Clinical relevance of classification according to weaning difficulty.

OBJECTIVE: To evaluate the clinical relevance of the weaning from mechanical ventilation classification system derived from the 2005 international consensus conference, in patients who receive mechanical ventilation for more than 48 hours, and evaluate its correlation with prognosis. METHODS: We conducted a retrospective cohort study in a 12-bed intensive care unit (ICU) in a teaching hospital. We included patients who required > 48 hours of mechanical ventilation and who passed a spontaneous breathing trial (SBT). Weaning and sedation were monitored according to standardized protocol-directed procedures. We collected data on physiological characteristics, mechanical ventilation duration, ICU and hospital stay, and mortality from the medical records database. We assessed one-year mortality with a prospective, standardized method. Multivariate logistic regression was performed to evaluate the association between weaning categories and outcome. RESULTS: We included 329 ventilation episodes, in which 115 patients passed at least one SBT. Thirty-four patients (30%) succeeded in their first SBT (simple weaning group), 47 patients (40%) succeeded in their 2nd or 3rd SBT or in less than 7 days of weaning (the difficult weaning group), and 34 patients (30%) required more than 3 SBTs or more than 7 days of weaning (the prolonged weaning group). There were significant differences in ICU and hospital mortality between the simple, difficult, and prolonged-weaning groups. Prolonged weaning was an independent risk factor for longer ICU stay (odds ratio 15.11, 95% CI 1.61-141.91, P = .01) and hospital mortality (odds ratio 3.66, 95% CI 0.99-13.51). However, the weaning process did not impact one-year mortality (odds ratio 2.61, 95% CI 0.82-8.35). CONCLUSIONS: The new weaning classification system is clinically relevant and correlates to ICU and hospital mortality, but not to one-year mortality.

Feasibility and potential cost/benefit of routine isoflurane sedation using an anesthetic-conserving device: a prospective observational study.

BACKGROUND: Inhaled sedation is efficient and easily controllable; in low concentrations it causes minimal changes in the patient and very little interference with hemodynamics. Awakening after inhaled sedation is quick and predictable. The major reason inhaled sedation has not become widely used in intensive care is that no commercially available administration device has been available. METHODS: In our intensive care unit we conducted a prospective observational study to assess the feasibility, benefits, and costs of routine isoflurane sedation via the AnaConDa anesthetic-administration device. We included 15 adult patients who required > 24 hours of deep sedation. Conventional intravenous sedation (benzodiazepine and opioid) had been administered according to a sedation protocol that included a predetermined target Ramsay-scale sedation score. We then switched to inhaled isoflurane via the AnaConDa, and measured sedation efficacy, cumulative dose, and daily cost of sedation. Adverse events were prospectively defined and monitored. RESULTS: The sedation goal was reached with isoflurane in all 15 patients (P < .01, compared to the conventional sedation protocol). Hemodynamic changes were nonsignificant, and no renal or hepatic dysfunctions were observed. The frequency of meeting the sedation goal was significantly better with isoflurane than with our usual sedation protocol. With isoflurane, awakening from sedation was always

Validation of a skills assessment scoring system for transesophageal echocardiographic monitoring of hemodynamics.

OBJECTIVE: Transesophageal echocardiography (TEE) is increasingly used in hemodynamic monitoring in the intensive care unit. This paper describes and validates a scoring system for assessing competence in TEE performed by intensivists for this indication. DESIGN: Prospective study over an 18-month period. SETTINGS: Two medical intensive care units. METHODS: The scoring system is used to assess four aspects of TEE: quality of the views (score out of 14); semiquantitative evaluation of respiratory variations in the superior vena cava, valve regurgitation, size of the right ventricle (score out of 10); accuracy of measurement of velocity-time integrals for pulmonary and aortic flow, peak velocity of the E and A waves of mitral flow, left ventricular fractional area change (score out of 8); summary and proposed treatment (score out of 8). The scoring system was validated by using it to assess intensivists after 1 month (M1), 3 months (M3) and 6 months (M6) of training. TEE was done on a mechanically ventilated, hypotensive patient and scored by comparing the intensivist's examination with that of the expert examiner. The intensivists were divided into two groups of theoretical expertise at the start of training. RESULTS: Nineteen intensivists were evaluated. The scores at M1 for level 0 (no experience in echocardiography) and level 1 (previous experience) were, respectively, 18.5 +/- 4 and 24.7 +/- 5. The scores at M1, M3, and M6 were, respectively, 20.4 +/- 5, 30.4 +/- 5 and 35.7 +/- 3. At M6, the intensivists had performed TEE 29 +/- 10 times. CONCLUSION: The scoring system was discriminatory and sensitive to change, and could be used as a tool to assess an intensivist's mastery of TEE.

Can lung ultrasonography predict prone positioning response in acute respiratory distress syndrome patients?

PURPOSE: The purpose was to assess whether lung ultrasonography (L-US) is a useful tool in prediction of prone positioning (PP) oxygenation response in patients with acute respiratory distress syndrome (ARDS). METHODS: In a prospective study, 19 ARDS patients were included for assessment of PP oxygenation response. The latter was assessed for at least 12 hours 6 different ultrasonography windows were performed on each hemithorax before prone (H0, H2, H12 before return to supine and at H14 (2 hours after return to supine). Patients were classified into 2 groups (responders / non responders) according their oxygenation response to PP. Ultrasonography videos were blindly evaluated by 3 expert clinicians to classify lung regions as "normal", "moderate loss of aeration," "severe loss of aeration," or "lung consolidation." Oxygenation parameters were collected at H0, H2, and H14. RESULTS: Association of each lung region aspect to PP oxygenation response was compared between the 2 groups. The normal aspect of the anterobasal regions was significantly associated with the oxygenation response (P = .0436), with a positive predictive value equal to or near 100%. DISCUSSION: Our results demonstrated that a simple and short L-US examination could be a useful tool in prediction of PP oxygenation response in ARDS patients. A normal L-US pattern of both anterobasal lung regions in supine position may predict a significant PaO2/FIO2 ratio improvement.

Gut dysfunction and endoscopic lesions after out-of-hospital cardiac arrest.

BACKGROUND: Cardiac arrest induces severe mesenteric ischaemia. The objective of this study was to assess the frequency of gut dysfunction and endoscopic lesions following resuscitation after cardiac arrest, and to evaluate the potential value of gut endoscopy performance in these circumstances. METHODS: This is a retrospective data files survey of 3617 patients from the database in a medical intensive care unit. A systematic review of medical and endoscopic files was performed within this database, using a standardised chart. PATIENTS: One-hundred and thirty consecutive patients who survived up to 48 h were admitted to our unit after out-of-hospital cardiac arrest. Seventy-eight of these patients (60%) presented with early clinical signs of gut dysfunction and/or lesions. Thirty-six patients underwent gut endoscopies (26%) and were included in the survey. RESULTS: Endoscopic lesions were observed in all cases; in 15 cases, gastrointestinal haemorrhage requiring intervention was identified. The occurrence of haemorrhagic and/or necrotic lesions was found to be associated with an initial rhythm of asystole, higher SAPS II values and epinephrine requirements, compared with cardiac arrest patients without such lesions. CONCLUSION: The frequent occurrence of endoscopic lesions in the presence of gut dysfunction following a cardiac arrest could suggest systematic gut endoscopy in such patients. However, an alternative recommendation would be to watch these patients very closely, treat all with prophylactic proton pump inhibitors, and endoscope only those with evidence of bleeding.

Impact of a nurses' protocol-directed weaning procedure on outcomes in patients undergoing mechanical ventilation for longer than 48 hours: a prospective cohort study with a matched historical control group.

INTRODUCTION: The aim of the study was to determine whether the use of a nurses' protocol-directed weaning procedure, based on the French intensive care society (SRLF) consensus recommendations, was associated with reductions in the duration of mechanical ventilation and intensive care unit (ICU) length of stay in patients requiring more than 48 hours of mechanical ventilation. METHODS: This prospective study was conducted in a university hospital ICU from January 2002 through to February 2003. A total of 104 patients who had been ventilated for more than 48 hours and were weaned from mechanical ventilation using a nurses' protocol-directed procedure (cases) were compared with a 1:1 matched historical control group who underwent conventional physician-directed weaning (between 1999 and 2001). Duration of ventilation and length of ICU stay, rate of unsuccessful extubation and rate of ventilator-associated pneumonia were compared between cases and controls. RESULTS: The duration of mechanical ventilation (16.6 +/- 13 days versus 22.5 +/- 21 days; P = 0.02) and ICU length of stay (21.6 +/- 14.3 days versus 27.6 +/- 21.7 days; P = 0.02) were lower among patients who underwent the nurses' protocol-directed weaning than among control individuals. Ventilator-associated pneumonia, ventilator discontinuation failure rates and ICU mortality were similar between the two groups. DISCUSSION: Application of the nurses' protocol-directed weaning procedure described here is safe and promotes significant outcome benefits in patients who require more than 48 hours of mechanical ventilation.

A prospective survey of early 12-h prone positioning effects in patients with the acute respiratory distress syndrome.

OBJECTIVES: To evaluate of the oxygenation effects of 12-h prone positioning (PP) in ARDS patients and to assess the safety of such a procedure. DESIGN AND SETTING: Prospective observational study in a medical intensive care unit (12 beds) of a university hospital. PATIENTS: 51 consecutive ARDS patients. INTERVENTION: PP for at least 12 h daily until recovery or death. MEASUREMENTS AND RESULTS: Arterial blood gases were collected before and during PP and 1 h after return to supine. Turning adverse events, cutaneous bedsores, and enteral nutrition intolerance were specifically monitored and collected daily by a referring physician. In total 224 PP sessions were performed. Oxygenation improved 1 h after the turn and continued improving over the 12-h period (4). The beneficial effect persisted 1 h after return to supine (01). We considered 96% patients responders: 45% as early responders and 53% persistent responders (persistent benefit after return to supine). Four significant adverse events occurred during the 448 turning maneuvers (0.9%). Stage III ulceration and stage IV necrosis cutaneous bedsores occurred in ten patients (20%). Enteral nutrition intolerance was reported in 25% but without inability to meet patient's caloric requirement. CONCLUSIONS: Twelve-hour PP is a safe procedure and allows a continuous oxygenation improvement throughout the entire session.

Noninvasive continuous positive airway pressure in elderly cardiogenic pulmonary edema patients.

OBJECTIVE: To compare the physiological effects and the clinical efficacy of continuous positive airway pressure (CPAP) vs standard medical treatment in elderly patients (> or =75 years) with acute hypoxemic respiratory failure related to cardiogenic pulmonary edema. DESIGN: A prospective, randomized, concealed, and unblinded study of 89 consecutive patients who were admitted to the emergency departments of one general, and three teaching, hospitals. INTERVENTION: Patients were randomly assigned to receive standard medical treatment alone ( n=46) or standard medical treatment plus CPAP ( n=43). MEASUREMENTS: Improvement in PaO(2)/FIO(2) ratio, complications, length of hospital stay, early 48-h and overall mortality, compared between the CPAP and standard treatment groups. RESULTS: Study groups were comparable with regard to baseline physiological and clinical characteristics (age, sex ratio, autonomy, medical history, cause of pulmonary edema). Within 1 h, noninvasive continuous positive airway pressure led to decreased respiratory rate (respiratory rate, 27+/-7 vs 35+/-6 breaths/min; p=0.009), and improved oxygenation (PaO(2)/F(I)O(2), 306+/-104 vs 157+/-71; p=0.004) compared with baseline, whereas no differences were observed within the standard treatment group. Severe complications occurred in 17 patients in the standard treatment group, vs 4 patients in the noninvasive continuous positive airway pressure group ( p=0.002). Early 48-h mortality was 7% in the noninvasive continuous positive airway pressure group, compared with 24% in the standard treatment group ( p=0.017); however, no sustained benefits were observed during the overall hospital stay. CONCLUSION: Noninvasive continuous positive airway pressure promotes early clinical improvement in elderly patients attending emergency departments for a severe pulmonary edema, but only reduces early 48-h mortality.

Influence of the humidification device during acute respiratory distress syndrome.

OBJECTIVE: To evaluate the effects of the humidification device on respiratory, hemodynamic and gas exchange parameters in acute respiratory distress syndrome (ARDS) patients. DESIGN: A prospective open study. SETTING: A medical intensive care unit of a university hospital. PATIENTS: Acute respiratory distress syndrome patients, with hypercapnia (PaCO(2)>60 mmHg). INTERVENTION: A progressive reduction of the humidification system dead space (DSh). The following five conditions were tested sequentially: (1). heat and moisture exchanger (internal volume=95 ml) with a tracheal closed-suction system (internal volume=25 ml; total DSh=120 ml), (2). heat and moisture exchanger (internal volume=45 ml) with the closed-suction system (DSh=70 ml), (3). heat and moisture exchanger (internal volume=25 ml) with the closed-suction system (DSh=50 ml), (4). heated humidifier with the closed-suction system (DSh=25 ml) and (5). heated humidifier alone (DSh=0 ml). Recordings were performed at baseline and every 30 min after each artificial dead-space reduction. All ventilatory settings remained constant during the measurement periods. RESULTS: Ten ARDS patients were included. A significant PaCO(2) decrease was observed at each humidification system dead-space reduction, compared to baseline: PaCO(2 )=80.3+/-20 mmHg at DSh(120) compared to PaCO(2 )=63.6+/-13 mmHg at DSh(0) ( p<0.05). No changes were observed for hemodynamic and ventilatory parameters between the different humidification devices. CONCLUSION: Artificial airway dead-space reduction allows a significant PaCO(2) reduction. Independently of any respiratory mechanical changes, this very simple maneuver may be of importance when low tidal volume ventilation is used in ARDS patients, and when PaCO(2) lowering is warranted.

Noninvasive continuous positive airway pressure ventilation using a new helmet interface: a case-control prospective pilot study.

OBJECTIVE: To evaluate the clinical efficacy of noninvasive continuous positive airway pressure ventilation (CPAP) using a new interface, constituted by a cephalic plastic helmet, in comparison with a standard facial mask. DESIGN AND SETTING: A prospective pilot study with matched-control group, in the emergency department of a teaching hospital. PATIENTS AND METHODS: Eleven consecutive adult patients with acute hypoxemic respiratory failure related to cardiogenic pulmonary edema (whether hypercapnic or not) were enrolled in the study, after failure of the initial medical treatment. Each patient treated with CPAP, using the helmet in addition to a standardized medical treatment, was matched with historical control-patient treated with CPAP using a standard facial mask, and selected by gender, age, and PaCO2 levels on admission. Primary end points were improvements of gas exchanges and clinical parameters of respiratory distress. tolerance was evaluated after each CPAP trial. RESULTS: The 22 patients and controls had similar characteristics at baseline. PaCO2 levels, and clinical parameters improved similarly in both groups. No interface intolerance was reported whether using standard facial mask or the helmet. No complications were observed in either group. The helmet allowed CPAP administration for a longer period of time (p=0.045). In-hospital mortality was not different between the two groups. CONCLUSION: Despite a high dead-space volume (9-15 l), this new helmet interface is an efficient alternative to standard face mask during CPAP, even in cases of severe respiratory acidosis and hypercapnia. It allowed to provide long-duration CPAP, without any adverse events or clinical intolerance.

Determination of the learning curve for ultrasound-guided jugular central venous catheter placement.

PURPOSE: Use of ultrasound (US) when introducing central venous catheters (CVC) may improve success rates, reduce the number of needle punctures, and decrease complication rates, but has been hampered by supposed difficulty in learning how to perform the technique. This study describes the learning curve for US-guided jugular CVC placement after a training program. METHODS: After an initial slide presentation and a video, intensivists who had not previously used US for CVC placement were evaluated qualitatively for US set up (score S1) and technical skills (score S2). Quantitative measures included durations of different components of the procedure (T1, time from entry of the US into the patient's room to sterile dressing of the intensivist; T2, time needed for sterile drapes, venous line preparation, and sterile sheath placement; T3, time from skin puncture to venous flashback; T4, time from guide insertion to dressing; T(tot), total duration of the procedure); number of skin punctures; and a difficulty score allocated by the intensivist. RESULTS: We performed 150 evaluations of 30 intensivists: 50% had no prior experience of CVC placement and 50% no prior US experience. Maximal S1 and S2 scores were obtained with the fourth and eighth placement procedures, respectively. T1 and T2 did not change with ongoing training (5 and 8 min, respectively), but T3 and T4 decreased, from 5 min (first procedure) to less than 1 min (seventh procedure), and from 10 min (first procedure) to 7 min (sixth procedure), respectively. T(tot) decreased from 34 to 21 min at the eighth procedure. The number of skin punctures and the difficulty score decreased rapidly with the number of evaluations. CONCLUSIONS: Our study demonstrates that skills in US-guided CVC placement can easily be acquired with training.

Number of supervised studies required to reach competence in advanced critical care transesophageal echocardiography.

PURPOSE: To determine the minimum number of supervised transesophageal echocardiography (TEE) that intensivists should perform to reach competence in performing and interpreting a comprehensive hemodynamic assessment in ventilated intensive care unit patients. METHODS: Prospective and multicentric study. Skills of 41 intensivists (trainees) with no (level 0) or little (level 1) experience in echocardiography was evaluated over a 6-month period, using a previously validated skills assessment score (/40 points). Trainees were evaluated at 1 (M1), 3 (M3) and 6 months (M6) by their tutor while performing 2 TEE examinations in ventilated patients. Competence was a priori defined by a skills assessment score >35/40 points. RESULTS: No difference in the score was observed between level 0 and level 1, except at M1 (22.2 ± 6.2 vs. 25.9 ± 4.4 points, p = 0.03). After 6 months, trainees performed a mean of 31 ± 9 supervised TEE. The score gradually increased from M1 to M6 (24 ± 6, 32 ± 3, and 35 ± 3 points, p < 0.001), regardless of trainees' initial level. A correlation was found between the number of supervised TEE and the skills assessment score (r (2) = 0.60; p < 0.001). The number of supervised TEE examinations which best predicted a score >35/40 points was 25, with a sensitivity of 81 % and a specificity of 93 % (area under the ROC curve: 0.91 ± 0.04). A number of 31 supervised TEE examinations predicted a score >35/40 points with a specificity close to 100 %. CONCLUSION: The performance of at least 31 supervised examinations over 6 months is required to reach competence in TEE driven hemodynamic evaluation of ventilated patient.

Impact of clinical guidelines to improve appropriateness of laboratory tests and chest radiographs.

OBJECTIVE: To assess the impact of clinical guidelines to improve appropriate use of routine laboratory tests and bedside chest radiographs in a medical intensive care. DESIGN: A two-year (Period-1: 2005, Period-2: 2006), retrospective, comparative study, before and after policy implementation. PATIENTS: All consecutive patients admitted during the study periods. SETTING: A university hospital 15-bed medical ICU. INTERVENTION: Multifaceted intervention combining a daily routine prescription help-guide developed by a multidisciplinary group and displayed at patient's bedside, educational sessions and feedbacks by information on volumes of prescription. Individual adaptation to patient's clinical status was allowed by protocol. ASSESSMENT: The overall number and cost of laboratory tests and chest radiographs during Period-2 (with the help guide; from 01 to 12-2006) were compared to Period-1 (from 01 to 12-2005). RESULTS: Patients' general characteristics were similar during the two periods. A relative reduction of routine laboratory tests performance was observed per patient-ICU-day, ranging from 38 to 71.5% depending on the type of tests (P < 0.001 in all cases). For chest radiographs, a 41% relative reduction was observed between the two periods (P < 0.001). Daily ICU laboratory tests and chest radiographs cost per patient decreased from 114 to 56 euros. An overall 300,000 euros ICU cost reduction was directly related to the protocol implementation. CONCLUSION: The implementation of a laboratory tests and chest radiographs prescription protocol within our ICU induced an important cost saving.