Search PubMed⌕ Search

Biomedical subjects

K Samii

Publications and source records attributed to K Samii.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1996

Binding of bupivacaine to human serum proteins, isolated albumin and isolated alpha-1-acid glycoprotein. Differences between the two enantiomers are partly due to cooperativity.

Binding parameters of R(+)- and S(-)-bupivacaine were determined for human serum proteins, human alpha-1-acid glycoprotein (AAG) and human serum albumin (HSA), using ultrafiltration. Binding parameters were estimated according to the Scatchard model of the law of mass action using nonlinear regression. A sigmoid (cooperativity) term was added when needed. Both enantiomers exhibited a two site binding profile for human serum and for a solution containing AAG and HSA at physiological concentrations. At concentrations lower than 40 microM (concentrations encountered in clinical situations), the low capacity, high affinity apparent site was predominant and S(-)-bupivacaine exhibited a higher free fraction than R(+)-bupivacaine. At concentrations higher than 60 microM, the opposite situation was observed and the S(-) enantiomer showed much higher binding to AAG than the R(+) enantiomer. Two cooperativity phenomena occurred. Negative cooperativity was observed when AAG and HSA were combined in the same solution. S(-) and R(+) enantiomers exhibited different behavior toward purified AAG and HSA due in part to complex allosteric cooperativity (positive or negative depending on the ligand/protein ratio). In conclusion, we observed stereoselective binding of bupivacaine to AAG and HSA. Moreover, cooperativity occurred, and the behavior of the two enantiomers showed marked differences in this respect.

Adult↗
PubMed1996

[Significance of organ donor characteristics in renal function at 1 month: reflection on the allocation of renal transplant].

In a series of 731 kidneys taken from brain-dead donors for renal transplantation, 652 were grafted, and the renal function at 1 month is known for 490 of them. The results show that some donor-related factors influence the outcome of the transplant. In particular, haemodynamic instability refractory to medical treatment is responsible for a 50 mumol increase of serum creatinine one month after transplantation and the use of UW solution during organ collection is responsible for an improvement of serum creatinine compared to other preservation solutions. Haemodynamic instability is a criterion which must be added to those already demonstrated in donors, such as the cause of death, age and sex. The authors propose that donor-related factors be taken into account in the allocation of organs in the same way as immunological factors which, at the present time, constitute the only criterion for kidney allocation.

Adolescent↗
PubMed1995

Contribution of bronchoalveolar lavage to the diagnosis of posttraumatic pulmonary fat embolism.

OBJECTIVE: To verify whether the determination of the percentage of cells recovered by bronchoalveolar lavage and containing fat inclusions is a useful diagnostic tool of posttraumatic pulmonary fat embolism. DESIGN: Prospective study. SETTING: Surgical Intensive Care Units in two university hospitals. PATIENTS: 56 successive trauma patients needing prolonged postinjury mechanical ventilation, including 4 with clinical definite fat embolism syndrome, 5 in whom the diagnosis had been clinically suspected but was impossible to confirm or exclude before bronchoscopy, and 47 with no clinical evidence of the syndrome. Control groups included 8 patients without previous trauma who developed ARDS and 6 healthy surgical patients. METHODS: Bronchoalveolar lavage was performed within the first post-traumatic 3 days in trauma patients, at the beginning of the pulmonary disease in non trauma ARDS patients and just after anesthesic induction in healthy ortopedic patients. The magnitude of lipid content in alveolar cells was compared with the clinical pattern of the pulmonary fat embolism syndrome retrospectively evaluated at the seventh day postinjury in trauma patients. RESULTS: All the patients with definite fat embolism syndrome had more than 70% of lavage cells containing fat droplets. The group of patients in whom the diagnosis of the fat embolism syndrome was suspected had percentages of fat cells above 30% in 4 out of 5 patients. A percentage of fat cells above 30% was only observed in 7 out of the 47 patients without clinical evidence of the syndrome. The percentage varied between 0% to 35% in the group of non trauma ARDS patients and between 0 to 5% in healthy surgical patients. CONCLUSION: Lipid inclusions in alveolar cells are common during traumatic and non-traumatic respiratory failure. Determination of the percentage of cells recovered by bronchoalveolar lavage and containing fat droplets may contribute to the diagnosis of the fat embolism syndrome in mechanically-ventilated trauma patients with respiratory failure provided that the significant threshold would be 30%.

Adult↗
PubMed1995

Role of systemic inflammatory response syndrome and infection in the occurrence of early multiple organ dysfunction syndrome following severe trauma.

OBJECTIVE: To evaluate the role of infection and systemic inflammatory response syndrome (SIRS) on the occurrence of early posttraumatic MODS. DESIGN: Retrospective study. SETTING: University Teaching Hospital ICU. PATIENTS: 163 consecutive patients hospitalized for more than 48 hours following severe trauma. MEASUREMENTS AND MAIN RESULTS: The patients were classified into two groups in respect to the existence of MODS at day 2. There was 27 patients in the MODS group and 136 patients in the no MODS group. The two groups were similar with respect to age, sex ratio and Simplified Acute Physiology Score. The MODS group had a higher mortality (52 versus 7%), Injury Severity Score (45 +/- 14 versus 31 +/- 13), hypovolemic shock rate (74 versus 30%), massive volume replacement rate (59 versus 6%) and SIRS rate (81 versus 54%) than the no MODS group (P < 0.05). The rate of infection was similarly low in the MODS and no MODS group (4 versus 6% respectively). CONCLUSION: Early MODS is often associated with hypotension and massive volume administration but very rarely with infection, despite the high rate of SIRS.

Adult↗
PubMed1995

Can immediate opioid requirements in the post-anaesthesia care unit be used to determine analgesic requirements on the ward?

The aim of this prospective study was to evaluate the efficacy of two dosage regimens of (i.m.) morphine calculated from an initial (i.v.) titrated dose in the early postoperative period. Seventy ASA I-III patients who underwent general anaesthesia (GA) (n = 58), regional anaesthesia (RA) (n = 10) or GA+RA (n = 2) for orthopaedic (n = 54), urological (n = 11) or abdominal surgery (n = 5) received i.v. titrated morphine in the post-anaesthesia care unit (PACU). Titration consisted of 3 mg morphine i.v. every ten minutes until patients had a visual analogue pain scale (VAS) < 3, without marked sedation. Seventeen patients did not complain at all or had good analgesia with an initial i.v. dose < or = 6 mg of morphine followed by paracetamol only. Patients who needed more than 6 mg i.v.morphine were randomly assigned to a "high-dose" or a "low-dose" group and received a systematic i.m. morphine regimen calculated from the initial titrated dose. Pain was assessed by VAS before each i.m. injection and the next morning. One patient had respiratory depression and one marked sedation in the PACU. These patients were excluded from the rest of the study. Only 16 patients were excluded from the rest of the study. Only 16 patients had a VAS > 3 at least once during the study period and only three needed rescue analgesia which was available on request. We conclude that a systematic i.m. morphine regimen adapted from an initial i.v. titration in the PACU provides efficacious and relatively inexpensive postoperative analgesia, applicable to a great majority of patients.

Adolescent↗
PubMed1995

Influence of timing on the analgesic effect of intravenous ketorolac after orthopedic surgery.

This study evaluated the pre-emptive analgesic effect of intravenous (i.v.) ketorolac (KET) for total hip replacement (THR). Sixty patients who underwent surgery for THR under general anesthesia were randomly allocated to 3 groups. Two i.v. injections were administered: one before induction and one after surgery. The patients were studied prospectively in a double-blind manner. The control group (CONT; n = 20) received 2 ml of normal saline (NS) for both injections. The pre-operative KET group (PRE; n = 20) received 60 mg of KET and then 2 ml of NS. The postoperative KET group (POST; n = 20) received 2 ml of NS and then 60 mg of KET. General anesthesia was standardized with a intra-operative cumulated dose of fentanyl limited to 4 micrograms/kg. In the recovery room (RR), pain was controlled with an i.v. tritration of morphine; thereafter, on the surgical ward, patients used a patient-controlled analgesia (PCA) pump (Abbott). Pain was evaluated with a visual analogue scale (VAS) at rest and movement in the RR, then every hour for 6 h and every 6 h for 5 days. The side effects monitored were: sedation, respiratory depression, nausea, perioperative bleeding. The patients and surgery were similar for the 3 groups. Upon arrival in the RR, VAS scores taken at rest and at movement were lower for the PRE group than for the CONT and POST groups. Otherwise, VAS scores were similar in all 3 groups. The cumulative dose of morphine in the PRE group was lower than that for the CONT and POST groups from 0 to 6 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Limited usefulness of urinary dipsticks to screen out catheter-associated bacteriuria in ICU patients.

The use of urinary dipsticks to screen out sterile urine specimens was investigated in catheterized ICU patients. During a three-month period, each urine sample quantitatively cultured was concurrently tested at the bedside with a dipstick. A total of 102 urine samples taken from 43 patients were analysed. Thirty-eight of them showed bacterial or yeast growths (incidence rate, 37%). The negative predictive value of the leukocyte esterase pad and/or the nitrate test pad to screen out sterile urine samples was 81%, indicating that dipsticks cannot routinely be proposed to select catheterized ICU patients for quantitative culture of urine.

Bacteria↗
PubMed1995

[Midazolam versus placebo before spinal anesthesia].

The goal of this randomized, double blind and multicentric study was to compare the effects of midazolam (M) and placebo (P) administered by titration before puncture for spinal anaesthesia on the comfort of 211 patients scheduled for elective surgery after oral premedication with hydroxyzine. The administered dose of midazolam was 3.4 +/- 1.3 mg (mean +/- SD). Anxiety was nil in 92% of the patients of the M group and in 64% of the patients of the P group (p < 0.001) and memorization of the pain of the puncture was reported in 34% of the patients of the M group and in 66% of the patients of the P group (p < 0.001). However cooperation of the patient and easiness of the puncture were similar in both groups. In conclusion titrated sedation with midazolam before puncture for spinal anaesthesia increases the comfort of the patient.

Adjuvants, Anesthesia↗
PubMed1994

Heterogeneous regional vascular responses to simulated transient hypovolemia in man.

OBJECTIVE: To describe the evolution of systemic and regional blood flows during and after hypovolemia in humans. DESIGN: Simulation of hypovolemia by a prolonged application of lower body negative pressure (LBNP). SETTING: Laboratory of Clinical Research, Surgical Intensive Care Unit of an University Hospital. PARTICIPANTS: 8 healthy male volunteers. INTERVENTIONS: 3 successive and increasing 15 min-levels of LBNP were followed by a progressive return (10 min) to atmospheric pressure, then a 60 min-recovery period. MEASUREMENTS AND MAIN RESULTS: Simulated hypovolemia induced a parallel one-third decrease in cardiac output (bioimpedance), musculocutaneous (venous plethysmography) and splanchnic (ICG clearance) blood flows. Adrenergic-mediated peripheral vasoconstriction prevented any change in mean arterial pressure. The decrease in renal blood flow (PAH clearance) was limited, glomerular filtration rate (inulin clearance) unchanged and thus filtration fraction increased. All the cardiovascular and biological variables returned to pre-LBNP values during the recovery period except for splanchnic blood flow which remained below control values 60 min after the return to atmospheric pressure. CONCLUSIONS: Since a sustained splanchnic vasoconstriction follows a transient normotensive hypovolemia in healthy men despite adequate treatment considering arterial pressure and cardiac output, the therapeutic goals of fluid resuscitation after hypovolemic shock might be revisited and a supranormal value of cardiac output proposed.

Adult↗
PubMed1994

Are pulse oximetry and end-tidal carbon dioxide tension monitoring reliable during laparoscopic surgery?

Cardiorespiratory changes induced by pneumoperitoneum and head-up tilt may generate alveolar ventilation to perfusion ratio changes and increased systemic vascular resistances. The reliability of end-tidal carbon dioxide tension and pulse oximetry in predicting arterial carbon dioxide partial pressure and arterial oxygen saturation may therefore be affected. The 35 ASA 1-2 patients in this study comprised 12 men and 23 women aged 48 (SD 17) years and weighing 71 (SD 14) kg. Twenty-nine were to undergo upper abdominal laparoscopy for cholecystectomy and six hyperselective vagotomy. Intra-abdominal pressure was 1.7 (SD 0.9) kPa and head-up tilt was 5.6 (SD 4.2) degrees. After abdominal insuflation, arterial carbon dioxide partial pressure significantly increased (p < 0.05). However, the arterial carbon dioxide partial pressure-end-tidal carbon dioxide partial pressure gradient remained constant throughout surgery. This gradient was highly correlated with arterial carbon dioxide partial pressure (p < 0.0001), but was not correlated with elapsed time, intra-abdominal pressure or head-up tilt. Arterial oxygen saturation was always greater than 95% in all patients and the arterial oxygen saturation-pulse oximetric saturation gradient was always less than or equal to +4%. In conclusion, end-tidal carbon dioxide partial pressure and pulse oximetric saturation allow reliable monitoring of arterial carbon dioxide partial pressure and arterial oxygen saturation in the absence of pre-existing cardiopulmonary disease and/or acute peroperative disturbance.

Adult↗
PubMed1994

[Cardiorespiratory management of severe injured patients in intensive care units].

Late mortality of severely injured patients could be prevented by the quality of early cardiorespiratory management. Indeed traumatized patients with high risk of multiple organ failure (according to age, ISS, amount of blood transfused, and/or metabolic acidosis) need a pulmonary artery catheterization as soon as possible (postdefinitive phase: during the surgical period or at the admission in the ICU). Such a procedure allows the intensivist to determine therapeutic goals in term of O2 delivery (DO2) and O2 uptake (VO2) in front of a frequent increased peripheral O2 demand, These goals (usually DO2 > or = 600 ml.min-1m-2 and VO2 > or = 150 ml.min-1.m-2) may be reached by the combination of prolonged mechanical ventilation (adapted to the pulmonary status), subnormal O2 carrying capacity (hematocrite between 30 and 35% in the absence of persistent bleeding), and increased cardiac output through an additional volume loading (without an excessive positive cumulated fluid balance on the second posttraumatic day) and the early administration of inotropic drugs (dobutamine). Reaching these goals usually permits a 61% reduction in the posttraumatic incidence of organ failure.

Critical Care↗
PubMed1993

[The real risks of locoregional anesthesia].

Regional anaesthesia involves its own risks of which five main categories appear to stand out: 1. Excessive indications, especially of epidural anaesthesia instead of nerve blocks or general anaesthesia. 2. Delayed use of vasopressive amines after excessive fluid infusion. 3. Toxicity of local drugs which can be largely avoided by slow injection. 4. Neurological complications of traumatic punctures, such as nerve root or dura mater injury. 5. Excessive complementary sedation.

Anesthesia, Conduction↗