Incidence of hypoglycaemia associated with transient loss of consciousness. A retrospective cohort study.

OBJECTIVE: To define the incidence of hypoglycaemia associated with transient loss of consciousness (TLoC). DESIGN: Retrospective cohort study using a nested case-control analysis. SETTING: Presentations to the emergency departments (EDs) of four general metropolitan hospitals in Azienda Sanitaria 10, Florence, Italy during 2012. PARTICIPANTS: The cohort consisted of 133,285 patients extracted from the database of ED presentations. All patients with TLoC were identified by nurse triage, and their levels of glycaemia were recorded. Clinical investigations were undertaken using patients' charts and witness statements. Patients were matched with controls according to year of birth, year of cohort entry and gender. RESULTS: Of the 133,285 patients, 3964 (2.9%) presented with TLoC, and 39 (1%) of the patients with TLoC had transient hypoglycaemia. Mean glycaemia in these 39 patients was 52 mg/dl (a level of 112 mg/dl was in controls). Symptoms associated with TLoC during hypoglycaemia differed from those characteristic of syncope. TLoC during hypoglycaemia mainly occurred in elderly patients with diabetes, who had relatively long disease duration, were receiving treatment, often also had renal failure and were experiencing symptoms as a result of lack of food intake. Together, these factors make it easier to diagnose hypoglycaemia associated with TLoC, and our results may prompt modification in medical practice. CONCLUSION: Correct diagnosis of hypoglycaemia associated with TLoC has economic benefits if a protracted and costly series of clinical investigations can be avoided. A diagnosis of hypoglycaemia might also facilitate the resolution of patients' symptoms through lifestyle changes and adjustment of therapy.

Copeptin: a blood test marker of syncope.

AIMS: Copeptin (CPT) is regarded as a stress hormone, and as a novel marker of acute disease, and it has never been tested for a role in diagnosing syncope. The main objectives of the study were to measure CPT in patients suffering from syncope, to determine its diagnostic sensitivity and specificity, and compare it with that in patients with falls and mild trauma. The secondary objective was to determine whether different types of syncope correlate with different levels of CPT. METHODS: Fifty-one patients suffering from syncope and 51 suffering from falls without syncope were included in this study. Patients with a diagnosis of acute comorbidity were excluded. The diagnostic work was in accordance with the Guidelines of the European Cardiology Society. The level of CPT was measured in each patient evaluating the mean values in syncope vs. falls and in the different syncope type and the values over or under the normal threshold. RESULTS: Of the 51 patients with syncope, 44 had abnormal and 7 normal CPT levels. Of the 51 patients with falls, 47 had normal and 4 abnormal levels of CPT. There was no difference in mean CPT levels in patients with different types of syncope. There was no correlation between levels of CPT and age or sex. There was a relationship between normal CPT levels and falls. CONCLUSION: Copeptin is an efficient marker of syncope. It is useful for confirming or ruling out a diagnosis of syncope in patients who are unable to provide a definite history or when the event is unwitnessed.

Effectiveness of different methods to control legionella in the water supply: ten-year experience in an Italian university hospital.

We report our ten-year experience of hyperchlorination, thermal shock, chlorine dioxide, monochloramine, boilers and point-of-use filters for controlling legionella contamination in a hospital hot water distribution system. Shock disinfections were associated with a return to pre-treatment contamination levels within one or two months. We found that chlorine dioxide successfully maintained levels at <100 cfu/L, whilst preliminary experiments gave satisfactory results with monochloramine. No contamination was observed applying point-of-use filters and electric boilers at temperatures of >58°C and no cases of nosocomial legionellosis were detected in the ten-year observation period. Our performance ranking in reducing legionella contamination was filter, boiler, chlorine dioxide, hyperchlorination and thermal shock. Chlorine dioxide was the least expensive procedure followed by thermal shock, hyperchlorination, boiler and filter. We suggest adopting chlorine dioxide and electric boilers in parallel.

[Active clinical surveillance for detection of Legionnaires' disease: implications for health care structures]. / Sorveglianza clinica attiva per la ricerca di polmoniti da Legionella: risultati e considerazioni per le strutture sanitarie.

In an university hospital of about 900 beds, a clinical surveillance was activated to detect cases of Legionnaires' disease in patients affected by community and/or nosocomial-acquired pneumonia. In the hospital Legionella spp was detected in the hot water distribution system and various disinfecting and control procedures were adopted to reduce contamination. Contemporary, the clinical surveillance began with the systematic detection of Legionella urinary antigen among recovered pneumonia, seroconversion as confirmation test and the collection of respiratory secretions or other biological materials to isolate the microorganism in patients positive to the urinary antigen. From September 2003 to May 2005, 486 pneumonia were followed, 98 of which considered of nosocomial origin. In total, 15 cases of community-acquired Legionnaires' disease were detected by the urinary test, whereas no cases of nosocomial origin were found. The characteristics of the detected cases are described in comparison with the other pneumonia and the surveillance cost was evaluated. The systematic clinical surveillance for Legionella infections is feasible with limit costs, allows to detect community-acquired cases otherwise unknown and to ascertain the absence/presence of nosocomial-acquired pneumonia, irrespective of the environment contamination.

Risk factors for particulate and microbial contamination of air in operating theatres.

This study was designed to standardize dust collection in recently built operating theatres equipped with a continuous monitoring system. The objectives were to establish the relationship between microbiological and dust contamination, and then to compare those parameters with the main indicators of surgical activity in order to better define risk factors affecting air quality. The air quality during 23 surgical operations was studied in three conventionally ventilated operating theatres. Microbiological air counts were taken using both passive and active sampling methods. Air dust particles, > or =0.5 and > or =5 microm in size, were measured using a light-scattering particle analyser. The overall dust load was mainly (98%) composed of fine particulate matter, most probably due to its longer suspension time before settlement. These particles positively correlated with operation length, but not with surgical technique, suggesting that fine particles may be a good tracer of operation complexity. In contrast, the surgical technique was the main predictor for the concentration of particles > or =5 microm, with a higher risk from general conventional surgery compared with scope surgery. The frequency of door-opening, taken as an index of staff and visitor movement, was the main negative predictor of over-threshold values of both fine and larger dust particles but, conversely, was a positive predictor of raised bacterial counts.

[The hospital medical director: his role and professional qualification in Modena (Italy) health care system]. / II Direttore di Presidio Ospedaliero: ruolo e requisiti professionali nell'esperienza dell'Azienda U.S.L. di Modena.

The development of health care system in Italy, from 1968, have changed the hospital medical director function and have put him in conflict with the desired physicians involvement in health care management. In Modena the health care system organisation, the self government and the responsibility decentralisation, promoted the achievement of an organisation model tempering every competence because the success of everyone's task depends on the other one's. Therefore, Italian laws are suitable of getting more efficiency and effectiveness in health care system without new rules, if the clinical governance becomes a way to involve the physicians in management and not an instrument to leave out managers and hospital medical directors.

[Strategic planning: integration of training and quality. Experience at the Umberto I Polyclinic of Rome]. / Pianificazione strategica: integrazione fra formazione e qualità, l'esperienza dell'azienda policlinico umberto I di Roma.

This work shows how personnel involvement is one change strategy used in a complex organization making use of education and quality as main reorganization factors in a hospital system based on old management that didn't consider personnel as a strategy resource within a reorganizational change.

Noninvasive monitoring of hypertensive breakthrough of cerebral autoregulation in a patient with acute ischemic stroke.

BACKGROUND AND PURPOSE: We describe the first documentation of hypertensive breakthrough of cerebral autoregulation in a patient with acute stroke with transcranial Doppler sonography. CASE DESCRIPTION: A 55-year-old patient with acute left hemispheric stroke was treated with moderate hypothermia. He died of transtentorial herniation 4 days after admission. Static cerebral autoregulation (sCA) of the unaffected hemisphere was evaluated 6 times during this period and always found to be intact. A bolus application of epinephrine resulted in a hypertensive episode (mean arterial pressure (MAP) 135 mm Hg); hypertensive breakthrough of cerebral autoregulation was evident when MAP exceeded approximately 110 mm Hg. Interestingly, no such breakthrough was evident during testing of sCA, even when MAP reached 120 mm Hg. CONCLUSIONS: Our observation suggests that (1) the pace of the MAP increase is crucial for the occurrence of a hypertensive breakthrough of the cerebral autoregulation and (2) the disturbance of cerebral autoregulation is potentially longer as previously assumed.

Effect of rosary prayer and yoga mantras on autonomic cardiovascular rhythms: comparative study.

OBJECTIVE: To test whether rhythmic formulas such as the rosary and yoga mantras can synchronise and reinforce inherent cardiovascular rhythms and modify baroreflex sensitivity. DESIGN: Comparison of effects of recitation of the Ave Maria (in Latin) or of a mantra, during spontaneous and metronome controlled breathing, on breathing rate and on spontaneous oscillations in RR interval, and on blood pressure and cerebral circulation. SETTING: Florence and Pavia, Italy. PARTICIPANTS: 23 healthy adults. MAIN OUTCOME MEASURES: Breathing rate, regularity of breathing, baroreflex sensitivity, frequency of cardiovascular oscillations. RESULTS: Both prayer and mantra caused striking, powerful, and synchronous increases in existing cardiovascular rhythms when recited six times a minute. Baroreflex sensitivity also increased significantly, from 9.5 (SD 4.6) to 11.5 (4.9) ms/mm Hg, P<0.05. CONCLUSION: Rhythm formulas that involve breathing at six breaths per minute induce favourable psychological and possibly physiological effects.

Cerebral vasoconstriction in vasovagal syncope: any link with symptoms? A transcranial Doppler study.

BACKGROUND: Cerebral vasoconstriction has been described previously in vasovagal syncope (VVS). This phenomenon appears paradoxical in view of the well-known decrease of systemic vascular resistances taking places during VVS. We aimed to assess (1) whether cerebral vasoconstriction in VVS is an independent paradoxical phenomenon and (2) whether cerebral vasoconstriction has any link with symptoms and/or VVS onsets. METHODS AND RESULTS: Seven young patients with recurrent VVS participated in the study. Each patient underwent monitoring of heart rate, blood pressure, cerebral blood flow velocity (by means of transcranial Doppler), end-tidal PCO(2), peripheral oximetry, respiratory rate, and tidal volumes both at rest and during head-up tilt. All the subjects experienced tilt-induced VVS. A significant increase of respiratory tidal volumes was observed in each subject >/=160 seconds before VVS. This deep breathing induced a PCO(2) decrease and, consequently, also a decrease in cerebral blood flow velocity and increase in cerebrovascular resistance (expressed by the increase of the pulsatility index). Within 40 seconds, 5 subjects started complaining of discomfort, in the absence of any significant blood pressure drop. CONCLUSIONS: Cerebral vasoconstriction is not a paradoxical phenomenon when it occurs before tilt-induced VVS but rather is only the physiological consequence of the hyperventilation-induced hypocapnia that occurs in habitual fainters. The large lag between the onset of syncope and cerebral vasoconstriction excludes the hypothesis that VVS is dependent on abnormal behavior of cerebral hemodynamics.

Sister chromatid exchanges and micronuclei in lymphocytes of operating room personnel occupationally exposed to enfluorane and nitrous oxide.

The objective of this article is to assess whether occupational exposure to anesthetics increases genotoxic risk. We investigated two cytogenetic biomarkers, sister chromatid exchanges (SCE) and micronuclei (MN), in the peripheral blood lymphocytes of 46 anesthesiologists (24 men), working in operating rooms and mostly exposed to enfluorane and nitrous oxide, and 66 controls (35 men), not exposed to chemicals and living in the same area. Contrary to what was expected, a lower frequency of SCE was found in male anesthesiologists than in controls. Smoking status was found to be positively associated with SCE frequency in each group, while no relation to age was evident. On the contrary, MN frequency was significantly higher in female, but not male, anesthesiologists than in controls. Age and smoking status did not modify the association. No relationship between MN frequency and duration of employment was found in anesthesiologists. Smoking status and mean number of cigarettes smoked per day in smokers were not associated with MN frequency in either anesthesiologists or in controls. MN analysis seems to be a sensitive index of possible genotoxic effects of occupational exposure to anesthesiologists, and women appear to be more susceptible to these effects than men.

Optical scattering (TAOS) by tire debris particles: preliminary results.

Tire debris particles from low severity laboratory wear tests have been investigated by the TAOS optical scattering facility at Yale University. The incident wavelength is 532 nm. After the TAOS event some particle samples have been imaged by a scanning electron microscope and microanalyzed. The TAOS intensity patterns recorded within a solid angle in the backward sector have been processed by cluster analysis and compared with the patterns computed by a T-matrix code. Preliminary agreement has been found between TAOS data and the particle models (size, shape, refractive index). The purpose of the investigation is to obtain signatures of the material, based on its TAOS pattern.

Automated identification of Doppler microembolic signals: comparison of two techniques.

An alternative technique for identification of Doppler microemboli signals (MES), based on intensity measurements in the vessel and in an arbitrary sample volume was recently reported. We evaluated the applicability of this approach as stand alone system, and compared it to the standard bigate method (TCD 8, version 8T). Bilateral TCD monitoring was performed in 11 patients with prosthetic heart valves and 15 patients during elective cardiac surgery, using three sample volumes (29 mm, 50 mm and 55 mm). All data was saved on digital audio tapes and evaluated by two experienced observers. Only signals unanimously identified as MES or artifacts by both observers were evaluated. A total of 6189 MES and 11,241 artifacts were further analysed. Sensitivity and specificity of the bigate approach and the technique utilising the arbitrary sample volume were 90.7%, 91.3% and 88%, 91.9% respectively. Simultaneous monitoring over three sample volumes and combination of the two detection algorithms could potentially provide an adequate stand-alone system for MES detection.

Disease-related syncope. Analysis of a community-based hospital registry.

Syncope is characterized by sudden and transient loss of consciousness that follows a reduction or interruption of cerebral blood flow. The present study was designed to assess the prevalence of disease-related syncope in a wide sample of in-patients admitted for different diseases. A total of 16 809 patients (age range 18-99 years) were recruited from three hospitals in Florence in 1998. The community-based registry was reviewed to identify all patients suffering from complaints associated with syncope. Each disease-related syncope was matched with the number of patients suffering from that disease. Furthermore, each disease was expressed as a percentage of total cases included in the study. The odds ratio was calculated to determine the index of significant correlation between syncope and occasional diseases. Total syncopes were 775 (prevalence 4.46%), vasovagal syncopes were 336 (1.9% of total sample and 44% of total syncopes), and the disease-related syncopes were 439 (56% of total syncopes). We found a significant association between syncope and orthostatic hypotension, complete heart block, chronic cerebral disease, migraine, acute gastrointestinal haemorrhages and aortic stenosis. Furthermore, we found a significant association with acute gastrointestinal haemorrhage, which has not been described previously. Significant relationships emerged from our data which yield a new insight into the association between syncope and a wide range of systemic diseases.

Cerebrovascular reactivity is impaired in patients with cardiac failure.

AIMS: We undertook this study to evaluate potential changes in cerebral vasoreactivity in patients with cardiac failure and their consequent dependence upon cardiac functional variables. METHODS AND RESULTS: A total of 50 patients with various degrees of heart failure, 20 age-matched controls and 20 normal controls were examined. Cerebrovascular reactivity was examined with the carbon dioxide technique. Mean flow velocities of both middle cerebral arteries as well as end-tidal carbon dioxide partial pressure were continuously registered. Normal controls were examined on two different occasions, to evaluate the technique's reproducibility. Cerebrovascular reactivity was significantly reduced in all examined patients as compared to controls, and in NYHA IV as compared to NYHA II and III patients. A significant relationship between cerebrovascular reactivity and left ventricular ejection fraction was evident. Reproducibility of the technique was satisfactory. CONCLUSION: Our study provided evidence of significantly reduced cerebrovascular reactivity in patients with cardiac failure, which was significantly related to the NYHA grade and the left ventricular ejection fraction.

Autonomic control of heart rate variability in vasovagal syncope: a study of the nighttime period in 24-hour recordings.

Patients experiencing vasovagal syncope have been claimed to show reduced vagal tone over 24-hour electrocardiography recordings. Assessment of sympathovagal balance in the absence of external stimuli, i.e., nighttime electrocardiography monitoring, might help to clarify if increased sympathetic activity is present in these patients. Heart rate variability was examined at nighttime in 40 patients with recurrent episodes of vasovagal syncope within the last 2 years (22 men; mean age, 37 years) and 20 comparable healthy volunteers. Time domain parameters (pNN50 [proportion of successive RR intervals difference >50 ms in %] and rMSSD [root-mean-square successive difference of RR intervals in ms]), indexes of vagal tone, and frequency domain parameters, expressing the overall heart rate variability, vagal (high frequency [HF]) and sympathetic (low frequency [LF]) activity, and autonomic balance (LF/HF ratio) were compared between groups by Mann-Whitney test. Significant (p<0.05) reduction of heart rate variability and vagal tone (pNN50 and rMSSD) were found for patients with vasovagal syncope, together with increased sympathetic activity (increased LF/HF ratio). These findings could open new insights in the pathogenesis of vasovagal syncope because of the shift of the autonomic balance toward sympathetic activation near the syncopal episode.

Autonomic control of the cerebral circulation during normal and impaired peripheral circulatory control.

OBJECTIVE: To determine whether oscillations in the cerebrovascular circulation undergo autonomic modulation in the same way as cardiovascular oscillations. DESIGN: Cardiovascular and cerebrovascular oscillations were monitored at rest and during sympathetic stimulation (head up tilt). The association with and transmission of the oscillations in the sympathetic (low frequency, LF) and respiratory (high frequency, HF) bands was assessed. SUBJECTS: 13 healthy volunteers, 10 subjects with vasovagal syncope, and 12 patients with complicated non-insulin dependent diabetes mellitus. MAIN OUTCOME MEASURES: Power spectrum analysis of cerebral blood flow velocity, arterial blood pressure, and heart rate. Coherence analysis was used to study the association between each pair of oscillations. Phase analysis showed the delay of the oscillations in the cardiovascular signals with respect to the cerebrovascular signals. RESULTS: The power in the sympathetic (LF) components in all the oscillations increased during head up tilt (p < 0.01) in the controls and in the subjects with vasovagal syncope, but not in patients with diabetes. Significant coherence (> 0.5) in the LF band was present between cerebrovascular and cardiovascular oscillations in most of the controls and in subjects with vasovagal syncope, but not in the diabetic patients (< 50% of the patients). In the LF band, cerebrovascular oscillations preceded the cardiovascular oscillations (p < 0.05) at rest in all groups: the phase shifts were reduced (p < 0.05) during head up tilt for all cardiovascular signals in healthy and syncopal subjects, but only for heart rate in diabetic patients. CONCLUSIONS: The cerebrovascular resistance vessels are subject to autonomic modulation; low frequency oscillations in cerebral blood flow velocity precede the resulting fluctuations in other cardiovascular signals. Autonomic neuropathy and microvascular stiffness in diabetic patients reduces this modulation.