ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundVentilator-associated pneumonia (VAP) has been implicitly accused of increasing mortality. However, it is not certain that pneumonia is responsible for death or whether fatal outcome is caused by other risk factors for death that exist before the onset of pneumonia. The aim of this study was to evaluate the attributable mortality caused by VAP by performing a matched-paired, case-control study between patients who died and patients who were discharged from the intensive care unit after more than 48 h of mechanical ventilation.MethodsDuring the study period, 135 consecutive deaths were included in the case group. Case-control matching criteria were as follows: (1) diagnosis on admission that corresponded to 1 of 11 predefined diagnostic groups; (2) age difference within 10 yr; (3) sex; (4) admission within 1 yr; (5) APACHE II score within 7 points; (6) ventilation of control patients for at least as long as the cases. Precise clinical, radiologic, and microbiologic definitions were used to identify VAP.ResultsAnalysis was performed on 108 pairs that were matched with 91% of success. There were 39 patients (36.1%) who developed VAP in each group. Multivariate analysis showed that renal failure, bone marrow failure, and treatment with corticosteroids but not VAP were independent risk factors for death. There was no difference observed between cases and controls concerning the clinical and microbiologic diagnostic criteria for pneumonia.ConclusionVentilator-associated pneumonia does not appear to be an independent risk factor for death.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundThe success of the neurolytic celiac plexus block, despite different approaches and methods used, depends on adequate spread of the injectate in the celiac area. This retrospective study was conducted to evaluate the patterns of alcohol spread and pain relief in patients with cancer or therapy-related anatomic distortion of the celiac area.MethodsFrom 177 cancer patients who underwent computed tomography (CT)–guided single-needle neurolytic celiac plexus blockviaan anterior approach, a radiologist, blind to the aim of the study, retrospectively selected 105 patients with abnormal anatomy of the celiac area as judged by CT images obtained before the block. To evaluate CT patterns of neurolytic (mixed with contrast) spread, the celiac area was divided on the frontal plane into four quadrants: upper right and left and lower right and left, as related to the celiac artery. Results were expressed as the number of quadrants into which contrast spread,i.e., four, three, two, or one quadrants with contrast. The patterns of contrast spread according to the number of quadrants with anatomic distortion were analyzed. Patient assessment by visual analog scale was reviewed to evaluate the degree of pain relief. Pain relief 30 days after block was considered long-lasting. Pain relief at 30 days after block was analyzed according to the number of quadrants with contrast.ResultsOverall, four, three, two, and one quadrants with contrast were observed in 9 (8%), 21 (20%), 49 (47%), and 26 (25%) patients, respectively. An inverse correlation was observed between the number of quadrants with anatomic distortion and the number of quadrants with contrast (P< 0.001). Long-lasting pain relief was noticed in nine of nine patients (100%; 95% confidence interval, 66–100) with contrast in fourquadrants, and in 10 of 21 patients (48%; 95% confidence interval, 26–70) with contrast in 3 quadrants (P< 0.01). None of the 75 patients with contrast in two quadrants or one quadrant experienced long-lasting pain relief.ConclusionsThese findings suggest that, using the single-needle anterior approach, the neurolytic spread in the celiac area is highly hampered by the regional anatomic alterations. It also appears that only a complete (four quadrants) neurolytic spread in the celiac area can guarantee long-lasting analgesia, and that this picture may be obtained in a very limited fraction of patients with regional anatomic alterations.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundInclusion of cardiac output and other physiologic parameters, in addition to or instead of, demographic variables might improve the population pharmacokinetic modeling of lidocaine.MethodsThirty-one patients were included in a population pharmacokinetic study of lidocaine. After bolus injection of lidocaine (1 mg/kg), 22 or 10 blood samples per patient were taken from a radial artery. During the experiment, cardiac output was measured using a thoracic electrical bioimpedance method. The following four population pharmacokinetic models were constructed and their performances investigated: a model with no covariates, a model with cardiac output as covariate, a model with demographic covariates, and a model with both cardiac output and demographic characteristics as covariates. Model discrimination was performed with the likelihood ratio test.ResultsInclusion of cardiac output resulted in a significant improvement of the pharmacokinetic model, but inclusion of demographic covariates was even better. However, the best model was obtained by inclusion of both demographic covariates and cardiac output in the pharmacokinetic model.ConclusionsWhen population pharmacokinetic models are used for individualization of dosing schedules, physiologic covariates,e.g., cardiac output, can improve their ability to predict the individual kinetics.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundThe aim of this study was to evaluate the association of a small dose of intrathecal ropivacaine with small doses of intrathecal clonidine for ambulatory surgery.MethodsOne hundred twenty patients, classified as American Society of Anesthesiologists physical status I and scheduled for knee arthroscopy, were studied. Patients were randomly assigned to receive 4 ml of one of the following double-blinded isobaric intrathecal solutions: 8 mg of ropivacaine (group 1; n =30); 8 mg ropivacaine plus 15 &mgr;g clonidine (group 2; n =30); 8 mg ropivacaine plus 45 &mgr;g clonidine (group 3; n =30); and 8 mg ropivacaine plus 75 &mgr;g clonidine (group 4; n =30). The level and duration of sensory anesthesia were recorded, along with the intensity and duration of motor block. Patient and surgeon were interviewed to evaluate the quality of anesthesia.ResultsIntrathecal ropivacaine (8 mg alone) produced short sensory anesthesia and motor blockade (132 ± 38 min and 110 ± 35 min; mean ± SD). However, the quality of anesthesia was significantly lower than in any other group (P< 0.05). Ropivacaine (8 mg) plus 75 &mgr;g clonidine produced significantly longer sensory and motor anesthesia (195 ± 40 min and 164 ± 38 min;P< 0.05). However, this was associated with systemic effects, such as sedation and reduction of arterial blood pressure. Ropivacaine (8 mg) plus 15 &mgr;g clonidine did not prolong sensory or motor blockade, afforded high quality anesthesia, and was not associated with detectable systemic effects.ConclusionSmall-dose intrathecal clonidine (15 &mgr;g) plus 8 mg intrathecal ropivacaine produces adequate and short-lasting anesthesia for knee arthroscopy.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundRopivacaine is a new long-acting amino-amide local anesthetic. However, there are no data on its use in infants. In the current study, the authors investigated the pharmacokinetics of caudal ropivacaine in 30 infants younger than 12 months.MethodsTwo groups of infants (group 1 [n = 15], aged 0–3 months; group 2 [n = 15], aged 3–12 months) were given a caudal bolus dose of 0.2% ropivacaine (2 mg/kg) and a standardized general anesthetic technique. Serial blood samples taken for up to 12 h were analyzed for total and free ropivacaine using high-performance liquid chromatography. Population pharmacokinetic modeling was performed to yield estimates of clearance, volume of distribution, and absorption rate constant. An analysis of covariates on the kinetic parameters also was made.ResultsMedian maximum free ropivacaine concentration was significantly higher in group 1 (99 &mgr;g/l) than in group 2 (38 &mgr;g/l) (P= 0.0002), as was the median free fraction of ropivacaine (10%vs.5 %;P= 0.01). Pharmacokinetic variables of the total population were best described by a one-compartment model with first-order absorption. Mean clearance was 0.31 l · h−1· kg−1(coefficient of variation [CV], 51%), volume of distribution was 2.12 l/kg (CV, 34%), and absorption rate constant was 1.61 h−1(CV, 46%). Mean absorption and elimination half-lives were 0.43 and 5.1 h, respectively. Age and percentage of free ropivacaine were significant covariates for clearance. Posterior Bayesian estimates of clearance were significantly higher (38%) in older children.ConclusionTotal and free plasma ropivacaine concentrations after caudal ropivacaine (0.2%, 2 mg/kg) in infants were within the range of concentrations previously reported in adults and older children. Age and percentage of free ropivacaine were significant covariates of clearance.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundThe authors evaluated a device designed to provide conscious sedation with propofol (propofol–air), or propofol combined with 50% nitrous oxide (N2O; propofol–N2O). An element of this device is the automated responsiveness test (ART), a method for confirming that patients remain conscious. The authors tested the hypotheses that the ART predicts loss of consciousness and that failure to respond to the ART precedes sedation-induced respiratory or hemodynamic toxicity.MethodsThe protocol consisted of sequential 15-min cycles in 20 volunteers. After a 15-min control period, propofol was infused to an initial target effect-site concentration of 0.0 &mgr;g/ml with N2O or 1.5 &mgr;g/ml with air. Subsequently, the propofol target effect-site concentration was increased by a designated increment (0.25 and 0.5 &mgr;g/ml) and the process repeated. This sequence was continued until loss of consciousness, as defined by an Observer’s Assessment of Alertness/Sedation (OAA/S) score of 10/20 or less, or until an adverse physiologic event was detected.ResultsThe OAA/S score at which only 50% of the volunteers were able to respond to the ART (P50) during propofol–N2O was 11.1 of 20 (95% confidence interval [CI]: 10.6–11.8); the analogous P50was 11.8 of 20 (95% CI: 11.4–12.3) with propofol–air. Failure to respond to the ART occurred at a plasma propofol concentration of 0.7 ± 0.6 &mgr;g/ml with propofol–N2O and 1.6 ± 0.6 &mgr;g/ml with propofol–air, whereas loss of consciousness occurred at 1.2 ± 0.8 &mgr;g/ml and 1.9 ± 0.7&mgr;g/ml, respectively. There were no false-normal ART responses.ConclusionThe ART can guide individual titration of propofol because failure to respond to responsiveness testing precedes loss of consciousness and is not susceptible to false-normal responses. The use of N2O with propofol for conscious sedation decreases the predictive accuracy of the ART.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundCombining bupivacaine with fentanyl for intrathecal analgesia in labor is well recognized, but dosages commonly used are arbitrarily chosen and may be excessive. This study aimed to determine the median effective dose (ED50) of intrathecal bupivacaine, defined as the minimum local analgesic dose (MLAD), and then use this to assess the effect of different doses of fentanyl.MethodsIn this double-blind, randomized, prospective study, 124 parturients receiving combined spinal epidural analgesia at 2–6-cm cervical dilatation were allocated to one of four groups to receive bupivacaine alone or with 5, 15, or 25 &mgr;g fentanyl, using the technique of up–down sequential allocation. Analgesic effectiveness was assessed using 100-mm visual analog pain scores, with less than or equal to 10 mm within 15 min defined as effective. MLAD was calculated using the formula of Dixon and Massey. Pruritus and duration of spinal analgesia were also recorded.ResultsMinimum local analgesic dose of intrathecal bupivacaine was 1.99 mg (95% confidence interval, 1.71, 2.27). There were similar significant reductions in MLAD (P< 0.001) for all bupivacaine–fentanyl groups compared with bupivacaine control. There was a dose-dependent increase in both pruritus and duration of spinal analgesia with increasing fentanyl (P< 0.0001).ConclusionUnder the conditions of this study, the addition of intrathecal fentanyl 5 &mgr;g offers a similar significant bupivacaine dose-sparing effect as 15 and 25 &mgr;g. Analgesia in the first stage of labor can be achieved using lower doses of fentanyl, resulting in less pruritus but with a shortening of duration of action.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundPreemptive analgesia has been difficult to show in human experiments. If ketorolac has preemptive effects, then there may be an advantage to administering it at the beginning of surgery despite the potential for increased blood loss.MethodsThe authors performed a randomized, double-blind, controlled trial of 48 patients scheduled for ankle fracture surgery in a county trauma hospital. Anesthesia management was standardized and included adequate opioid analgesia (5 &mgr;g/kg fentanyl and 0.1 mg/kg morphine). Intravenous 30 mg ketorolac was administered to 23 patients before tourniquet inflation and to 25 patients after tourniquet inflation. Visual analog scale pain scores, morphine patient-controlled analgesia consumption, nausea–vomiting, and postoperative bleeding were measured.ResultsThe 23 patients given ketorolac before tourniquet inflation had no increase in pain postoperatively compared with their preoperative baseline (P= 0.280). The 25 patients who received ketorolac minutes later after tourniquet inflation had significant increases in their postoperative pain compared with their preoperative baseline (P= 0.00116). This effect was short-lived, and by 6 h the pain score in this group was not significantly more than it was preoperatively. Intergroup comparison showed a lower visual analog scale score at 2 (P= 0.0203) and 4 h (P= 0.00549) in the preemptive group and lower nausea scores at hour 6 (P= 0.00704). There was no difference in patient-controlled analgesia consumption between groups.ConclusionsIntravenous 30 mg ketorolac appears to have preemptive analgesic effects in patients undergoing ankle fracture repair. Ketorolac administered before tourniquet inflation prevents postoperative pain being perceived as more intense than preoperative pain.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID