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Biomedical subjects

F Chung

Publications and source records attributed to F Chung.

At least 73 records · Page 4Linked to original sources
PubMed1997

Postoperative pain in ambulatory surgery.

UNLABELLED: Postoperative pain is a common reason for the delayed discharge and unanticipated hospital admission of out-patients. In this study, we examined the pattern of pain in ambulatory surgical patients and determined those factors that predict postoperative pain. Ten thousand eight consecutive ambulatory surgical patients were prospectively studied. Preoperative patient characteristics, intraoperative variables, and pain in the postanesthesia care unit (PACU) and the ambulatory surgical unit (ASU) and 24 h postoperatively were documented. The incidence of severe pain was 5.3% in the PACU, 1.7% in the ASU, and 5.3% 24 h postoperatively. In the PACU, younger male adults (36 +/- 13 vs 47 +/- 22 yr), ASA physical status I patients, and patients with a higher body mass index (26 +/- 5 vs 25 +/- 5 kg) had a higher incidence of severe pain. In the group with severe pain, the duration of anesthesia, the duration of stay in the PACU and the ASU, and the time to discharge was longer than in the group without severe pain. In the PACU, orthopedic patients had the highest incidence of pain (16.1%), followed by urologic (13.4%), general surgery (11.5%), and plastic surgery (10.0%) patients. In patients who had general anesthesia, the intraoperative dose of fentanyl was significantly smaller in the group with severe pain than in the group without severe pain when body mass index and duration of anesthesia were taken into consideration. Body mass index, duration of anesthesia, and certain types of surgery were significant predictors of severe pain in the PACU. This knowledge will allow us to identify those patients at risk of severe postoperative pain and manage them prophylactically. IMPLICATIONS: The pattern of pain was examined in 10,008 consecutive ambulatory surgical patients. The incidence of severe pain was 5.3% in the postanesthesia care unit, 1.7% in the ambulatory surgical unit, and 5.3% 24 h postoperatively. Body mass, duration of anesthesia, and certain types of surgery were significant predictors of pain in the postanesthesia care unit. These data will allow us to better predict those patients who need intense prophylactic analgesic therapy.

Adult↗
PubMed1997

Remifentanil versus remifentanil/midazolam for ambulatory surgery during monitored anesthesia care.

BACKGROUND: This study was designed to define the appropriate dose of remifentanil hydrochloride alone or combined with midazolam to provide satisfactory comfort and maintain adequate respiration for a monitored anesthesia care setting. METHODS: One hundred fifty-nine patients scheduled for outpatient surgery participated in this multicenter, double-blind study. Patients were randomly assigned to one of two groups: remifentanil, 1 microgram/kg, given over 30 s followed by a continuous infusion of 0.1 microgram.kg-1.min-1 (remifentanil), remifentanil, 0.5 microgram/kg, given over 30 s followed by a continuous infusion of 0.05 microgram.kg-1.min-1 (remifentanil+midazolam). Five minutes after the start of the infusion, patients received a loading dose of saline placebo (remifentanil) or midazolam, 1 mg, (remifentanil+midazolam). If patients were not oversedated, a second dose of placebo or midazolam, 1 mg, was given. Remifentanil was titrated (in increments of 50% from the initial rate) to limit patient discomfort or pain intraoperatively, and the infusion was terminated at the completion of skin closure. RESULTS: At the time of the local anesthetic, most patients in the remifentanil and remifentanil+midazolam groups experienced no pain (66% and 60%, respectively) and no discomfort (66% and 65%, respectively). The final mean (+/-SD) remifentanil infusion rates were 0.12 +/- 0.05 microgram.kg-1.min-1 (remifentanil) and 0.07 +/- 0.03 microgram.kg-1.min-1 (remifentanil+midazolam). Fewer patients in the remifentanil+midazolam group experienced nauses compared with the remifentanil group (16% vs. 36%, respectively; P < 0.05). Four patients (5%) in the remifentanil group and two patients (2%) in the remifentanil+midazolam group experienced brief periods of oxygen desaturation (SpO2 < 90%) and hypoventilation (< 8 breaths/ min). CONCLUSIONS: Remifentanil alone or combined with midazolam provided adequate analgesia and maintained adequate respiration at the doses reported. The low dose of remifentanil combined with 2 mg midazolam, compared with remifentanil alone, resulted in fewer side effects, slightly greater sedation, and less anxiety.

Adult↗
PubMed1997

Predictive factors in global and anesthesia satisfaction in ambulatory surgical patients.

BACKGROUND: Patient satisfaction is one of the variables that affect the outcome of health care and the use of health-care services. As more procedures are performed on an ambulatory basis, the role of the anesthesiologist becomes more important. To improve the delivery of care, the predictors of dissatisfaction with the entire process (global dissatisfaction) of ambulatory surgery and with anesthesia itself must be identified. The authors conducted a hypothesis-generating study to identify predictors; specifically, they hypothesized that satisfaction with anesthesia was a predictor of global satisfaction with ambulatory surgery and that 24-h postoperative symptoms were a predictor of satisfaction with anesthesia. METHODS: The authors prospectively studied 5,228 consecutive patients having surgery in the ambulatory setting during a 1-yr period. Preoperative, intraoperative, and postoperative variables were gathered and patient satisfaction was assessed using a postoperative telephone questionnaire administered 24 h after operation in 2,730 respondents. Significant univariate variables and clinically important variables were entered into multiple logistic regression models. Qualitative data on dissatisfaction were obtained by asking patients' reasons for dissatisfaction. RESULTS: Sixty-eight of the 2,730 respondents (2.5%) had global dissatisfaction with ambulatory surgery. Nine of these patients were dissatisfied with anesthesia. Dissatisfaction with anesthesia was associated with a 12-fold increase in global dissatisfaction (P = 0.0001). Thirty-one of the 2,730 respondents (1.1%) were dissatisfied with anesthesia. An increasing number of symptoms occurring 24 h after operation was associated with an exp(0.28 x N)-fold increase in dissatisfaction with anesthesia for N number of symptoms (P = 0.0001). Qualitative data showed that the most common reason for global dissatisfaction with ambulatory surgery was personal preference for inpatient care (26%), whereas intraoperative and postoperative adverse outcomes were the major causes of dissatisfaction with anesthesia (88%). CONCLUSIONS: Dissatisfaction with anesthesia is a predictor of global dissatisfaction with ambulatory surgery. An increasing number of symptoms 24 h after operation is a predictor of dissatisfaction with anesthesia. The rate of global dissatisfaction and anesthesia dissatisfaction is very low. The predictors from this model need to be validated by a second data set from either this or another center. Given the low rate of dissatisfaction, a focused study testing specific interventions to improve patient satisfaction would be difficult.

Adult↗
PubMed1996

Postoperative symptoms 24 hours after ambulatory anaesthesia.

PURPOSE: To test the hypothesis that the type of surgical procedure influences the incidence of postoperative symptoms. Also the effect of demographic and clinical risk variables: age, sex, ASA status, duration of anaesthesia on the postoperative symptoms were evaluated for each type of surgery. METHODS: Demographic, medical, anaesthetic and surgical data on 1,017 patients were prospectively collected by a research assistant who telephoned each patient 24 hr after discharge to administer a questionnaire to determine postoperative symptoms. Postoperative symptoms included incisional pain, nausea/vomiting, drowsiness, dizziness, headache and fever. In addition, 270 patients were asked the % (0-100) of their return to daily living function at 24 hr. RESULTS: Incisional pain (26.9%), headache (11.6%), and drowsiness (11.5%) were the most frequently reported symptoms. Dizziness was reported by 9.7% and nausea/vomiting by 7.1%. Approximately 50% of patients undergoing laparoscopy, orthopaedic and general surgery reported 24-hr postoperative incisional pain. The incidence of 24-hr postoperative nausea/vomiting was highest after general 17.4%, orthopaedic, 11.2%, and laparoscopic surgery, 9.4%. Drowsiness was highest after laparoscopy 36.1%, followed by general surgery, 21.4%. Dizziness was most frequent after laparoscopy, 24.1%, followed by general surgery, 16.1%. After laparoscopy, postoperative drowsiness or dizziness was related to anaesthesia duration. After general surgery, postoperative dizziness or drowsiness were related to age; the younger the patient, the more likely the symptoms. CONCLUSIONS: Postoperative pain, nausea/vomiting, drowsiness, dizziness, and headache were the more frequent postoperative symptoms 24 hr after ambulatory surgery and they were influenced by the type of surgical procedure. In addition, the type of surgery and the 24-hr postoperative symptoms determined the degree of return to daily living function.

Adult↗
PubMed1996

Anaesthesia drug cost, control and utilization in Canada.

PURPOSE: To investigate the attitudes of senior anaesthetists toward issues of anaesthesia drug cost control, utilization, and education, and to determine patterns of drug use of common clinical scenarios. METHODS: A questionnaire mailed to heads of anaesthesia departments in all large (> 200 beds) Canadian hospitals (n = 187). Data were analyzed with chi-square and t tests; P < 0.05 was considered significant. RESULTS: Sixty-eight per cent responded to the questionnaire. Ninety-four per cent considered cost when choosing anaesthetic agents, 63.7% indicated cheaper drugs could be used without decreasing quality of care, and 46.3% that restricted access to expensive agents was justified. Only 32.8% of hospitals currently imposed restrictions. Departmental practice guidelines were favoured by 82.1% of respondents. Fifty-three per cent considered resident education about drug cost to be inadequate, and 57.4% indicated that resident teaching justified the use of expensive agents. Most respondents (69.8-96.8%) felt they knew the cost of commonly used agents, many made considerable use of cheaper agents such as halothane, curare and morphine, and 61% re-used syringes containing residual drug. A few differences between teaching and non-teaching hospitals anaesthetists were identified. CONCLUSIONS: These anaesthetists demonstrated awareness of pharmacoeconomic issues, believed that cheaper anaesthetic agents could be used without compromising quality of care, identified few hospitals with policies that restricted drug use, and indicated drug cost education could be improved. Control and responsibility of drug utilization were shared within their hospitals. Many approved the idea of practice guidelines. In common clinical scenarios cheaper agents were preferred and syringe re-use was surprisingly common.

Anesthetics↗
PubMed1996

Preoperative multimodal analgesia facilitates recovery after ambulatory laparoscopic cholecystectomy.

Laparoscopy approach to cholecystectomy has shortened the recovery period, reducing discharge times from 1 to 3 days to same-day discharge. We hypothesize that the use of more than one modality to prevent postoperative pain may be more efficacious than single modality. Patients were randomized to a treatment (n = 24) or control (n = 25) group and studied using a prospective, double-blind design. Preoperatively, at 45 min before induction of anesthesia, the treatment group received an intramuscular (IM) bolus injection of meperidine 0.6 mg/kg and ketorolac 0.5 mg/kg. The control group received two bolus IM injections of placebo (normal saline). Ten minutes before incision, local anesthesia (treatment group) or saline (control group) was infiltrated into the skin of each patient. Anesthetic management, postoperative pain, and nausea treatment were standardized. Pain and nausea assessment were done 1 h preoperatively, 0, 0.5, 1, 2, 3, and 4 h postoperatively, at discharge, and 10, 24, and 48 h postoperatively. Patients were discharged by scoring criteria. Postoperatively, significantly more patients in the treatment group were without pain on arrival in the postanesthesia care unit (PACU), 12/21 (57.1%) vs 1/24 (4.2%) in the control group (P < 0.001). Similarly, the severity of pain was sixfold less in the treatment group than in the control group. The incidence of nausea in the PACU was significantly less in the treatment group; 4.7% vs 29.5% in the control group (P < 0.05). Patients from the treatment group satisfied Postanesthesia Discharge Score significantly earlier than those in the control group (281 +/- 12 min vs 375 +/- 19 min; P < 005). The concomitant use of local anesthetic and nonsteroidal antiinflammatory and opioid drugs proved to be highly effective in our patients, resulting in faster recovery and discharge.

Adult↗
PubMed1995

Discharge criteria--a new trend.

The safe, expeditious conduct of ambulatory surgical care can succeed only by careful selection of patients and procedures, appropriate intra- and postoperative anaesthetic management, and safe, timely discharge of patients. Discharge of patients should be achieved without compromising the quality of patient care. As the patients presenting for ambulatory surgery become more complex and compromised, and their surgical treatment more demanding, it is important to replace, or at least supplement, our existing qualitative, subjective method for evaluating patient discharge with a quantitative, objective technique to provide a simple and consistent method of determining home readiness. Practical discharge criteria or a postanaesthesia scoring system should be implemented in every ambulatory surgery centre to ensure safe recovery and discharge after anaesthesia. The Post-Anaesthesia Discharge Scoring System (PADSS) is simple, practical, easy to apply and to remember. In addition to permitting a uniform assessment of home readiness for patients, PADSS establishes a pattern of routine, repetitive evaluation of patients home readiness that is likely to contribute to improved patient outcome. In this way, PADSS also may have added medicolegal value. We recommend using the postanaesthesia recovery score (Aldrete score) to evaluate initial patient recovery. Once the Aldrete criteria are met, home-readiness can be evaluated by PADSS or modified PADSS in which input and output are eliminated (Table I, Table II). When the patient satisfies PADSS or modified PADSS criteria, he or she can be discharged home. We have discharged 30,000 patients safely home from our ambulatory surgical facility. Reduction in the length of stay in an ambulatory surgery unit by the prompt and safe discharge of patients can help to reduce costs and improve unit efficiency. For certain surgical procedures, ambulatory treatment is cheaper, even allowing for treatment failures and readmissions. However, we must remember that the application of any discharge criteria scoring system must include common sense, clinical judgment, and home-readiness of an outpatient does not assume street fitness.

Ambulatory Surgical Procedures↗
PubMed1995

A post-anesthetic discharge scoring system for home readiness after ambulatory surgery.

STUDY OBJECTIVE: To evaluate the validity and reliability of an objective scoring system, the Post-Anesthetic Discharge Scoring System (PADSS), which was compared against existing Clinical Discharge Criteria in the ambulatory surgery unit of our hospital. DESIGN: randomized, open study. SETTING: Ambulatory surgery unit at a university teaching hospital. PATIENTS: 247 ambulatory surgery patients undergoing general anesthesia. INTERVENTIONS: One hour after the operation, the initial assessment using PADSS and the Clinical Discharge Criteria was made by an independent observer. Evaluations were repeated at 30-minute intervals until patients obtained a Post-Anesthetic Discharge Score of at least 9 and fulfilled the Clinical Discharge Criteria. MEASUREMENTS AND MAIN RESULTS: There was a close correlation between the end of anesthesia to time patients were fit for discharge using either PADSS or the Clinical Discharge Criteria (Pearson's Correlation Coefficient r = 0.89). The internal consistency reliability of PADSS (alpha = 0.65) was superior to that of the Clinical Discharge Criteria (alpha = 0.14). CONCLUSIONS: We have found PADSS to have superior measurement scaling and diagnostic properties.

Adult↗
PubMed1995

A prospective randomized double-blinded study of the effect of intravenous fluid therapy on adverse outcomes on outpatient surgery.

This study investigated the impact of perioperative fluid status on adverse clinical outcomes in ambulatory surgery. Two hundred ASA grade I-III ambulatory surgical patients were prospectively randomized into two groups to receive high (20 mL/kg) or low (2 mL/kg) infusions of isotonic electrolyte solution over 30 min preoperatively. A standardized balanced anesthetic was used. A minimal amount of fluid was given during the intraoperative and postoperative periods. Adverse outcomes were assessed by an investigator blinded to the fluid treatment group at 30 and 60 min after surgery, at discharge, and the first postoperative day. The incidence of thirst, drowsiness, and dizziness was significantly lower in the high-infusion group at all intervals. We recommend perioperative hydration of 20 mL/kg for patients undergoing general anesthesia for short ambulatory surgery.

Acetates↗
PubMed1995

Recovery pattern and home-readiness after ambulatory surgery.

Despite increased use of ambulatory surgery, few data exist regarding patient recovery patterns and home-readiness. We prospectively identified the pattern of home-readiness, the persistent symptoms after surgery, and the factors that delay discharge after home-readiness criteria are satisfied. Five hundred patients were scored by the same investigator using the Postanesthetic Discharge Scoring System (PADSS) every 30 min, commencing 30 min after surgery, until the PADSS score was > or = 9. The same investigator telephoned each patient 24 h after discharge to administer a standardized questionnaire so that postoperative symptoms could be identified. Eighty-two percent of patients were discharged 2 h and 95.6% 3 h after surgery. These patients could have been discharged earlier. After home-readiness criteria were satisfied, some patients had delayed discharge because of the unavailability of immediate escorts or the recurrence of pain. Persistent symptoms delaying discharge occurred in 4.4% of patients. Patients who underwent certain ambulatory surgical procedures, such as laparoscopy or orthopedic and general surgery, had a sixfold increased risk of developing persistent symptoms in the ambulatory surgery unit. The time to home-readiness was 2.5-fold longer and the incidence of 24-h postoperative symptoms, two- to eightfold higher in the group with persistent symptoms in the ambulatory surgery unit. In summary, periodic objective evaluation of home-readiness revealed that the majority of patients would achieve a satisfactory score on or before 2 h after surgery. The time to home-readiness by objective evaluation correlated with the type of surgery. Most delays after satisfactory home-readiness scores were reached were due to nonmedical reasons.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Postoperative delirium in the elderly.

Postoperative delirium is common in the elderly in the postoperative period. It can result in increased morbidity, delayed functional recovery, and prolonged hospital stay. In surgical patients, factors such as age, alcohol abuse, low baseline cognition, severe metabolic derangement, hypoxia, hypotension, and type of surgery appear to contribute to postoperative delirium. Anesthetics, notably anticholinergic drugs and benzodiazepines, increase the risk for delirium. Despite the above recommendations, postoperative delirium in the elderly is poorly understood. Clearly, further studies are needed to determine the risk and long-term outcome of delirium in the elderly population. Research is also needed to define the effects of hypoxemia on cerebral function and whether oxygen therapy has any benefits. The geriatric-anesthesiologic intervention program of pre- and postoperative geriatric assessment, early surgery, thrombosis prophylaxis, oxygen therapy, prevention and treatment of perioperative decrease in blood pressure, and vigorous treatment of any postoperative complications showed some promise, but further definitive studies are needed.

Aged↗
PubMed1995

Coagulopathies in patients after transurethral resection of the prostate: spinal versus general anesthesia.

This prospective, randomized study evaluated the effects of spinal versus general anesthetic technique on perioperative blood loss and the development of postoperative coagulopathies in 50 patients undergoing transurethral resection of the prostate (TURP). Preoperative hematologic measurements included hemoglobin, platelet count, electrolytes, prothrombin time, partial thromboplastin time, fibrinogen, factor V, plasminogen, antithrombin III, and fibrinogen degradation product (FDP) levels. All hematologic blood samples wre repeated postoperatively at 1, 6, and 24 h. Intraoperative blood loss was not significantly different between the spinal and general anesthesia groups. The total blood loss after TURP was significantly correlated (r = 0.76; P < 0.0001) with the prostatic tissue weight. When the tissue weight resected exceeded 35 g, blood loss was in excess of the linear correlation shown with the weight of resected prostatic tissue. Platelet count decreased and prothrombin time increased in the spinal group at all postoperative time intervals compared to preoperative value (P < 0.05). There was no significant difference in measured coagulation variables (fibrinogen, factor V, plasminogen, antithrombin III, and FDP) between the spinal and general anesthesia groups, but there were significant decreases in postoperative fibrinogen and Factor V levels compared to preoperative values in both spinal and general anesthesia groups. Three patients (6%) had increased FDP levels 1 h postoperatively. The prostatic tissue weight and the surgical duration was significantly higher in these patients. We conclude that perioperative blood loss in TURP patients is not affected by the anesthetic technique. However, 6% of TURP patients developed subclinical intravascular coagulopathies which correlated with mass of resected prostate tissue.

Aged↗
PubMed1994

Cross-reactive antibodies in the serum of balb/c mice immunized with thyroid or eye muscle membranes.

During the course of immunizing balb/c mice with eye muscle (EM) or thyroid (THY) membranes for monoclonal antibody (MCAB) production their sera frequently contain antibodies which react against both EM and THY membranes in enzyme-linked immunosorbent assay (ELISA) and SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. In order to further study this phenomenon we have analyzed sera from 27 balb/c mice, including 10 that were studied serially, and their tissues examined histologically at sacrifice. Following immunization serum and, in some cases, the corresponding MCAB produced by fusion of the mouse spleen cells with a mouse myeloma cell line, were tested for EM and THY cross-reactivity in an ELISA and by immunoblotting. The number of antibodies demonstrated in Western blotting identified as bands of reactivity, and ELISA levels, expressed as optical density--increased with time, each peaking at around 10-12 weeks. THY and EM antibody cross-reactivity was demonstrated in the majority of mice, serum from mice immunized with THY membranes reacting with these membranes as well as with pig EM membranes in both ELISA and immunoblotting and, conversely, sera from mice immunized with pig EM membranes also reacting with THY membranes in the two tests. In Western blotting a variety of THY and EM-reactive antibodies were demonstrated including those directed against a 64 kDa protein, shown to be an important autoantigen in thyroid-associated ophthalmopathy. There was also some cross-reactivity with brain membranes, used as control antigen in both tests and in immunization, although to a lesser degree, but very little to liver and orbital connective tissue membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Regional and fibre type glycogen utilization patterns in the hamster diaphragm following swimming.

The purpose of this study was to determine the regional and myofibrillar ATPase (M-ATPase) fibre type glycogen utilization patterns in response to increased ventilation induced by pre-exhaustive (Pre-Exh) and exhaustive (Exh) durations of swimming. Twenty-eight hamsters were studied: six controls (Con), 11 Pre-Exh (swam 82 min), 11 Exh (swam to exhaustion). We examined the optical density of PAS-stained fibres from the different regions of the diaphragm as a measure of glycogen remaining after the exercise or control period. The optical densities of PAS-stained fibres in most M-ATPase fibre types and diaphragmatic regions for the Pre-Exh and Exh groups was less than those in the Con hamsters except for the optical densities of all the M-ATPase fibre types in the sternal region. The optical densities of PAS-stained fibres in different regions and M-ATPase fibre types did not differ in the Exh and Pre-Exh groups. This data indicates that significant glycogen utilization occurred in all three M-ATPase fibre types in the costal, and both the thoracic and abdominal surface of the crural diaphragm in hamsters following pre-exhaustive and exhaustive durations of swimming. Glycogen utilization was greater in type 1 fibres of the thoracic surface of the crural region than in the type 1 fibres of the sternal region of the Pre-Exh group. Further, significant utilization of glycogen did not occur in any of the three M-ATPase fibre types of the sternal region of the diaphragm following prolonged durations of swimming. It would appear that glycogen is an important substrate in the hamster diaphragm during swimming.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗
PubMed1994

Apparent extension of the atrioventricular interval due to sensor-based algorithm against supraventricular tachyarrhythmias.

Rapid ventricular tracking response to supraventricular tachyarrhythmia is one major limitation to DDD pacing. In a DDDR pacemaker, sensor-based algorithms have been used to control these arrhythmias. These include the use of an interim rate limit (conditional ventricular tracking limit) or a separate maximum tracking and sensor rate limits (discrepant upper rate). These algorithms limit inappropriate ventricular pacing rate during tracking of pathological supraventricular tachyarrhythmia and atrial flutter by Wenckebach-like prolongation of the AV interval. We observed that this may cause an unexpected extension of the AV interval in patients with high atrial rate and intact AV nodal conduction. This was due to P wave rate above the conditional ventricular tracking limit or maximum tracking limit, but AV paced interval prolongation was avoided by the occurrence of intrinsic conduction, albeit at an AV interval longer than the programmed AV interval. This might appear as failure of ventricular pacing on the ECG. This phenomenon is a modified form of "upper rate" behavior occurring in the AV interval, and should be recognized as a normal behavior rather than pacemaker malfunction.

Algorithms↗
PubMed1994

Anesthetic and hemodynamic effects of single bolus versus incremental titration of hyperbaric spinal lidocaine through microcatheter.

This study examined anesthetic development and hemodynamic changes during two techniques of hyperbaric lidocaine administration through 27-gauge intrathecal catheters for continuous spinal anesthesia in 55 elderly patients undergoing transurethral prostatic resection. Twenty-five patients were randomly assigned to receive hyperbaric lidocaine 5% solution in a single bolus of 75 mg to achieve blockade to approximately T6, and 30 patients to receive hyperbaric lidocaine 2.5% solution in increments of 25 mg to achieve T6 or to a maximum of three doses. Hemodynamic measurements of arterial pressure, heart rate, cardiac output, stroke volume, and ejection fraction were made serially after the induction of spinal anesthesia. Anesthesia failed to spread beyond the sacral region in 9/25 (36%) patients in the single-dose group (SD), but was successfully induced in all patients given titrated doses (TD) at total doses of 50 mg (n = 15) (TD50) and 75 mg (n = 15) (TD75). The mean maximal level of sensory block in all three groups was comparable: T5, T4, and T6 in groups SD, TD50, and TD75, respectively. The onset and progression of sensory block were rapid and similar in the SD and TD50 groups, in contrast to a gradual, stepwise development of block in group TD75. Grade 3 motor block occurred in response to the first dose of 25 mg lidocaine in 7/30 (23%) patients receiving titrated doses, but the overall incidence of leg paralysis did not differ among the three groups by the end of lidocaine dosing. Mean arterial pressure (MAP) decreased significantly relative to baseline in all three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Expression of major histocompatibility complex class II antigen in NOD mouse thyroid.

Non obese diabetic (NOD) mice spontaneously develop thyroiditis in addition to diabetes. Mononuclear cells begin to infiltrate the thyroid of these animals in the first month of life. The expression of major histocompatibility complex (MHC) class II (Ia) antigens by cells in the thyroid from NOD mice of various ages with and without thyroiditis was examined. We found that only 1 of the 9 infiltrated thyroids from 18 8-33 day old NOD mice surveyed expressed MHC class II antigens. Therefore Ia antigen expression appears to be secondary to infiltration and does not initiate the autoimmune process. Fourteen of 17 (82.2%) infiltrated and 7 of 11 (63.6%) uninfiltrated thyroids from NOD mice aged 51-73 days contained cells expressing Ia antigens. Sixteen of 18 (88.9%) infiltrated and all 7 of the uninfiltrated thyroids from mice aged > 89 days contained Ia positive cells. These MHC class II expressing cells included thyroid epithelial cells (TEC), as well as interstitial cells such as macrophages. Ia positive cells in the thyroid have the potential of presenting thyroid specific antigen to infiltrating T cells and thereby maintaining or potentiating thyroid autoimmune destruction. Macrophages were observed in thyroid tissue from 9 of 11 (81.8%) infiltrated and 12 of 15 (80%) uninfiltrated 8-33 day old NOD mice, thyroids from 11 of 16 (68.7%) infiltrated and 6 of 9 (66.7%) uninfiltrated 51-73 day old NOD mice, as well as 28 of 29 (96.5%) uninfiltrated and all 9 of the uninfiltrated thyroid from NOD mice aged > 89 days. Thyroids from control age matched non autoimmune BALB/c mice were consistently Ia antigen negative while macrophages were seen in some of the animals aged > 60 days.

Age Factors↗