Lyme snap: A feasibility study of on-line declarations of erythema migrans in a rural area of France

The incidence of Lyme borreliosis remains a matter of debate, but it can be estimated using the incidence of erythema migrans (EM), which is pathognomonic of the first phase. The aim of this prospective pilot study was to assess the feasibility of the on-line declaration of EM in rural areas where the incidence of Lyme borreliosis was previously estimated at 85 per 100,000 inhabitants per year. The study was limited to a rural area (Les Combrailles, Auvergne) of approximately 52,800 inhabitants and was preceded by an information campaign for the inhabitants and the healthcare professionals. Patients who sent a photo of the suspected EM by email or MMS message between April 2017 and April 2018 and who accepted to answer a questionnaire were included in the study. Two physicians then evaluated the quality of the photographs and the probability of EM. In parallel, the number of EM seen by physicians and pharmacists in the area over the given period was recorded. Out of the 113 emails and MMS messages received, 73 people were outside of the trial area or period and 9 did not complete the questionnaire. The photos of the remaining 31 people were analysed. The median age was 51.5 years old ([38-58] IQR) and 18 (58%) were women. Seven people (25%) stated that they did not have a smartphone and in 9 cases (29%) the photo was sent by a third party. The quality of the photos was considered very good in 22 (71%) cases, good in 7 (23%) cases, and average in 2 (6%) cases. The probability of EM was determined to be strong or possible in 12 (38%) cases, i.e. an estimated incidence of 22.7 per 100,000 inhabitants. Over the study period, 40 physicians and 20 pharmacists were contacted on a monthly basis. A median of 5 physicians [3;7] and 4 pharmacists [3 ;7] answered each month for a total of 18 and 36 declared EM respectively. The EM (strong probability/possible) collected by on-line declaration and those declared by healthcare professionals were all sent between April and October 2017. The total time spent on the information campaign and collection has been estimated at 265 h (divided between 10 people) for an overall cost of 10,669 Euros. The incidence of EM recorded by on-line self-declaration in our study seems to be lower than in previous studies, the under-reporting was probably linked to the low use of new technologies in the rural areas. Increasing the human resources and finances appears difficult to achieve in practice over a longer time period but the development of an application for the automatic recognition of EM could be one method for a more exhaustive collection in the long term and at lower cost.

Prevalence of Anaplasma phagocytophilum in small rodents in France

Anaplasma phagocytophilum is an emerging zoonotic tick-borne pathogen affecting a wide range of mammals. Rodents are suspected to be natural reservoirs for this bacterium, but their role in the epidemiologic cycles affecting domestic animals and wild ungulates has not been demonstrated. This study aimed to improve our knowledge on A. phagocytophilum prevalence in Apodemus sylvaticus, A. flavicollis and Myodes glareolus using data collected in 2010 in one area in eastern France and in 2012-2013 in two others areas in western France. Rodents were captured in each site and infection was tested using qualitative real-time PCR assays on either blood or spleen samples. Prevalence showed high variability among sites. The highest prevalence was observed in the most eastern site (with an average infection rate of 22.8% across all species), whereas no rodent was found to be PCR positive in the south-west site and only 6.6% were positive in the north-west of France. Finally, a significant increase in prevalence was observed in autumn samples compared to spring samples in the north-west, but no change was found in the other two sites.

Mapping human risk of infection with Borrelia burgdorferi sensu lato, the agent of Lyme borreliosis, in a periurban forest in France

Lyme borreliosis is a major zoonosis in Europe, with estimates of over 26,000 cases per year in France alone. The etiological agents are spirochete bacteria that belong to the Borrelia burgdorferi sensu lato (s. l.) complex and are transmitted by hard ticks among a large range of vertebrate hosts. In Europe, the tick Ixodes ricinus is the main vector. In the absence of a vaccine and given the current difficulties to diagnose and treat chronic Lyme syndromes, there is urgent need for prevention. In this context, accurate information on the spatial patterns of risk of exposure to ticks is of prime importance for public health. The objective of our study was to provide a snapshot map of the risk of human infection with B. burgdorferi s. l. pathogens in a periurban forest at a high resolution, and to analyze the factors that contribute to variation in this risk. Field monitoring took place over three weeks in May 2011 in the suburban Sénart forest (3,200ha; southeast of Paris), which receives over 3 million people annually. We sampled ticks over the entire forest area (from 220 forest stands with a total area of 35,200m(2)) and quantified the density of questing nymphs (DON), the prevalence of infection among nymphs (NIP), and the density of infected nymphs (DIN), which is the most important predictor of the human risk of Lyme borreliosis. For each of these response variables, we explored the relative roles of weather (saturation deficit), hosts (abundance indices of ungulates and Tamias sibiricus, an introduced rodent species), vegetation and forest cover, superficial soil composition, and the distance to forest roads. In total, 19,546 questing nymphs were collected and the presence of B. burgdorferi s. l. was tested in 3,903 nymphs by qPCR. The mean DON was 5.6 nymphs per 10m(2) (standard deviation=10.4) with an average NIP of 10.1% (standard deviation=0.11). The highest DIN was 8.9 infected nymphs per 10m(2), with a mean of 0.59 (standard deviation=0.6). Our mapping and modeling revealed a strong heterogeneity of risk within the forest. The highest risk was found in the eastern part of the forest and localized patches in the northwestern part. Lyme borreliosis risk was positively associated with stands of deciduous trees (mainly oaks) and roe deer abundance. Contrary to expectations, DIN actually increased with distance from the point of introduction of T. sibiricus (i.e., DIN was higher in areas with potentially lower abundances of T. sibiricus). Thus, despite the fact that T. sibiricus is an important reservoir host for B. burgdorferi s. l., our study found that other explanatory factors played a more important role in determining the density of infected ticks. Precise mapping of the risk of exposure to Lyme borreliosis in a highly visited forest represents an important tool for targeting prevention and control measures, as well as making the general public and local health officials aware of the risks.

Which forest bird species are the main hosts of the tick, Ixodes ricinus, the vector of Borrelia burgdorferi sensu lato, during the breeding season?

Wild birds are important hosts for vector-borne pathogens, especially those borne by ticks. However, few studies have been conducted on the role of different bird species within a community as hosts of vector-borne pathogens. This study addressed individual and species factors that could explain the burden of Ixodes ricinus on forest birds during the reproductive periods of both vectors and hosts. The goal was to identify which bird species contribute the most to the tick population at the community level. Birds were mist-netted on four plots in 2008 and on seven plots in 2009 in two forests (Sénart and Notre Dame, near Paris, France). The dependence of the tick load per bird upon environmental conditions (questing nymph density, year and plot) and on host species traits (species, age, sex, body size, vertical space use, level of innate and acquired immunity) was analysed. Finally, the relative contribution of each bird species to the local dynamics of ticks was estimated, while accounting for their respective abundance. Tick burden differed markedly between bird species and varied according to questing nymph density. Bird species with a high body mass, those that forage low in the vegetation, and those that had a high innate immune response and a high spleen mass were more likely to have a high tick burden. Four species (the Common Blackbird, Turdus merula, the European Robin, Erithacus rubecula, the Song Thrush, Turdus philomelos, and the Winter Wren, Troglodytes troglodytes) hosted more than 90% of the ticks in the local bird community. These species, and particularly T. merula which was host to a high proportion of the nymphs, are likely to contribute significantly to the circulation of pathogens for which they are competent, such as the agent of Lyme borreliosis.

Introduced Siberian chipmunks are more heavily infested by ixodid ticks than are native bank voles in a suburban forest in France

By serving as hosts for native vectors, introduced species can surpass native hosts in their role as major reservoirs of local pathogens. During a 4-year longitudinal study, we investigated factors that affected infestation by ixodid ticks on both introduced Siberian chipmunks Tamias sibiricus barberi and native bank voles Myodes glareolus in a suburban forest (Forêt de Sénart, Ile-de-France). Ticks were counted on adult bank voles and on adult and young chipmunks using regular monthly trapping sessions, and questing ticks were quantified by dragging. At the summer peak of questing Ixodes ricinus availability, the average tick load was 27-69 times greater on adult chipmunks than on adult voles, while average biomass per hectare of chipmunks and voles were similar. In adult chipmunks, individual effects significantly explained 31% and 24% of the total variance of tick larvae and nymph burdens, respectively. Male adult chipmunks harboured significantly more larvae and nymphs than adult females, and than juveniles born in spring and in summer. The higher tick loads, and more specifically the ratio of nymphs over larvae, observed in chipmunks may be caused by a higher predisposition--both in terms of susceptibility and exposure--to questing ticks. Tick burdens were also related to habitat and seasonal variation in age- and sex-related space use by both rodents. Introduced chipmunks may thus have an important role in the dynamics of local vector-borne pathogens compared with native reservoir hosts such as bank voles.

Local environmental factors characterizing Ixodes ricinus nymph abundance in grazed permanent pastures for cattle

Although Ixodes ricinus ticks are mainly associated with woodland, they are also present in open habitat such as pastures. The distribution of nymphal I. ricinus was monitored by drag sampling the vegetation in May-June 2003 on 61 grazed permanent pastures for cattle located in central France. After selecting explanatory variables from among a set of 155, tick abundance was modelled on the perimeter of the pasture using a negative binomial model that took into account data overdispersion. An abundant tree layer at the perimeter of the pasture associated with a high humidity before sampling greatly enhanced the average number of captured I. ricinus nymphs. The presence of apple or cherry trees around the pasture perimeter, the presence of trees or bushes at the pasture edge, woodland around the pasture and a high number of I. ricinus nymphs in the nearest woodland to the pasture were also favourable to nymph abundance in the pasture. The study highlighted that woodland vegetation associated with humidity and the presence of attractive foraging areas for tick hosts around the pasture played a key role in the abundance of I. ricinus. Finally, the results raised the question of whether and how transfer of ticks between woodland and grazed pastures occurs.

Prediction of outcome of anaesthesia in patients over 40 years: a multifactorial risk index

The prediction of outcome of anaesthesia in patients over 40 years of age was assessed using a multifactorial index based on current preoperative factors recorded prospectively. The study was conducted using a representative sample of anaesthetizations (except for cardiac surgery) including 517 cases with major complication (occurring during or within 24 hours of anaesthesia) and a one in fifty random sample comprising 1538 cases without complication. A split sample approach was adopted and a logistic regression model was applied to two subsets of similar size. Four preoperative factors were significantly associated with the occurrence of complications: ASA physical status, age, surgical procedure (major/minor) and type (elective/emergency). Goodness-of-fit of the model was assessed using another sample of 332 cases with complication and a different subset of 987 cases without complication. The model fitted the data well (p = 0.15).

Complications related to anaesthesia in infants and children. A prospective survey of 40240 anaesthetics

A prospective survey of anaesthesia-related mortality and morbidity in infants and children was carried out in a representative sample of anaesthetics performed in 440 institutions chosen at random in France. A total of 40240 anaesthetics were administered to patients younger than 15 yr, 2103 (5%) involving infants (younger than 1 yr). Twenty-seven major complications related to anaesthesia occurred during or within 24 h of the anaesthesia--an incidence of 0.7 per 1000 anaesthetics. Nine, of which four were associated with cardiac arrest, were observed in infants, whereas in children there were 18 complications of which eight were associated with cardiac arrest, one with fatal outcome. The risk of complications was significantly higher (P less than 0.001) in infants (4.3 per 1000) than in children (0.5 per 1000). Accidents observed in infants mainly occurred during maintenance of anaesthesia and were the result of respiratory failure. In children, circulatory failure was as frequent as respiratory failure and complications were observed almost equally during induction and maintenance and on recovery. The rate of complications increased significantly with the ASA score and the number of co-existing diseases. The incidence was also higher when a previous history of anaesthesia was present, when the procedure was an emergency, and when the duration of preoperative fasting was less than 8 h.

[Relation of the fall in PO2 in ventilation of the lower lung in pulmonary surgery and the preoperative distribution of respiratory function]

Hypoxaemia during one-lung ventilation is influenced by the anatomic distribution of lung perfusion and hypoxic vasoconstriction. This study aimed to assess whether preoperative selective bronchospirometry could predict the degree of peroperative hypoxaemia. Twelve patients scheduled for pneumonectomy, lobectomy, wedge resection or decortication were included in the study. Preoperative data included the usual spirometric parameters, oxygen consumption, minute ventilation of each lung and arterial blood gases. A Carlens or Robertshaw tube was inserted in each case; the patients were ventilated with 100% oxygen and halothane was used for anaesthesia. Blood gases were measured during surgery before and after upper lung exclusion. When both lungs were ventilated, mean PaO2 was 390.5 +/- 92.4 mmHg; during one-lung ventilation, it fell to 210.8 +/- 109.2 mmHg. Routine spirometry could not predict the magnitude of fall in PaO2; however, it was correlated with the bronchospirometric oxygen consumption of each lung (r = 0.83; p less than 0.01). The anatomical distribution of lung perfusion seemed to be the predominant factor influencing the decrease in PaO2 during one-lung ventilation.

[Hypoxia secondary to the failure of an oxygen-air-nitrous oxide mixer]

A case is reported of hypoxia occurring during anaesthesia in a spontaneously breathing ASA I patient. The patient became cyanotic twice when breathing a gas mixture delivered by a safety mixer. Changing the machine solved the immediate problem. The diagnosis was difficult to make because the rotameters all showed normal delivery of oxygen and nitrous oxide. Oximetry elucidated the cause, which was found to be a defective rapid oxygen control. Because these machines do not appear to be absolutely reliable, the use of gas analysers should become more systematic.

[Development of anesthetic technics for resection-anastomosis of the trachea]

A series is reported of 109 patients, 45 +/- 18 yr old, undergoing tracheal sleeve resection. 101 patients had iatrogenic tracheal stenosis, 5 tracheal cylindroma, 2 tracheal cancer and 1 tracheal trauma. 84 patients underwent preoperative laser coagulation to increase the airway internal diameter. Anaesthesia for the sleeve resection was induced by thiopentone, and maintained by an opiate, nitrous oxide and, if necessary, a volatile anesthetic. Patients were intubated, after having been given a muscle relaxant, with either a normal length and diameter tube with a low pressure cuff, or a narrow (internal diameter less than 6 mm) 50 cm long tube with or without a low pressure cuff. Patients with long tubes were ventilated with intermittent positive pressure, and the others with high frequency jet ventilation (HFJV) via a urethral catheter within the endotracheal tube. 20% of the long tubes had to be replaced during surgery because of perforation of the cuff by a tracheal stitch. In all, six patients died, one as a result of a pneumothorax and air embolus due to HFJV. Preoperative photocoagulation reduced the risk of induction and intubation; the choice of endotracheal tube no longer depended on the tracheal diameter, but on the method of ventilation chosen. However, HFJV has tended to be phased out, except for the surgery of lesions close to the carena; it has been replaced by intermittent positive pressure ventilation via long tubes. Because laser photocoagulation can completely cure small stenoses, these patients requiring surgery were those with long stenoses which were difficult to treat.(ABSTRACT TRUNCATED AT 250 WORDS)

The implications of a national study of risk of anaesthesia

In order to set up measures to improve safety in anesthesia, the French Ministry of Health charged the Institut National de la Santé et de la Recherche Médicale (I.N.S.E.R.M.) with conducting an epidemiological survey of complications associated with anaesthesia. A prospective survey was carried out from 1978 to 1982 in a representative sample of 198,103 anaesthesias performed in 460 public and private institutions randomly selected throughout the country. There were 268 major complications associated with anaesthesia occurring during or within 24 hours after anaesthesia (incidence 1.35 per 1000), among these 67 were followed by death and 16 by coma. The incidence of deaths and comas totally attributable to anaesthesia was one per 7924. Half of the deaths and comas totally attributable to anaesthesia were from post-anaesthetic respiratory depression which could be directly linked to a dramatic lack of recovery rooms. The extension of the study to all institutions revealed that 25% of teaching hospitals, 43% of non-teaching hospitals and 20% of private clinics did not have a recovery room available. A total number of 12,000 recovery beds was estimated to be necessary in France; 40% being currently available leaving 60% to be created.

Changes in intrathoracic pressures induced by positive end-expiratory pressure ventilation after cardiac surgical procedures

The consequences of controlled ventilation with positive end-expiratory pressure (PEEP) were studied, after cardiac surgical procedures, in two groups of patients supposed to have different lung and chest wall mechanical properties. The first group included 6 patients who had undergone coronary artery graft surgical procedures (CGS). The second group included 5 patients who had undergone a mitral valve replacement (MVR). Postoperatively, static lung and chest wall compliance was measured by stepwise inflation and deflation of the thorax. Esophageal, pericardial, and pleural pressures were then measured, and cardiac output was determined while PEEP was increased from 0 to 20 cm H2O. Lung and chest wall compliance values sharply decreased in MVR patients. This accounts for the lower values for pleural and pericardial pressures in this group than in the CGS patient group, but the transmission of airway pressure was identical in the two groups when PEEP was increased. The decrease in cardiac output induced by PEEP was similar in the two groups. The results suggest that the opposing influences of lung and chest wall compliance on airway pressure transmission could at least partly explain the hemodynamic effects of PEEP in patients in whom the mechanical properties of the lung and thorax are impaired. PEEP ventilation should be used cautiously in patients suspected of having thoracic rigidity.

Air entrainment during high-frequency jet-ventilation. Simulation of a bronchoscopy with a lung model

Air entrainment contribution to jet-ventilation during bronchoscopy was evaluated as a lung model (increasing compliance and airway resistance). Ventilation was provided through a 10 mm internal diameter tube using either jet alone without air entrainment, or injection with air entrainment (coaxial and lateral injectors). Three I/E ratios (0.25, 0.43 and 0.67) and nine rates of ventilation, ranging from 20 to 300 c X min-1, were assessed. The driving pressure of the injected air was 350 +/- 10 kPa. Air entrainment is an important part of total ventilation (63.7 +/- 5.5%). The magnitude of air entrainment depends upon the levels of peak and end expiratory airway pressures. Increase in lung volume varies linearly with the end expiratory pressure. Air entrainment contributes to keep the tidal volume above the model dead-space. CO2 elimination is related to the magnitude of ventilated volumes. The amount of entrained air interferes with the FIO2 of delivered gases. During bronchoscopy, lateral injection should be preferred because of smaller airway pressures (- 31.2 +/- 0.6%) and lung volumes, while tidal volumes remain adequate.

Complications associated with anaesthesia--a prospective survey in France

A prospective survey of complications associated with anaesthesia was carried out in France from 1978 to 1982 in a representative sample of 198,103 anaesthetics performed in 460 public and private institutions chosen at random in the country as a whole. There were 268 major complications associated with anaesthesia occurring during or within 24 hours of anaesthesia (one per 739 anaesthetics), among which 67 were followed by death within 24 hours and 16 by coma persistent after the 24th hour. The incidence of death and coma was one per 2387 anaesthetics. The incidence of death and coma totally attributable to anaesthesia was one per 7924 anaesthetics. Fifty-eight per cent of complications occurred during anaesthesia while 42 per cent were observed during the recovery period. Mortality was lower following complications during anaesthesia than for those during the recovery period. Half of the deaths and cases of coma totally attributable to anaesthesia were due to postanaesthetic respiratory depression. The rate of complications appeared to be dependent upon several risk factors: the patient's age, the number of associated diseases, the preoperative status, whether the operation was an emergency and the duration of procedure.

Indications and technique for endoscopic laser resections in bronchology. A critical analysis based upon 2,284 resections

Over a period of 6 years, we have treated 1,310 patients in 2,284 sessions using a neodymium-yttrium aluminum garnet laser. Indications are more often palliative than curative, with the primary goal to relieve an obstructed airway in a single treatment. The effectiveness of such resections is widely recognized, but indications for such a technique with its limitations deserve emphasis. The use of a rigid bronchoscope is important to provide satisfactory operating conditions and especially to manage hemorrhage rapidly while maintaining a satisfactory airway.

The pharmacokinetics of droperidol in anesthetized patients

A pharmacokinetic study of droperidol was performed in ten anesthetized patients receiving an intravenous bolus dose of 150 micrograms/kg of droperidol. Plasma concentrations were measured using a specific radioimmunoassay method. The pharmacokinetics of droperidol can be described according to a three-compartment open model. The mean (+/- SD) half-life for the rapid (t 1/2 pi) and slow distribution t 1/2 alpha) phases was 1.4 +/- 0.5 min and 14.3 +/- 6.5 min, respectively. The mean elimination half-life, t 1/2 beta was 103.8 +/- 20.2 min. The mean (+/- SD) total body clearance was 14.1 +/- 4.4 ml X min-1 X kg-1, and the total apparent volume of distribution (Vd beta) was 2.04 +/- 0.50 l/kg. The short terminal half-life of droperidol does not correlate with the well-known, relatively prolonged duration of its pharmacologic action.

What changes can be expected during high frequency jet ventilation when the rate of ventilation, the I:E ratio and the driving pressure are modified? A laboratory study

Changes in minute ventilation, tracheal airway pressure and lung volume have been measured using a jet ventilator (VS 600) during different rates of ventilation, I:E ratios and driving pressures. A lung model with a slightly increased compliance and an increased airway resistance was used. Five rates of ventilation (from 60 to 230 b.p.m.), three I:E ratios (0.25, 0.43, 0.67) and three driving pressures (200, 300 and 400 kPa) were studied. The increases in the rate of ventilation did not modify minute ventilation significantly, decreased peak airway pressure only slightly and increased end-expiratory pressure and lung volume. The increases in I:E ratio produced increases in minute ventilation, peak airway pressure, end-expiratory pressure and lung volume. The increases in driving pressure induced changes similar to those produced by the alterations in I:E ratio.

Pharmacokinetics of phenoperidine in patients undergoing cardiopulmonary bypass

Phenoperidine concentrations were studied, using radioimmunoassay, in five patients submitted to coronary artery bypass graft surgery. Administration of phenoperidine consisted of a 5-mg bolus dose followed by constant infusion of 5 mg h-1. Before cardiopulmonary bypass, phenoperidine concentrations were stable in an individual patient, but there was a large scatter between patients. The concentrations decreased immediately following the start of the bypass, but this decrease was short. During cardiopulmonary bypass, the phenoperidine concentrations increased progressively and were greater at the end of the bypass than before it. The increase in concentration continued following the discontinuation of bypass. The ratios of change of the observed results were in accord with a theoretical evaluation, although the observed concentrations were all greater than those calculated, except at one point. This difference in phenoperidine concentration is probably related to an alteration of liver plasma flow. Haemodilution as a result of the priming of the cardiopulmonary bypass circuit played only a transient role.

Pharmacokinetics of phenoperidine in anaesthetized patients undergoing general surgery

The pharmacokinetics of phenoperidine have been studied in five anaesthetized patients receiving a 2-mg bolus dose i.v. Plasma concentrations were measured using a sensitive radioimmunoassay method. The distribution of phenoperidine was described according to a two-compartment open model. The mean distribution half-life (T1/2 alpha) for the five patients was short (2.2 min); the mean elimination half-life (T1/2 beta) was 193 min. The mean whole body clearance was 22 ml min-1 kg-1 and the apparent steady state distribution volume (VSS) was 5.7 litre kg-1. Secondary concentration peaks occurred in all patients; in two patients these were substantial and occurred 80 min after injection.

Circulatory responses to thiopentone and tracheal intubation in patients with coronary artery disease. Effects of pretreatment with labetalol

The haemodynamic responses to induction and tracheal intubation have been studied in patients with coronary artery disease randomly assigned to a labetalol pretreatment group (n = 14) or to a placebo group (n = 16). Twelve hour before operation, treated patients received a bolus dose of labetalol 0.5 mg kg-1 followed by a constant infusion of 0.1 mg kg-1 h-1 i.v. Anaesthesia was induced with thiopentone and phenoperidine, and intubation performed following the administration of suxamethonium. At intubation, the changes in heart rate (P less than 0.01), mean arterial pressure (P less than 0.05) and rate-pressure product (P less than 0.01) were significantly smaller in the labetalol group compared with the placebo group. Labetalol pretreatment appears satisfactory and may be useful in patients with coronary artery disease who have a normal left ventricular ejection fraction.

Jet ventilation using low or high frequencies, during bronchoscopy

Jet ventilation, through a bronchoscope, was evaluated using a lung model (normal compliance and increased airway resistance). Three I/E ratios (0.25, 0.43, 0.67) and seven rates of ventilation (from 20 to 230 cycles per min (c min-1) were studied with the bronchoscope either unoccluded or partially occluded by a telescope. Increases in I/E ratio induced increases in minute ventilation, peak airway pressure, end-expiratory pressure and lung volume. Increase in the rate of ventilation decreased peak airway pressure, increased end-expiratory pressure and lung volume; minute ventilation increased in parallel with the increase in the rate of ventilation or remained constant when a high I/E ratio was used. The introduction of the telescope reduced minute ventilation, as a result of a decrease in the amount of air entrained, and increased end-expiratory pressure and lung volume. The risk of barotrauma as a result of high peak pressure is reduced during high frequency jet ventilation, but the increase in lung volume, particularly when the telescope is introduced, may be of clinical importance.

Pneumopericardium: an unusual complication of endotracheal laser surgery

The case report is presented of a patient with a left upper lobe tumour of the lung in whom use of laser photocoagulation induced a pneumopericardium. The possible causes of the complication are considered.

[Long-term peridural morphine analgesia in neoplastic and vascular pathology]

Epidural analgesia using morphine has been used on 44 patients with intractable chronic pain, resistant to analgesics (including opiates). The pain was due to cancer in 24 cases, of vascular origin in 20. An indwelling tunnelized epidural catheter afforded repeated injections of morphine for a long period (up to 129 days) either in hospital or at home. The quality of analgesia achieved was rated as excellent or good, in 68 p. 100 of cases. Two cases only were total failures. Side effects, relatively common, were usually transient and minor; no case of respiratory depression or of infection has been recorded.

High frequency jet ventilation v. manual jet ventilation during bronchoscopy in patients with tracheo-bronchial stenosis

Six patients with airway stenosis were submitted to bronchoscopy under general anaesthesia. Each was ventilated with a gas mixture of 50% oxygen and nitrogen using successively manual jet insufflation (JV) using the Sanders technique at 20 b.p.m., and high frequency jet ventilation (HFJV) at rates of 150, 300 and 500 b.p.m. The effects on alveolar ventilation were assessed by blood-gas analysis and the transcutaneous monitoring of carbon dioxide tension. It is concluded that HFJV achieves satisfactory operating conditions, and provides adequate gas exchanges up to a rate of 300 b.p.m. At the faster rate some degree of hypoxaemia and hypercarbia were noted. The correlation between PaCO2 and transcutaneous carbon dioxide tension was satisfactory.

Manual jet ventilation v. high frequency jet ventilation during laser resection of tracheo-bronchial stenosis

Manual jet ventilation (20 b.p.m.) and high frequency jet ventilation (300 b.p.m.) were compared during laser resection of tracheo-bronchial stenosis under general anaesthesia. Both methods provided similar blood-gas tensions at the 10th min of surgery in patients with tracheal stenosis. In patients with bronchial stenosis high frequency jet ventilation resulted in modest hypercarbia and manual jet ventilation appeared to be the preferred method in these particular patients.

[Comparison of the clinical effects of vecuronium and pancuronium bromide in general surgery]

50 patients selected at random were given vecuronium (group A) or pancuronium bromide (group B) at an initial dose of 0.05 mg X kg-1, followed by repeat injections of 0.0125 mg X kg-1. 34 other patients, separated in two groups: group C (vecuronium) and group D (pancuronium), received stronger doses of both drugs: 0.07 mg X kg-1 initially, followed by 0.022 mg X kg-1 repeat injections. The four groups were anaesthetized according to the same protocol; the patients underwent gastrointestinal and gynaecological surgery, lasting 122 +/- 50 min. The results showed that the time of onset and the duration of action of vecuronium were shorter, and that increasing the dose did not increase significantly the duration of action of these repeat doses: time of onset: 104 +/- 42 s (group A), 205 +/- 36 s (group B), 96 +/- 23 s (group C), 255 +/- 36 s (group D); duration of action: 19 +/- 6 min (group A), 36 +/- 6 min (group B), 24 +/- 7 min (group C), 43 +/- 13 min (group D); mean time between doses: 26 +/- 10 min (group A), 55 +/- 5 min (group B), 33 +/- 7 min (group C), 49 +/- 3 min (group D). The degree of muscle relaxation was always satisfactory in the four groups. Decurarization appeared to be particularly sudden with vecuronium. Neither an abnormally prolonged duration of action, nor any haemodynamic effect, nor any signs of histamine release were seen.

[Comparative clinical study of the effects of vecuronium and suxamethonium during oto-rhino-laryngeal and tracheobronchial laser surgery]

52 patients selected at random were assigned to four groups according to the surgery and muscle relaxant used: vecuronium (group A) and suxamethonium (group B) in ENT, vecuronium (group C) and suxamethonium (group D) for laser surgery. The first dose of vecuronium was 0.05 mg X kg-1, followed by repeat doses of 0.0125 mg X kg-1; suxamethonium was first given in a dose of 1 mg X kg-1, this being followed by a drip of 3 mg X kg-1. The anaesthetic protocol was the same for all groups. The results showed a shorter onset of action with suxamethonium (group A: 210 +/- 30 s, group B: 75 +/- 15 s, group C: 200 +/- 50 s, group D: 80 +/- 20 s) and a similar duration of action for the initial doses of the two drugs (group A: 9 +/- 3 min, group B: 6 +/- 3 min, group C: 11 +/- 4 min, group D: 7 +/- 2 min). Continuing the muscle relaxation proved easier with the suxamethonium; signs of decurarization occurred rather unexpectedly with vecuronium. No adverse effect was seen with vecuronium, whilst the diastolic blood pressure rose 20% during the first 25 min following the administration of suxamethonium. It can be concluded that, in the absence of monitoring of the curarization, the repeated administration of vecuronium with a first dose of 0.05 mg X kg-1 brought few advantages compared with the continuous infusion of suxamethonium.

[Role of vecuronium in comparison with curariform drugs used in man]

Vecuronium, a new non-depolarizing muscle relaxant, was more powerful than d-tubocurarine, gallamine and alcuronium. Its muscle blocking effect was similar to that of pancuronium. It had a smaller distribution volume and a quicker elimination half-life than the other non-depolarizing muscle blocking drugs. The time of onset and duration of action, as well as the time for recovery were also shorter, being 3-5 min, 17-22 min and 25 min respectively. The accumulation of vecuronium in the body was low; increasing the dose increases the duration of action, but not the recovery time. No adverse effect has been reported as yet. Compared with suxamethonium, a depolarizing muscle relaxant, it had a longer time of onset and duration of action. Vecuronium cannot therefore replace suxamethonium for endotracheal intubation.

Bronchoscopic management of tracheal lesions using the neodynium yttrium aluminium garnet laser

We report our first clinical trials with the NdYAG laser in the treatment of tracheal and bronchial tumours and stenoses. The beam is carried through a flexible fibre delivering a power of 50 to 90 watts. It can be introduced through the biopsy channel of a standard bronchoscope, or through a fibrescope. Anaesthesia must avoid inflammable gases. In most cases, general anaesthesia was used, and ventilation achieved with a mixture of 50% nitrogen and oxygen, using a modification of the Sanders injector. One hundred and sixty-four cases have been treated in 317 sessions (from one to five sessions per patient). They comprised: 72 cancers, 24 of which had just been diagnosed and had acute respiratory obstruction. In 16, one single session restored the patency of the airway. Forty-eight other cases were recurrent carcinomas after either surgery or radiotherapy, nine of which were caused by cancers of other origin invading the trachea; 21 benign or moderately malignant tumours; 44 iatrogenic stenoses, including 31 narrow ones. Of those 31 cases, 17 had an immediate satisfactory result, but eight recurred; 24 granulomas on bronchial suture lines. There were two deaths not directly related to surgery or anaesthesia. Bleeding was never more than moderate. The main difficulty lies in the critical respiratory condition of the patients, sometimes seen in acute asphyxia, referred to us as a last resort, especially those with carcinomas involving the trachea or main bronchi.

Anaesthetic management of tracheal surgery using the neodymium-yttrium-aluminium-garnet laser

A new technique for the management of tracheal or bronchial lesions (tumours or stenosis) using the NdYAG laser and bronchoscopy, was used in 55 patients without complications. The anesthetic problems are discussed. In some circumstances the procedure may be performed using sedation and topical anaesthesia. In most, general anaesthesia was used, controlled ventilation being achieved through the bronchoscope using a modification of the Sander's injector with mixture of 50% nitrogen and oxygen to avoid the risk of fire.

[Use of a laser beam (YAG) with a flexible fiber for endoscopic treatment of some broncho-tracheal lesions (author's transl)]

For several years we employed an endoscope permitting electro-coagulation in the treatment of some broncho-tracheal lesions and were able to observe the limits and accidents involved in this method. When compared with clinical results (work of Freche in ORL, laser CO2) and after experimental research, the use of a flexible laser beam (YAG) seems to bring about a noteworthy increase in therapeutic possibilities. This flexible fiber beam could easily be used by some medico-surgical teams who already possess appropriate of easily adaptable endoscopic equipment. Clinical studies are in progress.