Volume expansion in the first 4 days of shock: a prospective multicentre study in 19 French intensive care units.

PURPOSE: To describe the current practices of volume expansion in French intensive care units (ICU). METHODS: In 19 ICUs, we prospectively observed the prescription and monitoring practices of volume expansion in consecutive adult patients with shock [sustained hypotension and/or need of vasopressor therapy, associated with at least tachycardia and/or sign (s) of hypoperfusion]. Patients were included at the time of prescription of the first fluid bolus (FB). Thereafter, all the FBs administered during the 96 h following shock onset were surveyed. An FB was defined as an intravenous bolus of at least 100 ml of a blood volume expander intended to rapidly improve the patient's circulatory condition. RESULTS: We included 777 patients [age: 63 ± 15 years; female gender: 274 (35 %); simplified acute physiology score II: 55.9 ± 20.6; ICU length of stay: 6 days (interquartile range (IQR) 3-13); ICU mortality: 32.8 %] and surveyed 2,694 FBs. At enrolment mean arterial pressure was 63 mmHg (IQR 55-71). The most frequent triggers of FB were hypotension, low urine output, tachycardia, skin mottling and hyperlactataemia. Amount of fluid given at each FB was highly variable between centres. Crystalloids were used in 91 % (2,394/2,635) and synthetic colloids in 3.3 % (87/2,635) of FBs. Overall, clinicians used any kind of haemodynamic assessment (central venous pressure measurement, predictive indices of fluid responsiveness, echocardiography, cardiac output monitoring or a combination of these) in 23.6 % (635/2,694) of all FBs surveyed, with an important between-centre heterogeneity. CONCLUSIONS: High between-centre variability characterised all the aspects of FB prescription and monitoring, but overall haemodynamic exploration to help guide and monitor FB was infrequent.

Long-term sedation in intensive care unit: a randomized comparison between inhaled sevoflurane and intravenous propofol or midazolam.

PURPOSE: To evaluate efficacy and adverse events related to inhaled sevoflurane for long-term sedation compared with standard intravenous (i.v.) sedation with propofol or midazolam. METHODS: Randomized controlled trial. Sixty intensive care unit (ICU) patients expected to require more than 24 h sedation were randomly assigned to one of three groups: group S, inhaled sevoflurane; group P, i.v. propofol; group M, i.v. midazolam. All patients also received i.v. remifentanil for goal-directed sedation (Ramsay scale and pain score) until extubation or for a maximum of 96 h. Primary end points were wake-up times and extubation delay from termination of sedative administration. Proportion of time within Ramsay score 3-4, i.v. morphine consumption at 24 h post extubation, hallucination episodes after end of sedation, adverse events, inorganic fluoride plasma levels, and ambient sevoflurane concentrations were recorded. RESULTS: Forty-seven patients were analyzed. Wake-up time and extubation delay were significantly (P<0.01) shorter in group S (18.6 ± 11.8 and 33.6 ± 13.1 min) than in group P (91.3 ± 35.2 and 326.11 ± 360.2 min) or M (260.2 ± 150.2 and 599.6 ± 586.6 min). Proportion of time within desired interval of sedation score was comparable between groups. Morphine consumption during the 24 h following extubation was lower in group S than in groups P and M. Four hallucination episodes were reported in group P, five in group M, and none in group S (P=0.04). No hepatic or renal adverse events were reported. Mean plasma fluoride value was 82 µmol l(-1) (range 12-220 µmol l(-1)), and mean ambient sevoflurane concentration was 0.3 ± 0.1 ppm. CONCLUSIONS: Long-term inhaled sevoflurane sedation seems to be a safe and effective alternative to i.v. propofol or midazolam. It decreases wake-up and extubation times, and post extubation morphine consumption, and increases awakening quality.

A new index derived from the cerebrovascular pressure transmission and correlated with consciousness recovery in severely head-injured intensive care patients.

BACKGROUND: In patients with serious head trauma, a moderate (20-25 mm Hg) mean level of intracranial pressure (ICP) may fail to distinguish patients with a real deteriorated intracranial status from those who are stable or improving. Because of these limitations, we analyzed the ICP curve in search of other relevant information regarding cerebrovascular pressure transmission. We looked for parameters with physiological meaning extracted from spectral analysis of cerebrovascular pressure transmission and correlated with consciousness recovery in patients with severe head injuries. METHODS: A prospective cohort study was conducted in an intensive care unit of the University Hospital, Montpellier, France, from December 2003 to December 2005. Thirty consecutive patients admitted for severe head trauma were subjected to sedatives, mechanical ventilation, and intraparenchymatous recording of ICP and were evaluated with Glasgow Outcome Scale score. Simultaneous 60-s recordings of ICP and arterial blood pressure (BP) signals, beginning as soon as possible after head trauma, were repeated until death or clinical stabilization, every 15 min, with physicians blinded to the patients' data. Spectra of ICP and BP waveforms were computed with Fourier transform. Amplitudes of cardiac and respiratory harmonics were analyzed. Cardiac (or respiratory) gain was defined as the ratio of amplitudes of cardiac (or respiratory) harmonic of ICP to BP signals and referred to as Gc and Gr, respectively. RESULTS: Twenty of the 30 enrolled patients recovered consciousness (Glasgow Outcome Scale score = 3, 4, or 5). Gr/Gc averaged over the whole recording period performed better in discriminating consciousness recovery (area under receiver operating characteristic [ROC] curve: 0.98; 95% confidence interval [CI]: 0.91-1) than ICP (0.76; 95% CI: 0.54-0.97), cerebral perfusion pressure (0.75; 95% CI: 0.53-0.97) and Gc (0.77; 95% CI: 0.57-0.99) (P < 0.001 for each comparison). When considering the recording period 30 h posttrauma (hpt), 162 hpt, a value of Gr/Gc > or =4 was always associated with consciousness recovery, and the relative risk was equal to 9 (95% CI: 1.42-57.12). CONCLUSIONS: Gr/Gc, which characterizes the cerebrovascular transmission, better discriminates bad evolution than high values of ICP or low values of cerebral perfusion pressure in patients with severe head trauma. A reduction in Gr/Gc ratio might be an early alarm signaling worsening intracranial hemodynamic conditions.

Quantification of urinary F2-isoprostanes with 4(RS)-F4t-neuroprostane as an internal standard using gas chromatography-mass spectrometry Application to polytraumatized patients.

Isoprostanes are a family of prostaglandin isomers produced from oxidation of polyunsaturated fatty acids through a non-enzymatic free radical-catalyzed mechanism. Quantification of F(2)-isoprostanes (F(2)-IsoPs) provides a good index of oxidative stress and allows non-invasive assessment of lipid peroxidation in vivo. Since "interferences peaks" at m/z 573 co-elute with d(4)-15-F(2t)-IsoP preferentially used, we propose a new GC-NICI-MS approach to quantify urinary F(2)-IsoPs by using 4(RS)-F(4t)-neuroprostane as the internal standard. This method was applied to quantify urinary F(2)-IsoPs excretion in healthy volunteers and polytraumatized patients. Our results showed a significant increase (p<0.0001) in urinary F(2)-IsoPs in polytraumatized patients compared with healthy volunteers (4.73+/-2.75 ng/mg vs. 0.811+/-0.359 ng/mg creatinine).