Agents of change: the Gaston Labat awardees past, present, and future-the 2021 Gaston Labat Award lecture

The prior recipients of the Gaston Labat Award can be thought of as change agents because of their driving desire to challenge and improve the status quo. All of us are interconnected and should seek to collectively work toward meaningful change in our communities. The 2021 Gaston Labat lecture pays tribute to past agents of change and inspires those to come by urging everyone to become involved in the solution.

Feasibility and Rationale for Incorporating Frailty and Cognitive Screening Protocols in a Preoperative Anesthesia Clinic

BACKGROUND

Advanced age, frailty, low education level, and impaired cognition are generally reported to be associated with postoperative cognitive complications. To translate research findings into hospital-wide preoperative assessment clinical practice, we examined the feasibility of implementing a preoperative frailty and cognitive assessment for all older adults electing surgical procedures in a tertiary medical center. We examined associations among age, education, frailty, and comorbidity with the clock and 3-word memory scores, estimated the prevalence of mild to major cognitive impairment in the presurgical sample, and examined factors related to hospital length of stay.

METHODS

Medical staff screened adults ≥65 years of age for frailty, general cognition (via the clock-drawing test command and copy, 3-word memory test), and obtained years of education. Feasibility was studied in 2 phases: (1) a pilot phase involving 4 advanced nurse practitioners and (2) a 2-month implementation phase involving all preoperative staff. We tracked sources of missing data, investigated associations of study variables with measures of cognition, and used 2 approaches to estimate the likelihood of dementia in our sample (ie, using extant data and logistic regression modeling and using Mini-Cog cut scores). We explored which protocol variables related to hospital length of stay.

RESULTS

The final implementation phase sample included 678 patients. Clock and 3-word memory scores were significantly associated with age, frailty, and education. Education, clock scores, and 3-word scores were not significantly different by surgery type. Likelihood of preoperative cognitive impairment was approximately 20%, with no difference by surgery type. Length of stay was significantly associated with preoperative comorbidity and performance on the clock copy condition.

CONCLUSIONS

Frailty and cognitive screening protocols are feasible and provide information for perioperative care planning. Challenges to clinical adaptation include staff training, missing data, and additional administration time. These challenges appear minimal relative to the benefits of identifying frailty and cognitive impairment in a group at risk for negative postoperative cognitive outcome.

Incorporating airway examination photography into the electronic record

BACKGROUND

Photography of the airway has been used in research to validate preoperative airway assessment and the likelihood of identifying the difficult-to-mask ventilate and/or intubate patient. Up till now, no study has demonstrated the perceived utility of incorporation of airway photographs into the anesthesia preassessment.

METHODS

The University of Florida Health Presurgical Clinic routinely incorporates three photographs of all adult patients during their preanesthesia visit. The first is a head-on view of the patient opening the mouth widely as part of a Mallampati examination, and the second and third are side views of the patient prognathing and with the neck in maximal extension, respectively. After IRB approval, providers of anesthesia were surveyed regarding their opinions on the perceived value of the new process. Chi-square tests were used to determine if the responses to each question significantly differed from the distribution that would be predicted by chance. P < 0.05 was considered statistically significant.

RESULTS

The survey was emailed to 180 individuals, with 145 responding. The responses significantly (P < 0.0001) indicated that the photographs helped the providers plan care for their patients and improved their satisfaction with the preoperative assessment. Technical and educational barriers were overcome using iterative Plan-Do-Study-Act cycles and coaching, respectively.

CONCLUSIONS

Photographs of the airway assessment can successfully be taken and incorporated into an electronic medical record in a busy presurgical clinic. The pictures provide additional perceived value to the traditional written assessment of a patient's airway examination by someone else.

A single consent for serial anesthetics in burn surgery

Obtaining anesthesia informed consent for a series of repetitive debridements in burn-injured patients requires a significant time investment for anesthesiologists and patient families. A single consent form was introduced that covered multiple related anesthetics in burn patients. The number of consents per patient before and after implementation was analyzed using Welch ANOVA; Tukey-Kramer post hoc test, with 99% confidence intervals for mean differences was used to examine pairwise comparisons. The mean number of consents per patient was 4.5 ± 2.8 and 1.6 ± 0.51 (P < 0.001) before (2010) and after implementation (2013), respectively. The Multiple Related Anesthetics Consent Form in this population resulted in less time spent by anesthesia providers in obtaining consent for patients undergoing multiple related procedures while providing patient- and family-centric care.

Universal intravenous access cleaning device fails to sterilize stopcocks

BACKGROUND

Contamination of a central venous catheter may occur through use of conventional open-lumen stopcock devices (COLDs), or disinfectable, needleless, closed connectors (DNCCs). We investigated the effectiveness of a new universal IV access cleaning device (Site-Scrub) compared with 70% isopropyl alcohol prep pads for sanitizing COLDs or DNCCs inoculated with common catheter-associated pathogens.

METHODS

Site-Scrub was compared with 70% alcohol prep pads for sanitizing contaminated female Luer lock COLD or DNCC filled with sterile saline or propofol and 2 common bacterial central venous catheter contaminants (Staphylococcus epidermidis or Pseudomonas aeruginosa). Devices were contaminated using a glove touch (COLD and DNCC) or syringe tip (COLD). The primary end point of the study was colony-forming units (CFU) after 24 hours.

RESULTS

The use of glove touch contamination, the contaminants, S epidermidis and P aeruginosa, produced CFU in saline-filled COLDs treated with the Site-Scrub, but not in those treated with alcohol pads (P < 0.001). Similar results were observed with propofol-filled COLDs (P < 0.001). For DNCCs filled with saline or propofol, both alcohol and Site-Scrub effectively reduced CFU growth compared with contaminated controls (P < 0.001). When COLDs were contaminated by treated syringe tips, there was no significant evidence of reduction in CFU growth by using either alcohol pads or Site-Scrub compared with contaminated controls.

CONCLUSIONS

These data suggest that when the inner surface of the COLD is contaminated, both alcohol pads and Site-Scrub were not significantly effective in decontaminating the COLD. When the COLD rim is contaminated, however, alcohol pads outperform Site-Scrub. DNCCs were uniformly decontaminated with either treatment. Future work should focus on better access systems because current COLDs are difficult to decontaminate.

Anesthesiology leadership rounding: identifying opportunities for improvement

INTRODUCTION

Rounding that includes participation of individuals with authority to implement changes has been advocated as important to the transformation of an institution into a high-quality and safe organization. We describe a Department of Anesthesiology's experience with leadership rounding.

METHODS

The Department Chair or other senior faculty designate, a quality coordinator, up to four residents, the ward charge nurse, and patient nurses participated in rounds at bedsides.

RESULTS

During a 23-month period, 14 significant opportunities to improve care were identified. Nurses identified 5 of these opportunities, primary team physicians 2, the rounding team 4, and patients or their family members another 3. The anesthesiology service had sole or shared responsibility for 10 improvements.

CONCLUSION

A variety of organizations track specific measures across all phases of the patient experience to gauge quality of care. Chart auditing tools for detecting threats to safety are often used. These measures and tools missed opportunities for improvement that were discovered only through rounding. We conclude that the introduction of leadership rounding by an anesthesiology service can identify opportunities for improving quality that are not captured by conventional efforts.

Health-related quality of life after hip arthroplasty with and without an extended-duration continuous posterior lumbar plexus nerve block: a prospective, 1-year follow-up of a randomized, triple-masked, placebo-controlled study

BACKGROUND

We previously reported that extending an overnight continuous posterior lumbar plexus nerve block to 4 days after hip arthroplasty provides clear benefits during the perineural infusion in the immediate postoperative period. However, it remains unknown whether the extended infusion improves subsequent health-related quality of life.

METHODS

Patients undergoing hip arthroplasty received a posterior lumbar plexus perineural infusion of ropivacaine 0.2% from surgery until the following morning, at which time patients were randomized to continue either perineural ropivacaine (n = 24) or normal saline (n = 23) in a double-masked fashion. Patients were discharged with their catheter and a portable infusion pump, and catheters were removed on postoperative Day 4. Health-related quality of life was measured using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index preoperatively and then at 7 days and 1, 2, 3, 6, and 12 mo after surgery. The WOMAC evaluates three dimensions of health-related quality of life, such as pain, stiffness, and physical functional disability (global score of 0-96, lower scores indicate lower levels of symptoms or physical disability). For inclusion in the primary analysis, we required a minimum of three of the six timepoints, including Day 7 and at least two of Months 3, 6, and 12.

RESULTS

The two treatment groups had similar global WOMAC scores for the mean area under the curve calculations (point estimate for the difference in mean area under the curve for the two groups [extended infusion group-overnight infusion group] = 0.8, 95% confidence interval: -5.3 to + 6.8 [-5.5% to + 7.1%]; P = 0.80) and at all individual timepoints (P > 0.05).

CONCLUSIONS

This investigation found no evidence that extending an overnight continuous posterior lumbar plexus nerve block to 4 days improves (or worsens) subsequent health-related quality of life between 7 days and 12 mo after hip arthroplasty.

Health-related quality of life after tricompartment knee arthroplasty with and without an extended-duration continuous femoral nerve block: a prospective, 1-year follow-up of a randomized, triple-masked, placebo-controlled study

BACKGROUND

We previously provided evidence that extending an overnight continuous femoral nerve block to 4 days after tricompartment knee arthroplasty (TKA) provides clear benefits during the perineural infusion in the immediate postoperative period. However, it remains unknown if the extended infusion improves subsequent health-related quality of life between 7 days and 12 mo.

METHODS

Patients undergoing TKA received a femoral perineural infusion of ropivacaine 0.2% from surgery until the following morning, at which time patients were randomized to either continue perineural ropivacaine (n = 25) or normal saline (n = 25) in a double-masked fashion. Patients were discharged with their catheter and a portable infusion pump, and catheters were removed on postoperative day 4. Health-related quality of life was measured using the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index preoperatively and then at 7 days, as well as 1, 2, 3, 6, and 12 mo after surgery. The WOMAC evaluates three dimensions of health-related quality of life: pain, stiffness, and physical functional disability. For inclusion in the analysis, we required a minimum of 4 of the 6 time points, including day 7 and at least 2 of mo 3, 6, and 12.

RESULTS

The two treatment groups had similar WOMAC scores for the mean area under the curve calculations (point estimate for the difference in mean area under the curve for the two groups [overnight infusion group-extended infusion group] = 1.2, 95% confidence interval: -5.6 to +8.0; P = 0.72) and at all individual time points (P > 0.05).

CONCLUSIONS

We found no evidence that extending an overnight continuous femoral nerve block to 4 days improves (or worsens) subsequent health-related quality of life between 7 days and 12 mo after TKA. (ClinicalTrials.gov number, NCT00135889.).

Finite-Difference Modeling of the Anisotropic Electric Fields Generated by Stimulating Needles Used for Catheter Placement

The use of peripheral nerve blocks to control pain is an increasing practice. Many techniques include the use of stimulating needles to locate the nerve of interest. Though success rates are generally high, difficulties still exist. In certain deeper nerve blocks, two needles of different geometries are used in the procedure. A smaller needle first locates a nerve bundle, and then is withdrawn in favor of a second, larger needle used for injection. The distinct geometries of these needles are shown to generate different electric field distributions, and these differences may be responsible for failures of the second needle to elicit nerve stimulation when placed in the same location as the first. A 3-D finite-difference method has been employed to numerically calculate the electric field distributions for a commercial set of stimulating needles.

Falls associated with lower-extremity-nerve blocks: a pilot investigation of mechanisms

OBJECTIVE

Documented falls after lower-extremity-nerve blocks are rare. We believe this paucity of documented falls is the result of underreporting and the lack of serious complications resulting from these falls. In addition, the mechanism(s) for falls after lower-extremity-nerve blocks has not been elucidated.

CASE REPORTS

These reports highlight the mechanism of fall in a patient with a femoral-nerve block (FNB) and in a patient with a femoral-nerve and sciatic-nerve block (FNB/SNB). In addition, we report our findings when volunteers underwent FNB, sciatic-nerve block (SNB) and FNB/SNB and were studied in a gait-analysis laboratory.

CONCLUSIONS

Lower-extremity-nerve blocks result in decreased leg stiffness and lateral instability, which may lead to difficulty with pivoting maneuvers.

Ambulatory continuous interscalene nerve blocks decrease the time to discharge readiness after total shoulder arthroplasty: a randomized, triple-masked, placebo-controlled study

BACKGROUND

A continuous interscalene nerve block (CISB) may be used to provide analgesia after shoulder arthroplasty. Therefore, inpatient stays may be shortened if CISB (1) provides adequate analgesia without intravenous opioids and (2) improves shoulder mobilization. This study investigated the relationship between ambulatory CISB and the time to reach three discharge criteria after shoulder arthroplasty.

METHODS

Preoperatively, patients received a CISB. All patients received a perineural 0.2% ropivacaine infusion from surgery until 06:00 the following morning, at which time they were randomly assigned either to continue perineural ropivacaine or to switch to normal saline. The primary endpoint was the time from the end of surgery until three discharge criteria were attained (adequate analgesia, independence from intravenous analgesics, and tolerance to 50% of shoulder motion targets). Patients were discharged home as early as the afternoon after surgery with their CISB using a portable infusion pump.

RESULTS

Patients receiving perineural ropivacaine (n = 16) attained all three discharge criteria in a median (10th-90th percentiles) of 21 (16-41) h, compared with 51 (37-90) h for those receiving perineural normal saline (n = 13, P < 0.001). Unlike patients receiving perineural ropivacaine, patients receiving perineural normal saline often required intravenous morphine, but still experienced a higher degree of pain and tolerated less external rotation.

CONCLUSIONS

An ambulatory CISB considerably decreases the time until readiness for discharge after shoulder arthroplasty, primarily by providing potent analgesia that permits greater passive shoulder movement and the avoidance of intravenous opioids. Additional research is required to define the appropriate subset of patients and assess the incidence of complications associated with earlier discharge.

Total hip arthroplasty as an overnight-stay procedure using an ambulatory continuous psoas compartment nerve block: a prospective feasibility study

OBJECTIVE

Total hip arthroplasty (THA) results in severe postoperative pain requiring hospitalization to provide potent analgesia. Consequently, the average duration of hospitalization after THA in the United States is 4 to 5 days. This prospective study investigated the feasibility of converting THA into an overnight-stay procedure using a continuous psoas compartment nerve block provided at home with a portable infusion pump.

CASE REPORT

Preoperatively, patients undergoing THA had a psoas compartment perineural catheter placed. Postoperatively, perineural ropivacaine 0.2% was delivered through postoperative day (POD) 4. Patients were discharged home when they met specific, prospectively defined criteria, as early as POD 3 for the first phase and POD 1 for the second phase. Of the patients in the first phase (n = 7) who remained hospitalized for at least 3 postoperative nights, 5 met discharge criteria on POD 1 and the remainder on POD 2. Of the patients in phase 2 (n = 5), all but 1 met discharge criteria on POD 1 and 3 were discharged directly home on POD 1. Postoperative pain was well controlled, opioid requirements and sleep disturbances were minimal, and patient satisfaction high.

CONCLUSIONS

These results suggest that for a subset of patients without major comorbidities, it is feasible to convert THA into an overnight-stay procedure using an ambulatory continuous psoas compartment nerve block as part of a multimodal analgesic regimen provided at home. Additional research is required to replicate these results in a controlled trial, define the appropriate subset of patients, and assess the incidence of complications associated with this practice before its mainstream use.

Total elbow arthroplasty as an outpatient procedure using a continuous infraclavicular nerve block at home: a prospective case report

OBJECTIVE

Total elbow arthroplasty (TEA) often results in severe postoperative pain requiring hospitalization to provide potent analgesia. This prospective series investigated the feasibility of converting TEA into an ambulatory procedure using a continuous infraclavicular nerve block provided at home with a portable infusion pump.

CASE REPORT

Preoperatively, patients undergoing TEA had an infraclavicular perineural catheter and peripheral nerve block placed. Postoperatively, perineural ropivacaine was delivered through postoperative day (POD) 3 to 6. Patients were discharged home when they met specific, prospectively defined criteria as early as POD 1 for the first phase and directly from the recovery room for the second phase. Of the 2 patients in the first phase who remained hospitalized for at least 1 postoperative night, both met discharge criteria in the recovery room, required no medical interventions during their admission, and were discharged home the following morning. The patient of phase 2 met discharge criteria in the recovery room and was discharged home at that time. Postoperative pain was well controlled, opioid requirements and sleep disturbances were minimal, and patient satisfaction was high for all patients.

CONCLUSIONS

These cases suggest that for a subset of patients without major comorbidities, it is feasible to convert total elbow arthroplasty into an ambulatory procedure using a continuous infraclavicular nerve block as part of a multimodal analgesic regimen provided at home. Additional research is required to replicate these results in a controlled trial, define the appropriate subset of patients, and assess the incidence of complications associated with this practice before its mainstream use.

Joint range of motion after total shoulder arthroplasty with and without a continuous interscalene nerve block: a retrospective, case-control study

BACKGROUND AND OBJECTIVES

Although a continuous interscalene nerve block (CISB) has been shown to provide potent analgesia after major shoulder surgery, its potential effects on postoperative rehabilitation remain uninvestigated. Therefore, this retrospective case-control study was undertaken to determine the association between CISB and joint range-of-motion after total shoulder arthroplasty (TSA).

METHODS

The medical records for patients who underwent TSA at our institution in the previous 3 years were examined. Each patient with a CISB (cases) was matched with a patient without a CISB (controls) for the following variables: age, gender, and TSA type (primary v revision). Data collected included maximum shoulder elevation and external rotation (primary endpoints), along with pre- and postoperative pain scores.

RESULTS

Of 134 charts reviewed, 25 cases were matched with an equal number of controls. On postoperative day 1, patients with or without a CISB achieved a median (5th-95th percentiles) of 85% (51-100) and 33% (11-56) of their surgeon-defined goal for elevation (P = .048), respectively, and attained 100% (33-100) and 17% (-81-68) for external rotation (P < .001), respectively. The median numeric rating pain score (NRS) during shoulder movement for patients with CISB was 2.0 (0.0-8.7) versus 8.5 (1.8-10.0) for patients without CISB (P < .001). Least, median, and highest resting NRS for the 24 hours after surgery were 0.0 (0.0-5.8), 1.0 (0.0-6.4), and 3.0 (0.0-9.0) for patients with CISB, respectively, versus 2.0 (0.0-7.7), 6.0 (0.3-9.6), and 8.0 (0.0-10.0) for patients without CISB (P = .030, P < .001, and P < .001 between groups, respectively).

CONCLUSIONS

The day after TSA, a CISB is associated with increased shoulder range of motion, most likely resulting from the potent analgesia these nerve blocks provide.

Total Knee Arthroplasty as an Overnight-Stay Procedure Using Continuous Femoral Nerve Blocks at Home: A Prospective Feasibility Study

The average duration of hospitalization after total knee arthroplasty (TKA) in the United States is 4-5 days. In this two-phase study we investigated the feasibility of converting TKA into an overnight-stay procedure using a continuous femoral nerve block provided at home through postoperative day 4. Nine of 10 patients met discharge criteria and were discharged home the day after surgery. Pain was well controlled, opioid requirements and sleep disturbances were minimal, and patient satisfaction was high. Additional research is required to replicate these results in a controlled trial, define the appropriate subset of patients, and assess the incidence of complications associated with this practice before its mainstream use.

Total shoulder arthroplasty as an outpatient procedure using ambulatory perineural local anesthetic infusion: a pilot feasibility study

We investigated the feasibility of converting total shoulder arthroplasty (TSA) into an outpatient procedure using ambulatory interscalene perineural ropivacaine infusion. Of the patients of the first phase (n = 8) who were required to remain hospitalized for at least 1 postoperative night, 5 met discharge criteria in the recovery room. Of the subsequent patients of the second phase (n = 6), all met discharge criteria in the recovery room after surgery, and 5 were discharged directly home. For all patients, postoperative pain was well controlled, oral opioid requirements and sleep disturbances were minimal, range-of-motion consistently reached or exceeded the surgeon's expectations, and patient satisfaction was high. These results suggest that TSA may be performed on an outpatient basis using perineural local anesthetic infusion. Additional research is required to define the appropriate subset of patients and assess the incidence of complications associated with this practice before its mainstream use.

Continuous Peripheral Nerve Blocks at Home: A Review

Postoperative analgesia is generally limited to 12-16 h or less after single-injection regional nerve blocks. Postoperative analgesia may be provided with a local anesthetic infusion via a perineural catheter after initial regional block resolution. This technique may now be used in the outpatient setting with the relatively recent introduction of reliable, portable infusion pumps. In this review article, we summarize the available published data related to this new analgesic technique and highlight important issues related specifically to perineural infusion provided in patients' own homes. Topics include infusion benefits and risks, indications and patient selection criteria, catheter, infusion pump, dosing regimen, and infusate selection, and issues related specifically to home-care.

Clonidine Added to a Continuous Interscalene Ropivacaine Perineural Infusion to Improve Postoperative Analgesia: A Randomized, Double-Blind, Controlled Study

Although clonidine has been shown to increase the duration of local anesthetic action and prolong postoperative analgesia when included in single-injection nerve blocks, the only controlled investigation of the efficacy of this practice to improve analgesia for continuous perineural local anesthetic infusion failed to discern any clinically relevant benefits. For this study, we used a larger dose of clonidine in an attempt to improve analgesia. Patients (n = 20) undergoing moderately painful orthopedic surgery of the shoulder received an interscalene brachial plexus block (40 mL of mepivacaine 1.5%, epinephrine 2.5 microg/mL, and clonidine 50 microg) and a perineural catheter before surgery. After surgery, ropivacaine 0.2% or ropivacaine 0.2% plus clonidine 2 microg/mL was delivered via the catheter for 3 days (basal rate, 5 mL/h; patient-controlled bolus, 5 mL; lockout, 1 h). Investigators and patients were blind to random group assignment. The primary outcome variable was designated as the most intense pain during the day after surgery. Secondary end-points included additional pain scores, patient-controlled bolus doses, oral analgesic use, sleep quality, and catheter- or infusion-related complications. There were no statistically significant differences between groups for any of the variables investigated. We conclude that adding clonidine 2 microg/mL to a ropivacaine interscalene perineural infusion does not decrease breakthrough pain intensity the day after surgery. For the additional end-points, our negative findings are only suggestive of a lack of effect and require further study for verification.

Popliteal sciatic perineural local anesthetic infusion: a comparison of three dosing regimens for postoperative analgesia

BACKGROUND

This randomized, double-blind study investigated the efficacy of continuous and patient-controlled ropivacaine infusion via a popliteal sciatic perineural catheter in ambulatory patients undergoing moderately painful orthopedic surgery of the foot or ankle.

METHODS

Preoperatively, patients (n = 30) received a posterior popliteal sciatic perineural catheter and nerve block. Postoperatively, patients were discharged home with a portable infusion pump delivering 0.2% ropivacaine (500 ml) in one of three dosing regimens: the basal group (12-ml/h basal rate, 0.05-ml patient-controlled bolus dose), the basal-bolus group (8-ml/h basal rate, 4-ml bolus dose), or the bolus group (0.3-ml/h basal rate, 9.9-ml bolus dose).

RESULTS

The bolus group experienced an increase in baseline pain, breakthrough pain incidence and intensity, and sleep disturbances compared with the other two groups (P < 0.05 for all comparisons). Compared with the basal-bolus group, the basal group experienced an increase in these outcome measures only after local anesthetic reservoir exhaustion, which occurred earlier than in the other two groups (P < 0.05 for all comparisons). Satisfaction scores did not differ among the three groups.

CONCLUSIONS

This study demonstrates that when providing analgesia with 0.2% ropivacaine via a popliteal sciatic perineural catheter after moderately painful surgery of the foot or ankle, a continuous infusion is required to optimize infusion benefits. Furthermore, adding patient-controlled bolus doses allows for a lower continuous basal rate and decreased local anesthetic consumption and thereby increases the duration of infusion benefits when in an ambulatory environment with a limited local anesthetic reservoir.

Interscalene perineural ropivacaine infusion:a comparison of two dosing regimens for postoperative analgesia

BACKGROUND AND OBJECTIVS: A continuous interscalene nerve block with a perineural infusion of ropivacaine 0.2% at 8 mL/h has been shown to provide potent analgesia following moderately painful shoulder surgery. However, this high basal rate limits infusion duration for ambulatory patients who must carry the local anesthetic reservoir. We undertook this investigation to determine if the basal rate of an interscalene perineural ropivacaine infusion could be decreased by 50% with a concurrent 200% increase in patient-controlled bolus dose without compromising infusion benefits in ambulatory patients undergoing moderately painful orthopedic shoulder surgery.

METHODS

Preoperatively, patients (n = 24) received an interscalene perineural catheter and nerve block. Intraoperatively, patients received a standardized general anesthetic. Postoperatively, patients were discharged home with a portable infusion pump delivering ropivacaine 0.2% (500 mL reservoir) with a basal rate of 8 mL/h and a 2 mL patient-controlled bolus available each hour ("8/2" group, n = 12) or a 4 mL/h basal rate and 6 mL bolus dose ("4/6" group, n = 12), delivered in a randomized, double-blinded manner.

RESULTS

Patients in the 4/6 group had higher baseline pain scores only on postoperative day (POD) 2 (P =.011). However, these patients also experienced an increase in breakthrough pain incidence (5.8 boluses/d v 3.2, P =.035) and intensity ("worst" pain = 8/10 v 4/10, P <.05), sleep disturbances (2.0 v 0.0, P <.001), and a decrease in analgesia satisfaction (8 v 10, P =.003). Patients in the 8/2 group exhausted their local anesthetic reservoirs after a median of 61 hours, while the 4/6 group had a median of 131 mL remaining at infusion discontinuation after a median of 75 hours (P <.001).

CONCLUSIONS

Following moderately painful ambulatory shoulder surgery, decreasing an interscalene perineural ropivacaine 0.2% basal rate from 8 to 4 mL/h provides similar baseline analgesia and lengthens infusion duration, but compromises other infusion benefits.

Portable infusion pumps used for continuous regional analgesia: delivery rate accuracy and consistency

BACKGROUND AND OBJECTIVES

Multiple benefits of postoperative perineural local anesthetic infusion have been shown including potent analgesia, decreased opioid requirements, and improved rehabilitation. Consequently, portable infusion pumps have been used with increasing frequency to provide perineural infusion for medically unsupervised ambulatory patients. We believe that the infusion rate accuracy and reliability of these pumps infusing potentially toxic doses of medication should be investigated independently. Therefore, we studied the flow-rate accuracy and consistency of various portable infusion pumps that have not been examined previously.

METHODS

Using a computer/mass balance combination to record infusion rates, 6 pumps (3 electronic and 3 non electronic) were tested. Several factors that may influence pump performance were varied: temperature (ambient/skin), battery (replacement/addition), and catheter exchange (wound/perineural).

RESULTS

Infusion rate accuracy differed significantly among the pumps, exhibiting flow rates within +/-15% of their expected rate for 55% to 99% of their infusion duration. Furthermore, the profiles (infusion rate over time) of the various pumps differed significantly depending on the pump power source. Although elastomeric pump infusion rate increased with an increase in temperature, battery life was a limiting factor for one of the electronic pumps. Substituting wound catheters with commonly used perineural catheters did not significantly alter infusion profile.

CONCLUSIONS

Factors such as infusion rate accuracy and consistency, infusion profile, temperature sensitivity, and battery life affect the dose of medication administered by various portable pumps used for continuous regional analgesia. Health care providers should take these factors into consideration when choosing and using a portable infusion pump for local anesthetic administration.

Infraclavicular perineural local anesthetic infusion: a comparison of three dosing regimens for postoperative analgesia

BACKGROUND

In this randomized, double-blind study, the authors investigated the efficacy of continuous and patient-controlled ropivacaine infusions via an infraclavicular perineural catheter in ambulatory patients undergoing moderately painful orthopedic surgery at or distal to the elbow.

METHODS

Preoperatively, patients (n = 30) received an infraclavicular perineural catheter and nerve block. Postoperatively, patients were discharged home with both oral analgesics and a portable infusion pump delivering 0.2% ropivacaine (500-ml reservoir) in one of three dosing regimens: the basal group (12 ml/h basal, 0.05-ml patient-controlled bolus dose), the basal-bolus group (8 ml/h basal, 4 ml bolus), or the bolus group (0.3 ml/h basal, 9.9 ml bolus). Investigators and patients were blinded to random group assignment.

RESULTS

The basal group (n = 10) required more oral analgesics than the basal-bolus group (P = 0.002) and had a shorter median infusion duration than the other two groups (P < 0.001 for both). The bolus group had the longest median infusion duration (P < 0.001 for both) but experienced an increase in breakthrough pain incidence (P = 0.004) and intensity (P = 0.04 vs. basal-bolus group) as well as sleep disturbances (P < 0.001 for both) compared with the other groups. Overall satisfaction was greatest in the basal-bolus group (9.7 +/- 0.5 vs. 7.9 +/- 1.7 and 8.1 +/- 1.5; P < 0.05 for both).

CONCLUSIONS

After moderately painful orthopedic surgery at or distal to the elbow, 0.2% ropivacaine delivered as a continuous infusion combined with patient-controlled bolus doses via an infraclavicular perineural catheter optimizes analgesia while minimizing oral analgesic use compared with basal- or bolus-only dosing regimens.

Ambulatory perineural infusion: the patients' perspective

BACKGROUND AND OBJECTIVES

Ambulatory perineural local anesthetic infusion is a relatively new method for providing postoperative analgesia, and many aspects of this technique remain in the domain of conjecture and speculation. This retrospective chart review and survey was undertaken to investigate patients' opinions on various aspects of their ambulatory perineural infusion experience.

METHODS

Patients who had received an ambulatory perineural infusion from the University of Florida were identified via pharmacy records. Patients were contacted by phone and were asked various questions regarding their experiences and preferences during and after their perineural infusion.

RESULTS

Of 217 patients identified, 215 charts were located and retrieved. Of these, 137 (64%) were successfully contacted and 131 (61%) consented to take part in the survey. More than 97% of patients reported that they felt "safe" during home infusion, that one physician telephone call each night was optimal contact, and that they were comfortable removing the catheter with instructions given over the phone. Only 4% would have preferred to return for catheter removal, and 43% felt that they would have been comfortable with only written instructions for catheter removal.

CONCLUSION

This investigation suggests that perineural local anesthetic infusion is generally well tolerated by ambulatory patients.

Continuous infraclavicular perineural infusion with clonidine and ropivacaine compared with ropivacaine alone: a randomized, double-blinded, controlled study

Although clonidine has been shown to increase the duration of local anesthetic action and prolong postoperative analgesia when included in single-injection nerve blocks, a controlled investigation of the efficacy of this practice to improve analgesia for continuous perineural local anesthetic infusion has not been reported. In this study, ambulatory patients (n = 34) undergoing moderately painful upper extremity orthopedic surgery received an infraclavicular brachial plexus block (mepivacaine 1.5%, epinephrine 2.5 micro g/mL, and bicarbonate 0.1 mEq/mL) and a perineural catheter before surgery. After surgery, patients were discharged home with a portable infusion pump delivering either ropivacaine 0.2% or ropivacaine 0.2% plus clonidine 1 micro g/mL via the catheter for 3 days (basal, 8 mL/h; patient-controlled bolus, 2 mL every 20 min). Investigators and patients were blinded to random group assignment. Daily end-points included pain scores, patient-controlled bolus doses, oral analgesic use, sleep quality, and symptoms of catheter- or infusion-related complications. Adding clonidine to ropivacaine resulted in a statistically significant decrease in the number of self-administered 2-mL bolus doses on postoperative Days 0 and 1 (P < 0.02), but this decreased actual local anesthetic consumption by an average of only 2-7 mL/d (P < 0.02). There were no statistically significant differences between the two groups for any of the other variables investigated, including sleep quality or oral analgesic requirements. We conclude that adding 1 micro g/mL of clonidine to a ropivacaine infraclavicular perineural infusion does not provide clinically relevant improvements in analgesia, sleep quality, or oral analgesic requirements for ambulatory patients having moderately painful upper extremity surgery.

Continuous interscalene brachial plexus block for postoperative pain control at home: a randomized, double-blinded, placebo-controlled study

In this study, we investigated the efficacy of patient-controlled regional analgesia for outpatients undergoing moderately painful orthopedic surgery of the shoulder. Preoperatively, patients (n = 20) received an interscalene nerve block and perineural catheter. Postoperatively, patients were discharged home with both oral opioids and a portable infusion pump delivering either 0.2% ropivacaine or 0.9% saline, determined randomly in a double-blinded manner. Daily end points included pain scores, opioid use and side effects, sleep quality, and technique complications. Ropivacaine (n = 10) infusion significantly reduced pain compared with saline (n = 10) infusion. The average pain at rest (scale: 0-10) on postoperative day 1 (median, 25th-75th percentiles) was 4.8 (4.0-5.0) for the saline group, versus 0.0 (0.0-2.0) for the ropivacaine group (P < 0.001). Oral opioid use and related side effects were also significantly decreased in the ropivacaine group. On postoperative day 1, median tablet consumption was 8.0 (6.5-9.5) and 0.5 (0.0-1.0) for the saline and ropivacaine groups, respectively (P < 0.001). Sleep disturbance scores were nearly threefold greater on the first postoperative night for patients receiving saline (P = 0.013). We conclude that after moderately painful orthopedic surgery of the shoulder, ropivacaine infusion using a portable infusion pump and an interscalene perineural catheter at home decreased pain, opioid use and related side effects, and sleep disturbances.

IMPLICATIONS

This randomized, double-blinded, placebo-controlled study demonstrated that ropivacaine, infused with a portable infusion pump via an interscalene perineural catheter for 3 days at home, significantly decreased postoperative pain after orthopedic surgery of the shoulder. In addition to providing potent analgesia and increasing patient satisfaction, perineural infusion decreased opioid requirements and their associated side effects.

Visual loss and ophthalmoplegia after shoulder surgery

IMPLICATIONS

Ophthalmic complications can occur after a variety of non-ocular surgery. The etiology of postoperative visual loss and eye movement dysfunction is complex and multifactorial. In many cases, more than one perioperative factor may be associated with an adverse ophthalmic outcome.

Delivery rate accuracy of portable, bolus-capable infusion pumps used for patient-controlled continuous regional analgesia

BACKGROUND AND OBJECTIVES

Portable patient-controlled pumps used for perineural local anesthetic infusion appear to be gaining acceptance and are used for an increasing number of medically unsupervised ambulatory patients. The infusion rate accuracy and reliability of these pumps, which allow patient-controlled boluses of potentially toxic medication, has not been independently investigated. We performed this laboratory study to define the flow-rate accuracy, reliability, and profiles of various portable bolus-capable infusion pumps and varied several factors that may influence pump performance.

METHODS

Using a computer/scale combination, 4 electronic pumps were tested with 1 and 2 sets of batteries over 100 hours. One elastomeric pump was tested with its flow-regulator at room temperature (20 degrees C to 24 degrees C), skin temperature (32 degrees C), and increased temperature (36 degrees C). The elastomeric pump was also tested by varying the height of the pump relative to the distal end of the catheter.

RESULTS

Infusion rate accuracy differed significantly among the pumps, exhibiting flow rates within +/-15% of their expected rate for 29% to 100% of their infusion duration. Changing the batteries after 50 hours affected the profile of 1 of the 4 electronic pumps. For the elastomeric pump, an increase in temperature significantly increased the infusion rate. An increase or decrease in pump-to-scale height significantly increased or decreased the infusion rate, respectively.

CONCLUSIONS

These results suggest that factors such as flow-rate accuracy and consistency, infusion profile, and temperature sensitivity should be taken into consideration when choosing a portable infusion pump for local anesthetic administration.

The delivery rate accuracy of portable infusion pumps used for continuous regional analgesia

Portable pumps used for local anesthetic infusion during continuous regional analgesia are gaining acceptance. These pumps are often used for ambulatory patients who are medically unsupervised throughout most of the infusion. However, the performance of these pumps, which infuse potentially toxic medication, has not been independently investigated. We investigated the flow rate accuracy, consistency, and profiles of various portable pumps often used for local anesthetic infusion during continuous regional analgesia. By using a computer/scale combination within a laboratory to record infusion rates, 6 pumps were tested with their flow regulators at expected (30 degrees-32 degrees C) and increased (34 degrees-36 degrees C) temperatures. Infusion rate accuracy differed significantly among the pumps, exhibiting flow rates within +/-15% of their expected rate for 18%-100% of their infusion duration. An increase in temperature also affected pumps to differing degrees, with infusion rates increasing from 0% to 25% for each model tested. These results suggest that factors such as flow rate accuracy and consistency, infusion profile, and temperature sensitivity should be considered when choosing and using a portable infusion pump for local anesthetic administration.

IMPLICATIONS

Portable pumps often used for local anesthetic infusion during continuous regional analgesia exhibit varying degrees of delivery rate accuracy and consistency. Furthermore, increases in temperature result in an increased infusion rate for various pumps investigated. These factors should be taken into consideration when choosing and using a portable infusion pump.

Continuous popliteal sciatic nerve block for postoperative pain control at home: a randomized, double-blinded, placebo-controlled study

BACKGROUND

This randomized, double-blinded, placebo-controlled study investigated the efficacy of patient-controlled regional analgesia using a sciatic perineural catheter in the popliteal fossa and a portable infusion pump for outpatients having moderately painful, lower extremity orthopedic surgery.

METHODS

Preoperatively, patients (n = 30) received a sciatic nerve block and perineural catheter in the popliteal fossa. Postoperatively, patients were discharged with both oral opioids and a portable infusion pump delivering study solution (0.2% ropivacaine or 0.9% saline) via the catheter for 3 days. Investigators and patients were blinded to random group assignment. Daily end-points included pain scores, opioid use and side effects, sleep quality, and symptoms of catheter- or local anesthetic-related complications.

RESULTS

Ropivacaine (n = 15) infusion significantly reduced pain compared with saline (n = 15) infusion ( < 0.001). For example, the average pain at rest (scale: 0-10) on postoperative day 1 (median, 25th -75th percentile) was 4.0 (3.5-5.5) for the saline group, versus 0.0 (0.0-0.0) for the ropivacaine group (P < 0.001). Oral opioid use and related side effects were significantly decreased in the ropivacaine group. For example, on postoperative day 1, median tablet consumption was 8.0 (5.0-10.0) and 0.0 (0.0-0.0) for the saline and ropivacaine groups, respectively (P < 0.001). Sleep disturbance scores were more than 10-fold greater for saline administration than for ropivacaine infusion (P < 0.001). Overall satisfaction was significantly greater in the ropivacaine group. Other than two inadvertent catheter dislodgements, no catheter- or local anesthetic-related complications occurred.

CONCLUSIONS

After moderately painful orthopedic surgery of the lower extremity, ropivacaine infusion using a portable mechanical pump and a popliteal sciatic perineural catheter at home decreased pain, opioid use and related side effects, sleep disturbances, and improved overall satisfaction.

Continuous infraclavicular brachial plexus block for postoperative pain control at home: a randomized, double-blinded, placebo-controlled study

BACKGROUND

This randomized, double-blinded, placebo-controlled study investigated the efficacy of patient-controlled regional analgesia using an infraclavicular brachial plexus perineural catheter and a portable infusion pump for outpatients undergoing moderately painful, upper extremity orthopedic surgery.

METHODS

Preoperatively, patients (n = 30) received an infraclavicular nerve block and perineural catheter. Postoperatively, patients were discharged home with oral narcotics and a portable infusion pump delivering study solution (0.2% ropivacaine or 0.9% saline) via the catheter for 3 days. Investigators and patients were blinded to random group assignment. Daily end points included pain scores at rest and with limb movement, narcotic use and side effects, sleep quality, patient satisfaction, and symptoms of catheter- or local anesthetic-related complications.

RESULTS

Ropivacaine (n = 15) infusion significantly reduced pain compared with saline (n = 15) infusion (P < 0.001). For example, the average pain with movement (scale, 0-10) on postoperative day 1 was 6.1 +/- 2.3 for the saline group versus 2.5 +/- 1.6 for the ropivacaine group (P < 0.001). Oral narcotic use and related side effects were significantly decreased in the ropivacaine group. For example, on postoperative day 1, mean tablet consumption was 5.5 +/- 2.4 and 1.7 +/- 1.6 for the saline and ropivacaine groups, respectively (P < 0.001). Sleep disturbance scores were 10-fold greater for saline administration than for ropivacaine infusion (P < 0.001). Overall satisfaction was significantly greater in the ropivacaine group. No catheter- or local anesthetic-related complications occurred.

CONCLUSION

After moderately painful orthopedic surgery of the upper extremity, ropivacaine infusion using a portable, mechanical pump and an infraclavicular brachial plexus perineural catheter at home decreased pain, sleep disturbances, narcotic use and related side effects, and improved overall satisfaction.

Major surgery in the ambulatory environment: continuous catheters and home infusions

The ability to provide continuous peripheral nerve blocks to patients safely on an outpatient basis has been a major advance in ambulatory surgery over the past several years. The first reports of patients self-administering local anaesthetic via wound and perineural catheters were published in 1998. Such infusions have now become a necessary component for the success of various ambulatory procedures. The rapid development of these techniques has been based on advances in equipment manufacturing, drug development and the need to provide a greater degree of analgesia for patients in the ambulatory setting. Many of the concepts used to provide safe ambulatory infusion have been drawn from studies of patients receiving these types of therapies in a hospital setting. Few studies have actually examined these techniques is an outpatient environment. However, the advantages of these analgesic techniques over traditional oral narcotics for patients undergoing major surgery in the ambulatory environment have led to their rapid acceptance as a standard of care at many institutions.

Nerve sheath catheter analgesia after amputation

Although continuous infusion of local anesthetic through nerve sheath catheters provides excellent pain control after amputation, the influence of this technique on the incidence of phantom limb pain is controversial. The current retrospective study examined the influence of continuous nerve sheath catheter analgesia and primary anesthetic technique (general or regional anesthesia) on the incidence of phantom limb pain. After institutional review board approval, data were gathered on patients who had amputation from 1990 to 1999. Medical records were reviewed to determine the level of and indication for amputation, age at time of amputation, current disease status, date of diagnosis and surgery, and primary anesthetic technique. Six months after amputation, preoperative pain, phantom limb sensations, and phantom limb pain were assessed using a verbal scale ranging from 0 (no pain) to 10 (worst pain) and methods of pain control also were evaluated. Thirty-nine patients completed the study. The incidence of phantom limb pain (visual analog scale score > or = 3) was 67% and was lower than the historic incidence (80%) before the use of this analgesia technique. Incidence of phantom limb pain was higher for patients requiring proximal versus distal amputations. The primary anesthetic technique (general versus regional) did not affect the incidence of phantom limb pain. Long-term followup showed that the incidence of phantom limb pain in patients receiving continuous nerve sheath catheter infusion is lower than previously reported for patients who had amputation for oncologic indications.

Does dexamethasone with preemptive analgesia improve pediatric tonsillectomy pain?

OBJECTIVE

The study goal was to determine whether the combination of dexamethasone with preemptive analgesia has an additive effect in further improving recovery.

STUDY DESIGN

We conducted a prospective, randomized, double-blinded trial of 50 children undergoing tonsillectomy at a university ambulatory surgery center. One study group received 1 intravenous dose of dexamethasone, and another group received 1 dose of saline solution. All patients received tonsillar fossa injections of ropivacaine plus clonidine before tonsil excision.

RESULTS

The 2 study groups were similar in main outcome measurements. Pain intensity and quality of life were not statistically different between the groups. There was a small trend to less trismus and less cumulative codeine use in the steroid group. Overall, there was a very low incidence of nausea and vomiting in both groups, which may have been due to the preemptive analgesia.

CONCLUSION

Dexamethasone does not significantly improve the morbidity of pediatric tonsillectomy when preemptive analgesia with ropivacaine and clonidine is used concurrently.

A portable mechanical pump providing over four days of patient-controlled analgesia by perineural infusion at home

BACKGROUND AND OBJECTIVES

Local anesthetics infused via perineural catheters postoperatively decrease opioid use and side effects while improving analgesia. However, the infusion pumps described for outpatients have been limited by several factors, including the following: limited local anesthetic reservoir volume, fixed infusion rate, and inability to provide patient-controlled doses of local anesthetic in combination with a continuous infusion. We describe a patient undergoing open rotator cuff repair who was discharged home with an interscalene perineural catheter and a mechanical infusion pump that allowed a variable rate of continuous infusion, as well as patient-controlled boluses of local anesthetic for over 4 days.

CASE REPORT

A 77-year-old woman, who had previously required a 3-day hospital admission for acute postoperative pain following an open repair of her left rotator cuff, presented for an open repair of her contralateral rotator cuff. Preoperatively she received an interscalene block and perineural catheter. After the procedure she was discharged home with a portable pump that infused ropivacaine continuously at a rate of 6 mL/h and allowed a 2-mL patient-controlled bolus every 20 minutes (550-mL reservoir). The basal infusion was decreased, as tolerated, by having the patient reprogram the pump with instructions given over the telephone. Without the use of any oral opioids, the patient scored her surgical pain 0 to 1 (on a scale of 0 to 10) while at rest and 2 to 3 for 2 physical therapy sessions during which she used the bolus function to reinforce her analgesia. After 98 hours of infusion, the patient's husband removed the catheter with instructions given over the telephone, and her subsequent surgical pain was treated with oral opioids.

CONCLUSION

Continuous, perineural local anesthetic infusions are possible on an ambulatory basis for multiple days using a portable, programmable pump that provides a variable basal infusion rate, patient-controlled boluses, and a large anesthetic reservoir.

Ropivacaine with or without clonidine improves pediatric tonsillectomy pain

OBJECTIVE

To determine if preemptive analgesia with ropivacaine hydrochloride with or without clonidine hydrochloride decreases pain and hastens recovery after tonsillectomy.

DESIGN

Prospective, randomized, triple-blinded trial.

SETTING

University referral center; pediatric ambulatory practice.

PARTICIPANTS

Sixty-four children, aged 3 to 15 years, undergoing tonsillectomy.

INTERVENTIONS

Patients received injections in the tonsillar fossae of isotonic sodium chloride, ropivacaine, or ropivacaine plus clonidine prior to tonsil excision.

MAIN OUTCOME MEASURES

Visual analogue (pain) scale scores at rest and when drinking, opioid use, recovery time to normal activity, and incidence of symptoms such as otalgia.

RESULTS

Pain was reduced on postoperative day 0 in the ropivacaine-treated and ropivacaine plus clonidine-treated groups as compared with the isotonic sodium chloride-treated group (P<.05). Pain was also decreased in the ropivacaine plus clonidine-treated group on postoperative days 3 and 5 (P<.05). Intravenous narcotic use was decreased on day 0 in the ropivacaine-treated and ropivacaine plus clonidine-treated groups (P<.05). Cumulative codeine use was similar at day 3 for all patients, but was decreased at day 5 in the ropivacaine plus clonidine-treated group (P<.05). The incidence of otalgia decreased from 89% (16/18) in the isotonic sodium chloride-treated group to 63% (12/19) in the ropivacaine-treated and 61%(11/18) in the ropivacaine plus clonidine-treated groups (P<.01). Recovery to normal activity was shortened from 8.1 +/- 1.6 days to 5.8 +/- 2.9 days (mean +/- SD) in the isotonic sodium chloride-treated and ropivacaine plus clonidine-treated groups, respectively (P =.03).

CONCLUSION

Preincisional injection of ropivacaine with clonidine prior to tonsillectomy has a preemptive analgesic effect that outlasts the local anesthetic and decreases pain, opioid use, and the time to return to normal activity.

A unique approach to postoperative analgesia for ambulatory surgery

Postoperative analgesia for the ambulatory surgery patient is frequently inadequate. Continuous regional analgesia improves outcome and patient satisfaction in hospitalized patients. This paper describes the successful use of continuous regional analgesia following orthopedic surgery in the ambulatory setting.