The relationship between meniscal pathologies, cartilage loss, joint replacement and pain in knee osteoarthritis: a systematic review.

OBJECTIVE: We conducted a systematic review in order to understand the relationship between imaging-visualised meniscus pathologies, hyaline cartilage, joint replacement and pain in knee osteoarthritis (OA). DESIGN: A search of the Medline, Excerpta Medica database (EMBASE) and Cochrane library databases was performed for original publications reporting association between imaging-detected meniscal pathology (extrusion or tear/damage) and longitudinal and cross-sectional assessments of hyaline articular cartilage loss [assessed on magnetic resonance imaging (MRI)], incident joint replacement and pain (longitudinal and cross-sectional) in knee OA. Each association was qualitatively characterised by a synthesis of data from each analysis, based upon study design and quality scoring (including risk of bias assessment and adequacy of covariate adjustment using Cochrane recommended methodology). RESULTS: In total 4,878 abstracts were screened and 82 publications were included (comprising 72 longitudinal analyses and 49 cross-sectional). Using high quality, well-adjusted data, meniscal extrusion and meniscal tear/damage were associated with longitudinal progression of cartilage loss, cross-sectional cartilage loss severity and joint replacement, independently of age, sex and body mass index (BMI). Medial and lateral meniscal tears were associated with cartilage loss when they occurred in the body and posterior horns, but not the anterior horns. There was a lack of high quality, well-adjusted meniscal pathology and pain publications and no clear independent association between meniscal extrusion or tear/damage with pain severity, progression in pain or incident frequent knee symptoms. CONCLUSION: Meniscal features have strong associations with cartilage loss and joint replacement in knee OA, but weak associations with knee pain. Systematic review PROSPERO registration number: CRD 42020210910.

Nasal colonization by Staphylococcus aureus in active, independent, community seniors.

OBJECTIVE: to evaluate the prevalence of nasal colonization with Staphylococcus aureus (SA) in active, independent community seniors and old people in a nursing home. DESIGN: cross-sectional brief questionnaire and screening culture of anterior nares specimens from 165 elders at a community centre and cross-sectional data from a recent survey in a nursing home. RESULTS: the prevalence of SA colonization in community seniors (27%) was similar to that in the nursing home (29%). The proportion of SA isolates that were methicillin-resistant was much lower in the community seniors (2.3%) than in the nursing-home residents (31%). There was less antibiotic resistance in those living at home. CONCLUSION: in community seniors the prevalence of SA colonization was similar to that in nursing-home residents, but the prevalence of methicillin-resistant SA was lower. Susceptibility patterns of antibiotics tested against the SA showed less resistance than isolates from nursing-home patients.

Effects of motion, ambient light, and hypoperfusion on pulse oximeter function.

STUDY OBJECTIVE: To compare the performance of five pulse oximeters during hypoperfusion, probe motion, and exposure to ambient light interference. DESIGN: Prospective study. SETTING: Laboratory facility at a university medical center. PATIENTS: 8 unanesthetized, ASA physical status I volunteers. INTERVENTIONS: We evaluated five common pulse oximeters with respect to three scenarios: (1) an operating room light was shone on oximeter probes, (2) a motion generator was used to generate 2 Hz and 4 Hz hand motion, and (3) a pneumatic compression device overlying the brachial artery was used to simulate hypoperfusion. Electrocardiographic (ECG) and arterial blood gas values were considered gold standards for heart rate (HR) and oxygen saturation (SpO2) respectively. SpO2 nondisplay and values greater than 4% from simultaneous arterial SaO2-oximeter values were defined as errors. Nondisplay of HR, or HR greater than 5% from ECG values, were also considered errors. MEASUREMENTS AND MAIN RESULTS: The Ohmeda and Nellcor N200 with finger probe had the highest total failure rates with respect to both SpO2 and HR due to ambient light interference (p < 0.05). The Nellcor N200 with finger probe and N200 with C lock were the most accurate with regard to SpO2 during 2 Hz and 4 Hz motion (p < 0.05). However, all oximeters failed dramatically during 4 Hz motion when measuring HR. In the hypoperfusion model, the Nellcor N200 with finger probe and the Nellcor C Lock oximeters performed significantly better than all others in terms of both HR and SpO2 (P < 0.05), while the Criticare oximeter failed 100% of the time. CONCLUSION: There are significant differences in the accuracy of commercially available pulse oximeters during nonideal circumstances, with failure rates varying from approximately 5% to 50% depending on the oximeter and source of interference. Furthermore, no single oximeter performed the best under all conditions.

Pulse oximeter performance during desaturation and resaturation: a comparison of seven models.

STUDY OBJECTIVE: To compare pulse oximeter performance during induced hypoxemia. DESIGN: Prospective investigation in human volunteers. SETTING: Laboratory facility at a university medical center. PATIENTS: 8 unanesthetized, healthy ASA physical status I volunteers. INTERVENTIONS: We evaluated the accuracy and response times of seven popular pulse oximeters during induced hypoxemia. Arterial blood fractional oxygen saturation (SaO2) measurements were performed simultaneously and considered a gold standard. MEASUREMENTS AND MAIN RESULTS: All oximeters were accurate (+/-2%) while subjects were breathing room air. During maximal hypoxemia (induced by breathing a FIO2 = 10% in nitrogen), large differences were noted between oxygen saturation as measured by pulse oximetry (SpO2) and SaO2 values, with pulse oximeters consistently underreporting SpO2 when actual SaO2 values were 75% or less. The Ohmeda 3740 (Ohmeda, Boulder, CO) using an ear probe was the first to detect desaturation (change in SpO2 > 3%) in 4 of 8 subjects (p < 0.05), and the Nellcor N200 reflectance oximeter (Nellcor, Inc., Pleasanton, CA) was first in 3 of 8 subjects (p < 0.05). During resaturation (after administering 100% oxygen), the Novametrix Oxypleth (Novametrix, Wallingford, CT) was significantly faster than other oximeters (p < 0.05) to return to baseline (SpO2 = 98%). CONCLUSION: Most models of oximeters tested performed well when hemoglobin oxygen saturation was high, but all were inaccurate when SaO2 was approximately 75%. During induced hypoxemia, there were significant differences in the response times of oximeters tested, with no model demonstrably superior to others in all measures of performance.

Primary malignant melanoma of the lower lip.

Melanomas in the anatomically complex area of the head and neck impose formidable obstacles to treatment. Mucosal melanomas, for reasons which remain uncertain, are associated with a poorer prognosis. Because no systemic treatment is known to be effective, increased awareness by patients and a high index of suspicion is warranted. The disease is potentially curable if diagnosed and treated at an early stage.

Prediction of occult neck disease in laryngeal cancer by means of a logistic regression statistical model.

The ability to accurately predict the presence of subclinical metastatic neck disease in clinically N0 patients with primary epidermoid cancer of the larynx would be of great value in determining whether to perform an elective neck dissection. We describe a statistical approach to estimating the probability of occult neck disease given pretreatment clinical parameters. A retrospective study was performed involving 736 clinically N0 patients with primary laryngeal cancer who were treated surgically with primary resection and ipsilateral neck dissection. Nodal involvement was determined histologically after surgical lymphadenectomy. A logistic regression model was used to derive an equation that calculated the probability of occult neck metastasis based on pretreatment T stage, tumor location, and histologic grade. The model has a sensitivity of 74%, a specificity of 87%, and can be entered into a programmable calculator.

Effect of flumazenil on recovery after midazolam and propofol sedation.

BACKGROUND: Flumazenil, a benzodiazepine antagonist, reverses midazolam-induced sedation and amnesia. We designed a double-blind study to evaluate the effects of flumazenil on patient outcome when flumazenil was used to reverse large or small doses of midazolam as part of standardized monitored anesthesia care. METHODS: Ninety-nine healthy consenting women undergoing breast biopsy procedures with local anesthesia were randomly assigned to one of four treatment groups: group 1, propofol-placebo (control); group 2, propofol-flumazenil; group 3, midazolam-placebo; or group 4, midazolam-flumazenil. All patients received intravenous midazolam 2 mg and intravenous fentanyl 50 micrograms, followed by an infusion of either propofol 25-150 micrograms.kg-1.min-1 or midazolam 0.5-4 micrograms.kg-1.min-1. At the end of the operation, patients were intravenously administered either 10 ml saline (groups 1 and 3) or flumazenil 1 mg in 10 ml saline (groups 2 and 4). Amnesia was assessed by determining recall of pictures shown before and after the procedure. Subjective feelings of sedation, anxiety, clumsiness, and fatigue were evaluated using 100-mm visual analogue scales preoperatively and at 30-min intervals in the recovery room. Cognitive function was assessed using the digit-symbol substitution test at similar intervals. Early recovery was evaluated by the ability of the patients to be transferred directly from the operating room to the step-down unit, as well as by times to ambulation and discharge. A standardized questionnaire and telephone interview were used to assess "resedation" and other postdischarge side effects. RESULTS: Flumazenil (1 mg) enhanced early recovery and picture recall after high-dose (group 4) but not low-dose (group 2) midazolam. Only 32% of patients in group 3 were transferred directly to the step-down unit compared with 85% in group 4 (P < 0.05). Flumazenil significantly improved visual analogue scale and digit-symbol substitution test scores at the 30- and 60-min testing intervals (P < 0.05). At the 90-min interval, there were no significant differences between groups 3 and 4. Compared with group 3 (84 +/- 22 min), patients in groups 1, 2, and 4 were ready for discharge significantly earlier (60 +/- 23, 65 +/- 21, and 67 +/- 27 min, respectively) (P < 0.05). However, 33% of the patients in group 4 reported resedation after discharge (vs. 0-8% in the other three study groups) (P < 0.05). CONCLUSIONS: Early recovery after breast biopsy procedures with midazolam sedation and flumazenil reversal is similar to recovery after propofol sedation. However, the beneficial effects of flumazenil were apparent only during the first 60 min after the procedure and resedation after discharge is an important consideration in the outpatient setting.

Electroencephalogram spectral edge frequency, lower esophageal contractility, and autonomic responsiveness during general anesthesia.

Both the electroencephalogram (EEG) spectral edge frequency (SEF) and lower esophageal contractility (LEC) indices have been reported to be useful indicators of anesthetic depth. We designed a prospective study to evaluate the relationship between changes in these two variables and objective measurements of physiologic responsiveness to surgical stress (i.e., changes in hemodynamic variables and plasma levels of norepinephrine, epinephrine, total catecholamines, and vasopressin). Eighty-nine consenting adult males undergoing radical prostatectomy procedures under a standardized general anesthetic technique were studied according to a randomized, single-blinded protocol. General anesthesia was induced with 30 micrograms/kg intravenous (i.v.) alfentanil, 2.5 mg/kg i.v. thiopental, and 0.1 mg/kg i.v. vecuronium, and subsequently maintained with 0.5 microgram/kg/min alfentanil, nitrous oxide (N2O) 67% in oxygen, and 0.8 microgram/kg/min vecuronium. Following retropubic dissection, 81 patients (92%) manifested acute hypertensive responses, with mean arterial pressure increasing from 90 +/- 14 to 122 +/- 14 mm Hg (mean +/- SD). This acute hypertensive response was treated with one of three different treatment modalities (20 to 60 micrograms/kg i.v. alfentanil, 0.5 to 2.0% inspired isoflurane, or 0.05 to 0.15 mg/kg i.v. trimethaphan) to return the mean arterial pressure to within 10% of the preincisional (baseline) value within 5 to 10 minutes. Although the mean arterial pressure, heart rate, and plasma levels of catecholamines and vasopressin significantly increased following the surgical stimulus, and decreased after adjunctive therapy, the EEG-SEF and LEC index (LECI) values did not significantly change during these study intervals. Furthermore, using a logistic regression analysis, we observed that preincision EEG-SEF and LECI values could not predict whether patients would manifest a hypertensive response. Therefore, the EEG-SEF and LECI were unreliable indicators of anesthetic depth.

Epidermoid carcinoma of the oral cavity and oropharynx: validity of the current AJCC staging system and new statistical tools for the prediction of subclinical neck disease.

The 1983 and 1988 AJCC T- and N-staging systems were compared using the case records of 531 patients with primary epidermoid malignancies of the oral cavity. All patients had a minimum followup of 5 years. There were 390 patients with early stage (T1, T2) disease and 141 with advanced stage (T3, T4) lesions according to both the 1983 and 1988 T-definitions: 342 patients manifested no clinical nodes (NO), 189 had clinically evident nodes (N1-N3), and none had metastatic disease. Cox regression analysis demonstrated that the 1983/1988 T-stage definitions differentiated survival successfully (p < 0.001). The 1988 staging system for nodal disease showed a highly significant separation of N2 and N3 when compared with the 1983 system (p < 0.001). Of the 342 patients who were staged N0, 154 had primary neck dissection. Logistic regression predicted the incidence of subclinical disease according to the site and the T-stage of the primary tumor with a sensitivity of 78% and a specificity of 95%. We conclude that the 1988 N-stage definition is a better prognosticator of survival than the 1983 definition. Furthermore, a logistic regression model can be used to predict the probability of subclinical disease in primary oral cavity cancers.

A patient with 56 primary malignancies.

This very unusual case involves a 70-year-old white male who was within 50 miles of atomic bomb testing in the Mohave Desert and had 56 primary malignancies from 1946 to 1992. Major cytogenetic abnormalities sometimes found in patients with apparent genetic susceptibility for developing solid tumors are reviewed.

Patient-controlled drug administration during local anesthesia: a comparison of midazolam, propofol, and alfentanil.

STUDY OBJECTIVE: To evaluate the perioperative effects of alfentanil, midazolam, and propofol when administered using a patient-controlled analgesia (PCA) device during local anesthesia. DESIGN: Randomized, single-blind comparative study. SETTING: Outpatient surgery center at a university teaching hospital. PATIENTS: Ninety outpatients undergoing minor elective surgical procedures with local anesthetic infiltration were assigned to one of three treatment groups. INTERVENTIONS: After premedication with midazolam 1 mg intravenously (IV) and fentanyl 50 micrograms IV, patients were allowed to self-administer 2 ml bolus doses of either alfentanil 250 micrograms/ml, midazolam 0.4 mg/ml, or propofol 10 mg/ml at minimal intervals of 3 minutes to supplement a basal infusion rate of 5 ml/hr. MEASUREMENTS AND MAIN RESULTS: The total intraoperative dosages of alfentanil, midazolam, and propofol were 2.7 +/- 1.1 mg, 4.7 +/- 2.7 mg, and 114 +/- 42 mg, respectively, for procedures lasting 48 +/- 28 minutes to 51 +/- 19 minutes (means +/- SD). Propofol produced more pain on injection (39% vs. 4% and 6% in the alfentanil and midazolam groups, respectively). Episodes of arterial oxygen saturation less than 90% were more frequent with alfentanil (28%) than with midazolam (3%) or propofol (13%). Using the visual analog scale, patients reported comparable levels of discomfort, anxiety, and sedation during the operation in all three treatment groups. Postoperative picture recall was significantly decreased with midazolam versus alfentanil and propofol. Finally, postoperative nausea was reported more frequently in the alfentanil group (29%) than in the midazolam (10%) or propofol (18%) groups, contributing to a significant prolongation of the discharge time in the alfentanil-treated patients. CONCLUSIONS: When self-administered as adjuvants during local anesthesia using a PCA delivery system, alfentanil, midazolam, and propofol were equally acceptable to patients. However, propofol and midazolam were associated with fewer perioperative complications than was alfentanil.

Midazolam in combination with propofol for sedation during local anesthesia.

STUDY OBJECTIVE: To compare the sedative, anxiolytic, and amnestic effects, as well as the recovery characteristics, when midazolam (vs. a placebo) is administered to patients receiving a propofol infusion for sedation during local anesthesia. DESIGN: Randomized, double-blind, placebo-controlled study to evaluate the perioperative effects of intravenous (IV) midazolam. SETTING: Outpatient surgery center of a university-affiliated medical center. PATIENTS: One hundred thirty-nine consenting, ASA physical status I, II, and III outpatients undergoing elective surgical procedures under local anesthesia. INTERVENTIONS: Patients were randomly assigned to receive either midazolam 2 mg IV or saline 2 ml IV prior to injection of local anesthesia. Intraoperative sedation was maintained using a variable-rate propofol infusion. MEASUREMENTS AND MAIN RESULTS: Preoperative assessment of sedation, anxiety, and amnesia was performed before and after IV midazolam. Intraoperative evaluations included level of sedation, as well as cardiovascular and respiratory measurements, at 1- to 5-minute intervals during the operation. Postoperatively, recovery of psychomotor function and patients' subjective feelings were assessed using the visual analog scale and questionnaires. Amnesia was assessed using picture recall during the perioperative period. In the operating room, midazolam 2 mg IV, compared with the placebo, produced a significantly greater increase in patients' level of sedation (7 +/- 13 mm to 49 +/- 21 mm for midazolam vs. 8 +/- 11 mm to 19 +/- 21 mm for the placebo; p less than 0.01) and a greater decrease in anxiety level (62 +/- 25 mm to 21 +/- 21 mm for midazolam vs. 54 +/- 27 mm to 53 +/- 22 mm for the placebo; p less than 0.01). Although the propofol dosage requirements to maintain comparable levels of sedation were similar in both groups, midazolam decreased patients' recall of intraoperative events (e.g., propofol-induced pain on injection and discomfort with local anesthetic injection) without significantly altering cardiorespiratory parameters or prolonging times to ambulation and discharge from the outpatient facility. CONCLUSIONS: Premedication with midazolam 2 mg IV produced increased sedation, amnesia, and anxiolysis when administered immediately prior to the propofol infusion as part of a sedation technique for outpatient surgery. This combination did not prolong the recovery room stay when compared with propofol alone.

Comparative effects of desflurane and isoflurane on vecuronium-induced neuromuscular blockade.

STUDY OBJECTIVE: To evaluate the neuromuscular effects of a nondepolarizing muscle relaxant (vecuronium) during anesthesia with equipotent concentrations of either desflurane or isoflurane. DESIGN: Randomized open study comparing effects of desflurane and isoflurane on vecuronium-induced neuromuscular blockade. SETTING: University-affiliated medical center. PATIENTS: Forty-five healthy adults undergoing elective surgical procedures randomly assigned to receive either desflurane, nitrous oxide (N2O), and vecuronium or isoflurane, N2O, and vecuronium for maintenance of general anesthesia. INTERVENTIONS: Following a standardized induction sequence, patients receiving either desflurane and N2O or isoflurane and N2O were administered bolus doses of vecuronium equal to 0.01, 0.02, or 0.03 mg/kg intravenously (IV) during the maintenance period. Neuromuscular transmission was measured using a Relaxograph monitor. MEASUREMENTS AND MAIN RESULTS: Vecuronium produced similar depression of neuromuscular function at equipotent (50% of the minimum alveolar concentration) end-tidal concentrations of isoflurane 0.6% and desflurane 3.0%. Following administration of vecuronium 0.01 to 0.03 mg/kg IV, onset times (3.4 +/- 0.4 minutes to 3.2 +/- 0.4 minutes and 3.2 +/- 0.5 minutes to 3.0 +/- 0.6 minutes), maximum T1 twitch depression (80% +/- 10% to 95% +/- 9% and 81% +/- 9% to 97% +/- 10%), clinical duration of blockade (12 +/- 5 minutes to 20 +/- 8 minutes and 10 +/- 5 minutes to 19 +/- 17 minutes), and T1 recovery times (10 +/- 3 minutes to 12 +/- 6 minutes and 10 +/- 3 minutes to 12 +/- 4 minutes) were similar in the isoflurane and desflurane treatment groups, respectively (means +/- SD). CONCLUSION: Vecuronium has similar neuromuscular effects when administered in the presence of desflurane 3% and isoflurane 0.6%.

Effect of fentanyl and nitrous oxide on the desflurane anesthetic requirement.

The minimum alveolar anesthetic concentration (MAC) of desflurane (I-653) was determined when administered with 60% nitrous oxide (N2O) in oxygen after a standardized induction sequence consisting of 0, 3, 6, or 9 micrograms/kg intravenous (IV) fentanyl followed by 3-6 mg/kg IV thiopental and 1.5 mg/kg IV succinylcholine. For comparison, we also determined the isoflurane MAC with 60% N2O in oxygen after an induction dose of 3 micrograms/kg IV fentanyl and similar doses of thiopental and succinylcholine. All patients were undergoing elective surgical procedures. The minimum alveolar anesthetic concentration in patients given isoflurane and 60% N2O with 3 micrograms/kg fentanyl was 0.4%, approximately 20% below previously reported MAC values for isoflurane with 60% N2O alone. The minimum alveolar anesthetic concentration of desflurane with 60% N2O plus 0, 3, 6, and 9 micrograms/kg IV fentanyl was 3.7%, 3.0%, 1.2%, and 0.1%, respectively. Thus, the MAC-lowering effect of 3 micrograms/kg IV fentanyl appears to be similar with both isoflurane and desflurane. Fentanyl, 3-9 micrograms/kg IV, produces dose-dependent decreases in the MAC of desflurane.

Recovery profile after desflurane-nitrous oxide versus isoflurane-nitrous oxide in outpatients.

Thirty-eight healthy outpatients undergoing elective surgical procedures lasting 1-3 h were randomly assigned to receive either desflurane 3% (approximately 0.5 MAC) or isoflurane 0.6% (approximately 0.5 MAC) for maintenance of general anesthesia with nitrous oxide 60% in oxygen after a standardized induction sequence consisting of fentanyl 3 micrograms.kg-1, thiopental 4 mg.kg-1, and succinylcholine 1-1.5 mg.kg-1, intravenously. Although anesthetic conditions were similar during operations in the two treatment groups, significant differences were noted in the recovery profiles as measured by elimination kinetics, psychometric testing, and visual analog scales (to assess subjective feelings). The time required for the end-tidal concentration to decrease by 50% was 2.5 +/- 0.8 min for desflurane vs. 9.5 +/- 3.4 min for isoflurane (mean +/- standard deviation [SD]). Times to awakening and ability to follow simple commands were significantly shorter after desflurane than after isoflurane (5.1 +/- 2.4 vs. 10.2 +/- 7.7 min 6.5 +/- 2.3 min vs. 11.1 +/- 7.9 min, respectively). Postoperatively, patients who received desflurane exhibited less impairment of cognitive function (as measured using the Digit-Symbol Substitution Test) than did those who received isoflurane. Furthermore, visual analog scores indicated that patients receiving desflurane experienced significantly less discomfort (pain), drowsiness, fatigue, clumsiness, and confusion in the early postoperative period. We conclude that desflurane may offer clinical advantages over isoflurane when used for maintenance of anesthesia during outpatient surgical procedures.