Aviation medicine: challenges for telemedicine.

The number and seriousness of medical problems on passenger-carrying aircraft in flight are increasing. Medical incidents occur at a rate of approximately 10-50 per million passengers carried. Medical equipment carried on commercial aircraft is limited to three items: a first-aid kit, an emergency medical kit and sometimes an automatic external defibrillator. Telephone medicine, a lower level of telemedicine support, is well established for commercial air operations. The availability of satellite telecommunications on passenger-carrying aircraft permits more sophisticated forms of telemedicine. Recent telemedicine experiments have involved the transmission of three-lead electrocardiograms (ECGs), heart rate, blood pressure, arterial oxygen saturation, end-tidal CO2, respiratory rate, body temperature and realtime video. The challenge is to demonstrate that such techniques are practicable, improve patient outcomes and are cost-effective.

European Resuscitation Council Guidelines 2000 for Adult Advanced Life Support. A statement from the Advanced Life Support Working Group(1) and approved by the Executive Committee of the European Resuscitation Council.

The European Resuscitation Council (ERC) last issued guidelines for Basic Life Support (BLS) in 1998 [1]. These were based on the 1997 International Liaison Committee on Resuscitation (ILCOR) Advisory Statements [2]. In 1999 and 2000 representatives of ILCOR, at the invitation of the American Heart Association, met on a number of occasions in Dallas to agree a Consensus on Science upon which future guidelines would be based. Representatives from the ERC played a prominent role in the deliberations, which culminated in the publication of "Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care--A Consensus on Science" in August 2000 [3]. The consensus was evidence-based wherever possible. The ERC ALS Working Group has considered this document and has recommended some changes in the guidelines that will be suitable for European practice. These changes, together with a summary of the Sequence of Actions in ALS, are presented in this paper.

[Reimplantation lesion in the postoperative period of lung transplantation. Incidence, predictive factors, prognosis and outcome. The Lung Transplantation Group of Vall d'Hebron University General Hospital]. / Lesión de reimplantación en el postoperatorio del trasplante pulmonar. Incidencia, factores predictivos, pronósticos y evolución. Grupo de Trasplante Pulmonar del Hospital General Universitari Vall d'Hebron.

BACKGROUND: Reimplantation disease (RD) is a postoperative complication in lung transplantation. It is defined as hypoxemia (PaO2/FiO2 ratio < 150 mmHg), radiologic infiltrates and decrease of lung compliance. The aim of the study was to analyze the incidence, predictive factors, prognosis and outcome of the patients with RD. PATIENTS AND METHOD: 49 patients submitted to lung transplantation (June 1991-December 1996) were admitted in our intensive care unit (ICU). Donor and recipient conditions, surgical parameters and outcome in ICU were analyzed. Mann-Whitney, Kruskall-Wallis, Fisher, Pearson and ANOVA-Friedman tests were used for statistical analysis according to the different variables. RESULTS: 49% of the patients (29/49) developed RD, which was influenced neither by lung disease, nor by the kind of transplantation or by ischemia time. All patients with a long surgical time developed RD, versus only 41% in those where surgery was undertaken in a shorter period of time, OR: 2.8 (1.5-5.7; p = 0.0016). The patients with RD improved showing a PaO2/FiO2 ratio of 176 and 235 mmHg at 24 and 48 h respectively (ANOVA, p < 0.00001). The patients with RD needed 14 days of mechanical ventilation versus 7 days in those without RD (p = 0.013). There were no statistically significant differences in stay and mortality in ICU. CONCLUSIONS: RD is a common complication in the postoperative phase of lung transplantation. It is present in almost all the patients with long surgical time. Almost all of them improve, with the same survival but a longer period of mechanical ventilation.

[The prognostic value of eicosanoids in the acute respiratory distress syndrome]. / Valor pronóstico de los eicosanoides en el síndrome de distrés respiratorio agudo.

BACKGROUND: There is a great number of agents involved in the acute respiratory distress syndrome (ARDS) physiopathology, and some of them may have a prognostic value. The objective of the present study has been to analyse the prognostic value of eicosanoids in this syndrome. MATERIAL AND METHOD: A prospective study with 21 consecutive ARDS patients admitted to the intensive care unit of a therapy hospital in Barcelona, Spain, was carried out. In the first 48 h of the ARDS diagnosis, at baseline, the plasma levels, (in peripheral arterial and pulmonary arterial samples) of thromboxane B2 (TXB2), prostaglandin F1-alpha) (PGF1-alpha) and leukotriene B4 (LTB4) were analysed by RIA. Simultaneously we measured different pulmonary and systemic hemodynamical variables, as well as the pulmonary gas exchange data. We also studied the venous levels of the same eicosanoids in 17 healthy adults, used as reference. RESULTS: Plasma levels of eicosanoids in the ARDS patients were higher than reference subjects (p < 0.05). No differences were observed between systemic arterial and pulmonary arterial values. From all the eicosanoids, only LTB4, (in both systemic arterial and pulmonary blood), was correlated with LIS (r = 0.49, p < 0.05; and r = 0.45, p < 0.05, respectively). Patients who did not survive presented a lower systemic-pulmonary arterial gradient of eicosanoids levels than survivors (-1.27 vs -0.10 ng/ml; p < 0.01). CONCLUSIONS: In our ARDS patients only LTB4 plasma levels correlated with the severity of respiratory failure. Patients who did not survive presented a lower LTB4 gradient than survivors.

Anticoagulative effect of nitric oxide inhalation in ARDS.

Some studies have suggested that nitric oxide (NO) may cause platelet dysfunction. We present an ARDS patient who need this treatment, with a transient alteration of platelet function and a significant prolongation of bleeding time.

Neurological disturbances and hyperdynamic shock in a patient with esophagocoloplasty.

A 39-year-old man, with no history of alcohol intake, who had had an esophago-ileo-colo-gastroplasty with ileotransversostomy, developed diplopia, seizures, metabolic acidosis, and cardiac failure and finally refractory hyperdynamic shock. He died 20 h after admission to our intensive care unit from cardiocirculatory collapse. Postmortem results revealed low erythrocyte transketolase activity, which was increased by 22% by in vitro addition of thiamine diphosphate (TDP effect). Cerebral pathology showed the alterations of Wernicke's encephalopathy. We discuss the possible mechanisms of fatal cardiovascular collapse and the unusual presentation of a case without a history of alcoholic intake or clinical malnutrition.

Prospective, randomised, multicentre study of meropenem versus imipenem/cilastatin as empiric monotherapy in severe nosocomial infections.

The clinical and bacteriological efficacy and the tolerability of meropenem versus imipenem/cilastatin (both 1 g t.i.d.) in severe nosocomial infections were compared in a multicentre, randomised, nonblinded study. A total of 151 patients were recruited; 133 (66 meropenem, 67 imipenem/cilastatin) were clinically evaluable and 84 (42 meropenem, 42 imipenem/cilastatin) bacteriologically evaluable. Most clinically evaluable patients (90%) were in intensive care units, required mechanical ventilation (72%), and had received previous antibiotic therapy (62%). The mean (+/- SD) APACHE II score was 15.2 (+/- 6.6) in the meropenem group and 17.8 (+/- 6.8) in the imipenem/cilastatin group. The primary infections were nosocomial lower respiratory tract infections (56% of patients), intra-abdominal infections (15%), septicaemia (21%), skin/skin structure infections (5%), and complicated urinary tract infections (3%); 35% of the patients had two or more infections. There was no significant difference between the meropenem and imipenem/cilastatin groups in the rates of satisfactory clinical (weighted percentage 87% vs. 74%) or bacteriological (weighted percentage 79% vs. 71%) response. There was a slightly higher rate of clinical success with meropenem against primary or secondary lower respiratory tract infection (89% vs. 76%). Drug-related adverse events occurred in 17% and 15% of meropenem and imipenem/cilastatin patients, respectively. Meropenem (1 g t.i.d.) was as efficacious as the same dose of imipenem/cilastatin in this setting, and both drugs were well tolerated.

Comparative study of propofol versus midazolam in the sedation of critically ill patients: results of a prospective, randomized, multicenter trial.

OBJECTIVES: To compare the effectiveness, characteristics, duration of action, hemodynamic and biochemical effects, and side effects of propofol and midazolam used for continuous intravenous sedation of ventilated critically ill patients. DESIGN: Multicenter, prospective, randomized, nonblinded study. SETTING: Nine Spanish general intensive care units (ICUs). PATIENTS: Ninety-eight patients admitted to the ICU who were mechanically ventilated and required sedation for a minimum of 48 hrs. INTERVENTIONS: Propofol or midazolam was used for induction and maintenance of continuous intravenous sedation for a maximum of 5 days. The effectiveness of those two regimens was assessed according to their effects on ventilatory management and the presence of agitation. MEASUREMENTS AND MAIN RESULTS: In 93% of the patients studied, there was a medical cause necessitating mechanical ventilation. The mean (+/-SD) duration of sedation was 81 +/- 25 hrs and 88 +/- 27 hrs for the propofol and midazolam groups, respectively. The induction dose was 2.24 +/- 0.43 mg/kg over 318 +/- 363 secs for propofol, and 0.22 +/-0.07 mg/kg over 33 +/-29 secs for midazolam. The maintenance dose was 2.8 +/-1.1 mg/kg/hr for propofol and 0.14 +/- 0.10 mg/kg/hr for midazolam. There was no difference regarding the opiate and muscle relaxant requirements between the two groups. Sedation with propofol was more effective in achieving patient-ventilator synchrony than that with midazolam after the first hour of treatment (p < .01). Patients sedated with propofol awoke more rapidly and with less variability that those patients sedated with midazolam (23 +/- 16 mins vs. 137 +/- 185 mins, respectively, p < .05), particularly in those patients requiring deep sedation (27 +/- 16 mins vs. 237 +/- 222 mins, respectively, p < .01). No hemodynamic or biochemical changes were detected in any of the treatment groups. During induction, five patients in the propofol group and two patients in the midazolam group had hypotension. CONCLUSIONS: In this population of critically ill patients, propofol is an effective and safe alternative for sedation, with some advantages, such as short duration of action and high effectiveness over the conventional regimen with benzodiazepines and opiates.

Pattern of tracheal colonization during mechanical ventilation.

The relationship between gastric (GC) and tracheal (TC) colonization and the development of ventilator-associated pneumonia (VAP) remains controversial. TC, GC, and pharyngeal (PC) colonization were studied serially in 80 patients with mechanical ventilation (MV) to ascertain the routes and onset of TC. Simultaneous sample from pharynx, stomach, and trachea were obtained throughout the MV period. Quantitative cultures were performed. Seventy-two patients (90%) had TC at some time during MV. Only 19 patients presented TC after PC or GC by the same microorganisms. Indigenous gram-negative and gram-positive microorganisms colonized mainly the trachea from the start of or during MV without previous PC or GC (p < 0.05). Pseudomonas were the microorganisms causing TC principally during MV without previous PC or GC (p < 0.005). Enterobacteria produced TC without a preferential route. Of the 12 patients who developed VAP, the microorganisms responsible had already colonized the trachea in 10 patients. Only 10 of the 21 microorganisms isolated in VAP had previously colonized the pharynx or stomach. In summary, although some microorganisms have preferential routes for producing TC, the microorganisms isolated frequently change during MV. TC precedes VAP in most patients, but only a minority develop a VAP; therefore, together with TC other factors must be involved in VAP development.

[Energy requirement in patients after liver transplantation]. / Requerimiento energético en pacientes postransplante hepático.

We have made a study of the energy requirements of liver transplant patients in the immediate post-operative phase, by comparing different methods. A study of energy use was made with indirect Calorimetry (IC), of calculation of Resting Energy Expenditure (REE) according to Fick's formula modified by Liggett, and of the calculation of basal energy Expenditure (BEE) applying Harris-Benedict's equation (HB). The correlation between the REE calculation using indirect calorimetry and that of BEE using Harris-Benedict (r = 0.7567) did not give a correction factor, applied to the Harris-Benedict formula) (REE by IC/BEE), which was uniform for all patients, oscillating as it did between 1.0 and 1.8. We found no correlation between REE by IC and that calculated using the modified Fick method, nor between the modified Fick method and BEE as calculated by Harris-Benedict. Our conclusion is that, with the IC method as reference to evaluate energy use, the Harris-Benedict calculation appears to be more reliable than that using the modified Fick equation and that, in the group of patients studied, and given the individual variations in the REE ratio calculated by IC and the BEE calculated by HB, we were unable to find a suitable correction factor for them all. IC is therefore the ideal method for evaluating energy use in critical patients in the ICU.

[Snake bites in our environment. A biannual review of 7 cases]. / Mordeduras de serpientes en nuestro medio. A propósito de una revisión bianual de siete casos.

The clinical picture, treatment and evolution of seven patients presenting snake bites are analyzed. Local symptoms were constant, with a spontaneous favorable evolution in 7 to 10 days. The most relevant systemic manifestations were coagulation anomalies which appeared in two patients. Treatment always included local wound care, antitetanicum antibiotic and anticoagulant prophylaxis with specific antiophidic serum in five patients.

Incidence of pneumothorax and pneumomediastinum in patients with aspiration pneumonia requiring ventilatory support.

In a prospective study of patients with ventilatory support, six (38 percent) of 16 patients who had ventilatory support because of aspiration pneumonia developed pneumothorax and pneumomediastinum. In contrast, the incidence of barotrauma in the entire group of patients who had ventilatory support during a year was 4 percent (22/553) (P less than 0.001). This greater incidence in the group with aspiration pneumonia was also observed when patients who were receiving ventilatory support with positive end-expiratory pressure were excluded.