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Biomedical subjects

G Ronzoni

Publications and source records attributed to G Ronzoni.

At least 19 recordsLinked to original sources
PubMed2004

Positive end-expiratory pressure applied to the dependent lung during one-lung ventilation improves oxygenation and respiratory mechanics in patients with high FEV1.

BACKGROUND AND OBJECTIVE: The aim of this study was to test the efficacy of positive end-expiratory pressure (PEEP) to the dependent lung during one-lung ventilation, taking into consideration underlying lung function in order to select responders to PEEP. METHODS: Forty-six patients undergoing open-chest thoracic surgical procedures were studied in an operating room of a university hospital. Patients were randomized to receive zero end-expiratory pressure (ZEEP) or 10 cmH2O of PEEP to the dependent lung during one-lung ventilation in lateral decubitus. The patients were stratified according to preoperative forced expiratory volume in 1 s (FEV1) as an indicator of lung function (below or above 72%). Oxygenation was measured in the supine position, in the lateral decubitus with an open chest, and after 20 min of ZEEP or PEEP. The respiratory system pressure-volume curve of the dependent hemithorax was measured in supine and open-chest lateral decubitus positions with a super-syringe. RESULTS: Application of 10 cmH2O of PEEP resulted in a significant increase in PaO2 (P < 0.05). This did not occur in ZEEP group, considered as a time matched control. PEEP improved oxygenation only in patients with high FEV1 (from 11.6+/-4.8 to 15.3+/-7.1 kPa, P < 0.05). There was no significant change in the low FEV1 group. Dependent hemithorax compliance decreased in lateral decubitus, more in patients with high FEV1 (P < 0.05). PEEP improved compliance to a greater extent in patients with high FEV1 (from 33.6+/-3.6 to 48.4+/-3.9 mLcmH2O(-1), P < 0.05). CONCLUSIONS: During one-lung ventilation in lateral decubitus, PEEP applied to the dependent lung significantly improves oxygenation and respiratory mechanics in patients with rather normal lungs as assessed by high FEV1.

Analysis of Variance↗
PubMed2001

Recruitment and derecruitment during acute respiratory failure: a clinical study.

In a model of acute lung injury, we showed that positive end-expiratory pressure (PEEP) and tidal volume (VT) are interactive variables that determine the extent of lung recruitment, that recruitment occurs across the entire range of total lung capacity, and that superimposed pressure is a key determinant of lung collapse. Aiming to verify if the same rules apply in a clinical setting, we randomly ventilated five ALI/ARDS patients with 10, 15, 20, 30, 35, and 45 cm H2O plateau pressure and 5, 10, 15, and 20 cm H2O of PEEP. For each PEEP-VT condition, we obtained computed tomography at end inspiration and end expiration. We found that recruitment occurred along the entire volume-pressure curve, independent of lower and upper inflection points, and that estimated threshold opening pressures were normally distributed (mode = 20 cm H2O). Recruitment occurred progressively from nondependent to dependent lung regions. Overstretching was not associated with hyperinflation. Derecruitment did not parallel deflation, and estimated threshold closing pressures were normally distributed (mode = 5 cm H2O). End-inspiratory and end-expiratory collapse were correlated, suggesting a plateau-PEEP interaction. When superimposed gravitational pressure exceeded PEEP, end-expiratory collapse increased. We concluded that the rules governing recruitment and derecruitment equally apply in an oleic acid model and in human ALI/ARDS.

Adult↗
PubMed2001

Pulmonary lobectomy for lung cancer: a prospective study to compare patients with forced expiratory volume in 1 s more or less than 80% of predicted.

OBJECTIVE: To compare post-operative course, lung function and survival of lung cancer patients with a forced expiratory volume in 1 s (FEV1) more or less than 80% of predicted submitted to lobectomy. METHODS: The data of patients undergoing lobectomy for non small cell carcinoma at the Thoracic Surgery Unit of the Ospedale Maggiore Policlinico of Milan, Italy, were prospectively collected. Inclusion criteria were a radical resectable tumor with size less than 2.5 cm, negative mediastinal nodes, capability to complete pulmonary function tests, Exclusion criteria were FEV1 <40% of predicted, pre- or post-operative chemo or radiotherapy, lobe to be resected receiving more than 30% of the perfusion, incapacity to quit smoking. RESULTS: Eighty-eight patients entered the study and were divided into two groups according to their FEV1%: 45 patients were included in control group (mean FEV1: 92.2%) and 42 in chronic obstructive pulmonary disease group (mean FEV1: 64.2%). Post-operative complications, operative mortality and actuarial survival were the same in the 2 groups. Six months after lobectomy, the mean changes in FEV1 were -14.9% for first group and -3.2% for second group (P<0.001). CONCLUSION: Lobectomy for cancer can be performed successfully also in selected patients with chronic obstructive pulmonary disease. Post-operative course and survival of these patients is not different from that of patients with normal FEV1, on the contrary, patients with low FEV1 may lose less pulmonary function or even mend it.

Aged↗
PubMed2000

Valsalva leak point pressure: how to chose the best method.

Urinary continence is ensured as long as the urethral closure pressure remains greater than the intravesical pressure, in the presence of adequate support to the bladder and the proximal urethra. In order to select the appropriate surgical treatment, a correct diagnosis must be made; recently urodynamic evaluation has assumed a central role. In particular, the introduction of a new urodynamic parameter, the Valsalva Leak Point Pressure (VLPP), has provided new impetus to research in this area, even if different technical approaches have limited universal acceptance. The aim of the work is to describe the reasons why the authors have been led to prefer double measurement, both at partial filling and at maximum cystometric capacity, considering that this does not involve any additional economic burden. The authors underline the promising potential of the method, once standardized, in the urodynamic evaluation of urinary incontinence.

Female↗
PubMed1999

Unilateral testicular microlithiasis.

Testicular microlithiasis is a rare pathology which usually affects both testicles (less than 100 cases have been described in the literature), histologically characterized by numerous calcified deposits situated inside the seminiferous tubules, the diameter of which does not usually exceed 2 mm. The pathogenesis of the phenomenon is not completely clear; it has however been noted that there is a higher incidence in patients affected by cryptorchidism, subfertility, Klinefelter's syndrome and in particular those with testicular neoplasms, although the reason for this remains obscure. The case reported seems atypical in that there is no association with the conditions mentioned above and the finding is monolateral, something which is unusual in the literature reviewed.

Adult↗
PubMed1998

Preservation of anterograde ejaculation after transurethral resection of both the prostate and bladder neck.

OBJECTIVE: To determine whether anterograde ejaculation is preserved after transurethral resection of both the prostate and bladder neck (TURP and TURBN). PATIENTS AND METHODS: Between 1994 and 1997, 45 patients (mean age 53.2 years, range 42-62) with bladder neck obstruction and small obstructive adenomas (< 35 g) underwent TURP/TURBN, preserving part of the supramontanal prostate and prostatic urethra for > 1 cm from the verumontanum. They were assessed before and after 0.5-2 years to determine the type of ejaculation, symptom scores and sexual function, and compared with 10 similar patients who had undergone a conventional TURP. RESULTS: With preservation of > 1 cm of the supramontanal prostate, anterograde ejaculation was maintained in 80% of the patients, whereas only one patient in the control group retained anterograde ejaculation. CONCLUSIONS: The preservation of anterograde ejaculation after TURP (in approximately 20% of cases) and after transurethral incision of the prostate (> 90% cases) reported in the literature probably relates more to the presence of an adequate amount of residual prostatic tissue than to the existence of a hypothetical 'pre-prostatic sphincter'.

Adult↗
PubMed1998

[Therapy of vasomotor syndrome in the treatment of advanced prostatic cancer: apropos of 37 cases].

Castration, whether surgical (orchiectomy) or pharmacological (androgen blockade), used in the management of advanced prostatic carcinoma, induces as a secondary effect, immediately following impotence, the onset of a vasomotor syndrome characterized by hot flushes and sweating. This syndrome which may present with such intensity and frequency as to severely affect the quality of life and even the psychological equilibrium of the patient. Treatment with progestinic agents leads to the release of opioid peptides at hypothalamic level, thus decreasing the level of catecholamines responsible for the vasomotor syndrome. In the 37 cases treated with progestogens, a therapeutic efficacy of 80% was observed following cyproterone acetate and of 70% following medroxyprogesterone acetate.

Aged↗
PubMed1997

The ice-water test in the diagnosis and treatment of the neurogenic bladder.

OBJECTIVE: To determine the usefulness of the ice-water test (IWT) in the diagnosis and treatment of neurological bladder disease. PATIENTS AND METHODS: The IWT was carried out in 148 patients with neuropathic bladder dysfunction resulting from a traumatic lesion, to assist in their diagnosis and treatment, and in 130 patients with neuropathic bladder dysfunction and multiple pathogenic disorders; the results of the IWT were used to classify those patients with hyperactive bladders. RESULTS: The IWT was positive in 95% of patients affected by complete and in 86% of patients with incomplete medullary lesions. The IWT in patients with lower motor neuron medullary lesions was always negative. The test was used diagnostically in all patients with lower and in 43% of those with upper motor neuron lesions. In the latter, it was used in 48% of patients as a rehabilitation method during the medullary-shock phase to accelerate the appearance of the micturition reflex. In 9% of patients it was used to induce micturition during cystography. CONCLUSION: Because it is simple to perform, the IWT is a useful complement to urodynamic examinations in patients with neurological bladder disease and in patients with micturitional disorders that are otherwise difficult to interpret.

Cold Temperature↗
PubMed1995

Early metabolic treatment after liver transplant: amino acid tolerance.

OBJECTIVE: We investigated the amino acid (AA) tolerance during Total Parenteral Nutrition (TPN) in adult patients undergone liver transplant (LTX). DESIGN: The treatment (Glucose and AA), induced on the 2nd postoperative day, was later maintained with 27 kcal/kg Ideal Body Weight (IBW) as glucose and 0.12 (12 patients: protocol #1), 0.18 (10 patients: protocol #2) and 0.25 g nitrogen (N)/kg IBW (13 patients: protocol #3) till end of the 6th postoperative day. The N intake was sequentially modified in protocol #2 and #3 to increase the supply of the amino acid (AA) that resulted in an infusion plasma level below the expected "normal" range (between 1 and 1.6 times the overnight fasting plasma level of volunteer). PATIENTS: 35 consecutive adult patients without diabetes and organ failures for the entire study period. MEASUREMENTS: Plasma AA profile was measured before LTX and at the last TPN day under continuous infusion. During #1 and #2 protocol, many AA resulted below or at the lower range of the norm while, during 0.25 gN/kg IBW infusion, the majority of the administered AA significantly increased with respect to reference values. Nevertheless, they remained in the "normal" plasma range indicating that they were supplied in an optimal amount (particularly the aromatic and sulphurated ones, potentially toxic if liver function is impaired, and the branched chain AA (BCAA) given at consistent dosage: 0.5 g/kg). Arginine resulted significantly increased (Arg: 1.9 times the reference) and cystine (Cys: 0.45), serine (Ser: 0.8) and taurine (Tau: 0.85) remained significantly lower than "normal" as well as the not administered citrulline (Cit: 0.58) and alfa amino butyric acid (Aba: 0.41). The AA (and calorie) load almost balanced the N losses during the 5th (0.411 +/- 0.038) and 6th study day (0.305 +/- 0.019 gN/kg). CONCLUSIONS: 0.25 gN/kg could be considered the minimum N load in the uncomplicated adult LTX recipients, for reassuring a balanced plasma AA pattern and body N turnover in the early postoperative phase.

Adolescent↗
PubMed1995

Effect of infusion and withdrawl of glucose and insulin on gas exchange in injured ventilated patients.

PURPOSE: To evaluate the effect induced on gas exchange and on urea excretion by glucose and insulin infusion in injured patients. The magnitude and time necessary for the full development of the metabolic effect were investigated. METHODS: Six injured patients were investigated. During the first 24 hours, the fasting period, patients received 1 mg/kg*min of glucose; during the second 24 hours, the treatment period, infusion was increased to about the 95% of the energy production rate; during the last 8 hours, (stop period) the infusion rate was again set to 1 mg/kg*min. Gas exchange was determined in two consecutive 12-hour series, for 30 minutes every hour, either during a stabilized treatment or after its variation. Urea excretion was determinated on 4-hour samples. RESULTS: With respect to the fasting period, during the last 4 hours of the treatment period, the energy production rate did not vary; urea excretion (-25%) and oxygen consumption (-9%) decreased significantly. Carbon dioxide production (+16%), total respiratory quotient, and minute ventilation (+5%) increased significantly. Carbon dioxide production varied linearly with time (glucose infusion +1.74 mL/min*m2*h, P < .05; glucose withdrawal -1.89 mL/min*m2*h, P < .01). Minute ventilation decreased only during the withdrawal period by 65 mL/min*m2*h (P < .05). CONCLUSIONS: The infusion of glucose and insulin, in an amount slightly lower than the metabolic expenditure, leads to a consistently reduced amino acid catabolism and to a decreased oxygen consumption, without affecting energy requirements. Although it leads to an increase of carbon dioxide production, the measured change is so small and slow that it is not harmful unless there is severe respiratory insufficiency.

Adolescent↗
PubMed1994

[Inguinal-scrotal hernia of a bladder diverticulum].

Bladder diverticula may be involved in inguinal hernias usually in the form of a sliding hernia. We studied three patients with scrotal herniation of bladder diverticulum, one of them having a neurogenic bladder. All our patients have had the diagnosis before undergoing hernia repair--so iatrogenic lesions of the bladder during surgical manipulations could be avoided. Methods for an early diagnosis of this rare occurrence are discussed along with aspects of surgical approach.

Adult↗
PubMed1993

The independent metabolic effects of halothane and isoflurane anaesthesia.

Twelve healthy, unpremedicated women scheduled for total abdominal hysterectomy were given either isoflurane (n = 6) or halothane (n = 6) anaesthesia. They all received general anaesthesia for a period of 3 h, with surgery being carried out only in the last hour. The anaesthesia consisted of thiopentone, pancuronium and a mixture of oxygen-enriched air (FiO2 = 34%) supplemented with 1 MAC of either isoflurane or halothane. The patients were maintained normothermic, and with an arterial SaO2 above 95% throughout the period of the study. The following measurements were made before, during and after anaesthesia (with and without surgery): oxygen consumption (VO2), carbon dioxide production (VCO2); circulating concentrations of various hormones (insulin, growth hormone and cortisol); various metabolites; selected amino acids and albumin; forearm arterio-venous concentration difference of glucose, lactate, free fatty-acids and selected amino acids (four patients in each group). Whole body VO2 decreased significantly by over 20% during anaesthesia (with or without surgery), P < 0.05). Although the circulating concentration of most amino acids showed little or no change during anaesthesia alone, there was a tendency for the flux of most metabolites to decrease, and this persisted during surgery (P < 0.05). During anaesthesia alone there was a twofold reduction in the plasma cortisol concentration (P < 0.05), and a decrease in albumin concentration (P < 0.01). With the onset of surgery, plasma cortisol concentration increased rapidly (in association with several other hormones and metabolites) but hypoalbuminemia persisted.

Adult↗
PubMed1992

[Optimal dose of amino acids administered in total parenteral nutrition (TPN) of malnourished patients].

A plasmatic concentration for each aminoacid, between 1 and 1.5 times the normal value in fasting healthy subjects, is considered as an optimal target during total parenteral nutrition (TPN) in malnourished patients. We have analyzed the correlation between the aminoacid input and the aminoacid plasmatic concentration during TPN at different aminoacid composition. By exponential regression curves we then calculated the input required to keep each aminoacid plasma concentration in the optimal range.

Amino Acids↗
PubMed1992

Plasma amino acid concentration changes during total parental nutrition in critically ill patients.

In 16 critically ill patients with full-blown stress reaction and without severe organ failure, we studied the kinetics of the arterial plasma amino acid (aa) profile during the first 48 h of total parenteral nutrition (TPN) in order to assess the time necessary to reach the steady-state condition during infusion. Each patient was treated with one of three different amino acid solutions giving, with the same nitrogen load, different intakes of individual amino acids. We found four different responses to the administered amino acids. Some amino acids showed a different trend depending on the dose given. At lower doses a steady state was achieved sooner. Plasma levels of amino acids not supplied in the TPN were unaffected or decreased, achieving a steady state at various times during the study period. We conclude that, in critically ill patients, stable arterial plasma amino acid concentrations are obtained within 24 h of starting TPN. In such patients, valid studies of the effect of amino acid solutions may therefore be carried out over short periods of time, thereby minimizing errors due to a fluctuating and unstable clinical state.

Journal Article↗
PubMed1992

Urethroplasty of recurrent urethrocele: study of 41 cases.

Recurrent urethrocele is not often successfully treated surgically because, as is well known, pre-operative sterilization of the urethrocele is difficult, especially when it is very large. Furthermore the incomplete excision of the corpus callosum, because of the loss of urethral tissue this involves, often leads to post-operative fistulas and stenoses. This is why, very often, there are relapses no matter what technique is adopted. In 1978 both Juraschek and ourselves published a technique, derived from Monseur, in which the urethrocele and the corpus callosum were completely excised. The resulting loss of urethral tissue was remedied with the albuginea from the ventral surfaces of the corpora cavernosa after a 180 degrees rotation of the urethra. The results of this treatment in 41 cases of recurrent urethrocele are given in this paper. The follow-up period for the patients was from 15 to 2 years. Results have been excellent with very few complications (2 post-operative fistulas and 2 urethra stenoses). There have been no relapses.

Adolescent↗
PubMed1992

[Determination of the best amino acid input after orthotopic liver transplantation].

Ten-three patients were investigated during the early postoperative phase after orthotopic liver transplantation to assess the adequacy of the amino acid (AA) supply during both parenteral (days 1-5) and enteral (days 6-9) nutrition. Plasma AA profile was determined preoperatively, on day 4 and 5 during TPN and on day 8 and 9 during EN, urea production rate was measured every day. Calories input was 28 kcal.kg-.day as glucose, nitrogen intake was 0.25 g.kg- day, supplying individual AA on the basis of previous studies. Urea nitrogen production during TPN (9-11 gN/m2.day) outlines the ability of the transplanted liver to manage the overall nitrogen load. Individual AA plasma profile was considered the expression of an adequate input when comprised between 1 and 1.5 times the normal value, in this respect we obtained adequate levels of all essential AAs. Particularly phenylalanine, methionine and branched chain AA, critical during liver failure, were kept in this range by supplying 68, 48 and 500 mg.kg-1.day. According to AA profile the supply of cystine and tyrosine (conditionally essential AAs), and of histidine, taurine, proline and serine could be safely increased. Not given dispensable AAs (glutamine, asparagine, citrulline and alfa amino butyric) showed a plasma level below the norm and should be added to the diet.

Adolescent↗