evidence favors an ability of epidural analgesia to reduce postoperative cardiovascular and pulmonary complications and there is also consistent evidence that epidural analgesia with local anesthetics is associated with faster resolution of postoperative ileus after major abdominal surgery. Overall, regional analgesic techniques provide statistically superior analgesia compared with systemic opioids. SUMMARY: Perioperative use of regional analgesic techniques may provide improvement in conventional outcomes, although the benefit appears to be limited to high-risk patients and those undergoing high-risk procedures. The benefits conferred by perioperative regional anesthetic techniques need to be weighed against any potential risks and this should be assessed on an individual basis.

An Innovative Perioperative Pain Program for Chronic Opioid Users: An Academic Medical Center's Response to the Opioid Crisis.

Increased utilization of prescription opioids for pain management has led to a nationwide public health crisis with alarming rates of addiction and opioid-related deaths. In the surgical setting, opioid prescriptions have been implicated as a contributing factor to the opioid epidemic. The authors developed an innovative model to address aspects of pain management and opioid utilization during preoperative evaluation, acute surgical hospitalization, and postoperative follow-up for chronic opioid users. This program involves multidisciplinary teams that include acute and chronic pain specialists, psychiatrists, integrative medicine specialists, and physical medicine and rehabilitation services. It also features a novel infrastructure for triage and pain management education and treatment. Individualized patient plans are devised that can include preoperative opioid weaning, regional anesthesia that minimizes opioid use, and multimodal techniques for surgical pain treatment. Multidisciplinary programs such as this have the potential to both improve perioperative pain control and prevent escalation of opioid use among chronic opioid users.

A model for an institutional response to the opioid crisis.

The use of opioid analgesics for pain management has increased dramatically over the past decade, with corresponding increases in negative sequelae including overdose and death. Physicians, policymakers, and researchers are focused on finding ways to decrease opioid use and overdose. This crisis calls for a coordinated response that includes the entire healthcare sector. In this work, the authors lay out a blueprint for such a response at the level of the academic medical center. The proposed model is a comprehensive opioid overdose prevention, response, and education program to evaluate, monitor, and address prescription opioid-related adverse events and addiction among all patients within a healthcare system. The approach includes three inter-related elements: (1) creation of an organizational structure that is subdivided into subcommittees to facilitate cross-functional collaboration and implementation. These subcommittees will focus on Research and Design, Implementation, Advisory, and Compliance with the recommendation. (2) Development of an effective communication plan throughout the institution to enable the organization to function seamlessly and efficiently as a single unit, (3) development of a data tracking and reporting system that intended to have a 360° view of all aspects of opioid prescription and downstream patient outcomes. The most effective response system will require an organizational structure that facilitates the ad hoc constitution of cross-functional teams with members drawn from all levels of the organizational hierarchy (executive leadership to frontline staff). Such a structure provides the teams with immediate solutions as developed by the frontline staff and authority to remove institutional barriers that may delay or limit the successful implementation. The model described was developed in our institution by a cross-functional team that included members from the Johns Hopkins School of Medicine and Johns Hopkins University Carey Business School, Department of Operations Management. The multidisciplinary nature of collaboration allowed us to develop a model for an immediate institution-wide response to the opioid crisis, and one that other healthcare organizations could adopt with local modification as a template for execution. The model also meant to serve as a template for an institutional rapid-response that can be seamlessly implemented during any future drug-related crisis or epidemic.

Opioid-Prescribing Guidelines for Common Surgical Procedures: An Expert Panel Consensus.

BACKGROUND: One in 16 surgical patients prescribed opioids becomes a long-term user. Overprescribing opioids after surgery is common, and the lack of multidisciplinary procedure-specific guidelines contributes to the wide variation in opioid prescribing practices. We hypothesized that a single-institution, multidisciplinary expert panel can establish consensus on ideal opioid prescribing for select common surgical procedures. STUDY DESIGN: We used a 3-step modified Delphi method involving a multidisciplinary expert panel of 6 relevant stakeholder groups (surgeons, pain specialists, outpatient surgical nurse practitioners, surgical residents, patients, and pharmacists) to develop consensus ranges for outpatient opioid prescribing at the time of discharge after 20 common procedures in 8 surgical specialties. Prescribing guidelines were developed for opioid-naïve adult patients without chronic pain undergoing uncomplicated procedures. The number of opioid tablets was defined using oxycodone 5 mg oral equivalents. RESULTS: For all 20 surgical procedures reviewed, the minimum number of opioid tablets recommended by the panel was 0. Ibuprofen was recommended for all patients unless medically contraindicated. The maximum number of opioid tablets varied by procedure (median 12.5 tablets), with panel recommendations of 0 opioid tablets for 3 of 20 (15%) procedures, 1 to 15 opioid tablets for 11 of 20 (55%) procedures, and 16 to 20 tablets for 6 of 20 (30%) procedures. Overall, patients who had the procedures voted for lower opioid amounts than surgeons who performed them. CONCLUSIONS: Procedure-specific prescribing recommendations may help provide guidance to clinicians who are currently overprescribing opioids after surgery. Multidisciplinary, patient-centered consensus guidelines for more procedures are feasible and may serve as a tool in combating the opioid crisis.

Laparoscopic Total Pancreatectomy With Islet Autotransplantation and Intraoperative Islet Separation as a Treatment for Patients With Chronic Pancreatitis.

Importance: Pain management of patients with chronic pancreatitis (CP) can be challenging. Laparoscopy has been associated with markedly reduced postoperative pain but has not been widely applied to total pancreatectomy with islet autotransplantation (TPIAT). Objective: To examine the feasibility of using laparoscopic TPIAT (L-TPIAT) in the treatment of CP. Design, Setting, and Participants: Thirty-two patients with CP presented for TPIAT at a tertiary hospital from January 1, 2013, through December 31, 2015. Of the 22 patients who underwent L-TPIAT, 2 patients converted to an open procedure because of difficult anatomy and prior surgery. Pain and glycemic outcomes were recorded at follow-up visits every 3 to 6 months postoperatively. Main Outcomes and Measures: Operative outcomes included operative time, islet isolation time, warm ischemia time, islet equivalent (IE) counts, estimated blood loss, fluid resuscitation, and blood transfusions. Postoperative outcomes included length of stay, all-cause 30-day readmission rate, postoperative complications, mortality rate, subjective pain measurements, opioid use, random C-peptide levels, insulin requirements, and glycated hemoglobin level. Results: Of the 32 patients who presented for TPIAT, 20 underwent L-TPIAT (8 men and 12 women; mean [SD] age, 39 [13] years; age range, 21-58 years). Indication for surgery was CP attributable to genetic mutation (n = 9), idiopathic pancreatitis (n = 6), idiopathic pancreatitis with pancreas divisum (n = 3), and alcohol abuse (n = 2). Mean (SD) operative time was 493 (78) minutes, islet isolation time was 185 (37) minutes, and warm ischemia time was 51 (62) minutes. The mean (SD) IE count was 1325 (1093) IE/kg. The mean (SD) length of stay was 11 (5) days, and the all-cause 30-day readmission rate was 35% (7 of 20 patients). None of the patients experienced postoperative surgical site infection, hernia, or small-bowel obstruction, and none died. Eighteen patients (90%) had a decrease or complete resolution of pain, and 12 patients (60%) no longer required opioid therapy at a median follow-up period of 6 months. Postoperative random insulin C-peptide levels were detectable in 19 patients (95%) at a median follow-up of 10.4 months. At a median follow-up of 12.5 months, 5 patients (25%) were insulin independent, whereas 9 patients (45%) required 1 to 10 U/d, 5 patients (25%) required 11 to 20 U/d, and 1 patient (5%) required greater than 20 U/d of basal insulin. The mean (SD) glycated hemoglobin level was 7.4% (0.5%). Conclusions and Relevance: This study represents the first series of L-TPIAT, demonstrating its safety and feasibility. Our approach enables patients to experience shorter operative times and the benefits of laparoscopy, including reduced length of stay and quicker opioid independence.

Perioperative pain management education: a short structured regional anesthesia course compared with traditional teaching among medical students.

BACKGROUND AND OBJECTIVES: Previous research has demonstrated that a brief course on pain management improved knowledge and attitudes toward analgesic use among medical students. The purpose of this study is to compare a structured clinical instruction course on regional anesthesia techniques for perioperative pain management with traditional teaching given to senior medical students. METHODS: During a 1-month clerkship in anesthesiology, 40 fourth-year medical students were randomly and equally divided into 2 groups. The study group received a 2-hour structured course on regional anesthesia techniques for pain management, whereas the control group received a 1-hour lecture tutorial on regional anesthesia techniques for perioperative pain management and 1 hour of bedside teaching on acute pain management. Each student completed an objective structured clinical examination (OSCE) 2 weeks after completion of the course. RESULTS: The study group performed better on each of the 11 items of the OSCE and on the total performance scores (mean +/- SD of 36.2 +/- 7.3 for study group versus 14.8 +/- 8.4 for the control group; P < .05). All students rated the clinical course highly valuable (4.7 +/- 0.5). CONCLUSION: A structured clinical instructional course on regional techniques for perioperative pain management given to fourth-year medical students can significantly improve their understanding and knowledge compared with traditional teaching.

Does patient perception of pain control affect patient satisfaction across surgical units in a tertiary teaching hospital?

In this study, the relationship between patients' perceptions of pain control during hospitalization and their overall satisfaction with care was examined. Satisfaction data were collected from the federally mandated Hospital Consumer Assessment of Healthcare Providers and Systems survey for 4349 adult patients admitted to any surgical unit over an 18-month period. Patients' perceptions of pain control and staff's efforts to control pain were associated with their overall satisfaction scores. These perceptions varied widely among services and nursing units. Interestingly, patient satisfaction was more strongly correlated with the perception that caregivers did everything they could to control pain than with pain actually being well controlled. The odds of a patient being satisfied were 4.86 times greater if pain was controlled and 9.92 times greater if the staff performance was appropriate. Hospitals may improve their patients' satisfaction by focusing on improving the culture of pain management.

Comparison of the postoperative analgesic efficacy of intravenous patient-controlled analgesia with tramadol to intravenous patient-controlled analgesia with opioids.

BACKGROUND: Intravenous patient-controlled analgesia (IV PCA) with tramadol is an accepted method to deliver postoperative analgesia outside North America; however, the analgesic efficacy of this analgesic agent when compared with IVPCA with opioids is uncertain. As such, the authors undertook a systematic review to compare the analgesic efficacy of IVPCA tramadol with that of IVPCA with opioids. METHODS: The authors used the National Library of Medicine's Medline database to search for terms related to tramadol and patient-controlled analgesia. Inclusion criteria were randomized controlled trials (RCTs) comparing IVPCA tramadol with IVPCA opioid and RCTs published in the English language. Relevant data were abstracted from accepted studies. Meta-analysis was performed using RevMan 4.2.10 (The Cochrane Collaboration, 2004). A random effects model was used. RESULTS: A total of 190 abstracts were obtained from the above search, and a total of 12 RCTs met the above inclusion criteria. There was no difference in weighted visual analog scale pain scores between IVPCA tramadol versus IVPCA opioid at 48 hours postoperatively or risk of sedation or fatigue. IVPCA tramadol was associated with a higher odds of postoperative nausea and vomiting [odds ratio (OR) = 1.52, 95% confidence interval (CI) = 1.07-2.14) but a lower odds of pruritus (OR = 0.43, 95% CI = 0.19-0.98). DISCUSSION: IVPCA tramadol appears to produce similar pain scores when compared with that from IVPCA opioids; however, the side effect profile is different between the two groups. Because of the relatively small sample size, no determination of the relative "safety" (eg, respiratory depression) of one regimen over the other can be made, and larger RCTs would be needed for such a determination.

The effect of intravenous opioid patient-controlled analgesia with and without background infusion on respiratory depression: a meta-analysis.

BACKGROUND: Although the addition of a background infusion for intravenous patient-controlled analgesia (IV-PCA) has been identified as a risk factor for the development of respiratory depression, this has not clearly been examined in a systematic fashion. The authors undertook a systematic review and meta-analysis of available randomized controlled trials (RCTs) to examine whether the addition of a background or continuous infusion to an IV-PCA regimen would be associated with an increased risk of respiratory depression. METHODS: Studies were identified by searching the National Library of Medicine's PubMed database (1966 to November 30, 2008). Inclusion criteria were a clearly defined analgesic technique of demand-only IV-PCA versus IV-PCA utilizing both a demand dose and background infusion, opioid medication used, and randomized trials. Data were abstracted and analyzed with the RevMan 4.2.7 (The Cochrane Collaboration, 2004). RESULTS: The search yielded 687 abstracts from which the original articles were obtained and data abstracted with a total of 14 articles analyzed. There were 402 subjects in the continuous IV-PCA with demand group versus the 394 subjects in the demand-only IV-PCA group. Addition of a background infusion to the demand dose for IV-PCA with opioids was associated with a significant increased risk for respiratory depression (odds ratio [OR] = 4.68, 95% confidence interval [CI]: 1.20-18.21). Subgroup analysis revealed that this increased risk was seen in adult but not in pediatric patients. CONCLUSIONS: Our meta-analysis indicates that the addition of a continuous or background infusion to the demand dose for IV-PCA is associated with a higher incidence of respiratory events than demand IV-PCA alone in adult but not in pediatric patients; however, our overall results should be interpreted with caution due to the relatively small sample size and the wide range of definitions for respiratory depression in studies examined.