Fabrice Ferré

Lactate clearance for death prediction in severe sepsis or septic shock patients during the first 24 hours in Intensive Care Unit: an observational study

BackgroundThis study was design to investigate the prognostic value for death at day-28 of lactate course and lactate clearance during the first 24 hours in Intensive Care Unit (ICU), after initial resuscitation.MethodsProspective, observational study in one surgical ICU in a university hospital. Ninety-four patients hospitalized in the ICU for severe sepsis or septic shock were included. In this septic cohort, we measured blood lactate concentration at ICU admission (H0) and at H6, H12, and H24. Lactate clearance was calculated as followed: [(lactateinitial - lactatedelayed)/ lactateinitial] x 100%].ResultsThe mean time between severe sepsis diagnosis and H0 (ICU admission) was 8.0 ± 4.5 hours. Forty-two (45%) patients died at day 28. Lactate clearance was higher in survivors than in nonsurvivors patients for H0-H6 period (13 ± 38% and −13 ± 7% respectively, p = 0.021) and for the H0-H24 period (42 ± 33% and −17 ± 76% respectively, p < 0.001). The best predictor of death at day 28 was lactate clearance for the H0-H24 period (AUC = 0.791; 95% CI 0.6-0.85). Logistic regression found that H0-H24 lactate clearance was independently correlated to a survival status with a p = 0.047 [odds ratio = 0.35 (95% CI 0.01-0.76)].ConclusionsDuring the first 24 hr in the ICU, lactate clearance was the best parameter associated with 28-day mortality rate in septic patients. Protocol of lactate clearance-directed therapy should be considered in septic patients, even after the golden hours.

Integrated Use of Bedside Lung Ultrasound and Echocardiography in Acute Respiratory Failure : A Prospective Observational Study in ICU

BACKGROUND It has been suggested that the complementary use of echocardiography could improve the diagnostic accuracy of lung ultrasonography (LUS) in patients with acute respiratory failure (ARF). Nevertheless, the additional diagnostic value of echocardiographic data when coupled with LUS is still debated in this setting. The aim of the current study was to compare the diagnostic accuracy of LUS and an integrative cardiopulmonary ultrasound approach (thoracic ultrasonography [TUS]) in patients with ARF. METHODS We prospectively recruited patients consecutively admitted for ARF to the ICU of a university teaching hospital over a 12-month period. Inclusion criteria were age ≥ 18 years and the presence of criteria for severe ARF justifying ICU admission. We compared both LUS and TUS approaches and the final diagnosis determined by a panel of experts using machine learning methods to improve the accuracy of the final diagnostic classifiers. RESULTS One hundred thirty-six patients were included (age, 68 ± 15 years; sex ratio, 1). A three-dimensional partial least squares and multinomial logistic regression model was developed and subsequently tested in an independent sample of patients. Overall, the diagnostic accuracy of TUS was significantly greater than LUS (P < .05, learning and test sample). Comparisons between receiver operating characteristic curves showed that TUS significantly improves the diagnosis of cardiogenic edema (P < .001, learning and test samples), pneumonia (P < .001, learning and test samples), and pulmonary embolism (P < .001, learning sample). CONCLUSIONS This study demonstrated for the first time to our knowledge a significantly better performance of TUS than LUS in the diagnosis of ARF. The value of the TUS approach was particularly important to disambiguate cases of hemodynamic pulmonary edema and pneumonia. We suggest that the bedside use of artificial intelligence methods in this setting could pave the way for the development of new clinically relevant integrative diagnostic models.

Doppler renal resistive index for early detection of acute kidney injury after major orthopaedic surgery: a prospective observational study.

BACKGROUND Postoperative acute kidney injury (AKI) is a cause of morbidity and mortality. Its diagnosis requires better markers than variations in diuresis or postoperative serum creatinine. OBJECTIVES The aim of this study was to evaluate the accuracy of Doppler renal resistive index for early detection of AKI after hip or knee arthroplasty. DESIGN A prospective observational study. SETTING A single-centre study in a university hospital. PATIENTS Fifty men and women older than 65 years, requiring hip or knee replacement with at least two perioperative AKI risk factors, including diabetes, arteritis, chronic heart or renal dysfunction, and prescription of angiotensin-converting enzyme (ACE) inhibitors. Exclusion criteria were poor abdominal echogenicity, arrhythmia, respiratory failure or agitation. INTERVENTION Renal resistive index was measured preoperatively and in the postanaesthesia care unit. RESULTS Sixteen patients presented with AKI in the postoperative period. Resistive index was increased in this group in both the preoperative [0.72 (0.69 to 0.73) vs. 0.66 (0.58 to 0.71); P = 0.01] and postoperative periods [0.75 (0.71 to 0.75) vs. 0.67 (0.62 to 0.72); P = 0.0001]. Resistive index evaluated by ROC curves and AUC to detect AKI was 0.862 [95% confidence interval (95% CI) 0.735 to 0.943]. The most accurate cut-off value was a postoperative resistive index of 0.705 (sensitivity = 94%, specificity = 71%, LR+ = 3.19 and LR– = 0.09). The grey area between 0.705 and 0.73, corresponding to the inconclusive zone, included 26% (13/50) of all the patients. CONCLUSION Postoperative resistive index appears to be effective for early detection of AKI after major orthopaedic surgery. Resistive index can be measured in the postoperative care unit in patients at risk of AKI. TRIAL REGISTRATION NUMBER 29-0512.

Intra-abdominal pressure measurement method via the urinary-tube: bedside validation of a biomechanical model integrating urine column height and bladder urinary volume.

Background:The objective of this work was to demonstrate the possibility of accurately measuring intra-abdominal pressure (IAP) by using a common urine drainage bag (U-Tube) as a hydrostatic column of measurement. This has been done by integrating urine column height (h) and bladder urinary volume (BUV) in the IAP measurement method. Method:Seventy-eight newly admitted patients in a 22 bed university hospital intensive care unit (ICU) were studied. Two U-Tube IAP measurement methods were compared with the “Gold-standard” closed-system repeated measurement technique with bladder pressure transducer: U-Tube method I, where h (in cm) alone assesses IAP (in cm H2O) and U-Tube method II, integrating BUV according to a basic biomechanical model of bladder wall compliance to give a more accurate IAP estimation. Results:Correlation rate using linear regression analysis was better between the Gold standard method and method II than method I with R2 = 0.901, P < 0.0001 and R2 = 0.682, P < 0.0001, respectively. For method II, Bland-Altman analysis showed a mean bias of −1.0 ± 0.1 mm Hg (limits of agreement −3.4–1.4, percentage error ±7.7%). Area under the receiver operator characteristics curves to screen intra-abdominal hypertension (IAP ≥12 mm Hg) was significantly greater with method II than with method I: 0.99 versus 0.93, P < 0.05; sensitivity and specificity of method II were 95% and 98%, respectively. Conclusion:By integrating urine column height and BUV in the measurement method, it may be conceivable to screen IAH at the bedside via a U-Tube in ICU; bladder wall compliance should be estimated to avoid the emergence of false-positive subjects due to the possible occurrence of bladder wall compliance alteration before or during the ICU stay.

Combined Thoracic Ultrasound Assessment during a Successful Weaning Trial Predicts Postextubation Distress

Background: Recent studies suggest that isolated sonographic assessment of the respiratory, cardiac, or neuromuscular functions in mechanically ventilated patients may assist in identifying patients at risk of postextubation distress. The aim of the present study was to prospectively investigate the value of an integrated thoracic ultrasound evaluation, encompassing bedside respiratory, cardiac, and diaphragm sonographic data in predicting postextubation distress. Methods: Longitudinal ultrasound data from 136 patients who were extubated after passing a trial of pressure support ventilation were measured immediately after the start and at the end of this trial. In case of postextubation distress (31 of 136 patients), an additional combined ultrasound assessment was performed while the patient was still in acute respiratory failure. We applied machine-learning methods to improve the accuracy of the related predictive assessments. Results: Overall, integrated thoracic ultrasound models accurately predict postextubation distress when applied to thoracic ultrasound data immediately recorded before the start and at the end of the trial of pressure support ventilation (learning sample area under the curve: start, 0.921; end, 0.951; test sample area under the curve: start, 0.972; end, 0.920). Among integrated thoracic ultrasound data, the recognition of lung interstitial edema and the increased telediastolic left ventricular pressure were the most relevant predictive factors. In addition, the use of thoracic ultrasound appeared to be highly accurate in identifying the causes of postextubation distress. Conclusions: The decision to attempt extubation could be significantly assisted by an integrative, dynamic, and fully bedside ultrasonographic assessment of cardiac, lung, and diaphragm functions.

Pneumothorax as a complication of ultrasound-guided interscalene block for shoulder surgery.

Interscalene block is often used for shoulder and upper arm surgery. This form of regional anaesthesia decreases pain, nausea, vomiting associated with general anaesthesia, length of hospital stay and improves postoperative rehabilitation. The technique has undergone many changes from first use in 1970 to the start of the use of ultrasound. Several studies have observed a better success rate. However, there is no consensus on the contribution of ultrasound in reducing the incidence of complications. We obtained the consent of the patient to publish this report. A 77-year-old woman was scheduled for the insertion of a right shoulder reverse prosthesis. The patient was classed as ASA II for obesity (BMI 34), hiatal hernia and chronic myalgia. In the operation theatre, we performed an ultrasound-guided interscalene block. A linear ultrasound probe, 38 mm, 6 to 15 MHz (Sonosite) and a 22-gauge needle of 50 mm connected to a nerve stimulator (HNS 11, B Braun) delivering a current of 0.5 mA at 2 Hz were used throughout the procedure. Indeed, combining ultrasound and neurostimulation allows the identification of nerve roots visually. An experienced resident conducted the regional anaesthesia with a posterolateral approach (in the ultrasound’s plane) supervised by a consultant anaesthesiologist. Vascular structures (carotid artery and internal jugular vein), muscular structures (anterior and middle scalene), nerve structures (nerve roots C5, C6 and C7) and bone structures (transverse process of C6 and C7) were visualised during the procedure. A musculocutaneous response (flexion of the forearm) obtained at 0.5 mA confirmed the identification of the C5 nerve root. After negative aspiration, slow and fractioned injection of 25 ml of ropivacaine 0.475% combined with 4 mg dexamethasone was performed. After induction of general anaesthesia, the patient was ventilated in a volume-controlled mode with a tidal volume of 8 ml kg 1 with an insufflation pressure of 21 cmH2O.

Cardiovascular effects of low-dose spinal anaesthesia as a function of age: An observational study using echocardiography

BACKGROUND Spinal anaesthesia (SA) is a widely used technique of regional anaesthesia but hypotension is an adverse effect commonly observed, especially in elderly patients. OBJECTIVE The objective of this study was to assess the cardiovascular effects induced by a single injection of a low-dose SA during elective surgery by using transthoracic echocardiography (TTE) and to compare these effects in patients older and younger than 70 years of age. DESIGN Observational study. SETTING Single centre university hospital. PATIENTS OR OTHER PARTICIPANTS Forty-six patients scheduled for surgery under SA were included in the study (25 patients<70 years and 21 patients ≥ 70 years). INTERVENTION(S) A cardiologist, blinded to all clinical parameters, interpreted the TTE. MAIN OUTCOME MEASURES Two TTEs were performed for each patient: one at baseline before and the second 20 minutes after the placement of the SA. RESULTS Sixty-six percent of patients became hypotensive in the ≥ 70 years group whereas no episode of hypotension occurred in the<70 years group (P<0.0001). At baseline (i.e. prior to SA), when compared to younger patients, elderly patients had both a lower E/A ratio (0.8 [0.5-2.1] vs. 1.4 [0.7-1.6], P=0.001) as well as a lower LVEF (50.4% [37.7-72.3] vs. 60.9% [44.8-69.8], P<0.0001). SA in the elderly induced a larger decrease in the cardiac index (CI) (-0.5 L·min(-1)·m(-2) [-0.8 to -0.3] vs. -0.2 L·min(-1)·m(-2) [-0.8-0.1], P<0.0001), LV stroke volume (-8mL [-13-4] vs. -2mL [-14 to -1], P<0.0001) and systemic vascular resistances (SVR) (-2.2 WU [-6.7-0.3] vs. -0.8 WU [-2.3-0.1], P<0.0001). CONCLUSIONS Hypotension is more frequent among elderly patients, even after low-dose SA. Known age-related changes in cardiovascular performance, such as impaired myocardial relaxation and decreased systolic function could be responsible for the decrease in cardiac output (CO) and SVR seen in these patients.

Prophylactic phenylephrine infusion for the prevention of hypotension after spinal anesthesia in the elderly: a randomized controlled clinical trial ☆ ☆☆ ★

STUDY OBJECTIVE Hypotension frequently occurs during spinal anesthesia (SA), especially in the elderly. Phenylephrine is effective to prevent SA-induced hypotension during cesarean delivery. The objective of this study was to evaluate the efficacy and safety of prophylactic infusion of phenylephrine after SA for orthopedic surgery in the elderly. DESIGN This prospective, randomized, double-blind, and placebo-controlled study included 54 patients older than 60 years undergoing elective lower limb surgery under SA (injection of 10 mg of isobaric bupivacaine with 5 μg of sufentanyl). INTERVENTION Patients were randomized to group P (100-μg/mL solution of phenylephrine solution at 1 mL/min after placement of SA) or the control group C (0.9% isotonic sodium chloride solution). The flow of the infusion was stopped if the mean arterial blood pressure (MAP) was higher than the baseline MAP and maintained or restarted at 1 mL/min if MAP was equal to or lower than the baseline MAP. Heart rate and MAP were collected throughout the case. MEASUREMENTS Hypotension was defined by a 20% decrease and hypertension as a 20% increase from baseline MAP. Bradycardia was defined as a heart rate lower than 50 beats per minute. MAIN RESULTS Twenty-eight patients were randomized to group P and 26 patients to group C. MAP was higher in group P than in group C (92 ± 2 vs 82 ± 2 mm Hg, mean ± SD, P< .001). The number of hypotensive episodes per patient was higher in group C compared with group P (9 [0-39] vs 1 [0-10], median [extremes], P< .01), but the number of hypotensive patients was similar between groups (19 [73%] vs 20 [71%], P= 1). The time to onset of the first hypotension was shorter in group C (3 [1-13] vs 15 [1-95] minutes, P= .004). The proportion of patients without hypotension (cumulative survival) was better in group P (P= .04). The number of hypertensive episodes per patient and the number of bradycardic episodes per patient were similar between groups (P= not significant). CONCLUSION Prophylactic phenylephrine infusion is an effective method of reducing SA-induced hypotension in the elderly. Compared with a control group, it delays the time to onset of hypotension and decreases the number of hypotensive episodes per patient. More data are needed to evaluate clinical outcomes of such a strategy.

Ultrasound-guided proximal suprascapular nerve block: A cadaveric study: Proximal Suprascapular Nerve Block

Difficulty in identifying the susprascapular nerve (SSN) limits the success of US‐guided regional anesthetic injections. A proximal SSN block could be an effective and reliable approach. The primary objective was to validate the feasibility of the US‐guided proximal SSN block. The secondary objective was to quantify the spread of the colored local anesthetic to the phrenic nerve (PN). Fourteen brachial plexuses from seven cadavers were included. Characterization of the proximal SSN was performed using US to determine the diameter and depth of the origin of the SSN (orSSN). Ten mL of methylene blue‐infused ropivacaine 0.2% were then injected to the proximal portion of the SSN. After dissection, the distances between the tip of the needle and the orSSN and the PN were anatomically determined. The PN was also judged to be colored or not by the methylene blue. The mean diameter and depth of the orSSN were 0.2 cm (range, 0.1‐0.3 cm) and 1.5 cm (range, 0.6‐2 cm) respectively. The orSSN was successfully targeted in 14 of 14 specimens with US; the tip of the needle was a mean of 1.6 cm (range, 0.2‐2.5 cm) and 5.1 cm (range, 4‐6.5 cm) from the orSSN and PN respectively. The orSSN and PN were marked in 14 and 3 cases respectively. US‐guided proximal SSN block is effective and reliable. The origin of the SSN is an easily identifiable landmark. This regional anesthesia could also reduce the risk of phrenic nerve palsy following interscalene brachial plexus block. Clin. Anat. 31:824–829, 2018.

Effect of fluid challenge on renal resistive index after major orthopaedic surgery: A prospective observational study using Doppler ultrasonography

BACKGROUND A postoperative renal resistive index (RRI)>0.70 has the best threshold to early predict acute kidney injury (AKI). The response of RRI to a postoperative fluid challenge (FC) is unknown. The aim of our study was to assess the impact of a FC on RRI in suspected hypovolaemia patients after orthopaedic surgery. DESIGN In this single-centre observational study, we prospectively screened 156 patients in the recovery room after having undergone a hip or knee replacement. INTERVENTIONS Forty-six patients with a RRI>0.70 and requiring FC were included. RRI and cardiac output (CO) were measured before and immediately after a fluid challenge with 500mL of isotonic saline. A decrease in RRI>5% was considered significant (renal responders). RESULTS Overall, FC resulted in a consistent decrease in RRI (from 0.74 [0.72-0.79] to 0.70 [0.68-0.73], P<0.01). Thirty-four patients (74%) showed a significant decrease in their RRI (from 0.74 [0.73-0.79] to 0.69 [0.67-0.72], P<0.05, versus non-responders: from 0.73 [0.72-0.75] to 0.72 [0.71-0.79], P=NS). CO increased equally among renal responders and non-responders (P=0.56). No correlation was found between changes in RRI and CO (r2=0.04; P=0.064). AKI was more common in renal non-responders (7/12) than in responders (3/34, P=0.001). CONCLUSIONS After major orthopaedic surgery, a FC can decrease RRI in suspected hypovolaemia patients at risk of postoperative AKI, but the changes are not correlated to changes in CO. Decreases in RRI were associated with better renal outcome.