Comparison of continuous spinal with combined spinal-epidural anesthesia using plain bupivacaine 0.5% in trauma patients

We investigated the efficacy and complications of microcatheter spinal anesthesia (CSA) in comparison to a combined spinal-epidural technique (CSE) using plain bupivacaine 0.5%. Sixty trauma patients randomly received either CSA using a 22-gauge Sprotte needle and a 28-gauge microcatheter or CSE after insertion of a 22-gauge epidural catheter through an 18-gauge Tuohy needle followed by dural puncture with a 25-gauge pencil-point needle inserted through the backeye of the Tuohy needle. An initial subarachnoid bolus of 2 mL of plain bupivacaine 0.5% was injected. If analgesia did not reach T12 within 20 min, supplemental bupivacaine was injected either intrathecally or epidurally up to a maximum of 5 mL in the CSA group or 16 mL in the CSE group. Mean arterial blood pressure, heart rate, and analgesic levels were recorded. On postoperative Day 4, patients were interviewed for postanesthetic complaints. Technical problems were more frequent in the CSE group than in the CSA group (47% vs 13%). Performance of anesthesia was faster (8 +/- 3 vs 15 +/- 8 min) and the total dose of bupivacaine lower (3.2 +/- 1.0 vs 9.7 +/- 5 mL) in patients who received CSA. The incidence of hypotension did not differ significantly. However, more patients in the CSE group were treated for bradycardia (4 vs 0). The number of patients suffering from postdural puncture headache was comparable in both groups, but there were more patients with lower back pain in the CSE group (8 vs 2). In conclusion, our data suggest that microcatheter CSA is not associated with an increased rate of complication in patients with lower limb fractures.

[Life-threatening swelling of the tongue in antihypertensive therapy with ACE inhibitors]

Although generally showing a low incidence of side effects, inhibitors of angiotensin-converting enzyme (ACE) may in rare cases induce angioedemas, mainly located in the oro-facial area and larynx. The interval between the beginning of the ACE inhibitor therapy and the occurrence of such angioedemas may range from a few hours to a few years. Here, the case of a 53-year-old man with massive swelling of the tongue after dental surgery is presented who had started with ACE inhibitor therapy only 24 h before. At admission to the clinic, obstruction of the upper airway due to the tongue swelling had already progressed so far that fiberoptic intubation was necessary. Additionally, the patient was treated with corticosteroids, antihistaminics and epinephrine, avoiding any further administration of the ACE inhibitor. The swelling resolved within 48-72 h. Dentists and physicians should take into consideration this potential side effect in patients treated with ACE inhibitors.

Influence of assay method differences on multiple of the median distributions: maternal serum alpha-fetoprotein as an example

A straightforward statistical explanation is provided to show how differences between assay methods can affect the distribution of the multiples of the median (MoM). Evaluation of the impact of assay method differences reveals that the upper tails of the MoM distribution are not affected to the same degree as the lower tails of the distribution. The disparities in MoM distributions due to assay method differences result in various sensitivity/specificity combinations for different assays having the same fixed MoM cutoffs. Disparities do not exist if risks are calculated with use of the distributions for affected and unaffected populations that are based on a center's own assay method. Applying published risk tables, however, can affect the accuracy of the risk estimates. We used maternal serum alpha-fetoprotein as an example of an assay with an established history of reporting results in MoM values; however, the concepts presented apply equally well to any assay for which results are reported in MoMs.

Influence of assay method differences on multiple of the median distributions: maternal serum alpha-fetoprotein as an example

A straightforward statistical explanation is provided to show how differences between assay methods can affect the distribution of the multiples of the median (MoM). Evaluation of the impact of assay method differences reveals that the upper tails of the MoM distribution are not affected to the same degree as the lower tails of the distribution. The disparities in MoM distributions due to assay method differences result in various sensitivity/specificity combinations for different assays having the same fixed MoM cutoffs. Disparities do not exist if risks are calculated with use of the distributions for affected and unaffected populations that are based on a center's own assay method. Applying published risk tables, however, can affect the accuracy of the risk estimates. We used maternal serum alpha-fetoprotein as an example of an assay with an established history of reporting results in MoM values; however, the concepts presented apply equally well to any assay for which results are reported in MoMs.

[Changes in blood flow velocity in the basal cerebral arteries following neck dissection]

Cerebral blood-flow velocities (cm/s) and pulse index (PI) were studied pre- and postoperatively in a total of 15 male patients following bilateral radical/functional (group A; n = 10) or unilateral radical neck dissection (group B; n = 5) using a 2 MHz-pulsed transcranial Doppler ultrasonographical system (TCD), with a transtemporal approach to the middle cerebral artery. Systolic and mean flow velocities were significant reduced with subsequent increases in PI during the first postoperative sonography in group A-patients while no significant differences in TCD date developed in group B. Blood-flow velocities and PI reached control values within three days. General hemodynamic and respiratory parameters did not influence the changes in TCD flow profiles with the exception of moderate increases in arterial CO2 during the early postoperative period. It is concluded that the reductions in blood-flow velocities and concomitant increases in PI reflect a heightened resistance to flow in the arterial cerebral vasculature. The decrease in cerebral vascular compliance suggests increases in the cerebral venous outflow following the resection of essential drainage pathways. However, TCD does not provide any information about the adequacy of cerebral blood flow.

[Ophthalmological significance of stenosing carotid processes]

In a retrospective study we looked at the incidence of carotid artery stenosis in 191 ophthalmological patients, which underwent duplex sonography. In all these patients the oculist had considered carotid artery stenosis to be a possible reason for the present eye disease or visual disturbance. The incidence of stenosis found in these patients was compared to a group of 186 persons of the same mean age, which underwent routine-sonography without suffering from any symptoms related to carotid artery disease. Patients with amaurosis fugax, with occluded retinal veins and patients with glaucoma associated changes of the retina (in spite of normal eye pressure) suffered more often from carotis stenosis than asymptomatic persons (statistically significant), patients with occluded retinal arteries showed also more often carotid artery stenosis than the asymptomatic collective but without statistical significance. We conclude, that patients presenting with the mentioned symptoms should undergo carotid artery sonography. Furthermore these results could be of importance in evaluation the indication for carotid thrombendarterectomy (stadium II of cerebrovascular insufficiency).

Interference in an automated radial partition fluorescent immunoassay of thyrotropin associated with liver-function abnormalities

In a previous evaluation of a "sensitive" radial partition fluorescent immunoassay on the Stratus system, thyrotropin (TSH) values exhibited a positive bias in icteric samples when compared with results of a nonsensitive radioimmunoassay. In the present study, we evaluated 366 patients samples to assess whether any biochemical markers of liver function could identify samples for which TSH values would be falsely increased. gamma-Glutamyltransferase and total bilirubin concentrations were unrelated to discrepant TSH values. In contrast, alkaline phosphatase (ALP) was significantly positively correlated with differences in Stratus and RIA TSH concentrations (P less than 0.001). However, this correlation explained only 34% of the observed residual variability around the estimated regression line. On average, the higher ALP values were associated with larger discrepancies between Stratus and RIA TSH values, although several samples with increased ALP did not have falsely increased Stratus TSH values. TSH measurements performed with a Stratus should be interpreted with caution in patients with abnormal biochemical markers of liver function.

Interference in an automated radial partition fluorescent immunoassay of thyrotropin associated with liver-function abnormalities

In a previous evaluation of a "sensitive" radial partition fluorescent immunoassay on the Stratus system, thyrotropin (TSH) values exhibited a positive bias in icteric samples when compared with results of a nonsensitive radioimmunoassay. In the present study, we evaluated 366 patients samples to assess whether any biochemical markers of liver function could identify samples for which TSH values would be falsely increased. gamma-Glutamyltransferase and total bilirubin concentrations were unrelated to discrepant TSH values. In contrast, alkaline phosphatase (ALP) was significantly positively correlated with differences in Stratus and RIA TSH concentrations (P less than 0.001). However, this correlation explained only 34% of the observed residual variability around the estimated regression line. On average, the higher ALP values were associated with larger discrepancies between Stratus and RIA TSH values, although several samples with increased ALP did not have falsely increased Stratus TSH values. TSH measurements performed with a Stratus should be interpreted with caution in patients with abnormal biochemical markers of liver function.

Preoperative magnetic resonance imaging in Marfan syndrome

We report one of the first cases in Israel of composite-graft repair of an aortic aneurysm in Marfan syndrome, in which preoperative evaluation was done noninvasively using magnetic resonance imaging (MRI). Because of the relatively favorable outcome of surgical compared with medical treatment of aortic aneurysm in patients with Marfan syndrome, surgery is now more frequently considered, even in asymptomatic patients. MRI is an excellent diagnostic tool for evaluating the thoracic aorta and has been suggested as a replacement for preoperative cardiac catheterization. In the case presented here, MRI preoperative confirmation of a 6.0-cm aortic aneurysm in an asymptomatic 38-year-old man with Marfan syndrome, was followed by composite ascending aorta and aortic valve replacement. The postoperative course was good. This case supports the view that aortic aneurysm replacement can be performed based on a noninvasive preoperative evaluation using MRI.

Altered left ventricular volume and ejection fraction responses to supine dynamic exercise in athletes

Two-dimensional echocardiography was used to determine the responses of left ventricular volumes, ejection fraction and segmental left ventricular motion to supine dynamic exercise in 22 professional athletes, comparing these responses with those in 22 age- and gender-matched healthy untrained individuals. End-systolic volume was significantly greater at rest and during exercise in the athletes (50 +/- 6 versus 29 +/- 4 ml and 40 +/- 5 versus 17 +/- 4 ml, respectively, p less than 0.001 for both). It decreased during exercise in all the untrained subjects, but did not change or increased in nine athletes (41%). End-diastolic volume was greater in the athletes at rest (143 +/- 12 versus 98 +/- 9 ml) and during exercise (157 +/- 14 versus 121 +/- 13 ml, p less than 0.01 for both). It increased in all the untrained subjects, but decreased or did not change in six athletes (27%). Ejection fraction was significantly lower in the athletes at rest and during exercise (65 +/- 4% versus 70 +/- 5% and 73 +/- 5% versus 86 +/- 5%, p less than 0.01 and 0.001, respectively); the values augmented normally in all the untrained subjects, but increased only by less than 5% units, did not change or decreased in nine athletes (41%). Eight athletes (36.5%) failed to demonstrate the expected symmetric hyperkinetic wall motion changes during exercise, which were seen in all the untrained subjects. No correlation was found between atypical responses to exercise and electrocardiographic patterns.(ABSTRACT TRUNCATED AT 250 WORDS)

Radial partition fluorescent immunoassay of thyrotropin. Analytic evaluation and clinical correlation

The authors evaluated the analytic and clinical performance of a sensitive radial partition fluorescent enzyme immunoassay for thyrotropin (TSH) performed on Stratus and compared it with a nonsensitive radioimmunoassay (RIA) method. Sensitivity of 0.15 mIU/L was obtained, and precision, specificity, and linearity were acceptable. A good correlation was observed between the two assays in samples from 311 hospitalized patients (r = 0.976). Stratus TSH results were outside the reference range for 20% of clinically euthyroid patients (n = 126), and 2.4% had undetectable levels. The clinically hyperthyroid group (n = 11) with the exception of one patient had TSH values below 0.2 mIU/L. Only 39% of hypothyroid patients on thyroid hormone replacement (n = 74) had TSH values in the reference range, with 38% and 23% exhibiting low and high values, respectively. All untreated primary hypothyroid patients (n = 8) had elevated TSH concentrations. The authors conclude that this sensitive TSH assay is useful for diagnosing hyperthyroidism when there is a clinical suspicion but cannot be recommended for thyroid screening in hospitalized patients.

Stratus automated creatine kinase-MB assay evaluated: identification and elimination of falsely increased results associated with a high-molecular-mass form of alkaline phosphatase

We compared the performance of an automated assay of creatine kinase MB isoenzyme (CK-MB) mass (Stratus) with that of a CK-MB enzymatic assay routinely used at our institutions. Both of these assays use the same CK-MB-specific monoclonal antibody to immunocapture CK-MB, thus providing a direct means of comparing a mass assay with an activity assay. Routine CK-MB measurements for 206 samples within the analytical range of both assays revealed the following relationship: Stratus (micrograms/L) = 0.67 (activity U/L) + 0.18 (r = 0.95, Sx.y = 4.45). The linearity, sensitivity, and precision of the Stratus assay were acceptable for routine clinical use. Icteric, lipemic, and hemolyzed samples do not interfere with the assay. During our evaluation we identified a single, clinically significant false-positive sample. Because this patient had alkaline phosphatase values greater than 1100 U/L, we investigated additional samples with increased activities of alkaline phosphatase and found that samples from 12 of 23 patients selected for alkaline phosphatase values greater than 460 U/L produced falsely increased CK-MB values. We determined that a membrane-associated, high-molecular-mass form of alkaline phosphatase was a cause of these falsely increased values and instituted an approach to identify falsely increased Stratus CK-MB values. Samples from 23 of 1933 patients were falsely increased, the increase being clinically significant in samples from 14 of these patients. Consultation with the manufacturer resulted in the successful reformulation of the substrate/wash solution to minimize interferences from high-molecular-mass forms of alkaline phosphatase.

Stratus automated creatine kinase-MB assay evaluated: identification and elimination of falsely increased results associated with a high-molecular-mass form of alkaline phosphatase

We compared the performance of an automated assay of creatine kinase MB isoenzyme (CK-MB) mass (Stratus) with that of a CK-MB enzymatic assay routinely used at our institutions. Both of these assays use the same CK-MB-specific monoclonal antibody to immunocapture CK-MB, thus providing a direct means of comparing a mass assay with an activity assay. Routine CK-MB measurements for 206 samples within the analytical range of both assays revealed the following relationship: Stratus (micrograms/L) = 0.67 (activity U/L) + 0.18 (r = 0.95, Sx.y = 4.45). The linearity, sensitivity, and precision of the Stratus assay were acceptable for routine clinical use. Icteric, lipemic, and hemolyzed samples do not interfere with the assay. During our evaluation we identified a single, clinically significant false-positive sample. Because this patient had alkaline phosphatase values greater than 1100 U/L, we investigated additional samples with increased activities of alkaline phosphatase and found that samples from 12 of 23 patients selected for alkaline phosphatase values greater than 460 U/L produced falsely increased CK-MB values. We determined that a membrane-associated, high-molecular-mass form of alkaline phosphatase was a cause of these falsely increased values and instituted an approach to identify falsely increased Stratus CK-MB values. Samples from 23 of 1933 patients were falsely increased, the increase being clinically significant in samples from 14 of these patients. Consultation with the manufacturer resulted in the successful reformulation of the substrate/wash solution to minimize interferences from high-molecular-mass forms of alkaline phosphatase.

Usefulness of immediate postexercise two-dimensional echocardiography in post-myocardial infarction patients without ischemic ECG changes in stress testing: comparison with radionuclide angiography

Of 38 post-myocardial infarction (MI) applicants for a cardiac rehabilitation program, 17 (45%) did not have ischemic ECG changes in exercise testing. Ten (59%) of these 17 patients had echocardiographic wall motion abnormalities at rest. Immediate postexercise two-dimensional echocardiography demonstrated exercise-induced changes in 8 (47%) patients (2 with normal and 6 with abnormal results from rest studies). The comparative radionuclide (RNA) examinations showed that there were 6 patients with abnormal findings from rest RNA; exercise-induced changes were detected in 7 (44%) of 16 patients (3 with normal and 4 with abnormal results from rest RNA tests). Statistical analyses, using RNA as reference point, revealed that the total correctly diagnosed cases for the echocardiographic rest studies was 13/17 (77%) and for the exercise studies, 13/16 (81%). The negative predictive values were 7/7 (100%) and 7/8 (88%), respectively. The corresponding positive predictive values were 6/10 (60%) and 6/8 (75%). The same pattern was observed when each segment (septal, apical, and posterolateral) was evaluated separately. The authors conclude that in post-MI patients with a negative stress test, the efficacy of postexercise echocardiography equals that of RNA in the identification of additional patients with ischemia.

[Pulse oximetry in surgery of the bronchial system]

Oxygen saturation was determined by pulse oximetry in 35 children and adults during general anaesthesia using jet- or manually assisted ventilation for minor elective laryngeal and tracheo-bronchial surgery. The method is non-invasive and provides continuous information about the arterial oxygen saturation (saO2) and heart rate. Compromised arterial oxygenation during anaesthesia and the effects and brief ventilatory arrest are accurately detectable. Data such as pO2, pCO2 or pH cannot be assessed by pulse oximetry; carbon monoxide and methemoglobinaemia may lead to less accurate results. Pulse oximetry provides on-line information about sudden hypoxic events and allows early therapeutic intervention because arterial desaturation precedes the clinical signs and symptoms of hypoxia.

[High-frequency jet ventilation in emergency tracheal puncture]

A case of obstruction of the upper respiratory tract is reported, in which an intubation or insufflation by rigid tracheobronchoscopes was not possible. Due to the anatomical situation after multiple operations and irradiation, coniotomy could not be performed. Blind puncture of the trachea with subsequent High Frequency Jet Ventilation has proved successful as an emergency approach to maintain respiratory function.

Decreased stability of triglycerides and increased free glycerol in serum from heparin-treated patients

Triglycerides usually are stable in serum. However, for a few patients, we noted marked decreases in measured triglycerides when the same serum specimen was analyzed on successive days. This was found to be ascribable to intravenous administration of heparin. Measured triglyceride in serum of 11 patients being treated with heparin decreased 34% (SD 17%) in samples stored for one day at room temperature. Triglyceride values for sera from control patients remained unchanged. Increases in free glycerol corresponded to the observed decreased in triglycerides. Measurement of free glycerol thus provides a means of recognizing this problem.