Preoperative evaluation in infants and children: recommendations of the Italian Society of Pediatric and Neonatal Anesthesia and Intensive Care (SARNePI).

BACKGROUND: The preoperative assessment involves the process of evaluating the patient's clinical condition, which is intended to define the physical status classification, eligibility for anesthesia and the risks associated with it, thus providing elements to select the most appropriate and individualized anesthetic plan. The aim of this recommendation was provide a framework reference for the preoperative evaluation assessment of pediatric patients undergoing elective surgery or diagnostic/therapeutic procedures. METHODS: We obtained evidence concerning pediatric preoperative evaluation from a systematic search of the electronic databases MEDLINE and Embase between January 1998 and February 2012. We used the format developed by the Italian Center for Evaluation of the Effectiveness of Health Care's scoring system for assessing the level of evidence and strength of recommendations. RESULTS: We produce a set of consensus guidelines on the preoperative assessment and on the request for preoperative tests. A review of the existing literature supporting these recommendations is provided. In reaching consensus, emphasis was placed on the level of evidence, clinical relevance and the risk/benefit ratio. CONCLUSION: Preoperative evaluation is mandatory before any diagnostic or therapeutic procedure that requires the use of anesthesia or sedation. The systematic prescription of complementary tests in children should be abandoned, and replaced by a selective and rational prescription, based on the patient history and clinical examination performed during the preoperative evaluation.

[Preparation, premedication and parental presence]. / Preparazione, premedicazione e presenza dei genitori.

40% to 60% of children undergoing surgery under general anaesthesia develop anxiety in the preoperative period. Multiple factors contribute to the genesis of this disorder. Preoperative anxiety may complicate the induction of anaesthesia and can cause behavioural modifications in children even long after surgical procedures have been completed. It is important to focus on prevention of such problems. A preparation program, premedication and parental presence during induction of anaesthesia are valid tools for achieving this goal. We are herewith presenting a play preparation program carried out by play specialists and offered to all children prior to surgery. This approach proved effective in reducing preoperative anxiety in children and their mothers.

Oxidative status and malondialdehyde in beta-thalassaemia patients.

BACKGROUND: In beta-thalassaemia syndromes, decreased or impaired biosynthesis of beta-globin leads to accumulation of unpaired alpha-globin chains. Moreover, the iron overload in beta-thalassaemia patients generates oxygen-free radicals and peroxidative tissue injury. The aim of this study was to detect and correlate iron overload parameters with the oxidative stress and the antioxidant capability in beta-thalassaemia patients. DESIGN: Serum iron, transferrin saturation, serum ferritin, nontransferrin-bound iron (NTBI), levels of serum free and total (free + bound) malondialdehyde (MDA) and total peroxyl radical-trapping antioxidant parameter (TRAP) were evaluated in 21 regularly transfused beta-thalassaemia major (TM) patients, 13 untransfused beta-thalassaemia intermedia (TI) patients and 17 healthy controls. Blood from the TM patients was drawn 48 h after the last desferoxamine (20-40 mg kg(-1)) infusion and just before transfusion. RESULTS: Free and total MDA and NTBI levels were higher in the TM patients than in the TI. In the TM patients the free MDA levels correlated positively with serum iron (r = +0.3, P = 0.0006), whereas the total MDA correlated positively with NTBI (r = +0.45, P = 0.037). However, a negative correlation was observed between TRAP and NTBI (r = -0.4, P = 0.0006). In the TI patients there was no significant correlation between free or total MDA and TRAP or NTBI. CONCLUSIONS: Our results confirm the peroxidative status generated by iron overload in thalassaemia patients and highlight the rapid formation of marked amounts of free MDA despite the chelation therapy in TM patients.

Mechanisms of action of malondialdehyde and 4-hydroxynonenal on xanthine oxidoreductase.

Studies have been made on the possible involvement of malondialdehyde (MDA) and (E)-4-hydroxynon-2-enal (HNE), two terminal compounds of lipid peroxidation, in modifying xanthine oxidoreductase activity through interaction with the oxidase (XO) and/or dehydrogenase (XDH) forms. The effect of the two aldehydes on XO (reversible, XO(rev), and irreversible, XO(irr)) and XDH was studied using xanthine oxidase from milk and xanthine oxidoreductase partially purified from rat liver. The incubation of milk xanthine oxidase with these aldehydes resulted in the inactivation of the enzyme following pseudo-first-order kinetics: enzyme activity was completely abolished by MDA (0.5-4 mM), while residual activity (5% of the starting value) associated with an XO(irr) form was always observed when the enzyme was incubated in the presence of HNE (0.5-4 mM). The addition of glutathione to the incubation mixtures prevented enzyme inactivation by HNE. The study on the xanthine oxidoreductase partially purified from rat liver showed that MDA decreases the total enzyme activity, acting only with the XO forms. On the contrary HNE leaves the same level of total activity but causes the conversion of XDH into an XO(irr) form.

Oxidative stress and homocysteine in coronary artery disease.

BACKGROUND: Oxidative stress is present in cardiovascular diseases (CVDs), and hyperhomocysteinemia, an independent risk factor for these diseases, may play a role by inducing production of oxygen free radicals. METHODS: To evaluate the possible role of homocysteine (Hcy) in inducing oxidative stress in coronary artery disease (CAD), plasma Hcy was measured in 68 consecutive cardiovascular patients, and plasma malondialdehyde (MDA), both free and total (free + bound), was measured in 40 patients with CAD (18 with chronic stable angina and 22 with unstable angina). As controls, we tested 70 healthy volunteers. Hcy was measured by an immunoenzymatic method and MDA, an index of lipid peroxidation, by gas chromatography-mass spectrometry. RESULTS: Plasma Hcy concentrations were significantly higher in cardiovascular patients than in controls (10.2 vs 8.9 micromol/L; P <0.0002), with no significant difference between values in the stable and unstable angina subgroups. Similarly, total MDA was significantly higher in the CAD group than in the controls (2.6 vs 1.3 micromol/L; P <0.00001), again with no significant difference between stable and unstable angina patients. By contrast, free MDA, which was significantly higher in the CAD patients than the controls (0.4 vs 0.2 micromol/L; P < 0.00001), was also significantly higher in the unstable than in the stable angina group (0.5 vs 0.3 micromol/L; P <0.03). However, no correlation was observed among Hcy and free and total MDA. CONCLUSIONS: Our findings show that a moderate increase of Hcy is associated with CVD but that Hcy at the detected values cannot be considered completely responsible for oxidative damage. That lipid peroxidation is involved in CAD is shown by our observation of significantly increased plasma free and total MDA concentrations compared with controls. Moreover, free MDA values discriminated between unstable and chronic stable angina, and could thus represent a new diagnostic tool.

Dissociation of physical abstinence signs from changes in extracellular dopamine in the nucleus accumbens and in the prefrontal cortex of nicotine dependent rats.

The aim of the present study was to investigate the relationship between physical abstinence and changes in dopamine release in the nucleus accumbens and in the medial prefrontal cortex induced by mecamylamine and naloxone in rats chronically exposed to nicotine. The rats were implanted with osmotic minipumps (Alzet) delivering nicotine tartrate at a rate of 9 mg/kg/day (3.16 mg of free base) and 8 days later with a dialysis probe in the nucleus accumbens or in the medial prefrontal cortex. Steady-state dopamine output from the nucleus accumbens of the rats implanted with nicotine minipumps was higher than that of sham implanted rats; no differences were observed in the prefrontal cortex. In nicotine but not in sham implanted rats mecamylamine (1 mg/kg s.c.) precipitated a physical abstinence syndrome and brought dopamine output back to control values in the nucleus accumbens. In contrast mecamylamine (1 mg/kg s.c.) increased dopamine output in the medial prefrontal cortex of nicotine but not sham-implanted rats. Naloxone (2 mg/kg) precipitated a physical abstinence syndrome qualitatively similar to that produced by mecamylamine but failed to modify extracellular dopamine in the nucleus accumbens or in the prefrontal cortex of nicotine-implanted and sham-implanted rats. The results indicate that the mesolimbic and mesocortical dopamine system undergo opposite changes during mecamylamine-precipitated abstinence in rats chronically exposed to nicotine and that physical abstinence signs can be dissociated from changes in dopamine transmission.

[Recovery time after general anesthesia with propofol administered in continuous infusion or with isoflurane]. / Tempi di risveglio dopo anestesia generale con propofol in infusione continua o con isoflurano.

The recovery time after Propofol-Tiva (P) or Isoflurane-anesthesia (I) for elective plastic surgery was studied by the Authors in two series of patients: 60 in group P, 60 in group I. All patients received a standard premedication and induction-anesthesia (premedication: Atropine 0.005 mg/kg i.m.; induction: Fentanyl 2.1 micrograms/kg+Propofol 2.5 mg/kg i.m. and Succinylcholine 1 mg/kg i.v. for tracheal intubation) and a different maintenance (group P received an infusion of 12 mg/kg/h for 10 min, 9 mg/kg/h for the next 10 min and 6 mg/kg/h thereafter+Fentanyl 1.4 micrograms/kg/h, group I clinically appropriate inspired concentration of Isoflurane and both Fentanyl-bolus at demand). They were ventilated mechanically with air and oxygen mixture (FiO2 = 0.3) to maintain normal blood-oxygen tension and normocarbia. The results showed that the recovery time was significantly shorter in the group P than in the group I and that Propofol-Tiva is accompanied by a more rapid recovery than Isoflurane-anesthesia.

[Pneumonia in severe head injury. A prospective study]. / La polmonite nel trauma cranico grave. Uno studio prospettico.

Impairment of the state of consciousness is an important contributing factor in the onset of respiratory tract infections; in this study the data were collected prospectively to investigate the incidence and clinical implications of pneumonia in a population of head injured patients. The study was conducted on all patients treated at our centre throughout 1990. The incidence of pneumonia in the head injured was 10.8% versus 7.3% in the rest of the patients. Mortality in the group with pneumonia was not significantly different from the group without pneumonia. The average time of onset was on the fifth day from admission. The lung injury score (LIS) on the sixth day, the time on artificial ventilation and the length of stay in intensive care were significantly greater in those with pneumonia (1.18, 14.6 days and 21.9 days versus 0.8, 4.2 days and 12.9 days respectively). Staphylococcus was the single most frequently isolated germ. Our study concludes that pneumonia represents a relatively frequent and early complication in patients with head injury, and it is associated with prolonged artificial ventilation and longer staying in ICU.