Safety and Efficacy of Ultrasound-Guided Sympathetic Blockade by Proximal Intercostal Block in Electrical Storm Patients.

BACKGROUND: Electrical storm (ES) patients who fail standard therapies have a high mortality rate. Previous studies report effective management of ES with bedside, ultrasound-guided percutaneous stellate ganglion block (SGB). We report our experience with sympathetic blockade administered via a novel alternative approach: proximal intercostal block (PICB). Compared with SGB, this technique targets an area typically free of other catheters and support devices, and may pose less strict requirements for anticoagulation interruption, along with lower risk of focal neurological side effects. OBJECTIVES: The authors sought to describe the safety and efficacy of PICB in patients with refractory ES. METHODS: We reviewed our institutional data on ES patients who underwent PICB between January 2018 and February 2023 to analyze procedural safety and short- and long-term outcomes. RESULTS: A total of 15 consecutive patients with ES underwent PICB during this period. Of those, 11 patients (73.3%) were maintained on PICB alone, and 4 patients (26.6%) were maintained on combined block with SGB and PICB. Overall, 72.7% patients who were maintained on PICB alone and 77.8% patients who were maintained on bilateral PICB had excellent arrhythmia suppression. After PICB, implantable cardioverter-defibrillator therapies were significantly reduced (P < 0.05), with 93.3% of patients receiving PICB having no implantable cardioverter-defibrillator shock until discharge or heart transplant. Anticoagulation was continued in all patients and there were no procedure-related complications. Apart from mild transient neurological symptoms seen in 3 patients, no significant neurological or hemodynamic sequelae were observed. CONCLUSIONS: In patients with refractory ES, continuous PICB provided safe and effective sympathetic block (77.8% ventricular arrhythmia suppression), achievable without interruption of anticoagulation, and without significant side effects.

Sympathetic Blockade for the Management of Refractory Ventricular Tachycardia: A Case Report.

A 64-year-old man with a history of nonischemic cardiomyopathy (NICM) presented with electrical storm (ES). Episodes of ventricular tachycardia (VT) persisted despite endocardial catheter ablations and exhaustive pharmacotherapy. We used alternating regional anesthesia techniques, left stellate ganglion block, and proximal intercostal block to reduce sympathetic input to the heart, resulting in a significant decrease in VT burden. By using alternating catheter locations, we were able to maintain continuous sympathetic blockade for 31 days and bridge the patient to a successful orthotopic heart transplant.

Ultrasound-guided supraclavicular vs. retroclavicular block of the brachial plexus: comparison of ipsilateral diaphragmatic function: A randomised clinical trial.

BACKGROUND: The ultrasound-guided retroclavicular block (RCB) is a recently described alternative approach to brachial plexus blockade at the level of the cords. Although more distal blockade of the brachial plexus is thought to be associated with a lower incidence of phrenic nerve block, the impact of RCB on ipsilateral diaphragmatic function has not been formally investigated. OBJECTIVE: To compare the effects of supraclavicular and retroclavicular brachial plexus block on diaphragmatic function. SETTING: A single tertiary hospital, study period from December 2017 to May 2019. DESIGN: Double-blinded, randomised study. PATIENTS: A total of 40 patients undergoing upper extremity surgery below the axilla. Exclusion criteria included significant pulmonary disease, BMI more than 40 and contra-indication to peripheral nerve block. INTERVENTIONS: Patients were randomised to supraclavicular or retroclavicular brachial plexus block with ropivacaine 0.5%. OUTCOME MEASURES: Phrenic block was assessed by measuring changes in diaphragmatic excursion using M-mode ultrasound, and maximum inspiratory volume on incentive spirometry from baseline, at 15 and 30 min postblock, and postoperatively. Comparative assessment of block characteristics included timing and distribution of sensory and motor block onset in the upper extremity, and scanning and block performance times. RESULTS: The incidence of phrenic block in the supraclavicular group was higher by ultrasound imaging (70 vs. 15%) and also by pulmonary function testing (55 vs. 5%), with both diaphragmatic excursion and maximum inspiratory volume decreasing to a greater extent after supraclavicular block (SCB) compared with RCB at 15, 30 min and postoperative time points (repeated measures analysis of variance, P < 0.001). There was no difference in timing and extent of distal arm block, but suprascapular and axillary nerves were more consistently blocked after SCB than after RCB. CONCLUSION: The current study confirms the hypothesis that a RCB is significantly less likely to affect ipsilateral diaphragmatic function than a SCB. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02631122.

A prospective, randomized comparison of ultrasonographic visualization of proximal intercostal block vs paravertebral block.

BACKGROUND: Thoracic paravertebral blockade is an accepted anesthetic and analgesic technique for breast surgery. However, real-time ultrasound visualization of landmarks in the paravertebral space remains challenging. We aimed to compare ultrasound-image quality, performance times, and clinical outcomes between the traditional parasagittal ultrasound-guided paravertebral block and a modified approach, the ultrasound-guided proximal intercostal block. METHODS: Women with breast cancer undergoing mastectomy (n = 20) were randomized to receive either paravertebral (n = 26) or proximal intercostal blocks (n = 32) under ultrasound-guidance with 2.5 mg/kg ropivacaine prior to surgery. Block ultrasound images before and after needle placement, and anesthetic injection videoclips were saved, and these images and vidoes independently rated by separate novice and expert reviewers for quality of visualization of bony elements, pleura, relevant ligament/membrane, needle, and injectate spread. Block performance times, postoperative pain scores, and opioid consumption were also recorded. RESULTS: Composite visualization scores were superior for proximal intercostal compared to paravertebral nerve block, as rated by both expert (p = 0.008) and novice (p = 0.01) reviewers. Notably, both expert and novice rated pleural visualization superior for proximal intercostal nerve block, and expert additionally rated bony landmark and injectate spread visualization as superior for proximal intercostal block. Block performance times, needle depth, opioid consumption and postoperative pain scores were similar between groups. CONCLUSIONS: Proximal intercostal block yielded superior visualization of key anatomical landmarks, possibly offering technical advantages over traditional paravertebral nerve block. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02911168. Registred on the 22nd of September 2016.

Prediction of Pain and Opioid Utilization in the Perioperative Period in Patients Undergoing Primary Knee Arthroplasty: Psychophysical and Psychosocial Factors.

Objective: To identify factors associated with pain severity and opioid consumption in the early perioperative period. Design: Prospective observational cohort study. Setting: Tertiary academic medical center. Subjects: Patients with osteoarthritis older than age 45 years undergoing primary total knee replacement at Brigham and Women's Hospital. A total of 126 patients enrolled. Methods: Preoperatively, pain questionnaires and quantitative sensory testing were performed on patients to develop a psychosocial and psychophysical profile. Postoperatively, pain scores and opioid consumption were measured as primary end points. Univariate and multiple linear regression analyses were performed to determine the predictive value of these characteristics on perioperative pain scores and opioid consumption. Results: Regression analysis revealed several predictors of acute postoperative pain scores including temporal summation of pain (TSP; P = 0.001), body mass index (BMI; P = 0.044), number of previous knee surgeries (P = 0.006), and female gender (P = 0.023). Similarly, predictors of opioid utilization included TSP (P = 0.011), BMI (P = 0.02), age (P = <0.001), and tourniquet time (P = 0.003). Conclusions: The only significant, unique predictors of both pain and opioid consumption were TSP, an index of central pain facilitatory processes, and BMI. Interestingly, psychosocial factors, such as catastrophizing and somatization, although correlated with postoperative pain scores and opioid consumption, generally did not independently explain substantial variance in these measures. This study suggests that BMI and quantitative sensory testing, specifically the temporal summation of pain, may provide value in the preoperative assessment of patients undergoing total knee arthroplasty and other surgeries via predicting their level of risk for adverse pain outcomes.

Psychiatric Comorbidity Is Associated Prospectively with Diminished Opioid Analgesia and Increased Opioid Misuse in Patients with Chronic Low Back Pain.

BACKGROUND: Opioids are frequently prescribed for chronic low back pain (CLBP), but there are little prospective data on which patient subgroups may benefit. Psychiatric comorbidity, such as high levels of depression and anxiety symptoms (termed comorbid negative affect [NA]), is a common presentation and may predict diminished opioid analgesia and/or increased opioid misuse. METHODS: The authors conducted a 6½-month prospective cohort study of oral opioid therapy, with an active drug/placebo run-in period, in 81 CLBP patients with low, moderate, and high levels of NA. Treatment included an opioid titration phase with a prescribing physician blinded to NA group assignment and a 4-month continuation phase, during which subjects recorded daily pain levels using an electronic diary. The primary outcome was the percent improvement in average daily pain, summarized weekly. RESULTS: There was an overall 25% dropout rate. Despite the high NA group being prescribed a higher average daily dose of morphine equivalents, linear mixed model analysis revealed that the 24 study completers in each of the high NA and low NA groups had an average 21 versus 39% improvement in pain, respectively (P < 0.01). The high NA group also had a significantly greater rate of opioid misuse (39 vs. 8%, P < 0.05) and significantly more and intense opioid side effects (P < 0.01). CONCLUSIONS: These results indicate that the benefit and risk considerations in CLBP patients with high NA versus low NA are distinctly different. Thus, NA is an important phenotypic variable to characterize at baseline, before deciding whether to prescribe opioids for CLBP.

The clinical impact of a false-positive urine cocaine screening result on a patient's pain management.

BACKGROUND: The urine of a patient admitted for chest and epigastric pain tested positive for cocaine using an immunoassay-based drug screening method (positive/negative cutoff concentration 150 ng/mL). Despite the patient's denial of recent cocaine use, this positive cocaine screening result in conjunction with a remote history of drug misuse impacted the patient's recommended pain therapy. Specifically, these factors prompted the clinical team to question the appropriateness of opioids and other potentially addictive therapeutics during the treatment of cancer pain from previously undetected advanced pancreatic carcinoma. OBJECTIVE: After pain management and clinical pathology consultation, it was decided that the positive cocaine screening result should be confirmed by gas chromatography-mass spectrometry (GC-MS) testing. RESULTS: This more sensitive and specific analytical technique revealed that both cocaine and its primary metabolite benzoylecgonine were undetectable (i.e., less than the assay detection limit of 50 ng/mL), thus indicating that the positive urine screening result was falsely positive. With this confirmation, the pain management service team was reassured in offering intrathecal pump (ITP) therapy for pain control. ITP implantation was well tolerated, and the patient eventually achieved excellent pain relief. However, ITP therapy most likely would not have been utilized without the GC-MS confirmation testing unless alternative options failed and extensive vigilant monitoring was initiated. CONCLUSION: As exemplified in this case, confirmatory drug testing should be performed on specimens with unexpected immunoassay-based drug screening results. To our knowledge, this is the first report of a false-positive urine cocaine screening result and its impact on patient management.

2014 Neer Award Paper: neuromonitoring the Latarjet procedure.

BACKGROUND: We used intraoperative neuromonitoring to define the stages of the Latarjet procedure during which the nerves are at greatest risk. METHODS: Thirty-four patients with a mean age of 28.4 years were included. The Latarjet procedure was divided into 9 defined stages. Bilateral median and ulnar somatosensory evoked responses and transcranial motor evoked potentials from all arm myotomes were continuously monitored. A "nerve alert" was defined as averaged 50% amplitude attenuation or 10% latency prolongation of ipsilateral somatosensory evoked responses and transcranial motor evoked potentials. For each nerve alert, the surgeon altered retractor placement, and if there was no response to this, the position of the operative extremity was then changed. RESULTS: Of 34 patients, 26 (76.5%) had 45 separate nerve alert episodes. The most common stages of the procedure for a nerve alert to occur were glenoid exposure and graft insertion. The axillary nerve was involved in 35 alerts; the musculocutaneous nerve, in 22. Of the 34 patients, 7 (20.6%) had a clinically detectable nerve deficit postoperatively, all correlated with an intraoperative nerve alert. All cases involved the axillary nerve, and all resolved completely from 28 to 165 days postoperatively. Prior surgery and body mass index were not predictive of a neurologic deficit postoperatively. However, total operative time (P = .042) and duration of the stage of the procedure in which the concordant nerve alert occurred (P = .010) were statistically significant predictors of a postoperative nerve deficit. CONCLUSIONS: The nerves, in particular the axillary and musculocutaneous nerves, are at risk during the Latarjet procedure, especially during glenoid exposure and graft insertion.

The ultrasound-guided retrolaminar block.

PURPOSE: Paravertebral blocks have gained in popularity and offer the possible benefit of reduced adverse effects when compared with epidural analgesia. Nevertheless, pulmonary complications in the form of inadvertent pleural puncture are still a recognized risk. Also, the traditional paravertebral blocks are often technically difficult even with ultrasound guidance and constitute deep non-compressible area injections. We present our experience with the first three patients receiving ultrasound-guided retrolaminar blocks for managing the pain associated with multiple rib fractures. CLINICAL FEATURES: The vertebral laminae are identified by ultrasound imaging in a paramedian sagittal plane by sequentially visualizing the pleura and ribs, transverse processes, and the corresponding laminae (from lateral to medial). The block needle is guided to contact the lamina, and the local anesthetic injectate is visualized under real-time imaging. A catheter is inserted and used for continuous analgesia. In three consecutive patients, verbal rating scale (VRS) pain scores were reduced from 10/10 to less than 5/10, and no technical difficulties, complications, or adverse effects were encountered. CONCLUSIONS: Successful analgesia was achieved in all three cases utilizing continuous infusion and intermittent boluses with ultrasound-guided retrolaminar blocks. These results show the feasibility of this approach for patients with multiple rib fractures.

Interpreting urine drug tests: prevalence of morphine metabolism to hydromorphone in chronic pain patients treated with morphine.

OBJECTIVE: Pain medicine practitioners frequently use urine drug testing (UDT) to monitor adherence to opioid therapy. It can be difficult to interpret a result as normal or abnormal in relation to which opioid compounds are expected to be found in the urine. We investigated whether hydromorphone may be a metabolite of morphine normally appearing in UDT of patients prescribed morphine. DESIGN: This is a retrospective case-control study of urine toxicology results in pain patients taking only morphine. Inclusion criteria included urine results positive for morphine only (controls) or morphine and hydromorphone (cases). Demographic and medical history variables, and any history of aberrant drug behavior were recorded and related to the presence or absence of hydromorphone in the urine. RESULTS: Hydromorphone was present in 21 of 32 cases (66%), none of whom had a history of aberrant drug behavior. Positive cases occurred more frequently in women, in those taking higher daily doses of morphine, and in those with higher urine morphine concentrations (P < 0.05). Only morphine urine concentration was a significant predictor of the hydromorphone metabolite in a logistic regression model (P < 0.05). CONCLUSIONS: Hydromorphone is likely a minor metabolite of morphine, normally appearing in the UDT of patients taking morphine. This finding assists in determining whether a UDT result is normal or abnormal, and subsequently whether a patient is compliant with opioid therapy. This observation should be confirmed by a prospective study in a controlled environment. Variables such as gender, morphine dose, morphine urine concentration, and genetic determinants of morphine metabolism should be investigated further.

Urine toxicology screening among chronic pain patients on opioid therapy: frequency and predictability of abnormal findings.

OBJECTIVE: To examine the incidence of abnormal urine toxicology screening among chronic pain patients prescribed opioids for their pain and to relate these results to patient descriptors and type, number, and dose of prescribed opioids. METHODS: A retrospective analysis of data from 470 patients who had urine screening at a pain management program in an urban teaching hospital was performed. Urine samples were analyzed using gas chromatography-mass spectrometry. Patients were categorized as having urine screens that were "normal" (expected findings based on their prescribed drugs) or abnormal. Abnormal findings were those of (1) absence of a prescribed opioid, (2) presence of an additional nonprescribed controlled substance, (3) detection of an illicit substance, and (4) an adulterated urine sample. RESULTS: Forty-five percent of the patients were found to have abnormal urine screens. Twenty percent were categorized as having an illicit substance in their urine. Illicit substances and additional drugs were found more frequently in younger patients than in older patients (P<0.001). No other variables were found to predict abnormal urine screen results. DISCUSSION: These results confirm past findings that random urine toxicology screens among patients prescribed opioids for pain reveal a high incidence of abnormal findings. Common patient descriptors, and number, type, and dose of prescribed opioids were found to be poor predictors of abnormal results.

Predicting aberrant drug behavior in patients treated for chronic pain: importance of abuse history.

Physicians can encounter problems in prescribing opioids for some patients with chronic pain such as multiple unsanctioned dose escalations, episodes of lost or stolen prescriptions, and positive urine drug screenings for illicit substances. This study explored the usefulness of questions on abuse history in predicting problems with prescribing opioids for patients at a hospital-based pain management program. One hundred forty-five (145) patients who were taking long- and short-acting opioids for their pain were classified as high or low risk on the basis of their responses to interview questions about 1) substance abuse history in their family, 2) past problems with drug or alcohol abuse, and 3) history of legal problems. The treating physicians completed a questionnaire about problems that they had encountered with their patients. Problem behaviors were verified through chart review. No differences in demographic characteristics were found between those classified as high and low risk. Patients who admitted to a family history of substance abuse, a history of legal problems, and drug or alcohol abuse were prone to more aberrant drug-related behaviors, including a higher incidence of lost or stolen prescriptions and the presence of illicit substances in their urine (P < 0.05). Patients classified as high risk also had a significantly higher frequency of reported mental health problems and motor vehicle accidents. More of these patients smoked cigarettes, tended to need a cigarette within the first hour of the day, took higher doses of opioids, and reported fewer adverse effects from the medications than did those without such a history (P < 0.05). This study demonstrates that questions about abuse history and legal problems can be useful in predicting aberrant drug-related behavior with opioid use in persons with chronic noncancer pain.