Outcomes with spinal versus general anesthesia for patients with and without preoperative cognitive impairment: Secondary analysis of a randomized clinical trial.

INTRODUCTION: The effect of spinal versus general anesthesia on the risk of postoperative delirium or other outcomes for patients with or without cognitive impairment (including dementia) is unknown. METHODS: Post hoc secondary analysis of a multicenter pragmatic trial comparing spinal versus general anesthesia for adults aged 50 years or older undergoing hip fracture surgery. RESULTS: Among patients randomized to spinal versus general anesthesia, new or worsened delirium occurred in 100/295 (33.9%) versus 107/283 (37.8%; odds ratio [OR] 0.85; 95% confidence interval [CI] 0.60 to 1.19) among persons with cognitive impairment and 70/432 (16.2%) versus 71/445 (16.0%) among persons without cognitive impairment (OR 1.02; 95% CI 0.71 to 1.47, p = 0.46 for interaction). Delirium severity, in-hospital complications, and 60-day functional recovery did not differ by anesthesia type in patients with or without cognitive impairment. DISCUSSION: Anesthesia type is not associated with differences in delirium and functional outcomes among persons with or without cognitive impairment.

Pain, Analgesic Use, and Patient Satisfaction With Spinal Versus General Anesthesia for Hip Fracture Surgery : A Randomized Clinical Trial.

BACKGROUND: The REGAIN (Regional versus General Anesthesia for Promoting Independence after Hip Fracture) trial found similar ambulation and survival at 60 days with spinal versus general anesthesia for hip fracture surgery. Trial outcomes evaluating pain, prescription analgesic use, and patient satisfaction have not yet been reported. OBJECTIVE: To compare pain, analgesic use, and satisfaction after hip fracture surgery with spinal versus general anesthesia. DESIGN: Preplanned secondary analysis of a pragmatic randomized trial. (ClinicalTrials.gov: NCT02507505). SETTING: 46 U.S. and Canadian hospitals. PARTICIPANTS: Patients aged 50 years or older undergoing hip fracture surgery. INTERVENTION: Spinal or general anesthesia. MEASUREMENTS: Pain on postoperative days 1 through 3; 60-, 180-, and 365-day pain and prescription analgesic use; and satisfaction with care. RESULTS: A total of 1600 patients were enrolled. The average age was 78 years, and 77% were women. A total of 73.5% (1050 of 1428) of patients reported severe pain during the first 24 hours after surgery. Worst pain over the first 24 hours after surgery was greater with spinal anesthesia (rated from 0 [no pain] to 10 [worst pain imaginable]; mean difference, 0.40 [95% CI, 0.12 to 0.68]). Pain did not differ across groups at other time points. Prescription analgesic use at 60 days occurred in 25% (141 of 563) and 18.8% (108 of 574) of patients assigned to spinal and general anesthesia, respectively (relative risk, 1.33 [CI, 1.06 to 1.65]). Satisfaction was similar across groups. LIMITATION: Missing outcome data and multiple outcomes assessed. CONCLUSION: Severe pain is common after hip fracture. Spinal anesthesia was associated with more pain in the first 24 hours after surgery and more prescription analgesic use at 60 days compared with general anesthesia. PRIMARY FUNDING SOURCE: Patient-Centered Outcomes Research Institute.

Spinal Anesthesia or General Anesthesia for Hip Surgery in Older Adults.

BACKGROUND: The effects of spinal anesthesia as compared with general anesthesia on the ability to walk in older adults undergoing surgery for hip fracture have not been well studied. METHODS: We conducted a pragmatic, randomized superiority trial to evaluate spinal anesthesia as compared with general anesthesia in previously ambulatory patients 50 years of age or older who were undergoing surgery for hip fracture at 46 U.S. and Canadian hospitals. Patients were randomly assigned in a 1:1 ratio to receive spinal or general anesthesia. The primary outcome was a composite of death or an inability to walk approximately 10 ft (3 m) independently or with a walker or cane at 60 days after randomization. Secondary outcomes included death within 60 days, delirium, time to discharge, and ambulation at 60 days. RESULTS: A total of 1600 patients were enrolled; 795 were assigned to receive spinal anesthesia and 805 to receive general anesthesia. The mean age was 78 years, and 67.0% of the patients were women. A total of 666 patients (83.8%) assigned to spinal anesthesia and 769 patients (95.5%) assigned to general anesthesia received their assigned anesthesia. Among patients in the modified intention-to-treat population for whom data were available, the composite primary outcome occurred in 132 of 712 patients (18.5%) in the spinal anesthesia group and 132 of 733 (18.0%) in the general anesthesia group (relative risk, 1.03; 95% confidence interval [CI], 0.84 to 1.27; P = 0.83). An inability to walk independently at 60 days was reported in 104 of 684 patients (15.2%) and 101 of 702 patients (14.4%), respectively (relative risk, 1.06; 95% CI, 0.82 to 1.36), and death within 60 days occurred in 30 of 768 (3.9%) and 32 of 784 (4.1%), respectively (relative risk, 0.97; 95% CI, 0.59 to 1.57). Delirium occurred in 130 of 633 patients (20.5%) in the spinal anesthesia group and in 124 of 629 (19.7%) in the general anesthesia group (relative risk, 1.04; 95% CI, 0.84 to 1.30). CONCLUSIONS: Spinal anesthesia for hip-fracture surgery in older adults was not superior to general anesthesia with respect to survival and recovery of ambulation at 60 days. The incidence of postoperative delirium was similar with the two types of anesthesia. (Funded by the Patient-Centered Outcomes Research Institute; REGAIN ClinicalTrials.gov number, NCT02507505.).

Morphine Attenuates fNIRS Signal Associated With Painful Stimuli in the Medial Frontopolar Cortex (medial BA 10).

Functional near infrared spectroscopy (fNIRS) is a non-invasive optical imaging method that provides continuous measure of cortical brain functions. One application has been its use in the evaluation of pain. Previous studies have delineated a deoxygenation process associated with pain in the medial anterior prefrontal region, more specifically, the medial Brodmann Area 10 (BA 10). Such response to painful stimuli has been consistently observed in awake, sedated and anesthetized patients. In this study, we administered oral morphine (15 mg) or placebo to 14 healthy male volunteers with no history of pain or opioid abuse in a crossover double blind design, and performed fNIRS scans prior to and after the administration to assess the effect of morphine on the medial BA 10 pain signal. Morphine is the gold standard for inhibiting nociceptive processing, most well described for brain effects on sensory and emotional regions including the insula, the somatosensory cortex (the primary somatosensory cortex, S1, and the secondary somatosensory cortex, S2), and the anterior cingulate cortex (ACC). Our results showed an attenuation effect of morphine on the fNIRS-measured pain signal in the medial BA 10, as well as in the contralateral S1 (although observed in a smaller number of subjects). Notably, the extent of signal attenuation corresponded with the temporal profile of the reported plasma concentration for the drug. No clear attenuation by morphine on the medial BA 10 response to innocuous stimuli was observed. These results provide further evidence for the role of medial BA 10 in the processing of pain, and also suggest that fNIRS may be used as an objective measure of drug-brain profiles independent of subjective reports.

Ultrasound guided transversus abdominis plane versus sham blocks after caesarean section in an Ugandan village hospital: a prospective, randomised, double-blinded, single-centre study.

BACKGROUND: Transversus abdominis plane (TAP) block provides 12-24 h of analgesia to the parietal peritoneum and abdominal wall, and are best used combined with oral or intravenous medications. Despite ease of use, a large margin of safety, and a high success rate, TAP blocks remain under used in settings where patients could most benefit from their use. Previous studies have used oral or intravenous narcotics for supplementation. However, the efficacy of TAP blocks in low-resourced settings where patients do not have dependable access to these medications is unknown. This study examines TAP block analgesic efficacy after caesarean section in a poorly resourced setting. We compared the post-operative status of 170 women with self-administered paracetamol-diclofenac with or without TAP blocks. We hypothesised that the block would decrease pain at 8 h, 16 h, and 24 h at rest, with coughing and upon standing. METHODS: Between Oct 31, and Dec 28, 2013, 180 women were enrolled and randomly assigned to receive either TAP or sham blocks after caesarean section. Bi-institutional (Mbarara Regional Referral Hospital and Massachusetts General Hospital) institutional review board approval was obtained for this single-centre study. After informed written consent, patients received TAP or sham blocks after caesarian section. Inclusion criteria for enrolment were: age 18 years or older, weight at least 50 kg, no allergies to study medications, otherwise healthy (American Society of Anesthesiologists classification status I or II), and having undergone elective, urgent, or emergent caesarian section under spinal anaesthesia without sedation. Under ultrasound guidance, 20-25 mL of 0·25% bupivacaine (epinephrine 1:400 000) were injected near the triangles-of-Petit. Sham blocks consisted of a transducer with a needleless syringe pressed over each flank. In the post-anaesthesia recovery area, all patients received 1000 mg paracetamol and 50 mg diclofenac, orally, to be continued on an 8-h schedule for 3 days. A skilled (masked) research nurse collected all data. The primary outcomes measured were numerical rating scale at 8 h, 16 h, and 24 h at rest, with coughing, and upon standing. The association between the pain scores at each time and type of treatment (TAP vs sham blocks) was assessed using general linear model with repeated measures. Demographics were compared using the two sample t-test (appendix). FINDINGS: 170 patients completed the study; 86 in the sham group and 84 in the study group. Demographics (age, weight, and parity) were similar between both study groups. One participant from the sham group was missing parity information (appendix). Preliminary data analysis showed reduced pain scores at all times, and with all degrees of movement for the TAP group (appendix). The largest reduction in pain was at 8 h (resting 33%, coughing 36%, and standing 44%). With time, the pain scores of the TAP group changed a little, whereas a decreasing trend can be noted in the sham group. No adverse events occurred. INTERPRETATION: This study show a significant improvement in pain scores for obstetric patients receiving a transversus abdominis plane block in comparison to standard of care in a low income, limited resource setting. The use of these blocks shows the use of an easy, inexpensive, and achievable pain control option. Especially in resource-limited areas, this approach could allow for better pain management and a new standard of care for the world's most common operative procedure. FUNDING: Eleanor and Miles Harvard Medical School Shore Fellowship Grant, and Massachusetts General Hospital, DACCPM Faculty Development Grant.

Variable osteology of the sixth cervical vertebra in relation to stellate ganglion block.

BACKGROUND AND OBJECTIVES: Stellate ganglion block is often carried out using palpation of surface landmarks to guide needle placement. However, anatomic variation of the surface landmarks used is common and block failure has been reported in as many as 30% of patients, even when the surface landmarks that guide needle placement can be easily identified. METHODS: Computed tomography (CT) images of the cervical spine of 70 adult patients were examined to measure the distances in the coronal and sagittal planes between various points on the cricoid cartilage, anterior tubercle, posterior tubercle, and nadir of the vertebral gutter. The width of the tubercle in the caudal and cephalad plane was determined through multiplanar reformatted CT images in 6 randomly chosen patients. RESULTS: The mean distance from the lateral margin of the cricoid cartilage laterally to the anterior tubercle was 13 +/- 5 mm (range 3-22 mm) in men and 12 +/- 3 mm (range 6-22 mm) in women. The mean depth of the anterior tubercle as measured posteriorly from the midpoint of the trachea was 20 +/- 4 (range 10-33 mm) in men and 19 +/- 4 mm (range 9-33 mm) in women. The maximal and minimal cephalad-caudad dimensions of the transverse process of C6 were 9.3 +/- 0.3 mm, and 6.7 +/- 0.3 mm, respectively. CONCLUSIONS: Large variability was observed in the size and location of the landmarks used for needle placement during stellate ganglion block. Placement of the needle medially where the transverse process joins the lateral margin of the vertebral body provides a larger bony target that may potentially provide a safer, more reliable block.

Cervical transforaminal injection and the radicular artery: variation in anatomical location within the cervical intervertebral foramina.

BACKGROUND: Recent articles have detailed the adverse events associated with transforaminal steroid injections into the radicular arteries. Guidelines on strict transforaminal epidural techniques have been described to limit complications. There remains limited information regarding the cervical level of entry, location within the intervertebral foramina, and prevalence of the radicular arteries within the population. METHODS: With the aid of premortem angiography and postmortem latex-injected vasculature, a single detailed cadaveric dissection was performed to elucidate the specific anatomic location of the radicular arteries within the intervertebral foramina and the anastomoses of the arteries to the anterior spinal artery. RESULTS: Five radicular arteries (C5, C6, two at C7, C8) were traced entering the foramina either anteriorly or posteriorly to supply the anterior and posterior spinal arteries. Radicular arteries received blood supply from either the deep cervical (C8) or vertebral arteries. The C8 radicular artery entered the lateral aspect of the foramen and penetrated the dural sleeve within the inferior portion of the foramen, directly inferior to the exiting spinal nerve, to supply the anterior spinal artery. This artery was of a large enough caliber to be entered by a 22-gauge needle. CONCLUSIONS: A larger population is necessary to characterize the range of anatomic variations in arterial supply within the foramina. Available studies support the current technique of fluoroscopic needle insertion. Yet, there is wide anatomic variation in the origin and location of these vessels, and even with strict adherence to technique, it is feasible that a properly placed needle could penetrate a radicular artery.

Morphologic analysis of bipolar radiofrequency lesions: implications for treatment of the sacroiliac joint.

BACKGROUND AND OBJECTIVES: Sacroiliac (SI) joint dysfunction is an important cause of mechanical low-back pain. Bipolar radiofrequency ablation has been proposed as a long-lasting treatment for pain in patients with SI dysfunction who report temporary pain relief with local-anesthetic injection into the joint. No data are available to guide the technical aspects of bipolar radiofrequency lesion creation. This study documents the optimal spacing of cannulae and time required to produce bipolar lesions by use of radiofrequency technology. METHODS: Two radiofrequency cannulae were secured in a parallel position 2, 4, 6, 8, and 10 mm apart and submerged in egg white for lesion production in a medium that would allow visualization of the size and shape of the lesions as they were created. Temperatures of the probes were raised from 40 degrees C to 90 degrees C at a constant rate and were held at 90 degrees C for 190 seconds. The progress of lesion formation was photographed every 10 seconds, and the resultant surface area of the lesions was measured from the digital images. RESULTS: Contiguous strip lesions were produced when the cannulae were spaced 6 mm or less apart; unipolar lesions around each cannula resulted if they were spaced more than 6 mm apart. Ninety percent of the final lesion area was reached by 120 seconds, and the final lesion size was reached by 150 seconds, regardless of spacing. CONCLUSIONS: Bipolar radiofrequency treatment creates continuous "strip" lesions proportional in size to the distance between the probes when the distance between cannulae is 6 mm or less. Spacing the cannulae 4 to 6 mm apart and treating at 90 degrees C for 120 to 150 seconds maximizes the surface area of the lesion.