Compound A, formaldehyde and methanol concentrations during low-flow sevoflurane anaesthesia: comparison of three carbon dioxide absorbers.

AIM: To determine compound A, formaldehyde and methanol concentrations in low-flow anaesthesia using different carbon dioxide absorbers. METHODS: Fifteen patients scheduled for general or urological surgery were exposed to low-flow (500 ml/min) anaesthesia with sevoflurane. The patients were randomly allocated to three groups: soda lime, DrägerSorb Free or Amsorb Plus. The concentrations of compound A, formaldehyde and methanol were sampled and analysed from the limbs of the anaesthesia circuit at T30 (30 min after the start of low-flow sevoflurane anaesthesia), T90 (90 min) and T150 (150 min). The temperatures of the absorbers were measured at the same time. RESULTS: Statistically significant differences (P < 0.05) were found in the production of compound A from soda lime (with the highest values), DrägerSorb Free and Amsorb Plus at each measurement time. Only traces of methanol (ranging from < 0.131 to 3.799 mg/m(3)) were measured, higher with Amsorb Plus (statistically significant differences were found only at T90). The formaldehyde values (ranging from < 0.1227 to 17.79 mcg/m(3) p.p.b.) were higher with soda lime, and the difference was statistically significant at T150 and, in the inspiratory limb only, at T90. The temperatures of the absorbers were higher for soda lime and lower for Amsorb Plus; the difference was statistically significant at T0 in the upper canister and at T30 in both canisters. CONCLUSION: The concentrations of harmful products in the circuit were negligible and were lower using the new-generation absorbers. Using Amsorb Plus, the temperatures in the canisters were lower than with the other two absorbers.

Critical points for sepsis management at the patient bedside.

Following an interpretative philosophy, dyna-mic and faithful to the complexity theory, a clinical pathway is outlined close to the reality, at the patient bedside, that is comprehensive of the diagnostic process in its temporal dynamism, of the therapeutic process in its specificity (antibiotic therapy, surgical souce control), in the use of organs supportive therapy (haemodynamic, respiratory, renal, etc.) and in the use of adjunctive and immunomodulatory therapies (APC, AT, etc.). The importance of the contextual activation of microbiological, immunological and coagulative monitorings is underlined. Through a critical review of the more recent literature, a strict relationship, in sepsis and septic shock, between inflammation and coagulation is described, that allowed the activated protein C (drotrecogin alpha activated) success, in terms of reduction of the absolute and relative mortality. This therapeutic success is contextualized into two other important therapeutic successes, recently obtained in severe sepsis and septic shock, based on the medical evidence, one using low doses of corticosteroids and the other using the early (6 h) goal directed haemodynamic therapy to restore a balance between oxygen delivery and oxygen demand. Once systemic inflammation is complicated by organ failure, there are few options. Treatment with activated protein C lowers the risk of death but is associated with an increased risk of bleeding and is likely to be expensive. The strategies described by the groups of Rivers and Annane offer the opportunity for good therapeutic results, by preventing the progression or even the development of sepsis and its complications: septic shock and multiple organ dysfunction.

The abdominal compartment syndrome. Clinical relevance.

Increased intra-abdominal pressure (IAP) may occur in a number of different situations encountered by intensivists, such as tense ascites, abdominal hemorrhage, use of military antishock trousers, abdominal obstruction, during laparoscopy, large abdominal tumors and peritoneal dialysis.1-3 Both clinical and experimental evidence indicate that increased IAP may adversely affect cardiac, renal, respiratory and metabolic functions.1-5 Despite this, increased IAP is rarely recognized and treated in Intensive Care Unit (ICU) settings. There appears to be two reasons for this: the physiologic consequences of increased IAP are not well know, to most physicians and, more importantly, the capability of easily measuring IAP has not been well documented. In this chapter, we will discuss: 1) the different methods proposed to evaluate IAP in ICU; 2) the physiopathological consequences of increased IAP; 3) the existing clinical data about IAP in critically ill patients. Considering overall our data, we can conclude that: 1) different techniques are available at the bedside to estimate the IAP; 2) the IAP ranges between 10 and 20 cmH2O, substantially increased compared to normal subjects. Most of the patients have IAH, while few of them (<5%) present clinical characteristics of ACS; 3) the IAP is different among different categories of patients and its increase is not limited to surgical patients only; 4) the increase in IAP appears to influence respiratory function, homodynamic, kidney, gut and brain physiology; 5) the IAP seems to be correlated with severity scores but its relation to mortality is controversial; 6) the routine measurements of IAP by means of bladder pressure are not associated with an increased rate of urinary tract infections.

Lethal late onset cblB methylmalonic aciduria.

OBJECTIVE: To alert the physicians to the possibility of a late-onset inborn error of metabolism in an apparently previously healthy patient with acute clinical presentation. DESIGN: Case report. SETTING: Pediatric unit and general intensive care unit. PATIENT: An apparently previously healthy 12-yr-old female presented acutely with vomiting, fever, bronchopneumonia, and progressive loss of consciousness associated with ketoacidosis, hyperglycemia, and hyperammonemia. She died 3 days later with a diagnosis of insulin-dependent diabetes mellitus. INTERVENTIONS: Intravenous hydration, glucose and insulin, mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Organic acid analysis on a postmortem sample of aqueous humor revealed high levels of methylmalonic acid. Enzymatic studies on cultured fibroblasts were consistent with the diagnosis of cblB methylmalonic aciduria. CONCLUSIONS: The diagnosis of cblB methylmalonic aciduria was made in a postmortem patient who died with a misdiagnosis of insulin-dependent diabetes mellitus. Unclear biochemical findings and positive family history should strongly lead to suspicion of an inborn error of metabolism in an apparently previously healthy critically ill patient.

[Description of a case of Reye's-like syndrome with fatal outcome]. / Descrizione di un caso di Reye like syndrome ad esito fatale.

A Reye Like Syndrome case occurred in a twelve year-old little girl with a previous familiar history is reported. The little patient was admitted in the pediatric ward for fever, vomiting and aspecific respiratory symptoms and developed very quickly a severe metabolic acidosis, alterations of consciousness, hypoxia, tissular hypoperfusion, multiple organ failure (MOF) and a fatal outcome. The postmortem diagnosis pointed out a methyl malonic acidaemia, a fairly frequent cause of acute metabolic distress, which may occur also in prepuberal age. The correct diagnostic and therapeutic approach of these cases is stressed since they need a prompt and careful monitoring in intensive care unit and a close cooperation among pediatricians, intensive care specialists and the nearest centre for the study of metabolic diseases.

[Percutaneous dilatational tracheostomy. Critical considerations after one year's experience]. / La tracheostomia percutanea dilatativa. Considerazioni critiche dopo un anno di sperimentazione.

The authors discuss a series of 57 patients submitted to percutaneous dilational tracheostomy (PDT) in an Intensive Care Unit during a fifteen months periods. Patients were admitted for cardiac and/or respiratory failure in 27 cases (47%), sepsis in 13 cases (23%), shock in 12 cases (21%), coma in 5 cases (9%). Length of orotracheal intubation before PDT was 8.3 days +/- 3.9 without significant differences between Apache II and Saps scores at this time (17.4 +/- 6.3 and 20.4 +/- 4.3 respectively) and on admission day (19.3 +/- 6.25 and 20.8 +/- 3.6). The main complications we had to deal with during PDT were damage to previously inserted orotracheal tube, a pneumomediastinum, a small oozing of blood in three cases a serious bleeding in a septic patient with coagulation disorder. After these we performed PDT always coupled with fibrotrachoscopy in the aim to ameliorate PDT safety. On subsequent days the more frequent complication come up at the time of changing tracheal cannula and consisted in troubles ascribed to tracheal shreds (four cases) and one major bleeding after the maneuver always overcome. We also report one death due to impossibility cannula repositioning and subsequent failed intubation in a previously decannulated patient who developed trachobronchial obstruction. Although a supposed midline approach between second and third tracheal rings, was supposed autopsy (performed in three patients) revealed a lateralized cut in one case and an approach higher in another patient. The main advantages in our practice were the absence fo PDT related infections and an optimal and fast tracheal closure after cannula removal. In spite of some limits, this technique has quickly and totally replaced in our practice surgical tracheostomy.

[A case of HELLP syndrome with dramatic course successfully treated with early plasmapheresis]. / Un caso di Hellp syndrome a decorso drammatico risolto con plasmaferesi precoce.

A case of Hellp syndrome occurred in postpartum of a pregnancy elapsed without signs of preeclampsia is described. The evolution was particularly dramatic. Early plasmapheresis was the key treatment for a complete recovery in order to avoid Multiple Organ Dysfunction System (MODS). Emphasis on a multidisciplinary approach between Gynecologist, Anesthetist, Nephrologist and Hematologist is pointed out.

[Acute carbamazepine poisoning treated with plasmapheresis. Description of a clinical case]. / Intossicazione acuta da carbamazepina trattata con plasmaferesi. Descrizione di un caso clinico.

A case of severe Carbamazepine poisoning initially misdiagnosed is reported. Treatment consisted in plasmapheresis (3.5 liters exchanged) repeated for 3 consecutive days, in conjunction with activated charcoal and advanced life support. It was obtained a rapid decay in Carbamazepine plasmatic level (with rebound phenomenon only after first treatment day) and a contemporary improvement in clinical conditions. The patient was discharged without complications after 6 days stay in ICU. Taking pharmacokinetic characteristics into account, it is suggested that plasmapheresis may be useful in this kind of poisoning.

[Propofol-midazolam in continuous infusion for sedation in intensive care]. / Propofol-midazolam in infusione continua per la sedazione in terapia intensiva.

Two groups of 11 ICU respiratory patients ventilated with PSV have been sedated with propofol (group I) or with midazolam (group II). After the endovenous administration of the induction dose (propofol 1.5 mg/kg; midazolam 0.15 mg/kg) sedation was obtained with continuous infusion of the drugs (propofol 2 mg/kg/h; midazolam 0.24 mg/kg/h). In this setting the Authors evaluated the level of sedation (Ramsey scale) and the side effect of the two drugs. At induction midazolam caused a reduction of tidal volume for some minutes and a greatest sedation in comparison with propofol, while propofol caused reduction of MAP (p < 0.01) and transitory apnoea. Even if during the infusion of propofol the level of sedation decreased with time (p < 0.05; y = -0.0357 x + 3.07) it was more stable in comparison with that registered during continuous infusion of midazolam (p < 0.01; y = -0.2018 x + 5.19.

[Gastric tonometry. Experience of a polyvalent intensive care unit]. / Tonometria gastrica. Esperienza di una TI polivalente.

Tonomitor NG tube was positioned in the stomach of 11 critical ill patients during their stay in ICU and 48 measurements of intramucosal pH (pHi) have been performed. In 7 patients haemodynamic measurement were performed in concomitance with each pHi measure. The Authors looked for statistical relations between pHi and SAPS, pHa, HCO3-a, MAP, DO2/BSA, VO2/BSA, SvO2, diuresis and outcome. A good correlation was found between pHi and MAP (r = 0.47). Dividing the considered parameters into 2 groups in agreement with pHi values < or = and > 7.32 significant relations (p < 0.05) results between pHi and SAPS, MAP, pHa. More significant relations were found between pHi and outcome (p = 0.0015) and between the mean of the pHi values obtained from each patient (pHi-m) and outcome (p = 0.0005). The pHi-m of the surviving patients was always > 7.32 while the pHi-m of the deceased patients was always < 7.32. This results confirm the importance of the pHi measured during the stay in ICU as a prognostic index and suggest that the MAP may be the most important haemodynamic parameter which correlate with pHi values.

[The estimation of p50 by the algorithm proposed by Siggard-Andersen. Its experimental assessment in critical patients]. / Calcolo della p50 mediante l'algoritmo proposto da Siggaard-Andersen. Valutazione sperimentale in pazienti critici.

STUDY OBJECTIVE: To determine the ability of O. Siggaard-Andersen algorithm in the estimation of the "in vivo" p50 and standard p50 values from a single blood sample with sO2% less than or equal to 97. DESIGN: comparison between measured and calculated standard p50 values. SETTING: Intensive care unit. PATIENTS: thirteen cardio-pulmonary critical ill patients. Mean age of seventy-four years (range 53-84 years). MEASUREMENT: The experimental measurement of p50 standard (p50st sper) was performed tonometering the venous blood samples (60 specimens) using an IL-237 tonometer at 37 degrees C, with two different gas mixtures to obtain pCO2 at 5.33 kPa (DS = 0.06), and pO2 at levels to achieve sO2% values close to 50%. The gases's complete equilibration was not deemed important. The pO2 values were corrected to a pH of 7.40 using a Bohr factor = -0.48 and the p50 was taken by simple interpolation of points on the sO2%/pO2 diagram. Calculated standard p50 (p50st calc) and calculated "in vivo" p50 on the venous specimens (No. 60) and the correspondent arterial specimens with sO2% less than or equal to 97 (No. 40) were obtained by Siggaard-Andersen's computerized algorithm. Blood specimen analysis was performed by means of an ABL3 Radiometer gas analyzer and an OSM3 Radiometer oximeter. Statistical analysis was made by Anova test for liner regression. RESULTS: There was excellent correlation between the 60 experimental p50st determined by Siggaard-Andersen's oxygen dissociation curve on the same blood samples. The regression equation was: p50st sper = -0.79 + 1.21 x p50st calc, r = 0.90, R2 = 81.1%; with F = 249.5 and less than 10(-5). No good correlation was found between p50st and standards p50 calculated on arterial specimens (p50st calc art): p50 = 1.38 + 0.52 x p50st calc art, r = 0.52, R2 = 26.6%, F = 14 e P less than 10(-3). Regression of in vivo P50 calculated on correspondent venous samples (p50 ven) was: p50 ven = 0.79 = 0.77 x p50 art, r = 0.93, R2 = 87.2%, F = 256 and P less than 10(-5). CONCLUSION: Our results suggest that the curve describes the curve also at high saturation when it is not longer linear. Accurate measurement (including dishemoglobin percentage) and sO2% less than or equal to 97 are necessary. We did not perform experimental measurements of "in vivo" p50 but we postulate that as the p50st was well calculated so too would be the p50 "in vivo" at 37 degrees C.

[The use of Opticath in the correct measurement of the pulmonary capillary wedge pressure]. / L'uso dell'Opticath nella corretta misura della pressione di incuneamento (PCWP).

The Authors assess the utility of the on-line monitoring of SvO2 during 156 measurements of pulmonary capillary wedge pressure (PCWP) done on 52 Intensive Care Unit patients. The measurement was always right when the SvO2 increased more than 90%. The Authors found a good correlation between the SvO2 monitored during the measurement of the PCWP and the saturation of pulmonary capillary blood measured by cooximeter. These data suggest that the complex procedure to confirm the reliability of the measurement recommended by Gardner can be simplified by the observation of the trend of SvO2 on the monitor oximetrix. This allows to obtain saving time for the staff, saving blood for the patients, reduction of risk for the transmission of infective diseases due to the handling of blood and guarantees a further routinary control of reliability on the measure of PCWP.

[Usefulness of monitoring the mixed venous blood saturation (SvO2) in the diagnosis of heart rupture. A clinical case]. / Utilità del monitoraggio della saturazione del sangue venoso misto (SvO2) nell'iter diagnostico di rottura del cuore. Caso clinico.

We describe a case report of acute left ventricular free wall rupture during acute myocardial infarction in a sedated and curarised patient. Continuous monitoring of SvO2 was very useful on early diagnosis.

[Tetanus disease. Experience with 2 intensive treatments during 13 years]. / Malattia tetanica. Esperienza di due terapie intensive nell'arco di 13 anni di attività.

The Authors present a retrospective analysis of 58 cases of tetanus hospitalized in two ICU in 13 years of activity. The mortality reported (39.7%) is comparable to other Authors or statistical analysis but it is better if correlated to patient age. Patients of the highest classes (III and IV classes of Edmonson e Flowers) had the highest mortality but no significant variation was seen between patients of the III and IV class. The most frequent cause of death has been cardiac arrhythmia. Cardiac arrhythmias happened in most cases in the first 15 days of hospitalization. 37.9% of patients developed pneumonia: prolonged hospitalization (more than 15 days) and high classes of the disease have been the most important risk factors for Hospital-acquired pneumonia in tetanic patients.

[Hypoxia and oxygen content during dialysis]. / Ipossia e contenuto di ossigeno durante dialisi.

In a study of 72 patients treated with acetate and bicarbonate dialysis, the Authors verified if hypoxic hypoxia caused by dialysis depends on a deficit in oxygen content with an inherent risk of tissue hypoxia. PO2uv (uncompensated venous oxygen partial pressure) and CQ (cardiac compensation factor) derived from the oxygen absorption curve were studied by a new Ole Siggard-Andersen algorithm. The results do not show a risk of tissue hypoxia in the postdialytic period.