Anesthesia with sevoflurane in bariatric surgery.

BACKGROUND: Sevoflurane is a good halogen agent for bariatric surgery anesthesia because of its physical and chemical characteristics and its repartition coefficient (blood/gas = 0.65). METHOD: From November 1997 to April 1998, 98 bariatric surgery procedures with sevoflurane anesthesia were done: 17 lipectomies, 71 vertical gastroplasties, and 10 biliopancreatic diversions in 71 women and 27 men, average age 30.3+/-8.3 years, with body mass index 43.9+/-5.7. The average operating time was 50+/-15 minutes for vertical gastroplasty, 160+/-20 minutes for biliopancreatic diversion, and 80+/-12 minutes for lipectomy. The technique of anesthesia was as follows: preanesthesia with atropine sulfate 0.01 mg/kg (dosage refers to ideal weight), ranitidine 50 mg, fentanyl 0.1 mg, ketorolac 60 mg; induction with propofol 0.5-1 mg/kg, succinylcholine 1 mg/kg; orotracheal intubation; maintenance with O2-N2O 50%, sevoflurane 1% to 1.5%, actracurium 0.5 mg/kg (dosage refers to ideal weight); awakening and decurarization with atropine sulfate 1 mg and prostigmine 2 mg. RESULTS: This method permitted correct control of the anesthesia, a quick awakening with a low incidence of nausea and vomiting, a prompt regain of physical and psychological functioning, an early discharge from the hospital, and a larger turnover of patients with lower costs. CONCLUSION: Sevoflurane balanced anesthesia seems to be the best anesthesiologic method for bariatric surgery.

Unexpected finding of barium sulphate on the surface of a microspinal catheter.

During a study with a scanning electron microscope to evaluate the structure of microspinal catheter after its removal from subarachnoid space, we found an unusual case. The observation with the microscope of the tip of a catheter removed at the end of an operation for hip replacement in a old female showed the presence of grounded particles with a crystal shape covering the outer surface. Further analysis of this material with an Energy-Dispersive Spectrometer (EDS) showed that it was barium. The patient performed a large bowel barium enema 8 months earlier for a painful syndrome to the lower abdomen. Authors rule out the contamination from the skin and suggest two possible mechanisms of passage of barium from blood to cerebrospinal fluid (CSF) and so to the surface of the catheter.

Aortic arch surgery: retrospective analysis of outcome and neuroprotective strategies.

OBJECTIVE: To review intra- and postoperative data regarding surgical reconstruction of the aortic arch performed at our cardiosurgical centre during the past four years, and thus to deepen understanding of neurologic morbidity and of what constitutes the most effective neuroprotection. EXPERIMENTAL DESIGN: Retrospective study. SETTING: Regional University Hospital. PATIENTS: 29 patients who underwent reconstruction of aneurysm or dissection of the aortic arch. Intervention. Surgical replacement of the diseased aorta during deep hypothermia, alone or with selective cerebral perfusion (antegrade or retrograde). MEASURES: Overall mortality rate, neurologic morbidity rate, duration of extracorporeal circulation, of hypothermic circulatory arrest or of selective cerebral perfusion. Evaluation of the importance to neurological outcome of age, modality of operation (emergency or routine), biochemical parameters (glycemia, hematocrit) and perfusion technique. Recording of postoperative time of arousal, and possible correlation with length of selective cerebral perfusion. RESULTS: We observed a mortality rate of 39% (11 deaths) and a neurologic morbidity rate of 34%. Hypothermic circulatory arrest alone did not assure valid neuroprotection (5 cases, all with severe neurologic impairment), while better results were obtained with selective cerebral perfusion, especially antegrade (14 cases, with only 7% of neurologic morbidity rate). Hyperglycemia (>250 mg%) proved to be significantly associated (p=0.002) with increased incidence of adverse neurologic outcome, and the same association was observed between emergency status and adverse neurologic outcome (p=0.002). Moreover, we found an unexpected linear correlation between time of selective cerebral perfusion and postoperative time of arousal (r=0.728, p=0.000). CONCLUSIONS: Deep hypothermic circulatory arrest with selective cerebral perfusion currently represent a valid therapeutic option for brain preservation during reconstruction of the aortic arch in adults. It is mandatory to carry out a tight control of perfusion parameters (flow, pressures and temperature gradients) and biochemical variables (avoidance of hyperglycemia and modified ultrafiltration for fluid balance).

[Current views on the use of vasodilators in pulmonary hypertension]. / Attuali vedute sull'impiego dei vasodilatatori nell'ipertensione polmonare.

Vasodilators represent one of the main steps for the medical treatment of pulmonary hypertension; the rationale for their use is the reversibility of the pulmonary vasoconstriction, to be tested with a correct pharmacological trial. In this report the authors consider the use of calcium-channel blockers, prostaglandin and nitric oxide. Calcium blockers, the only drugs active when administered orally, provide a satisfactory clinical response in 25-30% of treated patients. Prostaglandins are active in a higher percentage of patients and can be infused in a domiciliary regimen with portable pumps even for long periods of time. Nitric oxide is the only selective pulmonary vasodilator; it is used in paediatric and adult cardiac surgery and in patients affected by respiratory distress syndrome, but its use is restricted to intensive care units and many cautions must be adopted. Finally some future therapeutic strategies are briefly reviewed: endothelin inhibitors, cGMP phosphodiesterase inhibitors etc.

Case reports in anesthesiology: their trend through 17 years.

UNLABELLED: The study objective was to delineate the trend of case reports (the simplest of the descriptive forms of study) in the anesthesiological literature by analyzing the frequency of publication, and citation, and especially of the place of citation of a sample of published case reports. It is our opinion that case report in anesthesia is particularly suitable for this specialty rather than for others and is often the first signal of a complication, an adverse event, an anesthetic problem in rare disease and alerts other anesthesiologists to the possibility of unexpected events. METHODS: We analyzed the case reports published on an Anesthesiological journal placed in the middle in term of Impact Factor, from January 1980 to December 1997. Citations of each case report were obtained using computer searches of the Science Citation Index (SCI). For each of these case reports we collected in a custom-designed data base the following data: year of publication, number of authors, number of citations per year, place of citation, type of article quoting the case report, number of self-citations, year of first citation. MAIN RESULTS: We identified 637 case reports and 1946 citations. The number of case reports increased through the years up to a peak in 1994-95 and the same trend was observed for citations and self-citations, the number of authors per case report was < or = 4 in 90.4%; 74.2% of total case reports cited were first cited within two years of publication, while 34.7% were never cited. The type of article quoting the case reports has been, in the majority of cases, an original article. CONCLUSIONS: The analysed case reports and the number of citations can give us information about the importance of a clinical situation at a particular time.

[Human error in the anesthesiological field. Up to what point is it possible to speak of prevention?]. / L'errore umano in campo anestesiologico. Fino a che punto e possibile parlare di prevenzione?

Human error (the act of judging true what is false and false what is true) has ever played and plays a significant role in the occurrence of incidents during anaesthesia. Purpose of the study. The Authors wanted to study how the different Authors analyzed the problem and to outline indications for preventive measures. Materials and methods. For this purpose we have selected papers and their references published on Journals indexed on Index. Medicus (1966-1996). The key words have been: anaesthesia or anesthesia, human error, incident and critical incident. We analyzed papers where human error in anaesthesia as a source of accidents was the main topic. The problem is analyzed starting from a classification of different errors and quantified with proper cognitive methods. Finally preventive measures are proposed. Results, Contribution of human error to the occurrence of accidents in anaesthesia ranges from 37% to 87% according to different. Authors employed techniques and sample size. Proper corrective measures on human, instrumental and environmental factors can lead to increased prevention. Conclusions. Human error exists now and will ever exist. Its gravity depends on its consequences and on preventive measures adopted.

[Prevalence and incidence. These (almost) unknowns]. / Prevalenza e incidenza. Queste (quasi) sconosciute.

OBJECTIVES: The purpose of the study is to point out some aspects of the most used terms in epidemiology, that is, erroneously, considered a simple and easy subject, but is often incorrectly applied, even in scientific studies. Sometimes the difficulties encountered in the application of epidemiology are underestimated; before the beginning of every scientific study the authors must be perfectly aware of the differences existing between different terms, even if very small. This for the optimal design of the study, and in order to gather as many data as possible and to draw correct conclusions for the readers and for other investigators. DATA SOURCES: The author reviewed indexed journals of Anesthesia of the last ten years looking for studies where epidemiological terms have been used, in order to better evaluate how frequently they occurred and if in the proper way. CONCLUSIONS: Sometime in the scientific literature these concepts are wrongly used, and this can be a source of incorrect data for both the reader and other investigators. Properly applied epidemiological concepts enhance the validity of the reported data and constitute a solid base of the paper itself.

Is there a bilateral block of the thoracic sympathetic chain after unilateral intrapleural analgesia?

UNLABELLED: This study was designed to ascertain, by telethermography and clinical observation, the effect of injecting anesthetic solutions into the intrapleural space on thoracic sympathetic chains and splanchnic nerves. We studied 15 patients with neoplastic (n = 8) or benign (n = 7) pain, divided into three groups of 5 patients each. The first group received 20 mL of bupivacaine 0.25% in the intrapleural space, the second received 20 mL of bupivacaine 0.5%, and the third received 20 mL of isotonic sodium chloride solution. Each patient was examined telethermographically 30, 60, 90, and 120 min after the blockade. Visceral pain intensity was measured in eight patients using a visual analog scale. Patients receiving bupivacaine had a uniform bilateral increase of cutaneous temperature (+2 degrees C). In those with diffuse visceral pain, the mean value of the pain score decreased from 82 +/- 10 mm at the time of injection to 16 +/- 5 at 120 min. We conclude that intrapleural bupivacaine 0.25% and 0.5% results in bilateral blockade of the thoracic sympathetic chain and also of the splanchnic nerves, which pass in front of the spinal column between the two thoracic sympathetic chains. Our data indicate that intrapleural analgesia can be used in the treatment of not only unilateral visceral and somatic pain, but also diffuse abdominal visceral pain. The bilateral increase of the cutaneous temperature of the trunk (measured telethermographically) and the reduction of the diffuse visceral pain suggest a bilateral block of the sympathetic chain and of the splanchnic nerves. IMPLICATIONS: We subjected 10 patients to monolateral intrapleural analgesia. Five other patients served as controls. The bilateral increase of the cutaneous temperature of the trunk (measured telethermographically) and the reduction of the diffuse visceral pain suggest a bilateral block of the sympathetic chain and of the splanchnic nerves. Our data indicate that intrapleural analgesia can be used in the treatment of not only unilateral visceral and somatic pain, but also diffuse abdominal visceral pain.

Does ethnicity predict lactation? A study of four ethnic communities.

Human lactation is influenced by a variety of interrelated factors. The purpose of the study was to see whether the racial/ethnic factor is predictive of the onset of lactation and of the volume of breast milk. We planned a prospective study enrolling 269 women who were classified into four ethnic groups: Group 1 Arabs, Group 2 Africans, Group 3 Eastern Europeans, Group 4 Italians. Data regarding the women's habits, medical history and pregnancy were collected. After delivery we recorded the onset of lactogenesis and volume of milk output up until the fifth post-delivery day. A Cox model was fitted in order to assess the independent role that ethnicity has on the time to lactation; a general linear model was used to relate ethnicity to the overall amount of milk produced. Mean age was 27 years and was similar in all groups; half of the women were primiparae. All babies were exclusively breast-fed. Median time to lactation was 36 hours (20-36) and the median daily amount of milk produced was 173.5 ml (119-215). The earliest onset of lactation and the highest milk output was registered among Arab and Eastern European women. On Cox regression analysis ethnicity appeared to be an independent predictor of earlier lactogenesis: breast milk output occurred significantly earlier in the immigrant population than it did in the Italian population. No difference was observed among the immigrants. The multiple regression model showed that ethnicity independently predicts the overall amount of milk production: the Immigrant population produced a significantly higher milk output than the Italian population. No differences were observed within the immigrant groups. Ethnicity has been shown to be associated with the characteristics of breast-feeding. Further research is needed to understand the underlying mechanism.

[Tourniquet pain: anatomic-physiological notes and clinical aspects]. / Il dolore da Tourniquet. Note anatomo-fisiopatologiche e considerazioni cliniche.

OBJECTIVES: The mechanism of tourniquet pain is quite complex. This paper, supported by the previous literature on this topic, tries to explain why the anaesthetic blockade of a limb, even when thechnically successful, not always prevents the occurrence of this pain. DATA SOURCES: Papers published between 1990 and 1995, listed on Index Medicus, with pertinent references. STUDY SELECTION: Reports dealing with physiological basis of tourniquet pain. CONCLUSIONS: Tourniquet pain is nociceptive, generated not only by activation of peripheral nociceptors, but also by direct axonal stimulation of nervous trunks. Is is hardly to tolerated by patients since ischemia and mechanical compression induce an activation of C fibres, resistent to ischemia. A beta fibres are involved as well, due to the activation of low-threshold mechanoceptors.

Graphic data representation in anaesthesiological journals: a proposed methodology for assessment of appropriateness.

Few authors have addressed the topic of graphic data presentation. The purpose of our study was to combine several guidelines in order to evaluate three anaesthesiology journals listed in Index Medicus (Australian, American and Italian) in terms of the appropriateness and the quality of presentation of graphs. Our analysis was based on concepts expressed by Cox and Tufte. We calculated the optimization of the amount of information in each graph using two parameters: Data Density Index (DDI) and Data Ink Ratio (DIR). The correctness and clearness of each component of the graph (scale, title, axes, legends and abbreviations) was evaluated on the basis of a binary score. We analysed 300 exploratory plots, quantitative graphs and summaries of statistical analysis. About 50% of papers had more than three graphs. Mean scores were 3.22 for the Italian journal, 3.47 for the American journal and 3.82 for the Australian journal. Tufte parameters were calculated on 42 scatterplots: DDI was 5.4 +/- 13.9 and DIR was 0.7 +/- 0.1. The criteria applied in our study appear sufficiently sensitive to differentiate the quality of graphs.

[Late hemorrhage as an unusual complication of placenta increta. A clinical case]. / Emorragia tardiva quale insolita complicanza di placenta increta. Caso clinico.

A 26 year old patient is urgently submitted to cesarean section for acute fetal pain. After 23 days, hysterectomy has been performed because of haemorrhagic shock. The pathology revealed a placenta increta. The lack of risk factors and the long, asymptomatic period between delivery and haemorrhage make this case noteworthy.

The influence of race on breast feeding.

We evaluated the beginning of lactogenesis and the milk quantity until the fifth post-delivery day, before discharge, in 10 primiparae and 11 pluriparae Gypsies, as compared to 12 primiparae and 11 pluriparae Italian women. The results showed that both in primiparae and in pluriparae Gypsies, the lactogenesis started significantly earlier and the milk quantity was significantly greater than in Italian women.

[A method for the evaluation of resource use in cardiac surgery: application of the ICR beta in an Italian reality]. / Un metodo per la valutazione del consumo di risorse in cardiochirurgia: applicabilità dell'IRC beta in una realtàa italiana.

The decreased availability of economic resources requires the use of methods to assess hospital efficiency. The aim of our study was to retrospectively evaluate the applicability to the Italian reality of a catalogue of medical acts (CdAM-champs beta) set up for the French Health System. We wanted to evaluate the amount of resource utilization of a Cardiothoracic Operating Room of a IRCCS regional general hospital. The study included 83 admissions, occurring in October 1996, to the cardiac surgery department. Medical acts were recorded for all admissions taking into account both the number of acts and the weight of acts expressed as standard cost index or ICR. This takes into account the use of human (medical and nursing staff) and technical resources. Calculation of ICR beta scores was achieved by means of two different expressions. We observed a lack of correlation between the two values of each ICR. The previous formula (1991) gives more emphasis on the different conditions in which the operation was carried out (American Society of Anesthesiology score), duration of anesthesia and patients disease with a statistical significant difference. The last formula (1995) only evaluate patients' disease. None of the two formula of ICR beta turns out to be completely appropriate index of resource utilization during anesthesia; therefore this analysis still remains a difficult problem. Yet it must be recognized that this system deserves the merit of having evaluated the anesthesiological duties, by separating them from the surgical ones.

[Qualitative characteristics of human exposure to air chemical pollutants in operating rooms]. / Caratteristiche qualitative dell'esposizione umana a contaminanti chimici aerodispersi in sale operatorie.

UNLABELLED: For more than two decades many studies have been published searching for a link between exposure to volatile anaesthetic agents and health damage even if it is noteworthy that many other chemical substances can be found in the Operating Room. Purpose of this study was to demonstrate that the Operating Room is not a totally confined environment and that it is possible to perform an, at least qualitative, evaluation of many different polluting contaminants, even unexpected, to whom the working staff is exposed. MATERIAL AND METHODS: The study has been performed in the Operating Rooms of the Departments of Urology and Orthopaedics. Two methods have been employed: a long-casting sampling of volumes of air (with a sampling device composed of an enrichment system and a low flow aspirating pump) and an anaesthetic vapours and gas continuous analyzer. Results. We never recorded environmental levels of anesthetic higher than the currently accepted ones. Many other organic compounds of different kind have been found (irritants, cancer-organs). Their presence, not desirable in a place where a demanding work is performed, deserve further investigation and a quantitative evaluation of these compounds.

Impact of the Hawthorne effect in a longitudinal clinical study: the case of anesthesia.

Clinical research can be influenced by many factors that are capable of invalidating results, and one of these factors is known as the Hawthorne effect: the mere awareness of being under observation can alter the way in which a person behaves. In experimental research this effect can be the undesired effect of the experiments themselves, and the stronger its presence, the greater it can influence the results. In anesthesia practice, owing to the particular emotional condition of a patient facing a surgical operation, the Hawthorne effect could be especially strong. The aim of our study was to show the impact that the knowledge of being included in a study has (Hawthorne effect), by comparing the postoperative changes in psychological well-being in two groups of patients undergoing knee arthroscopy and receiving different information about the study from the anesthetist during the preoperative interview. Other signs and symptoms such as postoperative knee pain, nausea, vomiting (the most feared occurrences), headache, return of spontaneous diuresis, analgesic request, anesthesia complications, as well as the intensity of anxiety were also assessed as secondary endpoints. Our results show that subjects who were aware that they were part of a study scored significantly better on postoperative measures of psychological well-being and postoperative knee pain, compared to subjects who were unaware. The size of the effect, as measured by the odds ratio, remains unchanged when controlling for potential confounding factors. The study has enabled us to demonstrate the presence of the Hawthorne effect in clinical research. Therefore, the Hawthorne effect should be acknowledged and accounted for in the design of a study and in the interpretation of results.

[Anesthesiologic management for lower pulmonary lobectomy intervention in patients with heart transplant. A clinical case]. / Condotta anestesiologica per intervento di lobectomia polmonare inferiore in paziente cardiotrapiantato. Caso clinico.

The Authors describe the case of a patient who had undergone human allograft cardiac transplant seven months before inferior pulmonary lobectomy for neoplasia. The pulmonary neoplasia had been revealed by X-rays during the periodic check-up examinations. Because of the high risk of infection following corticosteroid and immunosuppressive therapy, sterile equipment for invasive monitoring and oro-tracheal intubation has been used. The denervated heart presents peculiar haemodynamic and pharmacological aspects that the anaesthetist must pay attention to in the conduction of a general anaesthesia; moreover, arrhythmias are common in the recently transplanted heart. Anaesthesia has been induced and maintained by an association propofol-fentanyl that showed a good cardiocirculatory stability; neither arrhythmias have happened, nor the need for drugs different from those of anaesthesia and resuscitation have occurred.

[Atracurium besylate versus succinylcholine during laparoscopy]. / Besilato di atracurium versus succinilcolina in corso di laparoscopia.

The authors report their experience with 112 female patients undergoing laparoscopy: they have been divided into two groups according to the drug used for muscle relaxation (atracurium versus succinylcholine). During the procedure the following parameters were recorded: intraabdominal pressure, arterial pressure, heart rate, arterial blood oxygen saturation, end tidal CO2 and the occurrence of adverse effects. According to the collected data they assume that atracurium can be considered the ideal muscle relaxant for this surgical procedure.