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Rationale: Fever control may improve vascular tone and decrease oxygen consumption, but fever may contribute to combat infection.Objectives: To determine whether fever control by external cooling diminishes vasopressor requirements in septic shock.Methods: In a multicenter randomized controlled trial, febrile patients with septic shock requiring vasopressors, mechanical ventilation, and sedation were allocated to external cooling (n = 101) to achieve normothermia (36.5-37°C) for 48 hours or no external cooling (n = 99). Vasopressors were tapered to maintain the same blood pressure target in the two groups. The primary endpoint was the number of patients with a 50% decrease in baseline vasopressor dose after 48 hours.Measurements and Main Results: Body temperature was significantly lower in the cooling group after 2 hours of treatment (36.8 ± 0.7 vs. 38.4 ± 1.1°C; P < 0.01). A 50% vasopressor dose decrease was significantly more common with external cooling from 12 hours of treatment (54 vs. 20%; absolute difference, 34%; 95% confidence interval [95% CI], -46 to -21; P < 0.001) but not at 48 hours (72 vs. 61%; absolute difference, 11%; 95% CI, -23 to 2). Shock reversal during the intensive care unit stay was significantly more common with cooling (86 vs. 73%; absolute difference, 13%; 95% CI, 2 to 25; P = 0.021). Day-14 mortality was significantly lower in the cooling group (19 vs. 34%; absolute difference, -16%; 95% CI, -28 to -4; P = 0.013).Conclusions: In this study, fever control using external cooling was safe and decreased vasopressor requirements and early mortality in septic shock. [ABSTRACT FROM AUTHOR]

Several studies have pointed out ethical shortcomings in the decision-making process for withholding or withdrawing life-supporting treatments. We conducted a study to evaluate the perceptions of all caregivers involved in this process in the intensive care unit. A closed-ended questionnaire was completed by 3,156 nursing staff members and 521 physicians from 133 French intensive care units (participation rate, 42%). Decision-making processes were perceived as satisfactory by 73% of physicians and by only 33% of the nursing staff. More than 90% of caregivers believed that decision-making should be collaborative, but 50% of physicians and only 27% of nursing staff members believed that the nursing staff was actually involved (p < 0.001). Fear of litigation was a reason given by physicians for modifying information given to competent patients, families, and nursing staff. Perceptions by nursing staff may be a reliable indicator of the quality of medical decision-making processes and may serve as a simple and effective tool for evaluating everyday practice. Recommendations and legislation may help to build consensus and avoid conflicts among caregivers at each step of the decision-making process. [ABSTRACT FROM AUTHOR]

We studied endotracheal suctioning-induced alveolar derecruitment and its prevention in nine patients with acute lung injury. Changes in end-expiratory lung volume measured by inductive plethysmography, positive end-expiratory pressure-induced alveolar recruitment assessed by pressure-volume curves, oxygen saturation, and respiratory mechanics were recorded. Suctioning was performed after disconnection from the ventilator, through the swivel adapter of the catheter mount, with a closed system, and with the two latter techniques while performing recruitment maneuvers during suctioning (40 cm H2O pressure-supported breaths). End-expiratory lung volume after disconnection fell more than with all other techniques (-1,466 +/- 586, -733 +/- 406, -531 +/- 228, -168 +/- 176, and -284 +/- 317 ml after disconnection, through the swivel adapter, with the closed system, and with the two latter techniques with pressure-supported breaths, respectively, p < 0.001), and was not fully recovered 1 minute after suctioning. Recruitment decreased after disconnection and using the swivel adapter (-104 +/- 31 and -63 +/- 25 ml, respectively), was unchanged with the closed system (-1 +/- 10 ml), and increased when performing recruitment maneuvers during suctioning (71 +/- 37 and 60 +/- 30 ml) (p < 0.001). Changes in alveolar recruitment correlated with changes in lung volume (rho = 0.88, p < 0.001) and compliance (rho = 0.9, p < 0.001). Oxygenation paralleled lung volume changes. Suctioning-induced lung derecruitment in acute lung injury can be prevented by performing recruitment maneuvers during suctioning and minimized by avoiding disconnection.

Comprehension and satisfaction are relevant criteria for evaluating the effectiveness of information provided to family members of intensive care unit (ICU) patients. We performed a prospective randomized trial in 34 French ICUs to compare comprehension of diagnosis, prognosis, treatment, and satisfaction with information provided by ICU caregivers, in ICU patient family representatives who did (n = 87) or did not (n = 88) receive a family information leaflet (FIL) in addition to standard information. An FIL designed specifically for this study was delivered at the first visit of the family representative: it provided general information on the ICU and hospital, the name of the ICU physician caring for the patient, a diagram of a typical ICU room with the names of all the devices, and a glossary of 12 terms commonly used in ICUs. Characteristics of the ICUs, patients, and family representatives were similar in the two groups. The FIL reduced the proportion of family members with poor comprehension from 40.9% to 11.5% (p < 0.0001). In the representatives with good comprehension, the FIL was associated with significantly better satisfaction (21 [18 to 24, quartiles] versus 27 [24 to 29, quartiles], p = 0.01). These results indicate that ICU caregivers should consider using an FIL to improve the effectiveness of the information they impart to families.

We examined the hypothesis that recording multiple elastic pressure-volume (Pel/V) curves and calculating alveolar derecruitment (V(DER)) induced by decreasing positive end-expiratory pressure (PEEP) may allow determination of alveolar closing pressures, thus helping to select the optimal PEEP level. V(DER) measured in 16 patients with acute lung injury (ALI) was compared with the lower inflection point (LIP) and oxygenation changes. A modified automated method was used to record multiple Pel/V curves at low constant flow. PEEP was decreased in 5-cm H(2)O steps, from 20 or 15 cm H(2)O to 0 cm H(2)O (ZEEP). V(DER) was the volume loss between the curves recorded from PEEP and from ZEEP at the same Pel. Derecruitment occurred at each PEEP decrement, being spread almost uniformly over the 20/15 to 0 cm H(2)O range. V(DER) was not correlated with LIP. V(DER) changes correlated with Pa(O(2))/FI(O(2)) changes (rho = 0.6, p = 0.02). Linear compliance at ZEEP was correlated to V(DER) at PEEP 15 cm H(2)O (rho = 0.9, p = 0.001), suggesting that compliance above LIP may reflect the amount of recruitable lung. Thus, alveolar closure in ALI occurs over a wide range of pressures, and LIP is a poor predictor of alveolar closure.

Both reduction in tidal volume (VT) and alveolar recruitment may be important to limit ventilator-associated lung injury during mechanical ventilation of patients with the acute respiratory distress syndrome (ARDS). The aim of this study was to assess the risk of alveolar derecruitment associated with VT reduction from 10 to 6 ml/kg. Whether this VT-related derecruitment could be reversed, either by a recruitment maneuver or by an increase in positive end-expiratory pressure (PEEP) level, was also investigated. Fifteen patients with ARDS were successively ventilated using conventional VT (CVT = 10 +/- 1 ml/kg) and low VT (LVT = 6 +/- 1 ml/ kg); total PEEP (PEEPtot) was individually set at the lower inflection point (Plip) of the pressure-volume curve (PEEPtot = 11 +/- 4 cm H(2)O). Pressure-volume curves were recorded from zero PEEP (ZEEP) and from PEEP, and recruited volume (Vrec) was calculated as the volume difference between the two curves for a given pressure. Despite a similar PEEPtot, Vrec was significantly lower with LVT than with CVT, indicating low VT-induced alveolar derecruitment. Reduction in VT was associated with a reduced Sa(O(2)). In 10 patients, Vrec was also measured before and after a recruitment maneuver (two sustained inflations at 45 cm H(2)O), and after an increase in PEEP (by 4 cm H(2)O). Low VT-induced derecruitment was reversed by a recruitment maneuver and by increasing PEEP. We conclude that a reduction in VT could be responsible for alveolar derecruitment, which may be transiently reversed by a reexpansion maneuver or prevented by a PEEP increase above Plip.

Intensive care unit (ICU) caregivers should seek to develop collaborative relationships with their patients' family members, based on an open exchange of information and aimed at helping family members cope with their distress and allowing them to speak for the patient if necessary. We conducted a prospective multicenter study of family member satisfaction evaluated using the Critical Care Family Needs Inventory. Forty-three French ICUs participated in the study. ICU characteristics, patient and family member demographics, and data on satisfaction were collected. Factors associated with satisfaction were identified using a Poisson regression model. A total of 637 patients were included in the study, and 920 family members completed the questionnaire. Seven predictors of family satisfaction were found: one family-related factor, namely, family of French descent and six caregiver-related factors, namely, no perceived contradictions in information given by caregivers; information provided by a junior physician; patient to nurse ratio

Poor hemodynamic tolerance of intermittent hemodialysis (IHD) is a common problem for patients in an intensive care unit (ICU). New dialysis strategies have been adapted to chronic hemodialysis patients with cardiovascular insufficiency. To improve hemodynamic tolerance of IHD, specific guidelines were progressively implemented into practice through the year 1996 in our 26-bed medical ICU. To evaluate the efficiency of these guidelines we retrospectively compared all IHD performed during the years before (1995) and after (1997) implementation of these recommendations. Forty-five patients underwent 248 IHD sessions in 1995 and 76 patients underwent 289 IHD sessions in 1997. The two populations were similar for age, sex, chronic hemodialysis (26% versus 17%), and secondary acute renal failure. In 1997, patients were more severely ill with a higher SAPS II (50 +/- 17 versus 59 +/- 24; p = 0.036), and more patients required epinephrine or norepinephrine infusion before dialysis sessions (16% versus 34%; p < 0.0001). The compliance to guidelines was high, inducing a significant change in IHD modalities. As a result, hemodynamic tolerance was significantly better in 1997, with less systolic blood pressure drop at onset (33% versus 21%, p = 0. 002) and during the sessions (68% versus 56%, p = 0.002). IHD with hypotensive episode or need for therapeutic interventions were less frequent in 1997 (71% versus 61%, p = 0.015). The ICU mortality was similar (53.3% in 1995 versus 47.3% in 1997; p = 0.52) but death rate in 1997, but not in 1995, was significantly less than predicted from SAPS II (47.3% versus 65.6%; p = 0.02). Length of ICU stay was also reduced for survivors in 1997 (p = 0.04). Implementation of practice guidelines for intermittent hemodialysis in ICU patients lessens hemodynamic instability and may improve outcome.

Right heart catheterization (RHC) has been suspected of increasing mortality. The acute respiratory distress syndrome (ARDS) is a frequent reason for RHC. We designed a retrospective cohort study of 119 consecutive ARDS patients admitted to two medical intensive care units of tertiary care hospitals in which two different approaches are used for hemodynamic monitoring: RHC on demand (Henri Mondor Hospital [HM]) and no use of RHC (Ambroise Paré Hospital [AP]). The study tried to identify risk factors for death, and to assess the influence of RHC, with adjustment for the intensity of hemodynamic support as a confounding factor, using 98 patients in whom the delay between onset of ARDS, use of vasopressors, and RHC did not exceed 48 h. Several variables, including septic shock, cause of ARDS, Simplified Acute Physiology Score (SAPS) II, use of epinephrine/norepinephrine, and presence of RHC were entered into a logistic regression model to evaluate their independent prognostic roles. Mortality was different at HM and AP (36 of 55 patients [65.5%] versus 16 of 43 patients [37.2%], p < 0.005), and 29 of the 35 RHC-monitored patients died (82.8%), as compared with 23 of 63 patients (36.5%) treated without RHC (p < 0.0001). However, administration of epinephrine/norepinephrine and a nonpulmonary cause of ARDS were each independently associated with death. It is only when administration of vasopressors was omitted from the model that RHC, septic shock, and SAPS II became independent predictors of mortality. These results suggest that: (1) the use of vasopressors, but not of RHC, represents an important prognostic factor; and (2) not taking into account the use of these drugs may be misleading when assessing the influence of RHC on outcome.

The use of helium-oxygen (HeO(2)) was tested in combination with noninvasive ventilation (NIV) in 10 patients with acute exacerbation of chronic obstructive pulmonary disease (COPD). Effort to breathe as assessed by the respiratory muscle pressure-time index (PTI), work of breathing (WOB), and gas exchange were the main endpoints. Results of NIV-HeO(2) were compared with those obtained with standard NIV (AirO(2)), at two levels of pressure-support ventilation (PSV), 9 +/- 2 cm H(2)O and 18 +/- 3 cm H(2)O. Significant reductions in PTI were observed between HeO(2) and AirO(2) at both the low PSV level (n = 9; 160 +/- 58 versus 198 +/- 78 cm H(2)O/s/ min; p < 0.05) and the high PSV level (n = 10; 100 +/- 45 versus 150 +/- 82 cm H(2)O/s/min; p < 0.01). WOB also differed significantly between HeO(2) and AirO(2) (7.8 +/- 4.1 versus 10.9 +/- 6.1 J/min at the low PSV level, p < 0.05; and 5.7 +/- 3.3 versus 9.2 +/- 5. J/min, p < 0.01 at the high PSV level). HeO(2) reduced Pa(CO(2)) at both the low PSV level (61 +/- 13 versus 64 +/- 15 mm Hg; p < 0.05) and the high PSV level (56 +/- 13 versus 58 +/- 14 mm Hg; p < 0.05), without significantly changing breathing pattern or oxygenation. We conclude that use of HeO(2) during NIV markedly enhances the ability of NIV to reduce patient effort and to improve gas exchange.

We have designed a computerized system providing closed-loop control of the level of pressure support ventilation (PSV). The system sets itself at the lowest level of PSV that maintains respiratory rate (RR), tidal volume (VT), and end-tidal CO(2) pressure (PET(CO(2))) within predetermined ranges defining acceptable ventilation (i.e., 12 < RR < 28 cycles/min, VT > 300 ml [> 250 if weight < 55 kg], and PET(CO(2)) < 55 mm Hg [< 65 mm Hg if chronic CO(2) retention]). Ten patients received computer-controlled (automatic) PSV and physician-controlled (standard) PSV, in random order, during 24 h for each mode. An estimation of occlusion pressure (P(0.1)) was recorded continuously. The average time spent with acceptable ventilation as previously defined was 66 +/- 24% of the total ventilation time with standard PSV versus 93 +/- 8% with automatic PSV (p < 0.05), whereas the level of PSV was similar during the two periods (17 +/- 4 cm H(2)O versus 19 +/- 6 cm H(2)O). The time spent with an estimated P(0.1) above 4 cm H(2)O was 34 +/- 35% of the standard PSV time versus only 11 +/- 17% of the automatic PSV time (p < 0.01). Automatic PSV increased the time spent within desired ventilation parameter ranges and apparently reduced periods of excessive workload.

Measuring elastic pressure-volume (Pel-V) curves of the respiratory system and the volume recruited by a positive end-expiratory pressure (PEEP) allows one to study the pressure range over which recruitment occurs in acute lung injury (ALI), and to explain how recruitment affects the compliance. Pel-V curves were measured with the low flow inflation technique in 11 patients mechanically ventilated for ALI. Curve I was recorded during inflation from the volume attained after a prolonged expiration (6 s) at PEEP (9.0 +/- 2.2 cm H2O), and Curve II after expiration to the elastic equilibrium volume at zero end-expiratory pressure (ZEEP). By using the end-expiratory volume of the breaths, the curves were aligned on a common volume axis to determine the effect of a single complete expiration. In each patient, Curve II (from ZEEP) was shifted toward lower volumes than Curve I. The volume shift, probably due to derecruitment, was 205 +/- 100 ml at 15 cm H2O (p < 0.01) and 78 +/- 93 ml at 30 cm H2O (p < 0.01); thus, during inflation from ZEEP, the volume deficit was successively regained over a pressure range up to at least 30 cm H2O. At any pressure, compliance was higher on the curve from ZEEP than from PEEP, by 10.0 +/- 8.7 ml/cm H2O at 15 cm H2O (p < 0.01), and by 5.4 +/- 5.5 at 30 cm H2O (p < 0.01). It is concluded that in ALI, a single expiration to ZEEP leads to lung collapse. High compliance during insufflation from ZEEP indicates that lung recruitment happens far above the lower inflection point of the Pel-V curve.

Tracheotomy is widely performed on ventilator-dependent patients, but its effects on respiratory mechanics have not been studied. We measured the work of breathing (WOB) in eight patients before and after tracheotomy during breathing at three identical levels of pressure support (PS): baseline level (PS-B), PS + 5 cm H2O (PS+5), and PS - 5 cm H2O (PS-5). After the procedure, we also compared the resistive work induced by the patients' endotracheal tubes (ETTs) and by a new tracheotomy cannula in an in vitro bench study. A significant reduction in the WOB was observed after tracheotomy for PS-B (from 0.9 +/- 0.4 to 0.4 +/- 0.2 J/L, p < 0.05), and for PS-5 (1.4 +/- 0.6 to 0.6 +/- 0.3 J/L, p < 0.05), with a near-significant reduction for PS+5 (0.5 +/- 0.5 to 0.2 +/- 0.1 J/L, p = 0.05). A significant reduction was also observed in the pressure-time index of the respiratory muscles (181 +/- 92 to 80 +/- 56 cm H2O. s/min for PS-B, p < 0.05). Resistive and elastic work computed from transpulmonary pressure measurements decreased significantly at PS-B and PS-5. A significant reduction in occlusion pressure and intrinsic positive end-expiratory pressure (PEEP) was also observed for all conditions, with no significant change in breathing pattern. Three patients had ineffective breathing efforts before tracheotomy, and all had improved synchrony with the ventilator after the procedure. In vitro measurements made with ETTs removed from the patients, with new ETTs, and with the tracheotomy cannula showed that the cannula reduced the resistive work induced by the artificial airway. Part of these results was explained by a slight, subtle reduction of the inner diameter of used ETTs. We conclude that tracheotomy can substantially reduce the mechanical workload of ventilator-dependent patients.

Because animal studies have demonstrated that mechanical ventilation at high volume and pressure can be deleterious to the lungs, limitation of airway pressure, allowing hypercapnia if necessary, is already used for ventilation of acute respiratory distress syndrome (ARDS). Whether a systematic and more drastic reduction is necessary is debatable. A multicenter randomized study was undertaken to compare a strategy aimed at limiting the end-inspiratory plateau pressure to 25 cm H2O, using tidal volume (VT) below 10 ml/kg of body weight, versus a more conventional ventilatory approach (with regard to current practice) using VT at 10 ml/kg or above and close to normal PaCO2. Both arms used a similar level of positive end-expiratory pressure. A total of 116 patients with ARDS and no organ failure other than the lung were enrolled over 32 mo in 25 centers. The two groups were similar at inclusion. Patients in the two arms were ventilated with different VT (7.1 +/- 1.3 versus 10.3 +/- 1.7 ml/kg at Day 1, p < 0.001) and plateau pressures (25.7 +/- 5. 0 versus 31.7 +/- 6.6 cm H2O at Day 1, p < 0.001), resulting in different PaCO2 (59.5 +/- 15.0 versus 41.3 +/- 7.6 mm Hg, p < 0.001) and pH (7.28 +/- 0.09 versus 7.4 +/- 0.09, p < 0.001), but a similar level of oxygenation. The new approach did not reduce mortality at Day 60 (46.6% versus 37.9% in control subjects, p = 0.38), the duration of mechanical ventilation (23.1 +/- 20.2 versus 21.4 +/- 16. 3 d, p = 0.85), the incidence of pneumothorax (14% versus 12%, p = 0. 78), or the secondary occurrence of multiple organ failure (41% versus 41%, p = 1). We conclude that no benefit could be observed with reduced VT titrated to reach plateau pressures around 25 cm H2O compared with a more conventional approach in which normocapnia was achieved with plateau pressures already below 35 cm H2O.

The effects of flow triggering (FT) as compared with pressure triggering (PT) on breathing effort have been the focus of several studies, and discrepant results have been reported. In the initial part of our study, a lung model was used to quantify triggering effort (airway pressure-time product, PTPaw) for a range of sensitivity settings in nine new-generation ventilators. A ventilator providing both FT and PT was then used to compare these systems during pressure-support (PSV) and volume-targeted assist-control ventilation (ACV) in eight ventilator-dependent patients, using sensitivity settings (2 L/min for FT and -2 cm H2O for PT) that had proven significantly different in the initial bench study. Indexes of effort included the esophageal and transdiaphragmatic pressure-time products and inspiratory work of breathing per minute (PTPes/min, PTPdi/min, and Wi/min, respectively). The experimental study revealed significant differences between ventilators in PTPaw at commonly used settings. In two of three ventilators featuring both systems, PTPaw was significantly lower with FT than PT (p < 0.001). In the clinical study, FT as compared with PT, was associated with reductions in all indexes of breathing effort during PSV: 16 +/- 6% (p < 0.001), 13 +/- 10% (p < 0.01), and 14 +/- 12% (p < 0.05) for PTPdi/min, PTPes/min, and Wi/min, respectively. By contrast, no differences were found when FT was used during ACV. Although FT reduced triggering effort in both modes (p < 0.001), the effects observed during the post-trigger phase differed, and explained the discrepant results between the two modes. We conclude that FT more effectively reduces breathing effort when used in conjunction with a pressure-targeted mode than with a volume-targeted mode, especially when flow delivery is close to or below demand.

The influence of the endotracheal tube (ETT) during a T-piece trial remains controversial. Our aim was to compare the work of breathing of 14 successfully extubated patients at the end of a 2-h trial (T) and after extubation (E) of the trachea, and to assess, using the acoustic reflection method, the resistance of the endotracheal tube and of the supraglottic airway as well as their related work. We found that the work of breathing of the patients was identical between T and E (1.72 +/- 0.59 versus 1.63 +/- 0.45 J/L; p = 0.50 and 23.5 +/- 10.6 versus 22.6 +/- 9.7 J/min; p = 0.70). There was no significant difference between the beginning and the end of the T-piece trial (1.57 +/- 0.53 versus 1.72 +/- 0.59 J/ L, p = 0.10). The work caused by the ETT amounted to 11.0 +/- 3.9% of the total work of breathing. The supraglottic airway resistance was in the normal range and was significantly smaller than the endotracheal tube resistance (0.79 +/- 0.4 versus 1.43 +/- 0.31 cm H2O x s/L; p = 0.008, flow = 0.25 L/s). We conclude that a 2-h trial of spontaneous breathing through an endotracheal tube well mimics the work of breathing performed after extubation, in patients who pass a weaning trial and do not require reintubation.

Ventilator-associated pneumonia (VAP) is difficult to detect and is often unsuspected during adult respiratory distress syndrome (ARDS). We prospectively evaluated lower respiratory tract (LRT) colonization and infection in 30 patients with severe ARDS (PaO2/FIO2 ratio < 150 mm Hg), using repeated quantitative cultures of plugged telescopic catheter (PTC) specimens taken blindly via the endotracheal tube every 48 to 72 h after onset of ARDS. All patients except one were receiving antibiotics. When VAP was suspected on the presence of clinical criteria for infection, a repeated PTC and, when possible, a bronchoalveolar lavage (BAL) were obtained before any new antimicrobials were administered; samples growing > or = 10(3) cfu/ml (PTC) or > or = 10(4) cfu/ml (BAL) were considered diagnostic of infection. Twenty-four VAP episodes were diagnosed in 18 patients (60% of patients or 4.2/100 ventilator-days) a mean of 9.8+/-5.7 d after onset of ARDS. Eighteen LRT colonization episodes were recorded; 16 of 24 (66%) VAP episodes were preceded (by 2 to 6 d) by LRT colonization with the same organism(s), and only two episodes of colonization were not followed by VAP. We conclude that although VAP is of relatively late-onset during severe ARDS, its incidence is much higher than in other conditions and can be underestimated. Lower airways colonization is consistently followed by infection with the same organisms and precedes VAP in two thirds of episodes. Repeated protected specimens taken blindly may provide a useful means to predict infection and therefore allow early antimicrobial therapy in high-risk patients with diffuse lung injury.