A new technique for percutaneous dilatational tracheostomy (G-Trach): preliminary experience in pigs.

Tracheostomies are currently used for airway management in patients requiring long-term respiratory assistance. The dilatational percutaneous technique of forming tracheostomies is a valuable alternative to traditional surgical 'open' techniques. In this study, we tested a new dilatational percutaneous tracheostomy device using a balloon dilator with a particular innovative shape (G-Trach). At the Autonomous University of Barcelona Veterinary Institute, eight pigs (weighing 20-40 kg) were anaesthetised and underwent tracheostomy using the novel G-Trach technique. The mean (SD) procedure time was 2.63 (0.64) min from tracheal puncture to ventilation through the tracheostomy tube, and the mean (SD) time from positioning the dilator balloon to introducing the cannula was 0.71 (0.38) min. Vital functions and oxygen saturation remained constant throughout the procedures. Postmortem examinations did not reveal any tracheal injury. The G-Trach seems to be a safe and easy new dilatational percutaneous technique for forming tracheostomies. The minimal subcutaneous tissue dissection could potentially decrease complications when compared with standard dilatational percutaneous tracheostomy methods. To confirm this hypothesis a human trial is ongoing.

A misleading trismus.

We report the case of a 73-year-old women admitted to ICU with a diagnosis of tetanum supported by a mild trismus and treated with potentially unsafe drugs until the correct diagnosis was made.

Silybin-beta-cyclodextrin in the treatment of patients with diabetes mellitus and alcoholic liver disease. Efficacy study of a new preparation of an anti-oxidant agent.

BACKGROUND AND AIMS: In patients with non-insulin dependent diabetes mellitus (T2DM) and associated chronic liver disease, plasma levels of glucose, insulin and triglycerides are high, lipid peroxidation is increased and natural antioxidant reserves are reduced. Thus, we hypothesised that the re-balancing of cell redox levels and amelioration of liver function could result in a better glucose and lipid metabolism. To study this, we assessed the effect of a new oral formulation of an antioxidant agent - silybin-beta-cyclodextrin (named IBI/S) - in patients with chronic alcoholic liver disease and concomitant T2DM. METHODS: Sixty outpatients were enrolled in a three-centre, double blind, randomised, IBI/S vs placebo study. Forty-two (21 in the group IBI/S - 135 mg/d silybin per os - and 21 in the placebo group) concluded the 6-month treatment period. The efficacy parameters included fasting and mean daily plasma glucose levels, glycosylated hemoglobin (HbA1c), basal, stimulated C-peptide and insulin levels, total-, HDL-cholesterol and triglycerides levels in addition to conventional liver function tests. Insulin sensitivity was estimated by HOMA-IR. Malondialdehyde (MDA) was also measured before and after treatment as an index of oxidative stress. RESULTS: Fasting blood glucose levels, which were similar at baseline in IBI/S group and in the placebo group (173.9 mg/dl and 177.1 mg/dl, respectively), decreased to 148.4 mg/dl (-14.7% vs baseline; p = 0.03) in the IBI/S group while they were virtually unchanged in the placebo group. The comparison between the groups at mo 6 (T6) also showed a significant reduction of glucose levels in the IBI/S group (p = 0.03). The same trend was observed in mean daily blood glucose levels, HbA1c and HOMA-IR, although differences were not significant. Basal and stimulated C-peptide values showed that only a few changes had occured in both groups. Such results indicate that insulin secretion was virtually unaffected, as confirmed also by the insulinemia data. Plasma triglycerides concentrations dropped from a baseline value of 186 mg/dl to 111 mg/dl (T6) in the IBI/S group, with significant differences at all instances with respect to baseline values. By contrast, triglycerides increased from 159 mg/dl at entry to 185 mg/dl (T6) in the placebo group. The difference between the groups at T6 was highly significant (p < 0.01). Total and HDL cholesterol as well as liver function tests did not change significantly during the study in both groups. MDA decreased significantly only in the group receiving IBI/S. No clinically relevant side effects were observed in either group. CONCLUSIONS: Oral administration silybin-beta-cyclodextrin in patients with T2DM and compensated chronic alcoholic liver disease causes a significant decrease in both glucose and triglyceride plasma levels. These effects may be due to the recovery of energy substrates, consistent with a reduced lipid peroxidation and an improved insulin activity.

Reduction in gram-positive pneumonia and antibiotic consumption following the use of a SDD protocol including nasal and oral mupirocin.

The objective of this prospective, randomized, double-blind study was to evaluate the effect of the addition of mupirocin to the 'classical' topical SDD regimen (tobramycin 80 mg, polymyxin E 100 mg, amphotericin B 500 mg) on the development of ICU-acquired infections due to gram-positive bacteria. The study was carried out in an intensive care unit (ICU) of a 1400-bed community hospital. All patients admitted to the ICU during a 16-month period, who were expected to require mechanical ventilation for more than 24 hours, were randomized to receive either the 'classical' SDD regimen (Group A) or a modified regimen with mupirocin (Group B). Data from 223 patients requiring mechanical ventilation for at least 48 hours, who were neither infected nor receiving antibiotics on ICU admission, was analysed. A 2% paste containing tobramycin, polymyxin E and amphotericin B was applied every 6 hours in the oropharynx to the patients in Group A, while in Group B this formula was modified with the addition of 2% mupirocin. In Group B 0.2 ml of a 2% mupirocin ointment was also applied four times daily in both nostrils. Patients in Group A received a soft paraffin ointment as a placebo indistinguishable from mupirocin. Patients in both groups received the classic SDD regimen through the nasogastric tube. Systemic antibiotic prophylaxis was not used. Data on lower airway infection, and blood infection, infections of intravascular catheters, antibiotic consumption and expenditures for antibiotics were analysed. The diagnosis of ventilator-associated pneumonia (VAP) was based on quantitative cultures of protected specimen brush samples (PSB) or on the results of distal broncho-alveolar lavage (BAL). One hundred and four patients received the 'classical' SDD and 119 the modified regimen. Overall 29 patients, 20 in Group A and nine in Group B (p < 0.02) had a total of 33 cases of pneumonia. There were 23 episodes of pneumonia in Group A and 10 in Group B (p < 0.02). Gram-positive bacteria were isolated from samples in 17 episodes in Group A and six in Group B (p < 0.02). Staphylococcus aureus was isolated in nine cases of pneumonia in Group A and once in the 'mupirocin' group (p < 0.05). MRSA were isolated in seven out of nine cases in Group A and in the only case in Group B. There were no differences in the isolation of gram-negative bacilli. Antibiotic consumption and cost were lower in Group B. In conclusion, our data show that the topical use of a modified formula of SDD, with the addition of mupirocin to the oral paste and in the anterior nares, is associated with a reduction in lung infections caused by gram-positives and in a reduction in antibiotic consumption and in the overall expenditure for antibiotics.

Intra-operative spinal cord monitoring in orthopaedics.

The surgical correction of spinal deformities carries a small but significant risk of injury to the spinal cord. To detect the onset and possibly reverse the effects of surgical complication, a variety of neurophysiological monitoring procedures can be employed. The purpose of this review is to provide information regarding the various methodologies available for monitoring spinal cord and nerve root function during orthopaedic procedures. Intra-operative monitoring of cortically recorded somatosensory evoked potentials (SEPs) by peripheral nerve stimulation is of value during orthopaedic surgery and is the state-of-the-art in terms of non-invasiveness, versatility, time requirement, lateral discrimination, and ease of electrode placement. Monitoring of motor evoked potentials (MEPs) is useful particularly in combination with SEPs but is still considered investigational. Root function monitoring has limited application and requires more clinical research.

Myeloprotective effect of early primary granulocyte-colony stimulating factor during six courses of intensified 5-fluorouracil, epirubicin and cyclophosphamide (120FEC) chemotherapy for advanced breast cancer. Cooperative Group of Study and Treatment of Breast Cancer.

AIMS AND BACKGROUND: The neutropenia induced by six courses of an intensified FEC regimen is expected to be checked by early primary administration of G-CSF which is stopped eight days before the next chemotherapy course. Less information is available about megakaryocytic and erythroid toxicity over six courses. METHODS AND STUDY DESIGN: Sixty-six consecutive patients with metastatic breast cancer completed six courses of a randomized treatment with two FEC regimens administered every 21 days, in which 600 mg/m2 of cyclophosphamide and 5-FUwas associated with 60 or 120 mg/m2 of epirubicin (60FEC, 35 patients, vs 120FEC, 31 patients). 120FEC was supported by early primary G-CSF (days 4 to 13). Blood counts were obtained seven times during each course. RESULTS: The non-hematologic toxicity over 364 courses was similar in 60FEC and 120FEC. No cumulative hematologic toxicity was observed for white blood cells (WBC) and platelets (PLT), while for hemoglobin (Hb) a somewhat higher cumulative toxicity was observed with 120FEC than with 60FEC. WBC, PLT and Hb grade III-IV toxicity occurred in 40.1% and 45.6% (P=ns), in 23.1% and 0.8% (P <.0001) and in 15.6% and 3.0% (P <.005) of the two regimens, respectively. There were no febrile or hemorrhagic episodes. The epirubicin relative dose intensity delivered was 1.95 in 120FEC with respect to 60FEC. CONCLUSIONS: Our G-CSF schedule permitted to deliver six courses of 120FEC without any clinically relevant side effects. Grade III-IV leukopenia was similar with 120FEC and 60FEC, while grade III-IV thrombocytopenia and anemia occurred more often with 120FEC than with 60FEC.

Comparison of intravenous nifedipine and sodium nitroprusside for treatment of acute hypertension after cardiac surgery.

BACKGROUND: The present study was designed to compare the hemodynamic effects of nifedipine and sodium nitroprusside, intravenously administered to control acute systemic hypertension in the immediate postoperative period after open heart surgery. METHODS: The study was carried out on 16 patients who developed acute systemic hypertension, defined as mean systemic arterial pressure (MAP) values above 90 mmHg, within the first hour after ICU admission, which followed cardiac surgery for valvular and coronary disease. After control measurements during the hypertensive status, each patient was treated by alternating infusions of sodium nitroprusside and nifedipine in order to obtain MAP values of about 80 mmHg with each administration. All patients had preoperative left ventricular ejection fraction above 45%. RESULTS: Nifedipine produced a superior and significant increase in cardiac index (CI) (+28%) and stroke volume index (SVI) (+30%), and a greater decrease in systemic vascular resistance index (SVRI) (-39%), when compared with sodium nitroprusside [CI (+5%), SVI (no change), SVRI (-27%)]. On the contrary the right and left ventricular filling pressures were reduced significantly by sodium nitroprusside [pulmonary capillary wedge pressure (-30%), central venous pressure (-20%)], while nifedipine induced small and not significant changes in the preload values. No ECG changes suggesting ischemic myocardial events were observed in any patient. CONCLUSIONS: On the basis of these results it has been concluded that nifedipine affects primarily the arteriolar resistance vessels without significant changes in venous tone, which is on the contrary markedly reduced by sodium nitroprusside. The better improvement in cardiac index and stroke volume index obtained with the administration of nifedipine, makes this drug a good alternative to sodium nitroprusside for treatment of acute hypertension after cardiac surgery in patients with a good preoperative left ventricular function.

Paclitaxel in anthracycline-treated breast cancer patients.

Between May 1995 and July 1997, paclitaxel (TX) (175 mg/m2 by 3 h i. v. infusion every 21 days) was administered to 70 consecutive patients (median age: 57 years) previously treated with the FEC regimen (cyclophosphamide and 5-fluorouracil, 600 mg/m2, plus epirubicin, 60 or 120 mg/m2) as an adjuvant setting or as a first-line therapy for metastatic disease. Sixty-eight patients were evaluable for response, while two died early. Patients received a median of 4.7 (3-12 course) of TX for a total of 211 courses. The overall response and stable disease rate was 54% in 11 patients, who relapsed following adjuvant FEC, and 60% in 57 patients, who received FEC as first treatment for their metastatic disease. No complete respose was obtained. In patients pretreated for metastatic disease, response and stable disease rates were similar irrespective of previous response to FEC. Main hematologic toxicity of TX was of short duration, grade II/III leukopenia (86% of patients) and non-hematologic toxicity was grade II/III peripheral neuropathy, related to the cumulative dose of TX. At this schedule, TX offers a significant rate of partial responses or disease stabilization in patients with metastatic breast cancer previously treated with FEC.

REM sleep behaviour disorder differentiates pure autonomic failure from multiple system atrophy with autonomic failure.

Ten patients with primary autonomic failure, followed up in a prospective clinical and laboratory study, were finally diagnosed as pure autonomic failure or multiple system atrophy with autonomic failure. Polysomnographic studies were performed in all patients. Whereas all four patients with multiple system atrophy complained of sleep related episodes suggesting REM sleep behaviour disorder (RBD) confirmed by polysomnography, RBD remained absent in the remaining six patients with pure autonomic failure. The data indicate that RBD is an important clinical feature, often heralding multiple system atrophy, but which is absent throughout the course of pure autonomic failure; its recognition can thus be useful in the prognostic evaluation of early primary autonomic failure syndromes.

Searching for migraine genes: exclusion of 290 cM out of the whole human genome.

A linkage and association analysis was made on 14 Italian families with recurrent migraine. We analyzed five chromosomal regions surrounding the candidate genes 5HT1D (1p36.3-34.3), 5HT1B (6q13), 5HT2A (13q14-21), 5HT transporter (17q11.2-12), CACNLB1 (17q11.2-22) and FHM (19p13), using 29 DNA polymorphic markers. All two-point lod scores were negative, and the chi 2 sib-pair analyses were not significant, thus indicating the probable exclusion of these regions as sites of migraine genes in our population.

[Circulatory instability in potential donor organ patients in a state of brain death. Investigation of predictive factors]. / Instabilità circolatoria nei pazienti in stato di morte cerebrale potenziali donatori d'organo. Ricerca di fattori predittivi.

OBJECTIVE: To assess the factors influencing and predicting the degree of circulatory impairment of the brain-dead cardiac donors (BDCD). DESIGN: Retrospective study. SETTING: General ICU of a 1400 bed High Specialty Regional Hospital. PATIENTS: 53 patients undergoing brain death (BD) assessment as suitable cardiac-donors. INTERVENTIONS: Fluids were given up to a central venous pressure (CVP) > 5 mmHg and adrenergic drugs in a sequential manner trying to keep the systolic blood pressure > 90 mmHg. METHODS: Every hour during the time of BD assessment were recorded: invasive blood pressure (BP), CVP, fluid balance, the demographic data, the dosage of adrenergic drugs, the cause of admission, the time from admission to ICU to BD, the report of an echocardiogram. The patients were divided into 4 classes according to the dosage of the adrenergic drugs required to achieve the pressure-goal. The 4 classes were compared for the above mentioned parameters. RESULTS: No differences were found among the 4 groups. CONCLUSIONS: In BDCD the degree of circulatory instability and vasopressor needs cannot be anticipated by the parameters examined. This could be due partly to the relative homogeneity of these patients, since they underwent a clinical selection and similar interventions, partly to a possibly inadequate standard of monitoring. Anyway the unique hemodynamic situation after BD is probably not very affected by the previous events. Further studies are necessary to explain the variability of the circulatory instability and to assess its effects on the quality of the transplanted organs.

Long-term (12 months) treatment with an anti-oxidant drug (silymarin) is effective on hyperinsulinemia, exogenous insulin need and malondialdehyde levels in cirrhotic diabetic patients.

BACKGROUND/AIMS: Several studies have demonstrated that diabetic patients with cirrhosis require insulin treatment because of insulin resistance. As chronic alcoholic liver damage is partly due to the lipoperoxidation of hepatic cell membranes, anti-oxidizing agents may be useful in treating or preventing damage due to free radicals. The aim of this study was to ascertain whether long-term treatment with silymarin is effective in reducing lipoperoxidation and insulin resistance in diabetic patients with cirrhosis. METHODS: A 12-month open, controlled study was conducted in two well-matched groups of insulin-treated diabetics with alcoholic cirrhosis. One group (n=30) received 600 mg silymarin per day plus standard therapy, while the control group (n=30) received standard therapy alone. The efficacy parameters, measured regularly during the study, included fasting blood glucose levels, mean daily blood glucose levels, daily glucosuria levels, glycosylated hemoglobin (HbA1c) and malondialdehyde levels. RESULTS: There was a significant decrease (p<0.01) in fasting blood glucose levels, mean daily blood glucose levels, daily glucosuria and HbA1c levels already after 4 months of treatment in the silymarin group. In addition, there was a significant decrease (p<0.01) in fasting insulin levels and mean exogenous insulin requirements in the treated group, while the untreated group showed a significant increase (p<0.05) in fasting insulin levels and a stabilized insulin need. These findings are consistent with the significant decrease (p<0.01) in basal and glucagon-stimulated C-peptide levels in the treated group and the significant increase in both parameters in the control group. Another interesting finding was the significant decrease (p<0.01) in malondialdehyde/levels observed in the treated group. CONCLUSIONS: These results show that treatment with silymarin may reduce the lipoperoxidation of cell membranes and insulin resistance, significantly decreasing endogenous insulin overproduction and the need for exogenous insulin administration.

Effects on renal function of a continuous infusion of nifedipine during cardiopulmonary bypass.

OBJECTIVES: To evaluate the effects on renal function of continuously administered nifedipine during cardiopulmonary bypass (CPB) in patients undergoing cardiac surgery. DESIGN: The study was prospective, randomized, and controlled. SETTING: The study was performed in the Department of Anesthesia and intensive care unit of a regional hospital in Italy. PARTICIPANTS: Thirty-four patients scheduled for elective coronary artery surgery; all patients had preoperative renal and hemodynamic function within normal limits. INTERVENTIONS: The patients were randomly divided into two equal groups: nifedipine and control. Twenty patients were included in the study: 10 patients in the nifedipine group (group A) and 10 patients in the control group (group B). In group A, nifedipine was continuously administered during CPB at an infusion rate ranging from 0.24 to 0.59 micrograms/kg/min to maintain the mean systemic arterial pressure (MAP) between 60 and 70 mmHg. In group B, increases of MAP above 70 mmHg were treated with IV boluses of urapidil (5 mg). MEASUREMENTS AND MAIN RESULTS: Renal function was studied using creatinine clearance (CRCL), determined before, during, and after the operation, and the glomerular filtration rate (GFR) was measured the day before and after the operation by plasma and urine clearance of 51-chromium edetic acid (51Cr-EDTA). Hemodynamic monitoring was performed using a pulmonary artery catheter. In comparison with preoperative determinations, CRCL and GFR values increased significantly after CPB (p < 0.001) and after the operation (p < 0.01) in the patients treated with nifedipine, whereas the two parameters showed a small and not significant reduction at the same times in the control patients. Hemodynamic function was well maintained in all patients throughout the study. CONCLUSIONS: It is concluded that, besides the maintenance of adequate hemodynamics, a continuous infusion of nifedipine during CPB can be an additional therapeutic tool to protect renal function in cardiac surgical patients.

Hemodynamic responses to external counterbalancing of auto-positive end-expiratory pressure in mechanically ventilated patients with chronic obstructive pulmonary disease.

OBJECTIVE: To study the effect of positive end-expiratory pressure (PEEP) on right ventricular hemodynamics and ejection fraction in patients with chronic obstructive pulmonary disease and positive alveolar pressure throughout expiration by dynamic hyperinflation (auto-PEEP). DESIGN: Open, prospective, controlled trial. SETTING: General intensive care unit of a community hospital. PATIENTS: Ten patients sedated and paralyzed with an acute exacerbation of chronic obstructive pulmonary disease undergoing mechanical ventilation. INTERVENTIONS: Insertion of a pulmonary artery catheter modified with a rapid response thermistor and a radial arterial catheter. PEEP was then increased from 0 (PEEP 0) to auto-PEEP level (PEEP = auto-PEEP) and 5 cm H2O above that (PEEP = auto-PEEP +5). MEASUREMENTS: At each level of PEEP, airway pressures, flow and volume, hemodynamic variables (including right ventricular ejection fraction by thermodilution technique), and blood gas analyses were recorded. MAIN RESULTS: The mean auto-PEEP was 6.6 +/- 2.8 cm H2O and the total PEEP reached was 12.2 +/- 2.4 cm H2O. The degree of lung inflation induced by PEEP averaged 145 +/- 87 mL with PEEP = auto-PEEP and 495 +/- 133 mL with PEEP = auto-PEEP + 5. The PEEP = auto-PEEP caused a right ventricular end-diastolic pressure increase, but there was no other significant hemodynamic change. With PEEP = auto-PEEP + 5, there was a significant increase in intravascular pressures; this amount of PEEP reduced cardiac output (from 4.40 +/- 1.38 L/min at PEEP 0 to 4.13 +/- 1.48 L/min; p < .05). The cardiac output reduction induced by PEEP = auto-PEEP + 5 was > 10% in only five cases and this group of patients had significantly lower right ventricular volumes than the group with less cardiac output variation (right ventricular end-diastolic volume: 64 +/- 9 vs. 96 +/- 26 mL/m2; right ventricular end-systolic volume: 38 +/- 6 vs. 65 +/- 21 mL/m2; p < .05) without significant difference in the other variables that were measured. Neither right ventricular ejection fraction nor right ventricle volumes changed as PEEP increased, but there were marked interpatient differences and also pronounced changes in volume between stages in individual patients. CONCLUSIONS: In the study conditions, PEEP application up to values approaching auto-PEEP did not result in the impairment of right ventricular hemodynamics, while higher levels reduced cardiac output in selected patients.

Impact of emergency medical helicopter service on mortality for trauma in north-east Italy. A regional prospective audit.

The hypothesis that high level on-the-field ATLS could influence mortality in severe trauma patients was tested by means of a prospective study. During a 7 month period, data of all the victims of severe involuntary trauma (road traffic accidents, work and sport accidents) in 3 Provinces of north-east Italy were entered in a database and analysed. The whole area is covered by a single emergency service which has direct control over all the ambulances and the Emergency Helicopter Service (EMHS). The area concerned by the study has a surface of 7,300 kmq with a population of 1 million inhabitants and is served by 12 first level hospitals and 4 second level institutions (trauma centres). All the patients who were still alive at the time of arrival of the first rescuers were considered, but only severe trauma patients with ISS > 15 were enclosed into the study. All the patients were followed up to their discharge from the ICUs (end point). There were three different rescue approaches: 82 Patients (GROUP A) were rescued by EMTs with BLS training, transported to the nearest level 1 hospital for stabilisation and subsequently transferred to a trauma center; 98 Patients (GROUP B) were rescued by EMTs and directly transported to a trauma centre which was the nearest institution; 42 Patients were rescued on the scene by the EMHS team including an anaesthesiologist with 10 years experience in trauma care and directly transported to a trauma centre after full on-the-field stabilisation (GROUP C) RESULTS: 222 severe trauma patients (ISS > 15) were considered. Mean ISS was 35.1 +/- 18.2 in group A, 33.4 +/- 19.6 in group B and 36.0 +/- 17.8 in group C. 67 patients died previous to ICU discharge (31%). 31 over the 82 pts in Group A (38%) died. 23 of them died even before reaching the trauma centre. The mean time elapsed between the first emergency call and the arrival at the trauma centre was 162 min (90'-300'). Mean ICU stay for patients who survived was 15 days. In Group B 31 over 98 patients (32%) died before ICU discharge. The mean time between the emergency call and hospital admission was 27'. Mean ICU stay for patients who were discharged, was 13 days. 5 over 42 patients rescued by the EMHS (Group C) died, none of them in the pre-hospital setting. Stabilisation included tracheal intubation in 34 cases (81%) and thoracic drainage in 6 (14%). All the patients arrived at the hospital with 2 i.v. line. The average amount of infused fluids were 600 mls of colloids and 810 mls of crystalloid. 13 patients with hypotension received and average of 1000 mls of colloids and 1200 mls of crystalloid. The average time elapsed between the emergency call and the final admission to the definitive care institution was 55'. Mean ICU stay was 11 days. Mortality rate in this group was 12%, significantly lower than in group A (p < 0.005) and group B (p < 0.05).

[The thermodilution determination of right ventricular volumes and ejection fraction in the critical patient. Volumetric vs pressure measurement assessment]. / Determinazione mediante termodiluizione dei volumi e della frazione di eiezione del ventricolo destro nel paziente critico. Valutazione volumetrica vs pressumetrica.

The widespread use of hemodynamic investigation techniques, allowed a better understanding of the right ventricle (RV) pathophysiology and led to progressive reevaluation of its role. A modification of the classical Swan-Ganz catheter, made possible the measurement of the ejection fraction (EF) and of the end-systolic and end-diastolic volumes of RV just by the simple application of the thermodilution technique. In this paper, we first refreshed the basic theoretical principles of the technique and then presented our preliminary results of one-year experience in ICU. A non-homogeneous group of 36 critically ill patients (septic shock 17, COPD 13 and ARDS 6) was studied. Specifically we found that neither the data of central venous pressure nor those of RV end diastolic pressure, were able to estimate the real preload, i.e. RV end diastolic volume (r = 0.01 and r = 0.03 respectively with "p" not significant). We compared the data of RV EF with that of the end systolic pressure/volume (P/V) ratio in a group of patients before and during the administration of dobutamine to evaluate their sensitivity to identify changes of contractility. The results obtained support the superiority of RV end systolic P/V ratio over RV EF to detect variations of contractile status. We conclude that the use of the thermodilution technique to measure the volumes of RV, allows a real evaluation of the preload. At the same time it avoids all the problems associated with the measurement of transmural pressure and with the changes produced by shifting of intrapleural pressure. Finally the end systolic volume may be combined with the pressure data to estimate the contractile status and, in our experience, this parameter has proved more sensitive than EF in order to detect changes of contractility of the right ventricle.

Epidemiological impact of prolonged systematic use of topical SDD on bacterial colonization of the tracheobronchial tree and antibiotic resistance. A three year study.

OBJECTIVE: to evaluate the effect of the prolonged systematic use of topical SDD (tobramycin 80 mg, polymyxin E 100 mg, amphotericin B 500 mg) on ICU ecology as expressed by changes in tracheal colonization and bacterial resistances. DESIGN: Prospective microbiological survey. SETTING: Polyvalent ICU of a 2000 beds general hospital. PATIENTS: Data concerning bacterial strains isolated from the tracheo-bronchial aspirates of all the patients admitted to a polyvalent ICU over 3 consecutive periods of 12 months ('88, '89, '90) were prospectively entered in a database and subsequently analyzed. During a 3-year period 502 patients required artificial ventilation for more than 72 h and 332 of them ('89 and '90) were treated with SDD. All samples collected within 72 h from ICU admission were excluded as well as duplicate samples from the same patients. INTERVENTION: All the patients admitted to the ICU in '89 and '90 and submitted to artificial ventilation for at least 24 h were routinely treated with topical SDD without i.v. antibiotic prophylaxis; in '88 SDD was not employed. MEASUREMENTS AND RESULTS: Criteria for collecting sputum samples and microbiological procedures remained unchanged throughout the study-time. Positive sputum were significantly less in '89 (80.8% versus 92.3% p < 0.001) and this was due to a very sharp decrease in the isolation of Gram-negative strains from 43-28% (-64% p < 0.0001) involving both: Enterobacteriaceae (-45%) and Pseudomonaceae (-77%). In 1990; however, a new increase in Gram negative was observed, although the overall amount of Gram-negative was still 49% lower in '90 if compared to '88 (p < 0.0001). A dramatic increase in Pseudomonas isolation was the only factor responsible for the "rebound" observed. An increasing percentage of Pseudomonas developed a resistance towards tobramycin and only 45% of Pseudomonas strains turned out to be sensible to tobramycin in '90 against 79% in '88. A similar trend was registered for all aminoglycosides with the exception of amikacin. Gram-positive colonizations tended to increase (+63%) (p < 0.0001) and this was mainly due to Coagulase negative Staphylococci (+290% p < 0.0001) and S. pneumoniae, whereas S. aureus isolations decreased (-18%) but not significantly. CONCLUSIONS: Our data suggest that the prolonged use of SDD is associated with dramatic changes in ICU ecology: the incidence of Gram negative colonization is significantly diminished by SDD whereas Gram positive tend to increase. Pseudomonas developed an increasing resistance towards tobramycin one of the components of the SDD formula we used.