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Leukocyte depletion during cardiac operation: a new approach through the venous bypass circuit.

BACKGROUND: Leukocyte depletion recently has been introduced for cardiac surgical patients to attenuate leukocyte-mediated inflammation and organ reperfusion injury. We evaluated the feasibility of a new leukocyte depletion method in which systemic leukocyte depletion is achieved through the venous side of the cardiopulmonary bypass circuit under low blood flow. METHODS: Forty cardiac surgical patients undergoing cardiopulmonary bypass were allocated randomly to a leukocyte depletion group (n = 20) and a control group (n = 20). In the depletion group, leukocyte filtration was achieved with two filter sets located between the venous drainage and the venous reservoir. Leukocyte filtration was commenced after the start of rewarming but before the release of the aortic cross-clamp, and it was driven by a spare roller pump of the heart-lung machine. RESULTS: All the episodes of filtration went smoothly within a period of 10 minutes and with a blood flow rate of 400 mL/min. The mean leukocyte removal rate calculated at the end of filtration was 69%. Circulating leukocytes were reduced by 38% in the depletion group compared with the control group at the moment of cross-clamp release (4.3x10(9)/L versus 6.8x10(9)/L, p<0.05). The postoperative inflammatory response also was reduced as indicated by less production of interleukin-8 (p<0.05). Clinically, there was no significant difference between the two groups in postoperative PaO2 or pulmonary hemodynamics. CONCLUSIONS: It is technically feasible to deplete circulating leukocytes through the venous side of the cardiopulmonary bypass circuit with a low blood flow rate. Future studies should focus on the duration and timing of leukocyte depletion to optimize the methodology of leukocyte depletion for cardiac surgical patients.

Aged↗

Hyperthermia--its actual role in radiation oncology. Part IV: Thermo-radiotherapy for malignant brain tumors.

BACKGROUND: High-grade malignant gliomas have a dismal prognosis. Only achievement of long-term local control improves overall survival. Conventional treatments have not been successful, but thermoradiotherapy appears to be a promising new approach to this disease. PATIENTS AND METHODS: The review addresses the various HT techniques applied for brain heating, the biological rationale and experimental studies supporting the use of heat in addition to radiotherapy for brain tumors. Normal brain damage exposed to heat is critically evaluated. Clinical trials implementing HT for tumors of the brain accumulating more than 400 patients are discussed. RESULTS: HT is a feasible and effective approach to brain tumors. Important selection criteria are tumor size (< 6 cm) and location (supratentorial, peripheral). Acute treatment toxicity is relatively low and long-term side effects are similar to those observed for RT alone. In some studies a high response rate and improvement of survival was achieved. Tumor control and survival depend on histology (anaplastic astrocytoma vs. glioblastoma multiforme), extent of surgery (complete vs. incomplete), tumor status (primary vs. recurrent), age and performance status. Satisfactory heating also correlates significantly with favourable treatment outcome. CONCLUSIONS: The encouraging results of clinical trials may be biased by favourable tumor and patient selection. Randomized clinical trials comparing RT alone versus combined RT-HT for advanced and recurrent brain tumors are justified. Part I has covered biological and technical fundamentals of clinical hyperthermia and has been published in Strahlenther. Onkol. 168 (1992), 183-190. Part II has covered clinical fundamentals and results in superficial tumors of clinical hyperthermia and has been published in Strahlenther. Onkol. 169 (1993), 633-654. Part III has covered clinical rationale and results in deep seated tumors and has been published in Strahlenther. Onkol. 171 (1995), 251-264.

Animals↗

Random errors in anthropometry.

In order to present basic information on the magnitude of and variance due to the random error in anthropometry, 219 measurement items were taken on 12 subjects twice by the same observer. The precision (i.e., consistency between the repeated measurements) was investigated for these measurement items. The reliability was quantified using mean absolute difference (MAD), technical error of measurement (TEM), and reliability coefficient (R). MAD and TEM are highly correlated with each other and both represent the magnitude of error. They are not correlated with R, which represents the proportion of error-free variance. Larger measurements tend to have absolutely larger but relatively smaller random errors and higher reliability in the size range of 1-10 cm. Imprecision is inherent in anthropometry of the living because of the fact that the human body is not rigid. This may be responsible for the above tendency. Relatively large MAD and low R may be due to small absolute size, landmarks difficult to locate precisely, soft tissue deformation, and the inconsistency of the posture of the subject.

Adult↗

Comparison of two commercially available near-infrared spectroscopy instruments for cerebral oximetry. Technical note.

Two near-infrared spectroscopy (NIRS) devices were compared with regard to their responses to changes in cerebral hemoglobin oxygenation induced by hypoxia and hypercapnia in five healthy volunteers. Sensors belonging to each NIRS device were placed on opposite sides of the volunteer's forehead. The INVOS-3100A device, approved by the United States Food and Drug Administration, records the percentage of oxyhemoglobin (HbO2) saturation and the investigational NIRO500 device records absolute changes in HbO2, deoxyhemoglobin, and total hemoglobin in micromolar concentrations referenced to an arbitrary baseline. The volunteers breathed separate mixtures of 7% CO2 in O2 and 10% O2 for 5 minutes in random order. Arterial blood pressure, end-tidal CO2 (ETCO2), arterial O2 saturation, and electrocardiographic data were continuously monitored. Hypercapnia increased (p < 0.01) ETCO2 from 42+/-2 to 56+/-3 mm Hg (mean +/- standard deviation), resulting in a 7.3+/-0.2% increase (p < 0.005) in cerebral HbO2 saturation detected by the INVOS3100A device and an 11.6+/-3 microM increase (p < 0.0008) in HbO2 detected by the NIRO500. Hypoxia decreased (p < 0.01) arterial HbO2 saturation from 98+/-1 to 87+/-3%, causing a 5.1+/-1.2% decrease (p < 0.01) in the percentage of HbO2 saturation detected by the INVOS3100A device and a 9.7+/-6.3 microM decrease in HbO2 detected by the NIRO500. The responses of the NIRO500 and the INVOS3100A instruments to changes in cerebral oxygenation resulting from hypercapnia and hypoxia were generally similar; however, responses tended to be greater when recorded by the NIRO500 device, perhaps because, unlike the INVOS3100A device, the NIRO500 does not correct for skin and bone contamination.

Blood Gas Monitoring, Transcutaneous↗

[Sympatho-adrenergic reactions following theophylline administration with the use of various anesthesia technics].

The mechanism of action of theophylline is still the subject of controversy. Possible mechanisms that have been suggested are inhibition of phosphodiesterase, release of catecholamines, effects on intracellular calcium, and adenosine antagonism. With regard to these aspects, it was the aim of this study to compare sympatho-adrenal responses after theophylline application during different anesthetic techniques. A total of 60 patients scheduled for orthopedic surgery were investigated: they were divided into three groups of 20 patients who received either halothane anesthesia with thiopentone induction, modified neurolept anesthesia with fentanyl and midazolam, or spinal anesthesia with bupivacaine and mepivacaine. Within these three groups, the patients were randomly allocated to a theophylline collective receiving an injection of theophylline, 4 mg/kg body weight and to the control group. Plasma levels of epinephrine and norepinephrine (by HPLC/ECD), glucose, lactate and free glycerol and MAP and HR were determined over a period of 120 min. In all groups, epinephrine levels increased immediately after injection of theophylline; group levels of epinephrine were higher in the theophylline-groups than in controls (P less than 0.0001). A remarkable increase was observed within 60 min. Peak epinephrine concentrations were comparable after single injections of 100 micrograms or infusions of 5 micrograms/min. The norepinephrine increase after theophylline injection was brief and less pronounced. MAP, HR, glucose, lactate and free glycerol were not influenced by theophylline. A comparison of the theophylline patients showed no statistical differences attributable to the different anesthetic techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Treatment of acute rejection of cadaveric renal allografts with rabbit antithymocyte globulin.

In a prospective randomized single-blind trial, we compared the effectiveness of rabbit antithymocyte globulin (RATG) in the treatment of acute renal graft rejection with the results of treatment by high oral doses of prednisone. Twenty recipients of cadaveric kidneys were included in each group. In the RATG group, the prednisone dose was not increased and a dose-by-rosette protocol was used to keep T cell levels between 50 and 150/mm3. In this group 15 of the 20 patients responded to the treatment. One of these patients lost her kidney afterward because of a technical failure. In five patients rejection was irreversible despite a subsequent course of high-dose prednisone orally. In the prednisone group, 13 patients showed a good response, but 3 of them only after a subsequent course of RATG. The remaining seven patients underwent nephrectomy before a course of RATG could be given. One patient in this group died of septicemia. In either group there were six second rejection episodes, but they developed 2.2 months later in the RATG group. All second rejection episodes were treated with the alternative regimen and all patients responded to this treatment. Renal function after 6 months was similar in both groups. Less infections occurred in the RATG group. Prior to rejection, there were no differences in concentrations of peripheral T cells between both groups. Treatment of acute rejections with RATG is an effective and safe procedure which is steroid sparing.

Adult↗

Evaluation of the usefulness of intrathecal bupivacaine infusion for analgesia after hip and knee arthroplasty.

Spinal anaesthesia in 47 ASA I-III patients was induced with 0.5% bupivacaine 2 ml via a 28-gauge spinal catheter (L3-4 interspace) and 0.5-ml increments were given if needed before or during hip or knee arthroplasty. Intrathecal 24-h infusions consisted of 0.5% bupivacaine 0.4 ml h-1 (2 mg h-1) (n = 12), 0.5% bupivacaine 0.2 ml h-1 (1 mg h-1) (n = 12) or saline (n = 11) (12 exclusions). Patients received oxycodone 0.1-0.14 mg kg-1 i.m. for rescue analgesia. Infusion of bupivacaine 2 mg h-1 provided significantly better postoperative analgesia (19 oxycodone doses per group in 24 h) compared with bupivacaine 1 mg h-1 (36 doses of oxycodone per group) and saline (52 doses per group) (P < 0.05). Five patients in the bupivacaine 2-mg h-1 group and none in the other groups had measurable sensory block 24 h after the infusion was started. Three patients in the bupivacaine 2-mg h-1 group, two with concomitant arterial hypotension, and one patient in the bupivacaine 1-mg h-1 group experienced an increase in block on the ward. The incidence of nausea and vomiting was similar in all groups. Although an effective analgesic, intrathecal infusion of bupivacaine 2 mg h-1 cannot be recommended for routine pain relief because of the risk of increasing spinal block. Technical problems (19%) also reduced the overall efficacy of the continuous intrathecal analgesic regimen.

Analgesia↗

Role of misoprostol in overcoming an unsatisfactory colposcopy: a randomized double-blind placebo-controlled clinical trial.

OBJECTIVE: To assess the effectiveness of vaginal misoprostol in overcoming an unsatisfactory colposcopy and to analyse the factors that might influence the response to misoprostol, i.e. age, menopausal status, duration of menopause and cervical characteristics. STUDY DESIGN: A randomized double-blind placebo-controlled clinical trial. METHODS: Forty patients with unsatisfactory colposcopy were recruited from the colposcopy clinic and were randomly allocated to receive either 400 microg misoprostol or similar-looking placebo tablets vaginally. Repeat colposcopy was performed after 6 h noting the side effects, if any. RESULTS: One patient was excluded from the misoprostol group because postdrug colposcopic examination could not be done due to a technical fault. Of the 19 patients in the misoprostol group, 15 (78.9%) had satisfactory examination compared to only 6 of the 20 (30%) patients in the placebo group. This effect of misoprostol was statistically significant (p = 0.004). Misoprostol in the present study averted 3 cone biopsies and 12 endocervical curettages. The side effects of misoprostol were comparable in both groups. The slit-like external os and the posterior cervical lip as the site of unsatisfactory colposcopy had better conversion rates compared to pinhole os (66.6 vs.81.2%) and anterior lip involvement (85.7 vs.100%). CONCLUSION: Four hundred micrograms of intravaginal misoprostol is an effective and safe method to convert an unsatisfactory colposcopy into a satisfactory one.

Administration, Intravaginal↗

[Comparison of an auditory evoked potentials index and a bispectral index versus clinical signs for determining the depth of anesthesia produced by propofol or sevoflurane].

OBJECTIVES: To evaluate an anesthetic depth index (ADI) obtained from auditory evoked potentials and a bispectral EEG index (BIS) in comparison with clinical assessment of anesthetic depth using the modified observer's assessment of awareness/sedation scale (MOAA/SS), for induction of anesthesia with propofol or sevoflurane as the only agent. PATIENTS AND METHODS: The ADI and BIS were recorded simultaneously in this prospective study and compared to the MOAA/SS during the anesthetic induction of 26 adults undergoing elective heart surgery. Assignment of patients to two groups was random. Group A (n = 13) patients were induced with propofol (target dose 5 micrograms.ml-1 in 5 min). Induction in group B (n = 13) was with sevoflurane (8% tidal volume). A scheme of awake-sleeping-awake-sleeping was followed. The means of the two indexes were compared (Mann-Whitney test) one minute before the patient slept (awake) and one minute later (sleeping), and the evolution of the indexes was compared during awake/sleep and sleep/awake phase changes and while the patients were in a stable sleep phase. The sensitivity and specificity of each index was analyzed in function of the MOAA/SS. We also analyzed the time elapsing from the moment the patient fell asleep (MOAA/SS 2) until the two indexes reached published reference values (ADI = 38, BIS = 60). RESULTS: After induction with propofol (group A) the ADI fell to 29.2 +/- 11.7 and the BIS fell to 63.5 +/- 13.4. After induction with sevoflurane (group B) the ADI fell to 33.8 +/- 14.9 and the BIS to 66.8 +/- 15. The ADI value that best discriminated between arousal and sleeping (sensitivity 100%) was 38; the BIS value that best discriminated was 60. The responses to sound in decibels (dB) during "awake/sleeping" and "sleeping/awake" phases were, respectively, -3.8 dB and -4.5 dB for the ADI and -1.5 dB and -0.8 dB for the BIS. With the patient in stable sleep, response to the two indexes was at -0.79 dB. In group A, the ADI detected MOAA/SS 2 significantly earlier (ADI 13.1 +/- 30 s; BIS 56 +/- 36 s; p < 0.05). No patient reported remembering the study period. CONCLUSIONS: Monitoring anesthetic depth with the ADI or BIS was technically easy and effective for detecting whether patients were awake or sleeping. The ADI response was faster and identified awake/sleeping and sleeping/awake phase changes better than did the BIS.

Adult↗

Responses of black and white males to the special intervention program of the Multiple Risk Factor Intervention Trial.

Of the 12,866 males aged 35 to 57 years who were randomly assigned to the special intervention (SI) and usual care (UC) groups of the Multiple Risk Factor Intervention Trial (MRFIT), 931 (7.2%) were black. With use of a multivariate score from the Framingham study, all were assessed to be in the upper 10% to 15% of coronary risk because of their diastolic blood pressure, serum cholesterol level, and/or cigarette use. Blacks in the MRFIT were of lower educational and income levels and were less often employed in professional-technical-managerial or other white-collar jobs than whites. At baseline, blacks had higher mean blood pressures and a higher prevalence of hypertension than whites, were more often smokers but smoked fewer cigarettes per day, and had a higher prevalence of ECG abnormalities. Dietary lipid composition was similar for black and white males; so also were weight and body mass index, plasma total cholesterol levels, and low-density lipoprotein (LDL) cholesterol levels. High-density lipoprotein cholesterol levels were higher and triglyceride levels lower for blacks than whites. Attendance rates over the years of the trial were similarly high for blacks and whites. Among males in the SI group, smoking cessation rates, changes in dietary lipid composition and in plasma total and LDL cholesterol, and achievement of normotensive diastolic pressure with antihypertensive stepped-care treatment were comparable for black and white males. This MRFIT experience indicates ability to induce extensive changes in life-styles (eating and smoking habits) of both black and white American males of varying educational and socioeconomic backgrounds and also to achieve long-term effective adherence to programs for the treatment and control of hypertension.

Adult↗

Single-dose spinal anaesthesia versus incremental dosing for lower limb vascular surgery.

BACKGROUND: In patients scheduled for vascular surgery, atherosclerotic disease is highly prevalent. Haemodynamic reactions are often aggravated when spinal analgesia is used in this population. No randomized studies have been conducted comparing single shot (SS) with continuous spinal analgesia (CSA) for vascular patients. We did a prospective randomized study comparing haemodynamics when SS versus CSA was performed. METHODS: Sixty patients were randomized to have SS or CSA. The power of the study was 0.90. Patients in the SS group received 17.5 mg bupivacaine and in the CSA group 5 mg was given initially and incremental doses of 2.5 mg were given until an analgesic level of T-11 was reached. Mean arterial pressures (MAP) were measured invasively. ST-analysis was done continuously. Postoperatively, the patients were interviewed using a standardized questionnaire. Back pain, neurologic sequelae and post-dural puncture headache (PDPH) were investigated. RESULTS: There was no significant difference between the analgesic levels (T-7/T-8), the decrease in MAP, the number of patients needing ephedrine and the total amount of ephedrine given in the two groups. The motor blockade was more pronounced in the SS group (P < 0.001) and the total amount of bupivacaine used was 17.5 mg compared to 7.5 mg (5-17.5) in the CSA group (P < 0.001). One patient suffered PDPH which was slight and responded to a nonsteroidal anti-inflammatory drug. Two patients in each group had transient paraesthesias in the legs. There were technical problems with the spinal catheter in 4 patients, and these were excluded from the study. CONCLUSION: In this study we found no difference in the haemodynamic response to SS or CSA in patients scheduled for vascular surgery of the legs. SS is easier to apply and is recommended when the duration of surgery allows for it.

Adrenergic Agents↗

Antileukocyte antibodies in patients refractory to platelet transfusions.

Sera from 12 multitransfused patients who were refractory to random-donor platelets were tested for lymphocytotoxic and leukoagglutinating antibodies using panel cells from various volunteers whose HLA-A and -B antigens were known. All sera contained leukoagglutinins reactive with cells from at least one panel member, whereas only 33% had lymphocytotoxic antibodies. Patients whose sera reacted frequently with panel cells using the microcapillary agglutination technic seldom responded to HLA-matched paltelets, whereas those whose sera reacted infrequently usually responded satisfactorily. It is concluded that non-HLA antibodies may play a significant role in determining the responses to platelet transfusions in multi-transfused patients.

Agglutination Tests↗

[Genetic aspects of male infertility].

Cytogenetic investigations in sterile males showed that autosomal and sex chromosome anomalies can be responsible of the defect of spermatogenesis. Specific alteration of genes controlling spermatogenesis is excluded because all chromosomes are involved in the anomaly and breakpoints are distributed at random. In the aim to explain the spermatogenic failure, three mechanisms are proposed: X-autosome interaction, asynapsis, somatic lesion of the gonad, each mechanism might act alone or with the other. Beside chromosomal infertility, meiotic or sperm anomalies suggest the presence of gene mutations which interfere with the evolution of spermatogenesis or lead to the formation of abnormal spermatozoa. Insertion of technics of molecular biology in our researches could demonstrate the existence of these mutations; the same technics will allow to resolve the problem of the failure of a germ cell bearing a chromosomal anomaly particularly when this anomaly is balanced and involves the autosomes and not the sex chromosomes.

Humans↗

Techniques and results of laparoscopic antireflux surgery in Germany.

BACKGROUND: This study aimed to evaluate the development and outcomes of laparoscopic antireflux surgery in Germany using a nationwide representative survey. METHODS: A written questionnaire including 34 detailed questions and 288 structured items about diagnostic and therapeutic approaches, number of procedures, complications, and mortality was sent to 546 randomly selected German surgeons (33% of the registered general surgeons) at the end of 2000. RESULTS: The response rate was 72%, and a total of 2,540 antireflux procedures were reported. According to the survey, 81% of all procedures were performed laparoscopically, and 0.1% were performed thoracoscopically. As reported, 65% were total fundoplications, 31% were partial fundoplications, and 4% were other procedures. Of the surgeons who had experience with laparoscopic antireflux techniques (29%), 71% preferred a 5-trocar technique, and 91% used the Harmonic Scalpel for dissection. There were significant technical variations among the surgical procedures (e.g., use and size of the bougie, length of the wrap, additional gastropexy, fixation of the wrap). The overall complication rate for laparoscopic fundoplication was 7.7% (5.7% surgical and 2% nonsurgical complications), including rates of 0.6% for esophageal perforations and 0.6% for splenic lesions. The conversion rate was 2.9%; the reoperation rate was 1.6%; and the overall hospital mortality rate was 0.13%. The authors observed a striking learning curve difference in complication rates between hospitals performing fewer than 10 laparoscopic antireflux techniques annually and those performing more than 10 fundoplications per year (14% vs 5.1%, p < 0.001). Long-term dysphagia and interventions occasioned by dysphagia occurred significantly more often after total fundoplications than after partial fundoplications (6.6% vs 2.4%; p < 0.001). Similar findings were reported for Nissen versus floppy Nissen procedures. The overall failure rate, however, was similar for both groups (Nissen 8.7%; partial 9%, difference not significant). CONCLUSIONS: Until now, no unique laparoscopic antireflux technique has been accepted, and a number of different antireflux procedures with numerous modifications have been reported. The morbidity and mortality rates reported in this article compare very well with those in the literature, and 1-year-follow-up results are promising.

Gastroesophageal Reflux↗

No differences between 20, 30, or 40 mL ropivacaine 0.5% in continuous lateral popliteal sciatic-nerve block.

BACKGROUND AND OBJECTIVES: The aim of this study was to compare the anesthetic and analgesic characteristics of the administration of an initial bolus of 20, 30, or 40 mL of ropivacaine 0.5% through a lateral popliteal sciatic catheter. METHODS: Sixty patients scheduled for foot surgery under continuous sciatic lateral popliteal nerve block were included in this double-blinded study. Patients were randomly assigned to 1 of 3 groups: 20 mL, 30 mL, or 40 mL of ropivacaine 0.5%. Time to obtain a complete sensory block and duration of analgesia were recorded. Failure of the continuous block and complications such as technical or neurologic problems were noted. RESULTS: Data are presented as mean +/- SD, median and ranges, or percent of patients and were compared by application of analysis of variance or Kruskal-Wallis when required. Time to complete sensory block (31 [10-70] v 25 [5-50] v 25 [5-40] min), percentage of failure (5% v 5% v 0%), and duration of action (995 [278-1,800] v 967 [420-2,175] v 915 [190-1,900] min) were not statistically different between 20 mL, 30 mL, and 40 mL ropivacaine 0.5% groups, respectively. No complications were noted. CONCLUSIONS: This dose-response study shows that 20 mL of ropivacaine 0.5% injected through an indwelling lateral popliteal catheter is the optimal dose for foot surgery. Higher doses of 30 mL or 40 mL did not provide any further advantage.

Adult↗

An interpersonal communication analysis of relationship in psychotherapy.

In psychotherapy theorty, research, and practice, relationship has remained a controversial and elusive construct. Psychoanalytic theorists highlight transference-countertransference factors as central theoretical and technical components, but have yet to translate these constructs into a scientifically useful format. Rogerian theorists have consistently specified the relationship factors of positive regard, empathy, and congruence as "necessary and sufficient conditions" for constructive personality change in therapy and have evolved operational anchorings (e.g. Rogers, Gendlin, Kiesler, and Truax, 1967). Behaviorists (e.g., Wilson and Evans, 1978) conceptualize relationship factors as nonspecific variables which are important in enhancing the social influence and eliciting power of the therapist as an agent of change, while considering most client emotional responses toward the therapist as random factors which are generally irrelevant to the therapeutic process. My purpose in this paper is to offer a conceptual and empirical analysis of relationship in human behavior and in psychotherapy from an interpersonal communication perspective.

Communication↗

Five fractions of preoperative radiotherapy for selected cases of rectal cancer.

In locally advanced colorectal cancer, combined modality treatment is a standard adjuvant therapy in USA and Europe. The basic issue of the timing of radiotherapy and chemotherapy and preoperative radio-chemotherapy versus postoperative radio-chemotherapy is being addressed in prospective trials. Preoperative radiotherapy proved that causes more radiosensitivity due to that oxygen tension within the tumour may be higher prior to surgery. Technically, there are two approaches of preoperative radiotherapy. The aim of this article is to report the inclusion criteria, indications, advantages and results of short course preoperative radiotherapy.

Colorectal Surgery↗

Continuous spinal analgesia. Comparison between patient-controlled and bolus administration of plain bupivacaine for postoperative pain relief.

BACKGROUND AND OBJECTIVES: Adequate postoperative pain relief has been achieved in orthopedic patients by subarachnoid bolus administration of plain bupivacaine. This prospective randomized study compares bolus injections of bupivacaine with a patient controlled infusion via subarachnoid 28-gauge microcatheters for postoperative analgesia after elective hip replacement. METHODS: Forty-two patients (mean age, 69 +/- 11 years) were randomly allocated to one of two groups. Group. 1 patients received a constant subarachnoid infusion of 0.6 mg/h of bupivacaine by a patient-controlled device and were allowed to self-administer 0.6 mg every 30 minutes Group 2 patients received a nurse-administered bolus of 3.75 mg of plain bupivacaine on request. Pain was assessed by patients and nurses by a visual analog scale (VAS) every hour. The degree of motor block and the level of analgesia were documented every 4 hours. Hemodynamic and respiratory parameters were recorded hourly. Differences between groups were tested by analysis of variance for repeated measurement. RESULTS: Technical problems occurred in six patients were more frequent in group 1 but none in group 2. Patient-controlled analgesia resulted in lower pain scores than bolus application during 18 postoperative hours (VAS score 19 +/- 19 mm in group 1 and 39 +/- 30 mm in group 2; P < .01). Lower total doses of bupivacaine were required in group 1 (17.6 +/- 4 mg) than in group 2 (22.3 +/- 7 mg; P < .05). The groups did not differ with respect to the degree of motor block (Bromage score 3.5 +/- 0.5), the sensory level (L1-2 +/- 1), or hemodynamic or respiratory parameters. CONCLUSION: In spite of a higher incidence of technical problems, patient-controlled analgesia with a continuous background infusion via microspinal catheters provides more effective postoperative analgesia, without hemodynamic or respiratory side effects, than bolus administration.

Aged↗