Similar incidence of hypotension with combined spinal-epidural or epidural alone for knee arthroplasty

BACKGROUND: We hypothesized that the incidence of hypotension during total knee replacement (TKR) surgery is lower in patients given combined spinal-epidural (CSE) anesthesia vs those receiving epidural anesthesia alone. METHODS: In a prospective study, 80 American Society of Anesthesiologists I-II patients (aged 40-80 yr), undergoing elective TKR surgery were randomly assigned to either CSE anesthesia (CSE, n = 40) or epidural anesthesia alone (Epidural, n = 40). Hemodynamic measurements included oscillometric mean arterial blood pressure (MAP), heart rate (HR), and cardiac index (CI) as determined by thoracic bioimpedance; systemic vascular resistance (SVR) was calculated. Our primary endpoint (outcome) was the number of hypotension episodes (defined as MAP < 70 mmHg). RESULTS: Using univariate analysis, we found no differences between the groups in regards to MAP, HR, CI, or SVR during the perioperative period. The incidence of hypotension was similar in both groups (two patients in each group), as was the incidence of bradycardia (12 patients in CSE, 7 in Epidural; P = 0.2). There were no differences between groups in other hemodynamic measurements including CI and calculated SVR. Analgesia supplementation with fentanyl was more frequently required in the Epidural group (20 vs 6 patients - P = 0.03). CONCLUSION: Combined spinal-epidural anesthesia and epidural anesthesia alone during TKR surgery are associated with the same incidence of hypotension with statistically and clinically similar hemodynamic responses.     

Medical home care services for the housebound elderly.

In our health jurisdiction the proportion of elderly people is more than double the national average, and there is a severe shortage of both home care services and long-term care beds. To help the many elderly housebound people without primary medical care we initiated a medical services home care program. The goals were patient identification, clinical assessment, medical and social stabilization, matching of the housebound patient with a nearby family physician willing and able to provide home care and provision of a backup service to the physician for consultation and help in arranging admission to hospital if necessary. In the program's first 2 years 105 patients were enrolled; the average age was 78.9 years. More than 50% were widowed, single, separated or divorced, over 25% lived alone, and more than 40% had no children living in the city. In almost one-third of the cases there had never been a primary care physician, and in another third the physician refused to do home visits. Before becoming housebound 15% had been seeing only specialists. Each patient had an average of 3.2 active medical problems and was functionally quite dependent. Thirty-five of the patients were surveyed after 1 year: 24 (69%) were still at home, and only 1 (3%) was in a long-term care institution; 83% were satisfied with the care provided, and 79% felt secure that their health needs were being met. One-third of the patients or their families said that it was not easy to reach the physician when necessary. We recommend that programs similar to ours be set up in health jurisdictions with a high proportion of elderly people. To recruit and retain cooperative physicians hospital geriatric services must be willing to provide educational, consultative and administrative support.     

First-pass effects of verapamil on the intestinal absorption and liver disposition of fexofenadine in the porcine model.

The aim of this study in pigs was to investigate the local pharmacokinetics of fexofenadine in the intestine and liver by using the pig as a model for drug transport in the entero-hepatobiliary system. A parallel group design included seven pigs (10-12 weeks, 22.2-29.5 kg) in three groups (G1, G2, G3), and a jejunal single-pass perfusion combined with sampling from the bile duct and the portal, hepatic, and superior caval veins was performed. Fexofenadine was perfused through the jejunal segment alone (G1: 120 mg/l, total dose 24 mg) or with two different verapamil doses (G2: 175 mg/l, total dose 35 mg; and G3: 1000 mg/l, total dose 200 mg). The animals were fully anesthetized and monitored throughout the experiment. Fexofenadine had a low liver extraction (E(H); mean +/- S.E.M.), and the given doses of verapamil did not affect the E(H) (0.13 +/- 0.04, 0.16 +/- 0.03, and 0.12 +/- 0.02 for G1, G2, and G3, respectively) or biliary clearance. The E(H) for verapamil and antipyrine agreed well with human in vivo data. Verapamil did not increase the intestinal absorption of fexofenadine, even though the jejunal permeability of fexofenadine, verapamil, and antipyrine showed a tendency to increase in G2. This combined perfusion and hepatobiliary sampling method showed that verapamil did not affect the transport of fexofenadine in the intestine or liver. In this model the E(H) values for both verapamil and antipyrine were similar to the corresponding values in vivo in humans.     

Primary aldosteronism. Study of twenty-six operated cases

A follow-up study of 26 patients operated on for suspicion of primary aldosteronism was made. The preoperative investigative procedures, including serum potassium concentration, urinary aldosterone excretion, and plasma renin activity, could not differentiate between patients with cortical adenomas and those with cortical hyperplasia or normal glands. Preoperative roentgenologic examinations visualized only one third of the adenomas. Altogether 44 of the 52 suprarenal glands had to be explored to reveal the 21 adenomas. Patients with cortical adenoma often became normotensive, in contrast to those with cortical hyperplasia or normal adrenal glands histopathologically. The suprarenal glands were explored from behind according to Nesbit. The complications were few and minor.     

Real-time refinement of subthalamic nucleus targeting using Bayesian decision-making on the root mean square measure.

The subthalamic nucleus (STN) is a major target for treatment of advanced Parkinson's disease patients undergoing deep brain stimulation surgery. Microelectrode recording (MER) is used in many cases to identify the target nucleus. A real-time procedure for identifying the entry and exit points of the STN would improve the outcome of this targeting procedure. We used the normalized root mean square (NRMS) of a short (5 seconds) MER sampled signal and the estimated anatomical distance to target (EDT) as the basis for this procedure. Electrode tip location was defined intraoperatively by an expert neurophysiologist to be before, within, or after the STN. Data from 46 trajectories of 27 patients were used to calculate the Bayesian posterior probability of being in each of these locations, given RMS-EDT pair values. We tested our predictions on each trajectory using a bootstrapping technique, with the rest of the trajectories serving as a training set and found the error in predicting the STN entry to be (mean +/- SD) 0.18 +/- 0.84, and 0.50 +/- 0.59 mm for STN exit point, which yields a 0.30 +/- 0.28 mm deviation from the expert's target center. The simplicity and computational ease of RMS calculation, its spike sorting-independent nature and tolerance to electrode parameters of this Bayesian predictor, can lead directly to the development of a fully automated intraoperative physiological procedure for the refinement of imaging estimates of STN borders.     

Family violence among psychiatric in-patients as measured by the Conflict Tactics Scale (CTS)

The aim of this study was to analyse the frequency and pattern of family (domestic) violence in a group of psychiatric in-patients by using the Conflict Tactics Scale. The study is based on a consecutive series of 55 married or cohabiting psychiatric in-patients treated at Huddinge Hospital, Stockholm, Sweden in 1994. The study shows that males and females use similar types of both violent and non-violent strategies when trying to solve marital conflicts. Depressed patients use both non-violent and violent methods less often than non-depressed patients, while the opposite is true for patients with a personality disorder, and for schizophrenics. Psychosocial stressors appear to be of limited importance in this context, while poor general functioning is associated with destructive ways of trying to solve conflicts between husband and wife. However, there have been no Scandinavian population-based studies to establish the frequency and type of violence used when trying to solve marital conflicts. Thus there is a need for such studies, and the present investigation supports the American experience that the Conflict Tactics Scale is a usable and easily administered instrument for population-based studies.