Samir Jaber

The measurement of pain in intensive care unit: Comparison of 5 self-report intensity scales

&NA; Unlike wards, where chronic and acute pain are regularly managed, comparisons of the most commonly used self‐report pain tools have not been reported for the intensive care unit (ICU) setting. The objective of this study was to compare the feasibility, validity and performance of the Visual Analog Scale (horizontal (VAS‐H) and vertical (VAS‐V) line orientation), the Verbal Descriptor Scale (VDS), the 0–10 oral Numeric Rating Scale (NRS‐O) and the 0–10 visually enlarged laminated NRS (NRS‐V) for pain assessment in critically ill patients. One hundred and eleven consecutive patients admitted into a medical‐surgical ICU were included as soon as they became alert and were able to follow simple commands. Pain was measured using the 5 scales in a randomized order upon enrollment‐(T1) and after‐(T2) administration of an analgesic or, in absence of pain upon enrollment, after a nociceptive procedure. The rate of any response obtained both at T1 and T2 (success rate) was significantly higher for NRS‐V (91%) compared with NRS‐O (83%), VDS (78%), VAS‐H (68%) and VAS‐V (66%). Pain intensity changed significantly between T1 and T2, showing a good validity and responsiveness for the 5 scales, which correlated well between each other. The negative predictive value calculated from true and false negatives defined by real and false absence of pain was highest for NRS‐V (90%). In conclusion, the NRS‐V should be the tool of choice for the ICU setting, because it is the most feasible and discriminative self‐report scale for measuring critically ill patients’ pain intensity.

Evaluation of pulse pressure variation validity criteria in critically ill patients: a prospective observational multicentre point-prevalence study

BACKGROUND Respiratory variation in pulse pressure (ΔPP) is commonly used to predict the fluid responsiveness of critically ill patients. However, some researchers have demonstrated that this measurement has several limitations. The present study was designed to evaluate the proportion of patients satisfying criteria for valid application of ΔPP at a given time-point. METHODS A 1 day, prospective, observational, point-prevalence study was performed in 26 French intensive care units (ICUs). All patients hospitalized in the ICUs on the day of the study were included. The ΔPP validity criteria were recorded prospectively and defined as follows: (i) mechanical ventilation in the absence of spontaneous respiration; (ii) regular cardiac rhythm; (iii) tidal volume ≥8 ml kg(-1) of ideal body weight; (iv) a heart rate/respiratory rate ratio >3.6; (v) total respiratory system compliance ≥30 ml cm H2O(-1); and (vi) tricuspid annular peak systolic velocity ≥0.15 m s(-1). RESULTS The study included 311 patients with a Simplified Acute Physiology Score II of 41 (39-43). Overall, only six (2%) patients satisfied all validity criteria. Of the 170 patients with an arterial line in place, only five (3%) satisfied the validity criteria. During the 24 h preceding the study time-point, fluid responsiveness was assessed for 79 patients. ΔPP had been used to assess fluid responsiveness in 15 of these cases (19%). CONCLUSIONS A very low percentage of patients satisfied all criteria for valid use of ΔPP in the evaluation of fluid responsiveness. Physicians must consider limitations to the validity of ΔPP before using this variable.

Noninvasive respiratory support in the perioperative period.

Purpose of review The aims of this review are: to discuss the physiological rationale for noninvasive respiratory support (NRS) in the perioperative period; to give some practical recommendations to safely apply NRS; and to review available clinical data on preventive and curative NRS after cardiac, thoracic and abdominal surgery. Recent findings The most important morbid postoperative pulmonary complication is atelectasis formation, which increases significantly the risk for pneumonia and hypoxic acute respiratory failure. NRS refers to techniques allowing respiratory support without the need for an invasive airway. Two types of NRS are commonly used: noninvasive continuous positive airway pressure (nCPAP) and noninvasive positive pressure ventilation (nPPV). NRS may be an important tool to prevent (prophylactic treatment) or to treat acute respiratory failure avoiding intubation (curative treatment). The aims of NRS are: to partially compensate for the affected respiratory function by reducing the work of breathing; to improve alveolar recruitment with better gas exchange (oxygenation and ventilation); to reduce left ventricular afterload, increasing cardiac output and improving hemodynamics. Evidence suggests that NRS has been proven to be an effective strategy to reduce intubation rates, nosocomial infections, ICU and hospital lengths of stay, morbidity and mortality in postoperative patients. However, before initiating NRS any surgical complications must be treated. Summary The application of postoperative NRS by a trained and experienced ICU team, with careful patient selection, should optimize patient outcome.

Effects of steroids on reintubation and post-extubation stridor in adults: meta-analysis of randomised controlled trials

IntroductionThe efficacy of steroid administration before planned tracheal extubation in critical care patients remains controversial with respect to the selection of patients most likely to benefit from this treatment.MethodsWe performed an extensive literature search for adult trials testing steroids versus placebo to prevent reintubation or laryngeal dyspnoea. Studies were evaluated on a five-point scale based on randomisation, double-blinding and follow-up. Our analysis included trials having a score three or higher with patients mechanically ventilated for at least 24 hours and treated with steroids before extubation, taking into account the time of their administration (early vs late) and if the population selected was at risk or not.ResultsSeven prospective, randomised, double-blinded trials, including 1846 patients, (949 of which received steroids) were selected. Overall, steroids significantly decreased the risk of reintubation (relative risk (RR) = 0.58, 95% confidence interval (CI) = 0.41 to 0.81; number-needed-to-treat (NNT) = 28, 95% CI = 20 to 61) and stridor (RR = 0.48, 95% CI = 0.26 to 0.87; NNT = 11, 95% CI = 8 to 42). The effect of steroids on reintubation and stridor was more pronounced for selected high-risk patients, as determined by a reduced cuff leak volume (RR = 0.38, 95% CI = 0.21 to 0.72; NNT = 9, 95% CI = 7 to 19; and RR = 0.40, 95% CI = 0.25 to 0.63; NNT = 5, 95% CI = 4 to 8, respectively). In contrast, steroid benefit was unclear when trials did not select patients for their risk of reintubation (RR = 0.67, 95% CI = 0.45 to 1.00; NNT = 44, 95% CI ≥ 26 to infinity) or stridor (RR = 0.56, 95% CI = 0.20 to 1.55).ConclusionsThe efficacy of steroids to prevent stridor and reintubation was only observed in a high-risk population, as identified by the cuff-leak test and when it was administered at least four hours before extubation. The benefit of steroids remains unclear when patients at high risk are not selected.

Rapid Onset of Specific Diaphragm Weakness in a Healthy Murine Model of Ventilator-induced Diaphragmatic Dysfunction

Background: Controlled mechanical ventilation is associated with ventilator-induced diaphragmatic dysfunction, which impedes weaning from mechanical ventilation. To design future clinical trials in humans, a better understanding of the molecular mechanisms using knockout models, which exist only in the mouse, is needed. The aims of this study were to ascertain the feasibility of developing a murine model of ventilator-induced diaphragmatic dysfunction and to determine whether atrophy, sarcolemmal injury, and the main proteolysis systems are activated under these conditions. Methods: Healthy adult male C57/BL6 mice were assigned to three groups: (1) mechanical ventilation with end-expiratory positive pressure of 2–4 cm H2O for 6 h (n = 6), (2) spontaneous breathing with continuous positive airway pressure of 2–4 cm H2O for 6 h (n = 6), and (3) controls with no specific intervention (n = 6). Airway pressure and hemodynamic parameters were monitored. Upon euthanasia, arterial blood gases and isometric contractile properties of the diaphragm and extensor digitorum longus were evaluated. Histology and immunoblotting for the main proteolysis pathways were performed. Results: Hemodynamic parameters and arterial blood gases were comparable between groups and within normal physiologic ranges. Diaphragmatic but not extensor digitorum longus force production declined in the mechanical ventilation group (maximal force decreased by approximately 40%) compared with the control and continuous positive airway pressure groups. No histologic difference was found between groups. In opposition with the calpains, caspase 3 was activated in the mechanical ventilation group. Conclusion: Controlled mechanical ventilation for 6 h in the mouse is associated with significant diaphragmatic but not limb muscle weakness without atrophy or sarcolemmal injury and activates proteolysis.

A recruitment maneuver increases oxygenation after intubation of hypoxemic intensive care unit patients: a randomized controlled study.

IntroductionTracheal intubation and anaesthesia promotes lung collapse and hypoxemia. In acute lung injury patients, recruitment maneuvers (RMs) increase lung volume and oxygenation, and decrease atelectasis. The aim of this study was to evaluate the efficacy and safety of RMs performed immediately after intubation.MethodsThis randomized controlled study was conducted in two 16-bed medical-surgical intensive care units within the same university hospital. Consecutive patients requiring intubation for acute hypoxemic respiratory failure were included. Patients were randomized to undergo a RM immediately (within 2 minutes) after intubation, consisting of a continuous positive airway pressure (CPAP) of 40 cmH2O over 30 seconds (RM group), or not (control group). Blood gases were sampled and blood samples taken for culture before, within 2 minutes, 5 minutes, and 30 minutes after intubation. Haemodynamic and respiratory parameters were continuously recorded throughout the study. Positive end expiratory pressure (PEEP) was set at 5 cmH2O throughout.ResultsThe control (n = 20) and RM (n = 20) groups were similar in terms of age, disease severity, diagnosis at time of admission, and PaO2 obtained under 10-15 L/min oxygen flow immediately before (81 ± 15 vs 83 ± 35 mmHg, P = 0.9), and within 2 minutes after, intubation under 100% FiO2 (81 ± 15 vs 83 ± 35 mmHg, P = 0.9). Five minutes after intubation, PaO2 obtained under 100% FiO2 was significantly higher in the RM group compared with the control group (93 ± 36 vs 236 ± 117 mmHg, P = 0.008). The difference remained significant at 30 minutes with 110 ± 39 and 180 ± 79 mmHg, respectively, for the control and RM groups. No significant difference in haemodynamic conditions was observed between groups at any time. Following tracheal intubation, 15 patients had positive blood cultures, showing microorganisms shared with tracheal aspirates, with no significant difference in the incidence of culture positivity between groups.ConclusionsRecruitment maneuver following intubation in hypoxemic patients improved short-term oxygenation, and was not associated with increased adverse effects.Trial registrationNCT01014299

Empirical Micafungin Treatment and Survival Without Invasive Fungal Infection in Adults With ICU-Acquired Sepsis, Candida Colonization, and Multiple Organ Failure: The EMPIRICUS Randomized Clinical Trial

Importance Although frequently used in treating intensive care unit (ICU) patients with sepsis, empirical antifungal therapy, initiated for suspected fungal infection, has not been shown to improve outcome. Objective To determine whether empirical micafungin reduces invasive fungal infection (IFI)-free survival at day 28. Design, Setting, and Participants Multicenter double-blind placebo-controlled study of 260 nonneutropenic, nontransplanted, critically ill patients with ICU-acquired sepsis, multiple Candida colonization, multiple organ failure, exposed to broad-spectrum antibacterial agents, and enrolled between July 2012 and February 2015 in 19 French ICUs. Interventions Empirical treatment with micafungin (100 mg, once daily, for 14 days) (n = 131) vs placebo (n = 129). Main Outcomes and Measures The primary end point was survival without proven IFI 28 days after randomization. Key secondary end points included new proven fungal infections, survival at day 28 and day 90, organ failure, serum (1-3)-β-D-glucan level evolution, and incidence of ventilator-associated bacterial pneumonia. Results Among 260 patients (mean age 63 years; 91 [35%] women), 251 (128, micafungin group; 123, placebo group) were included in the modified intent-to-treat analysis. Median values were 8 for Sequential Organ Failure Assessment (SOFA) score, 3 for number of Candida-colonized sites, and 99 pg/mL for level of (1-3)-β-D-glucan. On day 28, there were 82 (68%) patients in the micafungin group vs 79 (60.2%) in the placebo group who were alive and IFI free (hazard ratio [HR], 1.35 [95% CI, 0.87-2.08]). Results were similar among patients with a (1-3)-β-D-glucan level of greater than 80 pg/mL (n = 175; HR, 1.41 [95% CI, 0.85-2.33]). Day-28 IFI-free survival in patients with a high SOFA score (>8) was not significantly different when compared between the micafungin vs placebo groups (HR, 1.69 [95% CI, 0.96-2.94]). Use of empirical micafungin decreased the rate of new invasive fungal infection in 4 of 128 patients (3%) in the micafungin group vs placebo (15/123 patients [12%]) (P = .008). Conclusions and Relevance Among nonneutropenic critically ill patients with ICU-acquired sepsis, Candida species colonization at multiple sites, and multiple organ failure, empirical treatment with micafungin, compared with placebo, did not increase fungal infection-free survival at day 28. Trial Registration clinicaltrials.gov Idenitfier: NCT01773876.

Severe metabolic or mixed acidemia on intensive care unit admission: incidence, prognosis and administration of buffer therapy. A prospective, multiple-center study.

IntroductionIn this study, we sought describe the incidence and outcomes of severe metabolic or mixed acidemia in critically ill patients as well as the use of sodium bicarbonate therapy to treat these illnesses.MethodsWe conducted a prospective, observational, multiple-center study. Consecutive patients who presented with severe acidemia, defined herein as plasma pH below 7.20, were screened. The incidence, sodium bicarbonate prescription and outcomes of either metabolic or mixed severe acidemia were analyzed.ResultsAmong 2, 550 critically ill patients, 200 (8%) presented with severe acidemia, and 155 (6% of the total admissions) met the inclusion criteria. Almost all patients needed mechanical ventilation and vasopressors during their ICU stay, and 20% of them required renal replacement therapy within the first 24 hours of their ICU stay. Severe metabolic or mixed acidemia was associated with a mortality rate of 57% in the ICU. Delay of acidemia recovery as opposed to initial pH value was associated with increased mortality in the ICU. The type of acidemia did not influence the decision to administer sodium bicarbonate.ConclusionsThe incidence of severe metabolic or mixed acidemia in critically ill patients was 6% in the present study, and it was associated with a 57% mortality rate in the ICU. In contradistinction with the initial acid-base parameters, the rapidity of acidemia recovery was an independent risk factor for mortality. Sodium bicarbonate prescription was very heterogeneous between ICUs. Further studies assessing specific treatments may be of interest in this population.

Cytomegalovirus and Herpes Simplex Virus Effect on the Prognosis of Mechanically Ventilated Patients Suspected to Have Ventilator-Associated Pneumonia

Objective Cytomegalovirus (CMV) and herpes simplex virus (HSV) are common viruses that can affect critically ill patients who are not immunocompromised. The aim of this study was to determine whether the identification of CMV and/or HSV in mechanically ventilated critically ill patients suspected of having pneumonia was associated with an increased mortality. Design Prospective epidemiological study. Setting Medical intensive care unit of a tertiary medical center. Patients Ninety-three patients with suspected pneumonia. Interventions Patients with suspected pneumonia had bronchoalveolar lavage and blood samples taken to confirm the diagnosis. Antigenemia was used to detect CMV in the blood. Bronchoalveolar lavage samples were submitted to testing using quantitative real-time Polymerase Chain Reaction. Measurements and Main Results We identified 22 patients with a CMV infection, 26 patients with an HSV infection and 45 patients without CMV or HSV infection (control group). Mortality at day 60 was higher in patients with a CMV infection than in patients from the control group (55% vs. 20%, P<0.01). Mortality at day 60 was not significantly increased in the group with HSV infection. Duration of ICU stay and ICU mortality were significantly higher in patients with CMV infections when compared to patients from the control group, whereas ventilator free days were significantly lower in patients with CMV infections when compared to patients from the control group. Conclusions In critically ill patients, a CMV infection is associated with an increased mortality. Further interventional studies are needed to evaluate whether treatment could improve the prognosis.

Clinical review: Update on neurally adjusted ventilatory assist - report of a round-table conference

Conventional mechanical ventilators rely on pneumatic pressure and flow sensors and controllers to detect breaths. New modes of mechanical ventilation have been developed to better match the assistance delivered by the ventilator to the patients needs. Among these modes, neurally adjusted ventilatory assist (NAVA) delivers a pressure that is directly proportional to the integral of the electrical activity of the diaphragm recorded continuously through an esophageal probe. In clinical settings, NAVA has been chiefly compared with pressure-support ventilation, one of the most popular modes used during the weaning phase, which delivers a constant pressure from breath to breath. Comparisons with proportional-assist ventilation, which has numerous similarities, are lacking. Because of the constant level of assistance, pressure-support ventilation reduces the natural variability of the breathing pattern and can be associated with asynchrony and/or overinflation. The ability of NAVA to circumvent these limitations has been addressed in clinical studies and is discussed in this report. Although the underlying concept is fascinating, several important questions regarding the clinical applications of NAVA remain unanswered. Among these questions, determining the optimal NAVA settings according to the patients ventilatory needs and/or acceptable level of work of breathing is a key issue. In this report, based on an investigator-initiated round table, we review the most recent literature on this topic and discuss the theoretical advantages and disadvantages of NAVA compared with other modes, as well as the risks and limitations of NAVA.