Prolongation of spinal duration by escalating doses of intrathecal epinephrine in lower limb arthroplasty.

Aim: The optimal dose of low-dose intrathecal epinephrine in the absence of intrathecal opioids is unknown. Materials & methods: Prospective, randomized, double blind clinical trial of patients undergoing lower limb arthroplasties. The primary end point was spinal block duration measured via motor and sensory block duration. Results: 30 patients undergoing lower limb arthroplasty were randomized into one of six groups with varying intrathecal epinephrine doses 0-100 mcg. There was a direct linear effect between motor block duration and intrathecal epinephrine dose with higher doses being associated with longer block duration (p = 0.011). Mean motor block duration was 3.74 ± 1.13, 3.36 ± 0.47, 3.39 ± 0.60, 4.06 ± 0.98 and 5.20 ± 1.41 h for the EPI0, EPI25, EPI50, EPI75 and EPI100 groups respectively. Conclusion: This study reveals that low-dose intrathecal epinephrine (75-100 mcg) in the absence of intrathecal opioids can be reliably used to prolong motor block duration in lower limb arthroplasty. Clinical Trial Registration: NCT02619409 (ClinicalTrials.gov).

What is this summary about? Here, we summarize the results of the addition of a medicine called epinephrine to a type of anesthesia called spinal anesthesia which involves injection of medication into the fluid surrounding the spinal cord. The study was to determine the optimal amount of epinephrine needed to prolong the effect of spinal anesthesia for patients undergoing replacements of their hips and/or knees. What were the results? The study showed that the addition of low-dose epinephrine to spinal anesthesia prolongs the motor block ­ or inability to move the leg ­ in a linear fashion with higher doses of epinephrine associated with longer motor block. Our results did not show a significant difference in sensory block, or the inability to feel the leg. What do the results mean? The study shows that the addition of low-dose epinephrine to spinal anesthesia can reliably prolong the effect of the anesthesia which may be needed in more complicated hip or knee surgeries.

Comparison of lateral quadratus lumborum and lumbar plexus blocks for postoperative analgesia following total hip arthroplasty: a randomized clinical trial.

INTRODUCTION: Effective analgesia after total hip arthroplasty must minimize pain and optimize early ambulation. Lumbar plexus blocks (LPBs) provide analgesia but may cause motor weakness. Quadratus lumborum blocks (QLBs) may provide analgesia with preserved motor strength. METHODS: This trial randomized subjects scheduled for elective hip arthroplasty to receive an LPB or lateral QLB for postoperative analgesia. The primary outcome was opioid consumption at 12-hour postoperative. Non-inferiority of lateral QLBs compared with LPBs was conducted using a one-sided two-sample t-test. Secondary outcomes included pain scores, cumulative opioid consumption, quadriceps strength, time to ambulation, and distance ambulated. Differences in pain scores and opioid consumption over time between groups were evaluated using a linear mixed model. RESULTS: The trial consented and randomized 111 subjects and 103 completed the study: LPB (n=50) and lateral QLB (n=53). Mean (95% CI) cumulative opioid consumption (mg) at 12-hour postoperative was not found to be non-inferior in the lateral QLB (15.9 (12.7 to 19.2)) vs the LPB (12.7 (10.2 to 15.1)) group (p=0.625). Pain scores in postoperative anesthetic care unit (PACU) and 24-hour postoperative did not differ. The maximum distance ambulated did not differ, but lateral QLB patients were 2.4 times more likely to ambulate in the first 12 hours (p=0.024) and had significantly greater quadriceps strength in PACU (p<0.001). DISCUSSION: Although we were unable to demonstrate non-inferiority for opioid consumption at 12-hour postoperative, strength and mobilization were improved in lateral QLB subjects. TRIAL REGISTRATION NUMBER: NCT04402437.

Anesthetic Management of Severe Pulmonary Hypertension in Pregnancy.

Pregnancy entails significant changes in maternal physiology that are not well-tolerated in patients with pulmonary arterial hypertension. The profound changes in plasma volume, cardiac output, and systemic vascular resistance can lead to increased strain placed on the right ventricle, leading to right-heart failure and cardiovascular collapse. Given the complex and sometimes opposing physiologic changes, managing these patients can be challenging. As such, these patients have a significantly increased reported maternal mortality rate. This report describes a parturient with newly diagnosed severe pulmonary arterial hypertension and her anesthetic management.

Quantitative evaluation of beam-hardening artefact correction in dual-energy CT myocardial perfusion imaging.

OBJECTIVES: To assess quantitatively the impact of a novel reconstruction algorithm ("kernel") with beam-hardening correction (BHC) on beam-hardening artefacts of the myocardium at dual-energy CT myocardial perfusion imaging (DE-CTMPI). METHODS: Rest-series of DE-CTMPI examinations from 14 patients were retrospectively analyzed. Six image series were reconstructed for each patient: a) 100 kV, b) 140 kV, and c) linearly blended MIX0.5, each with BHC (D33f kernel) and without (D30f kernel). Seven hundred and fifty-six myocardial regions were assessed. Seven equal regions of interest divided the myocardium in the axial section. Three subdivisions were created within these regions in areas prone to BHA. Reports of SPECT studies performed within 30 days of CT examination were used to confirm the presence and location of true perfusion defects. Paired student t-test was used for statistical evaluation. RESULTS: Overall mean myocardial attenuation was lower using BHC (D30f: 87.3 ± 24.1 HU; D33f: 85.5 ± 21.5 HU; p = 0.009). Overall relative difference from average myocardial attenuation (RDMA) was more homogeneous using BHC (D30f: -0.3 ± 11.4 %; D33f: 0.1 ± 10.1 %; p < 0.001). Changes in RDMA were greatest in the posterobasal myocardium (D30f: -16.2 ± 10.0 %; D33f: 3.4 ± 10.7 %; p < 0.001). CONCLUSIONS: A dedicated reconstruction algorithm with BHC can significantly reduce beam-hardening artefacts in DE-CTMPI. KEY POINTS: • Beam-hardening artefacts (BHA) cause interference with attenuation-based CT myocardial perfusion assessment (CTMPI). • BHA occur mostly in the posterobasal left ventricular wall. • Beam-hardening correction homogenized and decreased mean myocardial attenuation. • BHC can help avoid false-positive findings and increase specificity of static CTMPI.

Cardiovascular manifestations of heterotaxy and related situs abnormalities assessed with CT angiography.

Heterotaxy and situs abnormalities describe an abnormal arrangement of visceral organs in the thoracoabdominal cavity across the normal left-right axis of the body. It is associated with a high occurrence of congenital heart and abdominal defects, including anomalous pulmonary venous connections, systemic venous abnormalities, asplenia, and intestinal malrotation. Without proper diagnosis and surgical intervention, the prognosis of patients with heterotaxy syndrome and associated congenital defects is extremely poor. Complex intracardiac and extracardiac lesions are common in heterotaxy and can be difficult to assess by echocardiography. CT angiography (CTA) is a useful tool in this setting to accurately assess intracardiac and extracardiac abnormalities in this population for medical or surgical management. The intention of this pictorial essay is to review the most common cardiovascular defects involved with heterotaxy syndrome in addition to emphasizing the utility of CTA in the identification and classification of anomalies seen in these patients. This review briefly defines most common terminology used in situs abnormalities as well as presents CT images and 3-dimensional reconstructions of common anomalies associated with situs abnormalities. In summary, this review should prepare radiologists and pediatric cardiologists to describe heterotaxy and situs abnormalities in addition to recognizing the utility of CTA in these patients.

128-slice acceletated-pitch dual energy CT angiography of the head and neck: comparison of different low contrast medium volumes.

BACKGROUND: Our study aims to evaluate the image quality and feasibility of 128-slice dual-energy CTA (DE-CTA) for supra-aortic arteries using reduced amounts of contrast medium (CM). METHODS: A prospective study was performed in 54 patients receiving CTA of the head and neck with a 128-slice dual-source CT system. Patients were randomized into two groups with a volume of either 40 mL of CM (Group I) or 50 mL of CM (Group II). Arterial and venous enhancements were recorded for quantitative assessment. Qualitative assessments for images without bone removal (BR) were based on a) the visualization of the circle of Willis and b) streak artifacts due to residual CM in the subclavian or internal jugular veins ipsilateral to injection of CM. Qualitative assessment of dual-energy images using BR was based on the presence of bone remnants and vessel integrity. Quantitative data was compared using the Student t test. The χ(2) test was used for the qualitative measurements of streak artifacts in veins while the Mann-Whitney U test was used for the qualitative measurements of images with BR. RESULTS: Arterial and venous attenuation was significantly higher in Group II (P=0.000). Image quality regarding the circle of Willis was excellent in both groups (3.90±0.30 for Group I and 4.00±0 for Group II) . Imaging of the internal jugular veins was scored higher in Group I (1.87±0.72) compared with Group II (1.48±0.51) (P=0.021). Within Group I using BR, mean scores for bone remnants did not differ significantly (P>0.05) but mean scores of vessel integrity (P<0.05) did. CONCLUSIONS: Contrast-enhanced head and neck CTA is feasible using a scan protocol with low amounts of contrast medium (40 mL) on a 128-slice dual-energy CTA. The 40-mL protocol provides satisfactory image quality before and after dual-energy bone-removal post-processing.