[About laryngeal mask: is the lowest price material the better cost-efficacy choice?]. / Comparaison de quatre masques laryngés à usage unique pour la chirurgie carcinologique du sein: une approche médico-économique.

OBJECTIVE: The main goal of this study was to achieve a medico-economic comparison between four disposable laryngeal masks (LM) (LMA-Unique™, Ambu AuraOnce™, I-Gel™ and LMA-Suprême™). STUDY DESIGN: A prospective, randomized, monocentre study. MATERIAL AND METHODS: In a center, using routinely LMA-Unique masks, scheduled breast surgery patients were allocated into four groups according to the LM model. After the induction, the modalities of use were collected, as well as the intraoperative events that required additional anesthetic equipment. The real cost of each model was calculated (cost of the mask+extra cost related to complications). Using the LMA-Unique as a reference, we performed a cost-efficacy analysis. We realized a cost-efficiency analysis putting in parallel the impact on the cost and the incidence of the events. RESULTS: A total of 178 patients were included. According to the cost-efficacy analysis, the dominant model was the Ambu AuraOnce™ (Δreal cost: -34.2%, Δevents: -30.6%). The LMA-Unique™ was dominated because of a high morbidity rate. The I-Gel™ and LMA-Suprême™ models were more efficient but more expensive (Δreal cost: +16% and +22.5% respectively). To compensate for additional costs, it would be necessary to apply a price reduction of at least 50%. CONCLUSIONS: Despite their better efficiency and safety, the latest generation laryngeal masks are still expensive in spite of a low rate of complication. These results do not take into account very rare and severe complications not met in this study in the limited size; then the economic and medical impact can influence the choice beyond the simple analysis cost-efficiency.

[Impact of anaesthesia management on post-surgical ventilation in post-anaesthesia care unit]. / Impact de la prise en charge anesthésique sur la ventilation postopératoire en salle de surveillance postinterventionnelle.

INTRODUCTION: Control of residual muscle paralysis and hypothermia reduce postoperative complications rate. Short context sensitive half life anaesthetic agents allow a better adjustment of anaesthesia depth according to surgical requirement and a safe early extubation. Using a large clinical database, impact of these three strategies was assessed on clinical criteria such as use of neostigmine in postanaesthesia care unit (PACU), temperature, sedation score at the arrival into PACU and mechanical ventilation weaning. METHODS: This is a retrospective study on two separated periods. Since 2001, clinical events are entered into the database during and after anaesthesia in the same file. Agreement of anaesthesia staff to these strategies was assessed by the proportion of patients receiving modern anaesthetic agents (desflurane, sevoflurane and remifentanil) and the use of warming devices. Clinical impact was assessed by the number of patients receiving neostigmine in PACU, sedation score and temperature at the arrival in PACU and number of patients with mechanical ventilation in PACU. RESULTS: Between the two periods (12,033 and 11,805 patients, respectively), use of sevoflurane, desflurane and remifentanil markedly increased, as well as the use of warming devices. Number of patients with neuromuscular reversal in PACU decreased from 73 to 11 and sedation score improved dramatically. Incidence of postoperative ventilation in PACU decreased from 1.1% (n=132) to 0.2% (n=30). Incidence of postoperative hypothermia was not changed during the two periods but incidence of hypothermia in the mechanically ventilated patient increased from 34.1 to 46.6%. Length of stay in PACU decreased from 122 to 114 minutes (p<0.05). DISCUSSION: Implementation of new intraoperative protocols induced major effects on postoperative clinical parameters and especially postoperative mechanical ventilation. Failure of our hypothermia prevention associated with a fast return of consciousness lead to wean from mechanical ventilation hypothermic patients. Risks of this strategy were not estimated.

[Ischaemic and pharmacologic preconditioning: desflurane reduces renal reperfusion injury in rabbits]. / Préconditionnement rénal ischémique et pharmacologique par le desflurane: une étude histologique expérimentale.

BACKGROUND: Anaesthetic preconditioning, i.e. administration of volatile agents before ischemia, is known to have protective effects on several organs, but remains uncertain on the kidney. We developed a rabbit model for acute ischaemia-reperfusion injury, and examined a possible protective effect of desflurane preconditioning on the kidney. METHODS: Forty New Zealand male rabbits, 3 months old, weighing 2-3 kg, were anaesthetized by titrated intramuscular injections of xylazine-ketamine, mechanically ventilated and monitored. They were randomly assigned into four groups: group ischaemia (I), group ischaemic preconditioning (IPC), group desflurane preconditioning (DPC), and group SHAM (S). Groups I, IPC and DPC were subjected to 45 minutes of bilateral renal ischaemia followed by 3 hours reperfusion. Group IPC was subjected to 3 x 3 minutes ischaemia, 5 minutes before the 45-minute clamping period. Group DPC was administered one MAC desflurane for 30 minutes, before a 30-minute wash-out period. Histological analysis of the cortical zone of both kidneys were blindly performed. Tubular cell damage was graded from 1 (no lesion) to 4 (>50 % cell necrosis). Pycnotic nuclei and intratubular hyaline casts were counted on each section. RESULTS: DPC (1[1-2]) and S (1[1-1]) groups displayed lower histological grades than group 1(4[3-4]) (p<0.01); IPC had a grade of 3 (2-3), I and IPC groups had higher scores of pycnotic nuclei and hyaline casts than DPC and S. CONCLUSION: Desflurane preconditioning was associated with a diminution of tubular cell damage. Ischaemic preconditioning did not show a significant renal protective effect.

[Which settings to optimize anaesthetics delivery: fresh gas flow or delivered fraction?]. / Optimisation de l'administration des agents anesthésiques inhalés : débit de gaz frais ou fraction délivrée ?

INTRODUCTION: During volatile closed-circuit anaesthesia, a chosen end-tidal fraction (Fet) could be achieved by setting either delivered fraction (Fd) or fresh gas flow (FGF). This study compared the efficacy of both strategies and the resulting drug consumption. PATIENTS AND METHODS: Sixty patients (10 per group) were administered, after intravenous induction and intubation, desflurane, sevoflurane or isoflurane+50% N(2)O, to achieve a target Fet equal to one minimal alveolar concentration (MAC), according to one strategy: high FGF (HFGF) Fd fixed 20% above target Fet, FGF 10 l/min then 1l/min after achieving the target, FGF opened at 10 l/min at the end of surgery; low FGF (LFGF) FGF fixed at 1l/min, Fd at the maximal value on the vaporizer, then set at target Fet+20% after achieving Fet equal to one MAC, FGF maintained at 1l/min until extubation. RESULTS: The target Fet was achieved in all patients in LFGF within 2.1+/-0.9 min followed by 15% (isoflurane) to 57% (sevoflurane) overdosage, but only in nine patients out of 30 after 10 min in HFGF. Delays were similar between desflurane and sevoflurane. Volatile consumption was decreased by 75% in LFGF. Fifty percent decrement and extubation times were shorter with HFGF, similarly for the three agents. CONCLUSION: Massive overdosage of Fd is the fastest, reproducible and cheapest strategy to achieve (or to increase) a chosen Fet. High FGF is the fastest to decrease Fet during or at the end of anaesthesia. Combining Fd and FGF adjustments in order to maximize Fd/Fet gradients overwrites pharmacokinetic differences between desflurane and sevoflurane and reduces differences with isoflurane. Automatic adjustments based on volatile pharmacockinetics would be helpful to achieve a target Fet without overdosage.

[Implementation of quality management in medical departments of a teaching hospital: accelerators and inhibitors]. / Implantation d'une démarche qualité dans les services médicaux d'un hôpital universitaire : facteurs d'accélération et de frein.

BACKGROUND: The aims of this study were to assess the level of implementation of continuous quality management program and to identify the factors associated with its failure in the medical departments of a teaching hospital. METHODS: Semi-directive interviews were conducted with 52 hospitalists, including 16 department heads and 36 staff members in charge of quality management, in 30 medical departments that implemented a continuous quality management program from 1998 to 2002. The interviews were analyzed using a manual thematic method and a computerized semantic method. RESULTS: At the study endpoint (i.e., 2003), the continuous quality management program was still working in six departments and was stopped in 24 departments. The professionals complied with the model of intervention based on the identification and the resolution of department problems by multiprofessional working groups. The main external factors associated with the failure of the continuous quality management program included shortage in staff and the lack of time to devote to this activity. In addition, professionals cited the defect of commitment by the top management, the lack of acknowledgment of their efforts, and the hospital accreditation as factors with negative impact on staff motivation. The main internal factors associated with the failure of the continuous quality management program were related to the leadership in quality management. The personal involvement of the department head played a key role in the continuation of the quality management program. Most of the staff regretted the lack of involvement of the physicians and stated that methodological support was needed. CONCLUSION: The implementation of quality management in the medical departments remains difficult in the absence of institutional support. The leadership within the department plays a major role in the continuation of the process.

[Evaluation of the feasibility of a healthcare network for the management of severely head-injured patients]. / Evaluation de la pertinence d'un projet de réseau de santé prenant en charge les urgences neurotraumatiques graves.

The aim of the study was to realise a strategic analysis of the feasibility of implementing a health care network for the management of severely head-injured patients in the Alpine region. We conducted face-to-face semi-structured interviews. Manual and computerized analysis of interviews was realized. Textual analysis was performed using the ALCESTE software package. A strategic analysis according to Crozier and Friedberg was performed. Eighteen interviews were realised: 13 physicians, 3 hospital directors and 2 head nurses. We identified 5 types of problems in the management of severely head-injured patients: the lack of human and material resources (33.1% of the variance), problems of communication (12.2%) and surgical competence (24.00), trajectory of care influenced by the concurrence between hospitals (18.0%) and relationship between professionals (12.6%). The stabilisation of process of cooperation was expected by all the professionals and a health care network seemed to be adapted as a coordination tool. Its implementation needed to take into account 3 individual representations: the will for collaboration--cooperation (23.3%), the negotiation (48.4%) and the contracts of the cooperation (28.3%). This study confirms that actors noted the need for improving the management of severely head-injured patients in the Alpine region. However, negotiation to express and solve controversies appears being a precondition to prevent from the blocking of the network by resistances to change.

Effects of gamma radiation on Brugia malayi infective larvae and their intracellular Wolbachia bacteria.

Prior studies have shown that irradiated filarial larvae are developmentally stunted but capable of inducing partial immunity to filariasis in animals. The mechanisms for these effects are poorly understood. Recent studies suggest that intracellular Wolbachia bacteria are necessary for the normal development, reproduction and survival of filarial nematodes. The purpose of this study was to examine the effects of irradiation on Wolbachia in Brugia malayi infective larvae (L3) and on L3 development. The L3 were exposed to 0, 25, 35, 45, 55, 65 or 75 krad of gamma irradiation from a (137) Cesium source and cultured in vitro at 37 degrees C in NCTC/IMDM medium with 10% FCS for 12 days. Irradiation prevented molting of L3 to the L4 stage in a dose-dependent manner. Electron microscopy studies showed that irradiation damaged Wolbachia (25 krad) or cleared them from worm tissues (45 krad). In addition, majority of the irradiated L3s failed to develop the L4 cuticle. Real-time PCR studies showed that irradiation reduced Wolbachia DNA in worm tissues. Parallel in vivo studies confirmed decreased development of irradiated L3 in jirds, with associated effects on Wolbachia. Jirds injected s.c with normal L3 developed antibodies to Wolbachia surface protein (wsp) shortly after the onset of microfilarial patency. In contrast, jirds injected with irradiated L3 did not develop microfilaremia or antibodies to wsp. Additional studies are needed to test the hypothesis that irradiation retards growth and development of filarial L3 by killing Wolbachia.

Filariasis elimination in Egypt: impact of low microfilaraemics as sources of infection for mosquitoes.

The elimination strategy for lymphatic filariasis aims at reducing blood microfilaraemia to levels at which vector transmission cannot be sustained. We aimed to determine whether patients with pre-treatment low or ultra-low microfilaria (MF) counts could be a reservoir of infection after mass drug administration (MDA) with a combined regimen. Laboratory-reared mosquitoes were fed on 30 volunteers after 2 rounds of MDA. Microfilaria uptake, infectivity rates and number of Wuchereria bancrofti L3 per mosquito were assessed. One year after MDA-1, 6 subjects transmitted MF, but up to 9 months after MDA-2 transmission failed. Six months after MDA-2 > 90% had clear MF smears and either failed to transmit MF or transmitted MF that did not develop to L3. We conclude that the transmission cycle is seriously weakened after MDA-2.

Filariasis elimination in Egypt: impact of low microfilaraemics as sources of infection for mosquitoes

The elimination strategy for lymphatic filariasis aims at reducing blood microfilaraemia to levels at which vector transmission cannot be sustained. We aimed to determine whether patients with pre-treatment low or ultra-low microfilaria [MF] counts could be a reservoir of infection after mass drug administration [MDA] with a combined regimen. Laboratory-reared mosquitoes were fed on 30 volunteers after 2 rounds of MDA. Microfilaria uptake, infectivity rates and number of Wuchereria bancrofti L3 per mosquito were assessed. One year after MDA-1, 6 subjects transmitted MF, but up to 9 months after MDA-2 transmission failed. Six months after MDA-2 > 90% had clear MF smears and either failed to transmit MF or transmitted MF that did not develop to L3. We conclude that the transmission cycle is seriously weakened after MDA-2

Evaluation of a rapid-format antibody test and the tuberculin skin test for diagnosis of tuberculosis in two contrasting endemic settings.

OBJECTIVE AND SETTING: We evaluated a rapid-format antibody card test and the tuberculin skin test for diagnosis of active tuberculosis (TB) in high (Cairo, Egypt) and low (St. Louis, USA) prevalence areas. DESIGN: Prospective study of hospitalized TB patients and controls with other chest diseases. RESULTS: Test performance varied significantly in the two study sites. The antibody test detected 87% of 71 smear-positive pulmonary TB cases (86% of smear-negative pulmonary cases and 48% of TB meningitis cases) in Egypt; specificity was 82%. The tuberculin test was highly sensitive in Egypt in subjects with pulmonary TB (100%) but not in those with meningitis (23%); specificity was 70%. The sensitivity and specificity of the antibody test in St. Louis were 29% and 79%, respectively; 50% of St. Louis TB cases and 15% of controls had positive tuberculin tests. CONCLUSIONS: This convenient antibody card test may have value for diagnosis of patients suspected of having TB in high prevalence areas like Egypt. However, the specificity of the test is too low for it to be useful as a screening test. Our results suggest that neither the antibody test nor the tuberculin test have much diagnostic utility in low prevalence settings like St. Louis.

Long-term efficacy of single-dose combinations of albendazole, ivermectin and diethylcarbamazine for the treatment of bancroftian filariasis.

In a 'blinded' trial (in Sri Lanka, 1996-98) of 47 male asymptomatic microfilaraemic subjects with Wuchereria bancrofti infection, the safety, tolerability and filaricidal efficacy of 3 single-dose combination regimens were compared: albendazole 400 mg with ivermectin 200 micrograms/kg, albendazole 400 mg with diethylcarbamazine citrate (DEC) 6 mg/kg or albendazole 600 mg with ivermectin 400 micrograms/kg. Treated subjects were followed-up for 24 months. This represents the first long-term study using combinations of albendazole with DEC or ivermectin in the above doses against bancroftian filariasis. All subjects had pre-treatment microfilaria (mf) counts over 100/mL. All 3 treatments significantly reduced mf counts, with the albendazole-DEC-treated group showing the lowest mf levels at 18 and 24 months post-treatment. Filarial antigen tests suggested that all 3 treatments had significant activity against adult W. bancrofti; albendazole-DEC combination had the greatest activity according to this test, with antigen levels decreasing to 30.5% of pre-treatment antigen levels, 24 months after therapy. All 3 treatments were clinically safe and well tolerated. These results suggest that a single dose of albendazole 400 mg together with DEC 6 mg/kg is a safe and effective combination for suppression of microfilaraemia of bancroftian filariasis that could be considered for use in filariasis control programmes based on mass treatment of endemic populations.

Detection of Wuchereria bancrofti in mosquitoes by the polymerase chain reaction: a potentially useful tool for large-scale control programmes.

Focally endemic bancroftian filariasis is targeted for elimination in the Nile delta of Egypt. Improved methods are needed for identifying endemic villages to be included in the control programme and for monitoring its success. We have evaluated the performance of a polymerase chain reaction (PCR) assay in estimating Wuchereria bancrofti infection in pools of Culex pipiens (1-25 females) from 2 adjacent villages with high (El Qolzom, 10.8%) and low (Kafr Shorafa, 2.1%) prevalence rates of human filariasis. This assay detects a repeated sequence in W. bancrofti deoxyribonucleic acid (DNA). Mosquitoes resting within houses were captured by aspiration and pooled by house. Houses were classified as positive or negative for human filarial infection based on night blood examinations of residents. The assay detected parasite DNA in mosquitoes from 60% of 25 infected houses and 24% of 25 uninfected houses. PCR processing of mosquitoes caught within houses of unknown filariasis infection status (44 in El Qolzom, 37 in Kafr Shorafa) identified 31.8% and 8.1% of houses, respectively, as containing infected mosquitoes. These results support the validity of the PCR assay for evaluating filarial prevalence in different villages. C. pipiens collected outdoors in dry ice-baited traps and tested by PCR (266 in Qolzom, 82 in Kafr Shorafa) did not contain parasite DNA. Pools of female mosquitoes (296 in Qolzom, 240 in Kafr Shorafa) captured in oviposition traps were also negative. We concluded that the PCR based assay is a powerful epidemiological tool that can be used for evaluating W. bancrofti infection in villages in the Nile delta and for monitoring the application of control programmes in filariasis endemic areas.

A rapid-format antibody card test for diagnosis of onchocerciasis.

Improved methods are needed for field diagnosis of onchocerciasis, to support efforts aimed at elimination of the disease. A rapid-format card test was evaluated that detects IgG4 antibodies to recombinant Onchocerca volvulus antigen Ov16 with serum samples from patients with onchocerciasis and with various types of control serum samples. The sensitivity of the test with serum samples from 106 microfilariae-positive subjects was 90.6%. The test was equally sensitive with serum samples obtained from patients in Africa and Latin America. Specificity was excellent; positive tests were observed for 2 of 38 serum samples from patients with other filarial infections and for 1 of 23 serum samples from patients with nonfilarial helminth infections. The 3 "false-positive" serum samples were from West Africans who could have been coinfected with onchocerciasis. No positive tests were observed with nonendemic serum samples from normal adults, patients with autoimmune disorders, or patients with the hyper-IgE syndrome. This new test holds great promise as a simple tool for diagnosis of onchocerciasis.

The impact of environmental and entomological factors on intervillage filarial focality in the Nile Delta.

In the Nile Delta of Egypt, levels of W. bancrofti infection in humans vary among nearby villages. Ecological and entomological factors that might explain variability between adjacent villages, El Qolzom (QOL) and Kafr Shorafa (KSH) with respective 10.8% and 2.1% microfilaria (MF) prevalence were examined. The epidemiological study covered 127 and 79 houses scattered in QOL and KSH, respectively, and described 25 items relating to housing characters, socio-economic state and human activities. It revealed that QOL is more rural than KSH, and therefore would be more favorable to the vector mosquito population and hence, filarial parasite transmission in QOL. Weekly records (N = 81 and 62 for QOL and KSH, respectively) of ambient temperature, relative humidity and wind speed taken at sunset, over 3 months during summer, revealed no significant variation between villages. Those measured at sunrise revealed significant, although inconsistent, differences at a particular month, but no difference over the whole period. Whether climatological conditions could have influenced mosquito bionomics in the study villages is questionable. Abundance of female Cx. pipiens collected weekly by standard sampling methods using 247 and 240 dry ice-baited CDC trap-nights in QOL and KSH, respectively, oral aspiration from within 346 and 304 respective house-nights, and 65 and 40 respective ovitrap-nights, did not vary significantly over the whole study period. Daily survival and survival to infectivity rates of wild-caught mosquitoes were based on parity and were generally more elevated in QOL than KSH. Monthly records of abundance and survival seemed to favor filaria transmission by mosquitoes in QOL. Autogeny amounted to 6.5 and 20% for QOL and KSH, respectively. Experimental infection of Cx. pipiens from the study villages with W. bancrofti revealed that QOL females were 3.3 times more efficient vectors than KSH ones, mainly because QOL mosquitoes survived longer. The ultimate outcome of observed entomological factors might explain its preponderance in QOL.

A comparison of newer tests for the diagnosis of onchocerciasis.

Samples of human serum, skin and urine, collected in Cameroon, were used to assess the value of some newer methods for the diagnosis of onchocerciasis. Parasite DNA was detected in skin snips and urine by PCR, and parasite antigen was detected in serum and urine by immunoblotting. Serum concentrations of IgG4 antibodies reacting with recombinant Onchocerca volvulus antigens (OC3.6 and OC9.3) were also measured, using an ELISA. The PCR-based tests of skin snips and the serological tests for antigen and antibody tests showed higher sensitivities (90%-100%) than the urine PCR (14%) or the urine antigen test (68%). Although antibody detection is much easier to perform than tests based on PCR or antigen detection, the latter have an advantage in that they are only positive in people with current infections. Thus, antibody testing may be more useful for screening populations for infection or exposure to O. volvulus, whereas PCR and antigen testing are potentially more useful for diagnosis of infections in individuals and for monitoring the success of therapy.

Human antibody responses to Wuchereria bancrofti infective larvae.

Human IgG antibody responses to Wuchereria bancrofti third stage infective larvae (L3) surface and somatic antigens were studied by indirect immunofluorescence (IFA) and immunoblot with endemic Egyptian sera (n = 115) with the aim of identifying targets of protective immunity. Human sera variably recognized 14 major bands in L3 by immunoblot. The statistical significance of group differences in antibody prevalence was assessed by the chi-squared test. Children and young adults (aged 10-20 years) tended to have antibodies to more L3 somatic antigens than older adults, with significant differences for bands at 66, 60 and 5 kDa. Infected subjects had more consistent antibody responses to antigens at 55, 50 and 6 kDa than endemic normal subjects with negative serum filarial antigen tests, who are presumed to be uninfected. A 5 kDa antigen was preferentially recognized by the latter group. Antibodies to L3 surface antigens were equally prevalent in uninfected children (75%) and adults (90%) but less prevalent in people with microfilaremia (38%) than in amicrofilaremic subjects with or without filarial antigenemia (81%) (P < 0.001). IFA-positive sera showed significantly enhanced recognition of antigens at 66, 40 and 14 kDa in immunoblots relative to IFA-negative sera. Additional studies are needed to further characterize antigens identified in this study and to establish whether they are indeed targets of protective immunity in humans.