Lidocaine infusion adjunct to total intravenous anesthesia reduces the total dose of propofol during intraoperative neurophysiological monitoring

Total intravenous anesthesia (TIVA) with propofol and opioids is frequently utilized for spinal surgery where somatosensory evoked potentials (SSEP) and motor evoked potentials (tcMEP) are monitored. Lidocaine infusions can contribute to antinociception and unconsciousness, thus allowing for a reduction in the total dose of propofol. We examined our recent experience with lidocaine infusions to quantify this effect. After institutional review board approval, we conducted a retrospective review of propofol usage in propofol-opioid TIVA (with and without lidocaine) for spine cases monitored with SSEP and tcMEP over a 7 months period. The propofol infusion rate, cortical amplitudes of the SSEP (median nerve, posterior tibial nerve), amplitudes and stimulation voltage of the tcMEP (adductor pollicis brevis, tibialis anterior) were evaluated. The savings of propofol and sufentanil were estimated based on utilization in 50 milliliter (ml) bottles and 5 ml ampules, respectively. 129 cases were evaluated. Propofol infusion rates were reduced with lidocaine infusion from an average of 115–99 μg/kg/min (p = 0.00038) and sufentanil infusions from an average of 0.36–0.29 μg/kg/h (p = 0.0059). This reduction in propofol infusion was also seen when the cases were divided into anterior cervical, posterior cervical, or posterior thoraco-lumbar procedures. No significant differences in the cortical SSEP or tcMEP amplitudes or the tcMEP stimulation voltages used were observed. No complications were associated with the use of the lidocaine infusion. The total estimated drug savings included 104 50 ml bottles of propofol and 5 5 ml ampules of sufentanil. These cases indicate that a lidocaine infusion can be effectively utilized in spine surgery with SSEP and tcMEP monitoring as a means to reduce propofol and sufentanil usage without a negative effect on the monitoring.     

PASSIVE HIP RANGE OF MOTION IS REDUCED IN ACTIVE SUBJECTS WITH CHRONIC LOW BACK PAIN COMPARED TO CONTROLS

Background

Non‐specific low back pain is a common condition often without a clear mechanism for its presentation. Recently more attention has been placed on the hip and its potential contributions to non‐specific chronic low back pain (NSCLBP). Emphasis in research has mainly been placed on motor control, strength and endurance factors in relation to NSCLBP. Limited focus has been placed on hip mobility and its potential contribution in subjects with NSCLBP.

Purpose/Aim

The aim of this study was to compare passive ROM in hip extension, hip internal rotation, hip external rotation and total hip rotation in active subjects with NSCLBP to healthy control subjects. The hypothesis was that active subjects with NSCLBP would present with decreased total hip ROM and greater asymmetry when compared to controls.

Design

Two group case controlled

Setting

Clinical research laboratory

Participants

30 healthy subjects without NSCLBP and 30 active subjects with NSCLBP. Subjects categorized as NSCLBP were experiencing pain in the low back area with or without radicular symptoms of greater than three months duration.

Main Outcome Measure

Passive hip extension (EXT), hip internal rotation (IR), hip external rotation (ER) and total hip rotation ROM. A digital inclinometer was used for measurements.

Results

There was a statistically significant difference (p<0.001) in hip passive extension ROM between the control group and the NSCLBP group bilaterally. Mean hip extension for the control group was 6.88 bilaterally. For the NSCLBP group, the mean hip extension was ‐4.28 bilaterally. This corresponds to a difference of means between groups of 10.88. There was no statistically significant differences (p>0.05) in hip IR, ER, or total rotation ROM between groups.

Conclusions

The results of this study indicate that a significant difference in hip extension exists in active subjects with NSCLBP compared to controls. It may be important to consider hip mobility restrictions and their potential impact on assessment of strength in NSLBP subjects. Future studies may be needed to investigate the relationship between measurements and intervention strategies.

Level of Evidence

2b     

Hemodynamic Stability After Transitioning Between Endothelin Receptor Antagonists in Patients With Pulmonary Arterial Hypertension

Background

Maintenance of a favourable hemodynamic profile is central to therapeutic success in pulmonary arterial hypertension (PAH). There is little information about the safety of transitioning patients between oral therapies for PAH. Endothelin receptor antagonists (ERAs) have been a therapeutic mainstay in PAH, providing benefit to many patients. Three ERAs, bosentan, sitaxsentan, and ambrisentan have been approved for clinical use. Sitaxsentan was voluntarily withdrawn from the market in late 2010 resulting in the need to quickly transition a large number of stable patients.

Methods

We transitioned 30 clinically stable patients to either ambrisentan or bosentan. Patients underwent a right heart catheterization, measurement of serum N-terminal pro-brain natriuretic peptide (NT-proBNP), and assessment of functional class before changing ERA and again 4 months later. We present a retrospective analysis of those data.

Results

Of the 30 patients transitioned (15 to ambrisentan, 15 to bosentan), 23 had complete hemodynamic data. No significant change was observed in the groups in right atrial, mean pulmonary artery, and pulmonary artery wedge pressures, or in cardiac output, pulmonary vascular resistance, or NT-proBNP levels. There was no change in World Health Organization functional class. Four ambrisentan and 2 bosentan-treated patients reported fluid retention, and 3 bosentan-treated patients had elevation of hepatic transaminases. Two of the patients had a right atrial pressure increase of ≥5 mm Hg, and 4 had pulmonary artery wedge pressure increase of ≥5 mm Hg.

Conclusions

Transitioning between ERAs in stable PAH patients does not result in hemodynamic or clinical deterioration during the first 4 months posttransition. A minority of patients have developed increased cardiac filling pressures.     

Keratin immunohistochemistry detects clinically significant metastases in bone marrow biopsy specimens in women with lobular breast carcinoma

Some patients with breast cancer currently undergo bone marrow biopsy to make clinical decisions regarding therapy; however, lobular carcinoma can be difficult to detect in routine histologic sections. The authors reviewed retrospectively all available bone marrow biopsies from patients with lobular carcinoma diagnosed between January, 1, 1989, and September, 25, 1997, at the City of Hope National Medical Center to identify useful morphologic features and to determine the utility of pan-keratin immunohistochemical (IHC) staining. A total of 65 biopsies from 54 patients were reviewed. Thirteen of the 65 biopsies were classified initially as containing metastatic tumor based on histologic features alone. With the addition of keratin IHC, seven additional cases of metastatic disease were detected. Forty of the 54 patients received stem cell replacement or autologous bone marrow transplantation. Disease-free survival after high-dose chemotherapy with stem cell replacement or autologous bone marrow transplantation was stratified into three groups based on hematoxylin and eosin (H&E) staining and IHC results. Two-year disease-free survival was 33% for the H&E-/IHC+ group versus 90% for the H&E-/IHC- group (p = 0.005) among patients clinically free of disease at the time of stem cell replacement or autologous bone marrow transplantation. Two-year disease-free survival was 0% in the H&E+/IHC+ group (p = 0.04, compared with the H&E-/ IHC+ group). The authors conclude that routine morphologic examination without the aid of keratin IHC is unreliable in detecting clinically relevant metastatic lobular carcinoma in bone marrow biopsies. These findings suggest that pan-keratin immunostaining may be indicated on bone marrow biopsy specimens from lobular carcinoma patients if the biopsy appears histologically negative for metastatic tumor on H&E sections.     

Constitutional mutations in the WT1 gene in patients with Denys-Drash syndrome.

The Denys-Drash syndrome is characterised by a typical nephropathy, genital abnormalities and also predisposes to the development of Wilms' tumor. These patients eventually go into end stage renal failure. A candidate Wilms' tumor gene, WT1, from the 11p13 chromosome region has recently been cloned. We have analysed the DNA sequence in constitutional cells from eight patients and have shown heterozygous mutations in six of them. Four of the mutations were in exon 9, all resulting in missense mutations. Three were at nucleotide position 1180 resulting in an arg > trp amino acid change. The other was at position 1186 converting an asp > asn in the predicted resultant protein. One patient had a missense mutation in exon 8, converting an arg > his. A single base pair insertion at nucleotide position 821 in exon 6 resulted in the generation of a premature stop codon in the last patient. We were unable to find a mutation in one patient despite complete sequencing of the genomic sequence of the gene. The last patient carried a constitutional deletion of the 11p13 region and no additional mutation was found. There was no obvious correlation between the type of mutation and phenotypic expression. These results further demonstrate that the WT1 gene is important in both the development of the kidney and the genito-urinary system.     

A carcinoembryonic antigen-secreting adenocarcinoma arising within a retrorectal tailgut cyst: clinicopathological considerations

Retrorectal tailgut cysts (TGC) develop from postanal fetal gut remnants. They have specific radiological and histopathological features that distinguish them from dermoid cysts, enteric duplication cysts, and teratomas. We report a patient with a carcinoembryonic antigen-producing adenocarcinoma arising within a TGC who underwent resection through a combined anterior laparotomy/posterior pelvic approach. Despite complete resection and delayed but complete functional recovery, diffusely metastatic disease was encountered 6 months after resection. Diagnostic, therapeutic, histopathological, and oncological implications of this illustrative case are discussed. It seems possible to use carcinoembryonic antigen measurements for treatment planning and for assessing treatment response for this rare disease. The described outcome also suggests that TGC can develop malignant degeneration and should be resected at the time of diagnosis.     

Neuropsychiatric aspects of HIV-1 infection in gay men: Controlled investigation of psychiatric, neuropsychological and neurological status

The aim of this study was to determine whether HIV infection is associated with psychiatric morbidity or neuropsychological impairment in asymptomatic and early symptomatic stages of disease in gay men. The subjects were 100 gay men (68 HIV − ve, 32 HIV + ve, 6 being CDC IV). All subjects were recruited at the time of requesting their first HIV test and the assessment was double-blind to HIV serostatus. There were no differences in psychiatric status or neuropsychological performance between the HIV − ve and HIV + ve groups. Multiple regression analysis and logistic regression were used to identify factors associated with psychiatric morbidity, neuropsychological impairment and subjective reporting of memory problems and physical symptoms for all 100 subjects.

Previous psychiatric history and current illegal (non-dependent) drug use were associated with psychiatric morbidity, poor education was assciated with neuropsychological impairment and psychiatric status (score on HAD and PSE) was associated with subjective reporting of memory problems and physical symptoms.