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Biomedical subjects

K Samii

Publications and source records attributed to K Samii.

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

A comparison of propofol with a propofol-ketamine combination for sedation during spinal anesthesia.

Propofol (P) is increasingly used as a sedative during regional anesthesia. Providing titratable sedation and rapid recovery, it can compromise hemodynamic stability. However, in combination with ketamine (K), it provides stable hemodynamics during total intravenous anesthesia, avoiding emergence phenomena. We compared the efficacy, respiratory and hemodynamic profiles, and side effects of these two sedative regimes in patients undergoing spinal anesthesia. Forty patients, ASA physical status I and II, undergoing urologic or orthopedic procedures were randomly assigned to one of two groups (n = 20 each). Group 1 (P + K) received initial doses of 0.4 mg/kg P, 0.1 mg/kg K, followed by an intravenous infusion of 1.2 mg x kg(-1) x h(-1) and 0.3 mg x kg(-1) x h(-1), respectively. Group 2 (P) received bolus 0.5 mg/kg and infusion 1.5 mg x kg(-1) x h(-1). Subsequent infusion rates were titrated to a predetermined sedation level using a 5-point score. Heart rate, arterial pressure, respiratory rate, oxygen saturation end-tidal CO2, and oxygen requirements were recorded. Sedation scores were similar for both groups. There was no difference in total propofol requirements between Group 1 (146 +/- 94 mg) and Group 2 (137 +/- 52 mg) (mean +/- SD). Mean arterial pressure was significantly higher in the P + K group, e.g., 91 mm Hg (86-94) vs 75 mm Hg (69-83) at 30 min (mean +/- SD). Administration of vasopressors and fluids as well as recovery and emergence phenomena were similar between groups. Although the described additive effect of propofol and ketamine was not confirmed, the combination conferred hemodynamic stability during spinal anesthesia.

Adult↗
PubMed1997

Serious complications related to regional anesthesia: results of a prospective survey in France.

BACKGROUND: Serious complications related to regional anesthesia have previously been described primarily in case reports and retrospective surveys. The authors prospectively evaluated a multicenter series of regional anesthetics, using preplanned criteria to measure the incidence and characteristics of associated serious complications. METHODS: Requests were sent to 4,927 French anesthesiologists in advance of a subsequent 5-month study period. Participating anesthesiologists were asked for detailed reports of serious complications occurring during or after regional anesthetics performed by them during the study interval. Details regarding each complication then were obtained via a second questionnaire. RESULTS: The number of responding anesthesiolgists was 736. The number of regional anesthetics performed was 103,730, corresponding to 40,640 spinal anesthetics, 30,413 epidural anesthetics, 21,278 peripheral nerve blocks, and 11,229 intravenous regional anesthetics. Reports of 98 severe complications were received, with follow-up information being obtained for 97. In 89 cases, complications were attributed fully or partially to regional anesthesia. Thirty-two cardiac arrests, seven of which were fatal, occurred during the study. Of these, 26 occurred during spinal anesthesia, with 6 being fatal, 3 occurred during epidural anesthesia, and 3 more occurred during peripheral blocks. The higher incidence of cardiac arrest during spinal anesthesia (6.4 +/- 1.2 per 10,000 patients) compared with all other regional anesthesia (1.0 +/- 0.4 per 10,000 patients) was statistically significant (P < 0.05). Of 34 neurologic complications (radiculopathy, cauda equina syndrome, paraplegia), 21 were associated either with paresthesia during puncture (n = 19) or with pain during injection (n = 2), suggesting nerve trauma or intraneural injection. Twelve patients who had neurologic complications after spinal anesthetics had no paresthesia during needle placement and no pain on injection. Of these 12 patients (7 with radiculopathy and 5 with cauda equina syndrome), 9 received intrathecal hyperbaric lidocaine, 5%. The incidence of neurologic injury was significantly greater after spinal anesthesia (6 +/- 1 per 10,000 cases; P < 0.05) than after each of the other types of regional procedures (1.6 +/- 0.5 per 10,000 cases for the weighted average). Seizures attributed to elevated serum levels of local anesthetics occurred in 23 patients, but none suffered a cardiac arrest. CONCLUSIONS: (1) The incidence of cardiac arrest and neurologic injury related to regional anesthesia were very low, but both were more than three SDs greater after spinal anesthesia than after other regional procedures. (2) Two thirds of the patients with neurologic deficits had either a paresthesia during needle placement or pain on injection. (3) Seventy-five percent of the neurologic deficits after nontraumatic spinal anesthesia occurred in patients who had received hyperbaric lidocaine, 5%.

Adult↗
PubMed1996

Microangiopathic hemolytic anemia complicating FK506 (tacrolimus) therapy.

We describe 3 episodes of microangiopathic hemolytic anemia (MAHA) in 2 solid organ recipients under FK506 (tacrolimus) therapy. In both cases, discontinuation of FK506 and treatment with plasma exchange, fresh frozen plasma replacement, corticosteroids, aspirin, and dipyridamole led to resolution of MAHA. In one patient, reintroduction of FK506 led to rapid recurrence of MAHA. FK506-associated MAHA is probably rare but physicians must be aware of this severe complication. In our experience and according to the literature, FK506 does not seem to cross-react with cyclosporin A (CyA), an immuno-suppressive drug already known to induce MAHA.

Adrenal Cortex Hormones↗
PubMed1996

Left ventricular function after severe trauma.

OBJECTIVE: To evaluate cardiac function at the early phase of severe trauma. DESIGN: Prospective, clinical study. SETTING: Anesthesiological Intensive Care Unit. PATIENTS: 7 consecutive patients admitted after severe trauma (ISS: 38 +/- 9, mean +/- SD), without preexisting cardiac disease. INTERVENTIONS: Each patient received midazolam and sufentanyl for sedation. Right heart catheterization (Swan-Ganz) and transesophageal echocardiography (TEE) were performed. The fractional area change (FAC) of the left ventricle was calculated within 6 h following trauma and at day 1 and day 2 in order to evaluate left ventricular function. MEASUREMENTS AND RESULTS: All of the patients had a low FAC value < 50% at day 0 (43.2 +/- 2.4%, range 39-46%), which increased significantly at day 2 (52.5 +/- 4%, range 47-59%, p = 0.001), whereas heart rate and preload (assessed by left ventricular end diastolic area and pulmonary arterial occlusion pressure) were constant and afterload, assessed by systolic blood pressure, increased significantly between day 0 and day 2 (112 +/- 21 to 145 +/- 24 mmHg, p = 0.02). CONCLUSION: The initial phase of severe trauma is associated with an abnormal cardiac function, suggested by a low FAC value. This myocardial dysfunction must be taken into account for early resuscitation after severe injury.

Adult↗
PubMed1996

Transgastric, pulsed Doppler echocardiographic determination of cardiac output.

OBJECTIVE: The aim of this study was to evaluate the accuracy of cardiac output measurement with transesophageal echocardiography (TEE) using a transgastric, pulsed Doppler method in acutely ill patients. DESIGN: Cardiac output was simultaneously measured by thermodilution (TD) and a transgastric, pulsed Doppler method. SETTING: The study was carried out in a surgical intensive care unit as part of the management protocol of the patients. PATIENTS: Thirty consecutive acutely ill patients with a Swan-Ganz catheter, mechanically ventilated, sedated and with a stable hemodynamic condition were included. MEASUREMENTS: Pulsed Doppler TEE was performed using a transgastric approach in order to obtain a long axis view of the left ventricle. Cardiac output was calculated from the left ventricular outflow tract diameter, the velocity time integral of the blood flow profile and heart rate. RESULTS: One patient was excluded because of the presence of aortic regurgitation and another, because of the impossibility of obtaining a transgastric view. Twenty-eight simultaneous measurements were performed in 28 patients. A clinically acceptable correlation and agreement were found between the two methods (Doppler cardiac output = 0.889 thermodilution cardiac output +0.74 l/min, r = 0.975, p <0.0001). CONCLUSION: Transgastric pulsed Doppler measurement across the left ventricular outflow tract with TEE is a very feasible and clinically acceptable method for cardiac output measurement in acutely ill patients.

Adult↗
PubMed1996

Is lidocaine-prilocaine cream (EMLA) always useful for venous puncture in preoperative autologous blood donation?

PURPOSE: The goal of the present study was to evaluate in adults the benefit of the Eutectic Mixture of Local Anesthetics (EMLA) for preoperative autologous blood donation. METHODS: Twenty-six adult patients requiring three blood samples were studied. The pain of venipuncture was assessed by the patient using a 100 mm Visual Analogue Scale (VAS) and a four-category Verbal Rating Scale (VRS). The first puncture was performed without anaesthesia, as a "reference puncture". The second and third punctures were performed with EMLA and placebo in a double-blind cross-over randomization. For statistical analysis, the patients were allocated to two groups according to the VAS scores of the reference puncture: (Group 1) VASref < 20 mm; (Group 2) VASref > or = 20 mm. RESULTS: For the whole 26 patients, the VAS and the VRS pain scores were lower for EMLA puncture than for both the placebo and reference punctures (P < 0.05). Twenty patients had a VASref < 20 mm and six patients a VASref > or = 20 mm. In Group 1, there was no difference between EMLA and placebo for both the VAS and VRS scores. In contrast, in Group 2, the VAS score was lower for EMLA than for both the placebo and the reference punctures (respectively 11 +/- 7.1, 28.9 +/- 7.9, 29.1 +/- 6.4; P < 0.01); the VRS score was also lower for EMLA puncture than for placebo puncture (P < 0.05). CONCLUSION: In adults requiring repeated venous punctures, pain from cannulation may be evaluated at the first puncture with a Visual Analogue Scale, thus indicating or not the need for EMLA.

Adult↗
PubMed1996

Clonidine and or adrenaline decrease lignocaine plasma peak concentration after epidural injection.

Clonidine is an alpha 2-adrenoceptor agonist increasingly used in combination with lignocaine for spinal or epidural anaesthesia because of a prolonged analgesic effect. Life adrenaline, it may decrease lignocaine peak concentration (Cmax), thus leading to decreased toxicity. However, the effects of clonidine on resorption of lignocaine into the systemic circulation from the epidural space remain to be established. We studied the pharmacokinetics of lignocaine after epidural injection of lignocaine with or without clonidine, adrenaline and both drugs. Total body clearance and apparent volume of distribution were similar in the four groups, but the maximum observed concentration (Cmax) was markedly increased in the plain solution group as compared with the other groups; (plain lignocaine: 7.15 +/- 2.04 micrograms ml-1, lignocaine + adrenaline: 3.11 +/- 136 micrograms ml-1, lignocaine + clonidine: 4.48 +/- 1.26 micrograms ml-1, lignocaine + adrenaline + clonidine: 4.06 +/- 1.42 micrograms ml-1 [mean +/- s.d.]). Our results show that, clonidine decreases lignocaine Cmax to the same extent as adrenaline.

Adolescent↗
PubMed1996

Effects of carbon dioxide embolism with nitrous oxide in the inspired gas in piglets.

We have compared cardiorespiratory variables in anaesthetized piglets whose lungs were ventilated with oxygen in nitrous oxide (N2O group) or nitrogen (N group) after right ventricular carbon dioxide boluses (0.5 or 1 ml kg-1; n = 12) or slow graded injections (n = 6). Boluses affected all variables studied significantly (P < 0.05) except mean systolic arterial pressure. Significant changes in PE'CO2 (P = 0.012) and PaO2 (P = 0.048) values were observed in the N2O group. Changes in PaCO2 were related to volumes of injected carbon dioxide (P = 0.044). Boluses of 1.0 ml kg-1 induced severe circulatory collapse in two piglets in the N2O group. Slow embolization altered respiratory variables significantly (P < 0.001)). PaO2 decreased significantly in the N2O group (P < 0.0001). Mean pulmonary arterial pressure increased significantly over time (P = 0.001) and lasted longer in the N2O group (P < 0.05). Volumes and time required to induce a 50% increase in mean pulmonary arterial pressure differed significantly between groups (P < 0.05). We conclude that nitrous oxide worsened the effects of rapid and slow carbon dioxide emboli on cardiopulmonary variables. Rapid carbon dioxide embolism altered respiratory and haemodynamic variables, while slow carbon dioxide embolism changed only respiratory variables.

Anesthesia, General↗
PubMed1996

Acute bilateral carpal tunnel syndrome associated with human parvovirus B19 infection.

Human parvovirus B19 has been described as a causative agent of erythema infectiosum (a disease common in children), aplastic crisis in patients with hemolytic disorders, and arthralgias and arthritis. Joint involvement may be a prominent clinical feature of parvovirus B19 infection and may last for several weeks. We describe three cases of acute bilateral carpal tunnel syndrome associated with parvovirus B19 infection as evidenced by serological data and, in one case, by detection of parvovirus B19 DNA in blood with use of PCR.

Acute Disease↗
PubMed1996

Use of the coagulase gene typing method for detection of carriers of methicillin-resistant Staphylococcus aureus.

Strains of Staphylococcus aureus can be typed on the basis of the polymorphism of the coagulase gene. DNA fragments generated after amplification by polymerase chain reaction (PCR) of the variable region of this gene and digested with the restriction enzyme HaeIII can be compared by their restriction fragment length polymorphism (RFLP). Seventy-nine of 86 (91.8%) methicillin-resistant S. aureus (MRSA) strains isolated in various hospitals had a characteristic RFLP pattern. This pattern differed from those of 32 methicillin-susceptible S. aureus (MSSA). Only one MSSA shared with MRSA the same RFLP pattern. After modification, we applied this method to the rapid detection of MRSA from 255 nasal swabs from patients hospitalized in intensive care units. When screened by plating on Chapman agar, 55 of these samples contained MRSA, whereas 40/55 yielded the expected restriction profile after amplification by PCR. No DNA was amplified by PCR in 9/55 samples and restriction profiles were uninterpretable in six cases. When compared to culture, the positive and negative predictive values of the PCR test were 100% and 93%, respectively. The specificity was 100% and the sensitivity was 72.7%. Since control of spread of MRSA strains in hospitals is based in part on rapid isolation of carriers, this method which allows detection of epidemic MRSA in nasal swabs within a day could be helpful, though culture would still be necessary to confirm the result.

Bacterial Typing Techniques↗
PubMed1996

Prospective, randomized trial of two antiseptic solutions for prevention of central venous or arterial catheter colonization and infection in intensive care unit patients.

OBJECTIVES: To compare the efficacy of a newly available antiseptic solution (composed of 0.25% chlorhexidine gluconate, 0.025% benzalkonium chloride, and 4% benzyl alcohol), with 10% povidone iodine, on the prevention of central venous or arterial catheter colonization and infection. DESIGN: Prospective, randomized clinical trial. SETTING: Surgical-trauma intensive care unit (ICU) in a university hospital. PATIENTS: All patients admitted to the ICU and requiring the insertion of a central venous and/or an arterial catheter from July 1, 1992 to October 31, 1993. INTERVENTIONS: Patients were randomly assigned to one of two groups according to the antiseptic solution used for insertion and catheter care. The same solution was used for skin disinfection from the time of catheter insertion to the time of removal of each catheter. MEASUREMENTS AND MAIN RESULTS: Catheter distal tips were quantitatively cultured when catheters were no longer necessary, if there was a suspicion of catheter-related infection, and routinely after 7 days of use for arterial catheters, or after 15 days of use for central venous catheters. The rate of significant catheter colonization (i.e., > or = 10(3) colony-forming units [cfu]/mL by quantitative culture), and catheter-related sepsis (as defined by sepsis abating following catheter removal per 1,000 catheter-days), were significantly lower in the chlorhexidine group (12 vs. 31 [relative risk 0.4, 95% confidence interval 0.1 to 0.9, p < .01] and 6 vs. 16 [relative risk 0.4, 95% confidence interval 0.1 to 1, p = 0.5], respectively). The rate of central venous catheter colonization and central venous catheter-related sepsis per 1,000 catheter-days were also significantly lower in the chlorhexidine group (8 vs. 31 [relative risk 0.3, 95% confidence interval 0.1 to 1, p = .03] and 5 vs. 19 [relative risk 0.3, 95% confidence interval 0.1 to 1, p = .02], respectively). Finally, the rate of arterial catheter colonization per 1,000 catheter-days was significantly lower in the chlorhexidine group (15 vs. 32 [relative risk 0.5, 95% confidence interval 0.1 to 1, p = .05]), whereas the rate of arterial catheter-related sepsis per 1,000 catheter-days was similar for the two study groups (8 in the chlorhexidine group vs. 10 in the povidone iodine group [relative risk 0.8, 95% confidence interval 0.1 to 2.2, p = .6]). The 0.25% chlorhexidine solution was superior to the 10% povidone iodine solution in preventing catheter colonizations and catheter-related sepsis due to Gram-positive bacteria (5 vs. 20 [p < .001], and 2 vs. 10 [p < .001], respectively), whereas the activity of the 0.25% chlorhexidine solution was nonsignificantly superior in preventing Gram-negative infections (7 vs. 4 [p = .5], and 4 vs. 2 [p = .8], respectively). CONCLUSIONS: The 4% alcohol-based solution of 0.25% chlorhexidine gluconate and 0.025% benzalkonium chloride was more effective than 10% povidone iodine for insertion site care of short-term central venous and arterial catheters. This effect appeared related to a more efficacious prevention of infections with Gram-positive bacteria.

Adult↗
PubMed1996

Effect of lignocaine in myocardial contusion: an experiment on rabbit isolated heart.

1. The reported incidence of myocardial contusion after blunt chest trauma varies from 16 to 76%. Of these patients, about 6% present a severe, life threatening contusion. We used an isolated heart preparation to examine the effect of lignocaine on myocardial performance after contusion. 2. Thirty hearts obtained from male New Zealand rabbits were perfused at constant flow according to the Langendorff technique and were divided into four groups. The following parameters were measured at frequent intervals for 60 min: mean coronary perfusion pressure (CPP), left ventricular diastolic pressure (LVDP), developed pressure (DP), dP/dtmax, dP/dtmin. 3. Group 1 (n = 6) served as control, group 2 (n = 7) received lignocaine for 20 min (15 microM for the first 10 min and 30 microM for the following 10 min), group 3 (n = 9) had a contusion leading to a 30-50% decrease in dP/dtmax and group 4 (n = 8) had the contusion and the lignocaine infusion was started 10 min after the contusion and stopped after 30 min. Lignocaine concentration was measured in the effluent. 4. Lignocaine alone moderately decreased contractility in group 2. In group 3, after contusion, DP, dP/ dtmax, and dP/dtmin were markedly decreased during the 60 min recording period. In group 4, lignocaine infusion rapidly restored contractility. DP, dP/dtmax and dP/dtmin returned towards their basal values. This improvement of contractility remained stable, even after lignocaine infusion was discontinued. 5. In our rabbit isolated heart preparation, lignocaine at a low therapeutic concentration was able to restore contractility after contusion. These results need to be confirmed by other studies but this may lead to promising therapeutic intervention.

Analysis of Variance↗
PubMed1996

Influence of experimental rat model of multiple organ dysfunction on cefepime and amikacin pharmacokinetics.

We adapted an experimental model of multiple organ dysfunction to study the alterations it induces in the pharmacology of cefepime and amikacin. The half-lives of both antibiotics were significantly prolonged because of nonsignificant enhancement of the volume of distribution and reduced renal elimination. In the presence of multiple organ dysfunction, the concentration of each antibiotic in the lungs, compared with that in the lungs of healthy controls, was significantly decreased, despite similar concentrations in plasma, indicating that the application of a standard antibiotic concentration in plasma could lead to underdosage in tissues during the initial days of therapy.

Amikacin↗
PubMed1996

Assessment of gastric mucosal perfusion during simulated hypovolemia in healthy volunteers.

We described here an original device for laser Doppler (LD) flowmetry measurements of gastric mucosal perfusion, which was used here in healthy volunteers. A modified nasogastric tube containing the LD probe was inserted. Aspiration via a catheter, fixed in parallel to the probe, held the probe against the gastric wall. This new device was used to assess gastric mucosal perfusion in seven volunteers during simulated hypovolemia induced by lower body negative pressure (LBNP) application. The LBNP consisted of three successive levels of depression (-10, -20, and -30 mm Hg). Although mean arterial pressure remained unchanged during negative pressure application, there was a significant decrease in cardiac output (transthoracic electrical impedance) at each stage of LBNP. In contrast, gastric mucosal perfusion decreased significantly only at higher level of sympathetic stimulation corresponding to unloading of both cardiopulmonary and arterial baroreflexes (-30 mm Hg). It may be hypothetized that local vascular mechanisms exist to maintain gastric mucosal perfusion during moderate sympathetic stimulation induced by selective unloading of cardiopulmonary receptors. In the healthy volunteers studied, we found that LD flowmetry is a valuable tool to evaluate gastric mucosal perfusion when the probe is maintained in a constant position by the technique described here.

Adult↗