PubMed Health⌕ Search

Biomedical subjects

B Allaouchiche

Publications and source records attributed to B Allaouchiche.

At least 37 records · Page 2Linked to original sources
PubMed2002

Noise in the postanaesthesia care unit.

BACKGROUND: Although the postanaesthesia care unit (PACU) can be noisy, the effect of noise on patients recovering from anaesthesia is unknown. We studied the sources and intensity of noise in the PACU and assessed its effect on patients' comfort. METHODS: We measured noise in a five-bed PACU with a sound level meter. Noise levels were obtained using an A-weighted setting (dBA) and peak sound using a linear scale (dBL). Leq (average noise level at 5-s intervals), maximum Leq (LeqMax), minimum Leq (LeqMin) and noise peaks (Lpc) were calculated. During recording, an independent observer noted the origin of sounds from alarms and noise above 65 dB intensity (P65dB). Two hours after leaving the PACU, patients were asked about their experience and to rank their complaints on a visual analogue scale (VAS) using unstructured and structured questionnaires. RESULTS: We made 20,187 measurements over 1678 min. The mean Leq, LeqMax and LeqMin were 67.1 (SD 5.0), 75.7 (4.8) and 48.6 (4.1) dBA respectively. The mean Lpc was 126.2 (4.3) dBL. Five per cent of the noise was at a level above 65 dBA. Staff conversation caused 56% of sounds greater than 65 dB and other noise sources (alarm, telephone, nursing care) were each less than 10% of these sounds. Five patients reported disturbance from noise. There was no significant difference in Leq measured for patients who found the PACU noisy and those who did not [59.5 (3.1) and 59.4 (2.4) dBA respectively]. Stepwise multiple logistic regression indicated that only pain was associated with discomfort. CONCLUSIONS: Even though sound in the PACU exceeded the internationally recommended intensity (40 dBA), it did not cause discomfort. Conversation was the most common cause of excess noise.

Adult↗
PubMed2002

Alveolar and serum oxidative stress in ventilator-associated pneumonia.

BACKGROUND: In several lung diseases, oxidative stress can be demonstrated. This has not been shown in patients with ventilator-associated pneumonia (VAP). METHODS: We studied plasma and bronchoalveolar lavage (BAL) samples for markers of oxidative stress, taken from patients with VAP. Seventy-eight patients likely to have VAP and 10 patients who were not suspected of having VAP were studied prospectively. A diagnosis of VAP was based on a positive quantitative mini-lavage culture of > or = 10(3) colony-forming units per ml. Blood and BAL samples were collected and analysed for thiobarbituric acid reactant substances (TBARS) and antioxidant activity. RESULTS: Plasma and alveolar TBARS increased significantly in patients who developed VAP compared with those who did not, by 43% and 259% respectively. Red cells and alveolar glutathione peroxidase concentrations (antioxidant activity) were lower in those with VAP compared with the non-VAP group, by 43% and 68% respectively. No significant differences were found for serum superoxide dismutase activity. Significant differences were found for alveolar glutathione peroxidase concentrations over time in the VAP group. No significant differences between survivors and non-survivors were found in the blood or BAL assays, in patients with VAP. CONCLUSIONS: VAP is associated with evidence of early oxidative stress in the alveolar fluid and blood.

Adult↗
PubMed2002

Penetration of piperacillin/tazobactam (4 g/500 mg) into synovial tissue.

The degree of penetration of an antibiotic into the infected site is an important criterion for therapeutic success. This is particularly true for bone and joint infections. The association of piperacillin and tazobactam has been widely used in the treatment of serious infections including bone infections, but no study has been devoted to the subject of its diffusion into synovial tissue. Our objective was to quantify piperacillin/tazobactam synovial tissue penetration and to estimate the efficacy of the association against the microorganisms usually encountered in joint infections. In an open-label study, 6 subjects with similar age, weight, height and creatinine clearance, who were undergoing elective total hip replacement, received a single, parenteral, 4 g/500 mg dose of piperacillin/tazobactam. Plasma and synovial tissue samples were collected and analyzed by a validated HPLC method. The mean concentrations of piperacillin and tazobactam 1.5 h after the initiation of infusion were 69.9 +/- 4.9 microg/mL and 7.7 +/- 0.3 microg/mL, respectively, in plasma and 37.1 +/- 2.1 microg/g and 2.8 +/- 0.4 microg/g, respectively, in synovial tissue. The synovial tissue/plasma ratios were 0.5 +/- 0.0 for piperacillin and 0.4 +/- 0.0 for tazobactam. The piperacillin/tazobactam ratios were 9.1:1 in plasma and 13.5:1 in synovial tissue. The concentrations achieved in synovial tissue are above the MICs of most of the susceptible pathogens usually involved in joint infections, which suggests that the piperacillin/tazobactam combination should be effective in the treatment of most joint infections caused by susceptible microorganisms.

Aged↗
PubMed2002

Pharmacokinetic parameters of ciprofloxacin (500 mg/5 mL) oral suspension in critically ill patients with severe bacterial pneumonia: a comparison of two dosages.

The authors determined the pharmacokinetic parameters of a new immediate-release ciprofloxacin suspension in tube-fed intensive care patients with bacterial pneumonia, to compare two dosage regimens: 500 mg b.i.d and 750 mg b.i.d. in this prospective clinical trial. The 20 patients were critically ill and on mechanical ventilation and enteral feeding with bacterial pneumonia. They were randomized to receive two different ciprofloxacin dosages: 500 mg b.i.d (group 1) versus 750 mg b.i.d. (group 2). Blood samples were collected from these patients after reaching steady-state and the pharmacokinetic parameters were determined. The mean (range) serum steady-state concentration at 2 h after enteral administration was: C(max 500) = 2.6 (1.2-4.3) mg/L in group 1 and C(max 750) = 3.5 (1.5-5.9) mg/L in group 2. The mean (range) calculated 12-h area under the serum concentration was high in both groups: AUC(0-12 (500)) = 24.7 (12.9-36.2) mg.h/L in group 1 and AUC(0-12 (750)) = 28.9 (18.3-47.5) mg.h/L in group 2. In conclusion, ciprofloxacin oral suspension was well absorbed via nasogastric route in intensive care patients with severe pneumonia, achieving reliable pharmacokinetic parameters for most of the pathogens and important cost reduction compared to intravenous delivery. However, with less susceptible pathogens such as Staphylococcus aureus or Pseudomonas aeruginosa, higher dosages than 750 mg b.i.d. should be given.

Administration, Oral↗
PubMed2002

Diffusion of isepamicin into cancellous and cortical bone tissue.

The degree of penetration of an antibiotic into the infection site is an important factor in its therapeutic efficacy, particularly in bone and joint infections. In the present study, we examined the bone tissue penetration of isepamicin at a dose of 15 mg/Kg, and the results were correlated to microbiologic data to estimate the clinical efficacy of isepamicin in bone infections. In this open-label, single-arm, noncomparative study, subjects of similar age, body weight, height and creatinine clearance who were undergoing elective total hip replacement received a single, parenteral 15 mg/Kg dose of isepamicin. Plasma and bone tissue samples were collected a mean 1.3 hours later and analyzed by a high-pressure liquid chromatography method. Twelve patients (3 men and 9 women; mean age, 73.5 years; mean body weight, 53.5 Kg, mean creatinine clearance, 58.5 mL/min) were enrolled. The mean +/- SD plasma concentration of isepamicin at the time of bone removal was 43.0 +/- 10.4 microg/mL. The mean +/- SD isepamicin concentrations were 11.6 +/- 7.1 microg/mL in cancellous bone tissue and 12.0 +/- 7.3 microg/mL in cortical bone tissue. The mean +/- SD ratios of isepamicin concentration in bone and plasma (bone/plasma) were 0.28 +/- 0.14 for cancellous bone tissue and 0.31 +/- 0.20 for cortical bone tissue. The concentrations achieved in both cancellous and cortical bone tissue were greater than the minimum concentrations required to inhibit the growth of 90% of strains (MIC90) of most of the susceptible pathogens commonly involved in bone infections.

Adult↗
PubMed2001

[Pulmonary diffusion of antibiotics. Critical analysis of the literature].

OBJECTIVES: Collect exhaustive data from the literature concerning the diffusion of antibiotics into lung tissue and calculate their inhibitory quotient towards the germs most frequently encountered in pulmonary infections. DATA SOURCES: Review of the literature. Data collected from the Medline database with the key words: lung, diffusion, disposition, antibiotics. Inhibitory quotients calculated from these data. RESULTS: The results were relatively similar for the different types of samples, though some differences existed between the studies. These differences were caused in particular by methodological difficulties for the tissue dosage of antibiotics. CONCLUSION: Further standardized studies, measuring in particular the antibiotic concentration in the epithelial lining fluid and in the alveolar macrophages, are necessary to obtain more reliable results in terms of inhibitory quotients. Only clinical studies, perhaps with the help of these data, could establish the real efficiency of antibiotics in lung infections.

Animals↗
PubMed2001

Influence of sepsis on sevoflurane minimum alveolar concentration in a porcine model.

Sevoflurane is widely used in anaesthetic protocols for patients undergoing surgical procedures. However, there are no reports on the influence of sepsis on minimum alveolar concentration of sevoflurane (MAC(SEV)) in animals or in humans. The aim of this study was to test the hypothesis that sepsis could alter the MAC(SEV) in a normotensive septic pig model. Twenty young, healthy pigs were used. After they had received 10 mg kg(-1) of ketamine i.m. for premedication, anaesthesia was established with propofol 3 mg kg(-1) and the trachea was intubated. Sevoflurane was used as the sole anaesthetic agent. Baseline haemodynamic recording included electrocardiography, carotid artery blood pressure and a pulmonary thermodilution catheter. Baseline MAC(SEV) in each pig was evaluated by pinching with a haemostat applied for 1 min to a rear dewclaw. MAC(SEV) was determined using incremental changes in sevoflurane concentration until purposeful movement appeared. Pigs were assigned randomly to two groups: the saline group (n = 10) received a 1-h i.v. infusion of sterile saline solution while the sepsis group (n = 10) received a 1-h i.v. infusion of live Pseudomonas aeruginosa. Epinephrine and hydroxyethylstarch were used to maintain normotensive and normovolemic haemodynamic status. In both groups, MAC(SEV) was evaluated 5 h after infusion. Significant increases in mean artery pulmonary pressure, filling, epinephrine and vascular pulmonary resistances occurred in the sepsis group. MAC(SEV) for the saline group was 2.4% [95% confidence interval (CI) 2.1-2.55%] and the MAC(SEV) for the sepsis group was 1.35% (95% CI 1.2-1.45%, P<0.05). These data indicate that MAC(SEV) is significantly decreased in this normotensive septic pig model.

Analgesics↗
PubMed2001

Influence of sepsis on minimum alveolar concentration of desflurane in a porcine model.

The effect of sepsis on the minimum alveolar concentration of desflurane (MAC(DES)) in humans and other animals has not been reported previously. The aim of this study was to test the hypothesis that sepsis might alter MAC(DES) in a normotensive septic porcine model. Twenty-four young healthy pigs were premedicated with ketamine 10 mg kg(-1 )i.m and then anaesthesia was established with propofol 3 mg kg(-1) and the trachea was intubated. Baseline MAC(DES) in each pig was evaluated by pinching with a haemostat applied for 1 min to a rear dewclaw. MAC(DES) was determined by changing desflurane concentrations stepwise until purposeful movement appeared. Pigs were randomly assigned to two groups of 12 animals: the saline group received a 1 h i.v. infusion of saline solution while the sepsis group received a 1 h i.v. infusion of live Pseudomonas aeruginosa. Epinephrine and hydroxyethylstarch were used to maintain normotensive and normovolaemic haemodynamic status. In both groups, MAC(DES) was evaluated 5 h after infusion. Significant increases in heart rate, cardiac output, mean pulmonary artery pressure and pulmonary vascular resistance occurred in the sepsis group. MAC(DES) was 9.2% (95% confidence interval (CI) 6.8-10.6%) for the saline group and 6.7% (95% CI: 4.7-10.4) for the sepsis group (P<0.05). These data indicate that MAC(DES) is significantly decreased in this normotensive hyperkinetic septic porcine model.

Anesthetics, Inhalation↗
PubMed2001

The analgesic effect of sufentanil combined with ropivacaine 0.2% for labor analgesia: a comparison of three sufentanil doses.

UNLABELLED: The combination of opioids with local anesthetics is commonly used for epidural labor analgesia. We examined whether increasing sufentanil in doses of 5, 10, and 15 microg prolonged the duration of labor analgesia produced by ropivacaine. One hundred healthy parturients in the first stage of labor who requested epidural analgesia were enrolled. Parturients were randomized to receive 12 mL ropivacaine 0.2% alone or with sufentanil 5 microg, sufentanil 10 microg, or sufentanil 15 microg. The duration of analgesia, pain score, degree of motor blockade (using a four-point Bromage scale), heart rate, blood pressure, respiratory rate, oxygen saturation, and incidence of nausea and pruritus were recorded. The mean duration of epidural analgesia was 96 +/- 32 min for patients without sufentanil, 134 +/- 27 min for Group 5 (p < 0.01 versus control), 135 +/- 33 min for Group 10 (p < 0.01 versus control), 130 +/- 33 min for Group 15 (p < 0.01 versus control) without differences among sufentanil groups. Between 30 and 90 min, the sufentanil groups (5 microg, 10 microg, and 15 microg) had lower pain scores than the control group (p < 0.01 versus control) but there were no differences among the sufentanil groups. No patient in any group had a Bromage score more than 1. No significant difference was found for opioid-related side effects. We conclude that 5-10 or 15 microg sufentanil induced a similar prolongation of analgesia when combined with ropivacaine 0.2% for initiation of labor analgesia. IMPLICATIONS: We studied the effect of adding one of three possible sufentanil doses to epidural ropivacaine 0.2% for labor analgesia. Adding sufentanil increased the duration of analgesia but there was no advantage in adding more than 5 microg of sufentanil.

Adult↗
PubMed2001

An evaluation of the Gram stain in protected bronchoalveolar lavage fluid for the early diagnosis of ventilator-associated pneumonia.

We investigated the usefulness and reliability of the Gram stain value versus quantitative cultures in the early diagnosis of ventilator-associated pneumonia (VAP) using the protected bronchoalveolar lavage (PBAL). One hundred four mechanically ventilated patients (age = 52 +/- 19; SAPS II = 38 +/- 15) with a strong suspicion of VAP were consecutively included. One hundred sixteen PBAL were performed and mini-bronchoalveolar lavage were analyzed using the Gram stain standard method and the conventional quantitative culture technique. VAP diagnosis was based on a positive quantitative culture of mini-bronchoalveolar lavage fluid (cutoff > or = 10(3) CFU/mL). A final diagnosis of VAP was established in 67 patients and there was no infection in 49 cases. Regarding detection of bacteria using the Gram stain, we found a sensitivity of 76.2%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 75.4%. There was a good agreement with the final diagnosis (kappa statistic 0.73; concordance 86.2%). The degree of qualitative agreement between Gram stain and quantitative cultures was analyzed in the VAP group: the correlation was complete in 39% (26 of 67 VAP), partial in 28% (19 of 67 VAP) and there was no correlation in 33% (22 of 67 VAP). We conclude that despite its overall "good agreement," the Gram stain is of limited use for the rapid diagnosis of VAP and unreliable for the early adaptation of empirical antimicrobial therapy when using the noninvasive PBAL procedure.

Adult↗
PubMed2001

Oxidative stress status during exposure to propofol, sevoflurane and desflurane.

UNLABELLED: We evaluated the circulating and lung oxidative status during general anesthesia established with propofol, sevoflurane, or desflurane in mechanically ventilated swine. Blood samples and bronchoalveolar lavage fluid (BAL) specimens were respectively performed via an internal jugular vein catheter and a nonbronchoscopic BAL for baseline oxidative activity measurements: malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPX). A 4-h general anesthesia was then performed in the three groups of 10 swine: the Propofol group received 8 mg x kg(-1) x h(-1) of IV propofol as the sole anesthetic; the Desflurane group received 1.0 minimum alveolar concentration of desflurane; and the Sevoflurane group received 1.0 minimum alveolar concentration of sevoflurane. We observed significantly larger levels of MDA in plasma and BAL during desflurane exposure than with the other anesthetics. We also observed smaller concentrations of circulating GPX and alveolar GPX. We found a significant decrease for MDA measurements in the plasma and the pulmonary lavage during propofol anesthesia. We also found larger values of GPX measurements in the serum and the pulmonary lavage. No significant changes were observed when animals were exposed to sevoflurane. No significant changes were found for circulating concentrations of SOD during exposure to all anesthetics. In this mechanically ventilated swine model, desflurane seemed to induce a local and systemic oxidative stress, whereas propofol and sevoflurane were more likely to have antioxidant properties. IMPLICATIONS: Superoxide is an unavoidable byproduct of oxygen metabolism that occurs in various inflammatory reactions. Inhalation of volatile anesthetics under mechanical ventilation induces an inflammatory response. We evaluated the bronchoalveolar and systemic oxidative stress in swine during exposure to propofol and newer volatile anesthetics. Desflurane induces more lipid peroxidation than do the other anesthetics.

Anesthetics, Inhalation↗
PubMed2000

Estimation of cardiac preload changes by systolic pressure variation in pigs undergoing pneumoperitoneum.

BACKGROUND: Variations in systolic pressure arterial waveform (SPV) and its component have been shown to be a reasonable indicator of left ventricular preload. Creation of a pneumoperitoneum (PMOP) by insufflation of CO2 increases intrathoracic pressure, leading to overestimation of preload as assessed by pressure methods. The purpose of this study was to compare SPV with other standard methods in anaesthetized pigs. METHODS: We measured SPV and its DeltaDown component (deltaDown), pulmonary artery occlusion pressure (PAOP) and left ventricular short-axis cross-sectional area using transthoracic echocardiography (TTE) in 7 pigs, at baseline, after 12 mmHg PMOP and after an intravascular load with 10 ml/kg hydroxylethylstarch (HES). RESULTS: PMOP increased SPV from 12.9+/-4.9 to 16.9+/-5.5 mmHg (P<0.05) and decreased pulmonary compliance, with no change in PAOP or end-diastolic area assesssed by TTE. Intravascular volume loading significantly decreased SPV from 16.9+/-5.5 to 11.2+/-4.9 mmHg and deltaDown from 9.9+/-7.1 to 5.2+/-4.5 (P<0.05), and increased PAOP and end-diastolic area. Significant correlation between changes in deltaDown and EDA was noted following HES (r=0.78, P<0.05). CONCLUSION: In anaesthetized pigs, the creation of a PMOP alters SPV, likely by decreasing lung compliance. Once PMOP is established, changes in cardiac preload could be estimated by SPV analysis.

Animals↗
PubMed2000

Metabolic acidosis and respiratory acidosis impair gastro-pyloric motility in anesthetized pigs.

UNLABELLED: Acidosis impairs smooth muscle function in various organs. However, the effects of acidosis on the gastroduodenal tract are unknown while its dysfunction has potential perioperative harmful consequences. We investigated the effects of metabolic (MA) and respiratory acidosis (RA) on upper gut motility in tracheally ventilated pigs whose anesthesia was induced with halothane and maintained with alpha-chloralose-urethane administration (IV). Increased dead space and perfusion of hydrochloric acid 1 N (150 mL over 30 min) were used to induce RA and MA, respectively. Measurements of fundic tone using an electronic barostat, antro-pyloroduodenal phasic motility with perfused manometry and antro-duodenal electric control activity by electromyography were used to evaluate gastroduodenal function. Acidosis increased the fundic tone as reflected by a decrease in barostat volumes from 275+/-83 to 194+/-88 mL for MA and from 278+/-93 to 236+/-106 mL for RA. Pyloric and duodenal basal tones were not affected by either acidosis. A decrease in pyloric contraction amplitude from 95+/-24 to 62+/-26 mm Hg during MA and from 94+/-26 to 64+/-20 mm Hg during RA was observed. Both acidosis altered antral control activity that became dysrhythmic. Acidosis could be implicated in perioperative complications, such as gastroparesis, emesis, and regurgitation of gastric contents. IMPLICATIONS: Metabolic and respiratory acidosis mainly affects gastric antral rhythms and has a major effect on fundic tone. Acidosis could be implicated in perioperative complications, such as gastroparesis, emesis, and regurgitation of gastric contents.

Acidosis↗