Cervical zygapophyseal joints: geometrical parameters and relationship to cervical kinematics

The relationship was examined between the height and slope of the cervical zygapophyseal joints and the patterns of motion of the cervical vertebrae. The height and orientation of the C₃---C₇ superior articular processes were measured in lateral radiographs of 40 normal subjects. The C₄-C₆ facets were oriented at approximately 40° to the vertical, while the C₃ and C₇ facets were more steeply oriented. The heights of the superior articular processes were found to increase at progressively lower vertebral levels. Contrary to published views, the slope of the superior articular facets has no bearing on the pattern of motion of the cervical vertebrae. No relationship was found between slope of the facets and the location of the instantaneous axes of rotation of the cervical vertebrae. In contrast the height of the articular processes was perfectly related to the location of the axes of rotation. Articular height, but not slope, is a major determinant of the patterns of motions of the cervical vertebrae.

This study provides data necessary to confirm or deny the putative roles of the cervical zygapophyseal joints in determining motion of the cervical spine in the sagittal plane.     

The effect of dyshemoglobins on pulse oximetry: Part I,theoretical approach and part II,experimental results using an in vitro test system

Pulse oximeters are known to be inaccurate in the presence of elevated concentrations of carboxyhemoglobin and methemoglobin. This paper attempts to alleviate some of the confusion that exists between fractional and functional saturation, and to clarify the comparison of each with SpO₂. A series of theoretical relationships between pulse oximeter reading (SpO₂) and actual oxygen saturation (both fractional and functional) is derived using simple absorption theory. The theoretical relationships are checked using an experimental in vitro test system. This consists of a blood circuit containing a model finger, capable of simulating the pulsatile transmission signals through a real finger. Theoretical predictions and experimental results are compared and are found to agree well in the presence of carboxyhemoglobin, but less well with methemoglobin. Possible reasons are discussed.     

The Relationship of Plasma Glucose and HbA1c Levels among Emergency Department Patients with No Prior History of Diabetes Mellitus

Objectives: Patients without a history of diabetes mellitus may be incidentally found to be hyperglycemic in the emergency department (ED). If the hyperglycemia is due to undiagnosed diabetes, then an opportunity for detection exists. Hemoglobin A1c (HbA1c) provides a weighted average of blood glucose levels over the past several months; high HbA1c levels could indicate diabetes. The objective of this study was to determine whether hyperglycemia in ED patients without a history of diabetes was associated with higher HbA1c levels.
Methods: This was a prospective nonconsecutive case series of adults aged 18 years or older presenting to the ED with acute illness for whom a plasma glucose sample was drawn for clinical management. A history of diabetes/hyperglycemia or current symptoms of diabetes excluded patients. HbA1c levels were analyzed for a glucose cutoff of 110 mg/dL; the data were further analyzed using additional glucose cutoffs. Based on the Third National Health and Nutrition Examination Survey outpatient screening data, an HbA1c level ≥6.2% was considered elevated (sensitivity of 63% and specificity of 97% for identifying diabetes).
Results: There were 541 patients enrolled; the glucose level correlated with the HbA1c level ( r = 0.60, p < 0.001). Among the 331 patients with a glucose level ≥110 mg/dL, 22.4% had an elevated HbA1c level; among the 210 patients with a glucose level < 110 mg/dL, 7.6% had an elevated HbA1c level. There were few patients ( n = 13) with a glucose level ≥200 mg/dL, but most (85%) had an elevated HbA1c level. Among the 140 patients with a mildly elevated glucose level (110–125 mg/dL), 16.4% had an elevated HbA1c level.
Conclusions: Elevated HbA1c levels are found in ED patients with elevated random plasma glucose values. ED patients with hyperglycemia may warrant referral for diabetes testing.     

Clinical assessment of a flow-through fluorometric blood gas monitor

We performed an observational study to evaluate a flow-through fluorometric instrument (Gas-STAT) that continuously measures the carbon dioxide tension (PCO ₂), oxygen tension (PO ₂), and pH of blood in the cardiopulmonary bypass circuit. Setup and calibration of the instrument typically required 20 minutes. During bypass, 129 blood samples were drawn from 16 patients for comparison with conventional measurements obtained with a blood gas machine. Data for each variable, within each sensor, were analyzed by linear regression. The ranges of the standard errors of the estimate were 0.7 to 4.2 mm Hg forPCO ₂, 18.3 to 78.7 mm Hg for the highPO ₂ range, 1.4 to 7.1 mm Hg for the lowPO ₂ range, and 0.008 to 0.049 for pH. The regression lines differed from the identity line (P<0.05) in at least one variable in most patients, and large deviations from the line of identity in both slope and intercept were common. Among 58 sensors evaluated, failures occurred in 5 (2.9%) of the 174 optodes, and minor leakage occurred in 2 (3.4%) of the flow-through cells. We conclude that although this flow-through fluorometric instrument is an adequate monitor of trends in blood gases during cardiopulmonary bypass, it is not accurate enough to supplant conventional laboratory measurements.Supported in part by grant HL-30881 from the National Institutes of Health.Presented in part at the National Meeting of the American Association for Clinical Chemistry, Atlanta, GA, July 1985, and at the Annual Meeting of the American Society of Anesthesiologists, San Francisco, CA, Oct 1985.The authors thank Dr Brenda Townes for supervising the bypass outcome study of which this was a component; our surgical colleagues, Drs Margaret Allen, Peter McKeown, and Gregory Misbach for allowing us to study their patients; cardiopulmonary perfusionists Gary Tarter, David Anderson, Roland Alberto, and Debora Bley; and the technologists of the Department of Laboratory Medicine.Gas-STAT and disposables were provided by Cardiovascular Devices, Inc.     

Brief Motivational Intervention to Increase Self-reported Safety Belt Use among Emergency Department Patients

Objectives:  Brief motivational interventions have shown promise in reducing harmful behaviors. The authors tested an intervention to increase safety belt use (SBU) among emergency department (ED) patients.
Methods:  From February 2006 to May 2006, the authors conducted a randomized trial of adult ED patients at a teaching hospital in Boston. ED patients were systematically sampled for self-reported SBU. Those with SBU other than "always" were asked to participate. At baseline, participants answered a 9-item series of situational SBU questions, each scored on a 5-point Likert scale. SBU was defined as a continuous variable (9-item average) and as a dichotomous variable (response of "always" across all items). Participants were randomized to an intervention or a control group. The intervention group received a 5- to 7-minute intervention, adapted from classic motivational interviewing techniques, by a trained interventionist. Participants completed a 3-month follow-up phone survey to determine changes from baseline SBU. Continuous and dichotomous SBU were analyzed via analysis of covariance and chi-square testing.
Results:  Of 432 eligible patients, 292 enrolled (mean age 35 years, standard deviation [SD] ±11 years; 61% male). At baseline, the intervention and control groups had similar mean (±SD) SBU scores (2.8 [±1.1] vs. 2.6 [±1.1], p = 0.31) and SBU prevalence (each 0%). At 3 months, 81% completed follow-up. The intervention group had significantly greater improvement in mean (±SD) SBU scores than controls (0.76 [±0.91] vs. 0.34 [±0.88], p < 0.001). Also, SBU prevalence of "always" was higher for the intervention group than controls (14.4% vs. 5.9%, p = 0.03).
Conclusions:  Participants receiving a brief motivational intervention reported higher SBU at follow-up compared to controls. An ED-based intervention may be useful to increase SBU.     

The prevalence of hypoxemia detected by pulse oximetry during recovery from anesthesia

Pulse oximetry was used to assess the prevalence of hypoxemia (arterial oxygen saturation of 90% or less) at various times in the immediate postoperative period: five minutes after arrival, 30 minutes later, and just before discharge. Among 149 inpatients studied, one or more hypoxemic measurements were made in 21 (14%) during their postoperative course. Of 92 outpatients, 1 (1%) was found to be hypoxemic. For inpatients, the prevalence of hypoxemia preoperatively, 5 minutes after arrival in recovery, 30 minutes later, and at discharge was 2%, 4%, 6%, and 9%, respectively. Patient factors associated with a significantly higher prevalence of hypoxemia were obesity (22%), body cavity surgical procedures (24%), age over 40 years (18%), American Society of Anesthesiologists physical status (I, 7%; II, 17%; III, 18%; IV, 100%), duration of anesthesia longer than 90 minutes (18%), and intraoperative administration of greater than 1,500 ml of fluid (20%). Unrecognized hypoxemia in postsurgical inpatients with or without these risk factors is common. Therefore routine monitoring of these patients with a pulse oximeter is suggested.     

Rizatriptan (MAXALT) for the Acute Treatment of Migraine and Migraine Recurrence. A Placebo-Controlled, Outpatient Study

Rizatriptan is a novel 5-HT_1B/1D agonist which is rapidly absorbed after oral administration. The efficacy and tolerability of oral rizatriptan (5 mg and 10 mg) were examined in this multicenter, double-blind, outpatient study of 1473 migraineurs which featured randomized, placebo-controlled treatment of migraine recurrences. On experiencing moderate or severe migraine headaches, patients rated headache severity prior to dosing and at 30-minute intervals for 2 hours after dosing. Onset of effect was seen as early as 30 minutes after dosing with rizatriptan 10 mg. At 2 hours postdose, the percentage of patients with pain relief was significantly higher after rizatriptan 5 mg (62%) or 10 mg (71%) compared with placebo (35%). Complete relief was also significantly higher after rizatriptan 5 mg (33%) and 10 mg (42%) compared with placebo (10%). In patients experiencing headache recurrence after initial benefit, further relief was obtained in 71% with rizatriptan 5 mg (placebo 54%) and in 82% with rizatriptan 10 mg (placebo 44%). Complete relief of recurrent headache was obtained in 36% with rizatriptan 5 mg, 49% with rizatriptan 10 mg, and 15% with placebo ( P <0.05). The most common drug-related adverse experiences were dizziness, somnolence, asthenia/fatigue, and nausea (the incidences of which were low and dose related). There was no increase in the incidence of adverse experiences after use of up to three doses of rizatriptan within 24 hours. We conclude that both doses of rizatriptan are effective and well tolerated in the acute treatment of migraine and migraine recurrence, with the l0-mg dose preferred as it is more effective with a faster onset of action.     

Usefulness of 3′-[F-18]Fluoro-3′-deoxythymidine with Positron Emission Tomography in Predicting Breast Cancer Response to Therapy

Objective The usefulness of 2-deoxy-2-[F-18]fluoro-d-glucose (FDG)–positron emission tomography (PET) in monitoring breast cancer response to chemotherapy has previously been reported. Elevated uptake of FDG by treated tumors can persist however, particularly in the early period after treatment is initiated. 3′-[F-18]Fluoro-3′-deoxythymidine (FLT) has been developed as a marker for cellular proliferation and, in principle, could be a more accurate predictor of the long-term effect of chemotherapy on tumor viability. We examined side-by-side FDG and FLT imaging for monitoring and predicting tumor response to chemotherapy. Methods Fourteen patients with newly diagnosed primary or metastatic breast cancer, who were about to commence a new pharmacologic treatment regimen, were prospectively studied. Dynamic 3-D PET imaging of uptake into a field of view centered over tumor began immediately after administration of FDG or FLT (150 MBq). After 45 minutes of dynamic acquisition, a clinically standard whole-body PET scan was acquired. Patients were scanned with both tracers on two separate days within one week of each other (1) before beginning treatment, (2) two weeks following the end of the first cycle of the new regimen, and (3) following the final cycle of that regimen, or one year after the initial PET scans, whichever came first. (Median and mean times of early scans were 5.0 and 6.6 weeks after treatment initiation; median and mean times for late scans were 26.0 and 30.6 weeks after treatment initiation.) Scan data were analyzed on both tumor-by-tumor and patient-by-patient bases, and compared to each patient's clinical course. Results Mean change in FLT uptake in primary and metastatic tumors after the first course of chemotherapy showed a significant correlation with late (av. interval 5.8 months) changes in CA27.29 tumor marker levels (r = 0.79, P = 0.001). When comparing changes in tracer uptake after one chemotherapy course versus late changes in tumor size as measured by CT scans, FLT was again a good predictor of eventual tumor response (r = 0.74, P = 0.01). Tumor uptake of FLT was near-maximal by 10 minutes after injection. The time frame five to 10 minutes postinjection of FLT produced standardized uptake value (SUV) values highly correlated with SUV values obtained after 45-minute uptake (r = 0.83, P < 0.0001), and changes in these early SUVs after the first course of chemotherapy correlated with late changes in CA27.29 (r = 0.93, P = 0.003). Conclusion A 10-minute FLT-PET scan acquired two weeks after the end of the first course of chemotherapy is useful for predicting longer-term efficacy of chemotherapy regimens for women with breast cancer.     

A Survey of the Emergency Department Population and Their Interest in Preventive Health Education

OBJECTIVE: To determine which preventive health information the emergency department (ED) population (patients and visitors) would be most interested in having available to them while they spend time in the waiting area. METHODS: This was a prospective survey of consecutive adults seated in the ED waiting area during a representative week on predetermined shifts. The survey asked them to indicate whether they would be interested in obtaining information about the following preventive health issues: breast cancer, prostate cancer, smoking, obesity, stress reduction, exercise programs, alcohol/drugs, HIV, blood pressure screening, immunizations, referrals to primary care physicians, Pap smears, car safety, smoke detectors, domestic and youth violence, depression, gun safety, and safe sex. RESULTS: Of the 1284 subjects approached, 878 (68%) made up the study group (56% female, mean age = 44 years, 60% white); 406 refused. The information people were most interested in obtaining was the following: 52% of the respondents were interested in referral to stress reduction programs, 51% in information about exercise programs, 42% in blood pressure screening, 40% in information about breast cancer screening, 33% in depression information/screening, 33% in prostate cancer screening, 26% in immunization against pneumococcus, 24% in immunization against tetanus, 26% in smoking cessation programs, and 26% in safe driving information. Women were most interested in breast cancer screening (64%); and men, in prostate cancer screening (55%). CONCLUSIONS: Of the 878 subjects in the study group, 96% were interested in obtaining information about one or more preventive health issues. An opportunity exists to respond to this interest by providing material for public health education in the waiting area of EDs.