Midterm effects of fluid resuscitation strategies in an experimental model of lung contusion and hemorrhagic shock.

BACKGROUND: This study compared three different fluid resuscitation strategies in terms of respiratory tolerance and hemodynamic efficacy in a pig model of blunt chest trauma with lung contusion and controlled hemorrhagic shock. We hypothesized that the choice of fluid resuscitation strategy (type and amount of fluids) may impact differently contused lungs in terms of extravascular lung water (EVLW) 20 h after trauma. METHODS: Anesthetized female pigs (n = 5/group) received five bolt shots to the right thoracic cage and allowed to hemorrhage for 30 min, with 25 to 30 mL/kg of blood loss. Pigs were randomly assigned to resuscitation groups that maintained a minimum mean arterial blood pressure of 70 mmHg with one of three methods: normal saline (NS), unrestricted normal saline; NOREPI, low-volume normal saline with norepinephrine; or HS-HES, hypertonic saline with hydroxyethyl starch. Control pigs were anesthetized, but received no injury or treatment. After 20 h, animals were killed to measure EVLW by gravimetry. RESULTS: Fluid loading was significantly different in each group. All three treatment groups had higher EVLW than controls. Moderate, bilateral pulmonary edema was observed in the NS and HS-HES groups. The three treatment groups showed similar reductions in oxygenation. Static pulmonary compliance was diminished in the NS and HS-HES groups, but compliance was similar in NOREPI and control groups. The NOREPI group had pathological lactate levels. CONCLUSIONS: This study demonstrated the impact of fluid resuscitation on contused lungs. Twenty hours after the trauma, all three resuscitation approaches showed modest clinical consequences, with moderate lung edema and reduced compliance in response to the infused volume.

Leaks can dramatically decrease FiO2 on home ventilators: a bench study.

BACKGROUND: Long term oxygen therapy improves survival in hypoxemic patients with chronic obstructive pulmonary disease (COPD). Because pressure support ventilation with a home care ventilator is largely unsupervised, there is considerable risk of leakage occurring, which could affect delivered FiO2. We have therefore conducted a bench study in order to measure the effect of different levels of O2 supply and degrees of leakage on delivered FiO2. Ventilator tested: Legendair® (Airox™, Pau, France). Thirty-six measures were performed in each four ventilators with zero, 5 and 10 l.min-1 leakage and 1,2,4 and 8 l O2 flow. FINDINGS: FiO2 decreased significantly with 5 l.min-1 leakage for all O2 flow rates, and with 10 l.min-1 at 4 and 8 l.min-1 O2. CONCLUSION: During application of NIV on home ventilators, leakage can dramatically decrease inspired FiO2 making it less effective. It is important to know the FiO2 dispensed when NIV is used for COPD at home. We would encourage industry to develop methods for FiO2 regulation Chronic use of NIV for COPD with controlled FiO2 or SpO2 requires further studys.

Evaluation of early mini-bronchoalveolar lavage in the diagnosis of health care-associated pneumonia: a prospective study.

INTRODUCTION: Health care-associated pneumonia (HCAP) has been proposed as a new category of respiratory infection to identify patients at risk of multidrug-resistant (MDR) pathogens. The American Thoracic Society's recommendation for HCAP treatment is to use broad-spectrum and multiple antibiotics. However, this strategy may be economically expensive and promote antimicrobial resistance when a multisensitive pathogen is not identified. METHODS: We prospectively included all patients presenting with HCAP in the emergency department. Blood cultures and fiberoptic bronchoscope-guided distal protected small volume bronchoalveolar lavage (FODP mini-BAL) were performed in each patient. Empirical antibiotic therapy was adapted when microbiological findings were available. The primary objective was to assess whether FODP mini-BAL is more efficient than blood cultures in identifying pathogens with the ratio of identification between both techniques as principal criteria. RESULTS: We included 54 patients with HCAP. Pathogens were identified in 46.3% of cases using mini-BAL and in 11.1% of cases using blood cultures (P <0.01). When the patient did not receive antibiotic therapy before the procedure, pathogens were identified in 72.6% of cases using mini-BAL and in 9.5% of cases using blood cultures (P <0.01). We noted multidrug-resistant pathogens in 16% of cases. All bronchoscopic procedures could be performed in patients without complications. CONCLUSIONS: FODP mini-BAL was more efficient than blood cultures for identifying pathogens in patients presenting with HCAP. When bacteriological identification was obtained, antibiotic therapy was adapted in 100% of cases.See related letter by Sircar et al.,http://ccforum.com/content/17/2/428.

Prognostic significance of blood lactate and lactate clearance in trauma patients.

BACKGROUND: Lactate has been shown to be a prognostic biomarker in trauma. Although lactate clearance has already been proposed as an intermediate endpoint in randomized trials, its precise role in trauma patients remains to be determined. METHODS: Blood lactate levels and lactate clearance (LC) were calculated at admission and 2 and 4 h later in trauma patients. The association of initial blood lactate level and lactate clearance with mortality was tested using receiver-operating characteristics curve, logistic regression using triage scores, Trauma Related Injury Severity Score as a reference standard, and reclassification method. RESULTS: The authors evaluated 586 trauma patients (mean age 38±16 yr, 84% blunt and 16% penetrating, mortality 13%). Blood lactate levels at admission were elevated in 327 (56%) patients. The lactate clearance should be calculated within the first 2 h after admission as LC0-2 h was correlated with LC0-4 h (R=0.55, P<0.001) but not with LC2-4 h (R=0.04, not significant). The lactate clearance provides additional predictive information to initial blood lactate levels and triage scores and the reference score. This additional information may be summarized using a categorical approach (i.e., less than or equal to -20 %/h) in contrast to initial blood lactate. The results were comparable in patients with high (5 mM/l or more) initial blood lactate. CONCLUSIONS: Early (0-2 h) lactate clearance is an important and independent prognostic variable that should probably be incorporated in future decision schemes for the resuscitation of trauma patients.

Maintenance of normothermia during burn surgery with an intravascular temperature control system: a non-randomised controlled trial.

BACKGROUND: Hypothermia remains one of the major factors limiting surgery in extensively burned patients. We evaluated the effectiveness of an intravascular rewarming technique using CoolGard 3000™ system and Icy™ catheter to maintain normothermia during surgeries of severe burned patients and compared these findings to a historical control group. METHODS: This was a controlled non-randomised trial conducted between March 2008 and August 2009. Patients with burns greater than or equal to 40% of the total body surface area were included. Before the first burn excision, the Icy™ catheter was placed in the inferior vena cava via the femoral vein. Warming was then initiated and maintained until the bladder temperature reached over 37.5°C. The bladder temperature was recorded every 30min during surgery and for the first hour post-operatively and compared to a historical control group. RESULTS: We enrolled 4 patients and 11 surgeries in the CoolGard™ group and compared them to 3 patients and 10 surgeries in the historical cohort. All intraoperative bladder temperatures from T=30 were statistically different in the two groups. In the CoolGard™ group, no patient became hypothermic and no surgery was aborted because the patient's temperature had rapidly fallen below the threshold temperature (35.5°C). No device-related complication was reported. CONCLUSION: The use of an intravenous warming catheter is a novel approach to maintain normothermia during surgery in burn victims and may be more effective than traditional methods.

Noninvasive detection of elevated intracranial pressure using a portable ultrasound system.

OBJECTIVE: The aim of this study is to prospectively compare the accuracies of transcranial color-coded sonography (TCCS) and transcranial Doppler (TCD) in the diagnosis of elevated intracranial pressure. METHODS: A prospective, blinded, head-to-head comparison of TCD and TCCS methods using intracranial pressure (ICP) measured continuously via an intraparenchymal catheter as the reference standard in 2 groups of 20 neurocritical care patients each: high ICP (group 1) and normal ICP (group 2). Middle cerebral artery (MCA) pulsatility index (PI) recordings from all patients' sonographic reports were selected based on the highest left or right recorded MCA PI. Transcranial Doppler was performed using a dedicated TCD device, and TCCS was performed using a portable ultrasound system. RESULTS: The PI values obtained did not differ significantly between the 2 methods (group 1, P = .46; group 2, P = .11). Linear regression analysis identified a significant relationship between PI obtained with both methods (r = 0.897; P < .0001). The duration of PI measurement was statistically longer with TCCS than TCD (group 1, P < .01; group 2, P < .01). Diagnostic accuracies were good and similar for both methods (TCD area under curve, 0.901; TCCS area under curve 0.870; P = .69). CONCLUSIONS: This work is a pilot study comparing TCCS and TCD in the detection of elevated ICP. This study suggests that a bedside portable ultrasound system may be useful to determine MCA PI with accuracy similar to that of a dedicated TCD device.

Iatrogenic post-intubation tracheal rupture treated conservatively without intubation: a case report.

BACKGROUND: Tracheal rupture is a rare but life-threatening complication that most commonly occurrs after blunt trauma to the chest, but which may also complicate tracheal intubation. We report a case of post-intubation tracheal rupture after cataract surgery under general anesthesia treated conservatively. CASE PRESENTATION: Four hours after extubation, a 67 year-old woman developed subcutaneous emphysema of the facial, bilateral laterocervical and upper anterior chest. Tracheobronchial fiberendoscopy showed a posterior tracheal transmural rupture 4 cm long located 2.5 cm above the carina that opened in inspiration. The location of the lesion and features of the patient favoured conservative treatment with antibiotic cover. The patient made a full and uncomplicated recovery and was discharged fourteen days after the original injury. CONCLUSION: Two therapeutic strategies are currently employed for post-intubation tracheal rupture: a non-surgical strategy for small injuries and a surgical strategy for larger injuries. This case report presented the non-surgical therapeutic strategy of a large tracheal injury.

Protective ventilation in ARDS: as soon as possible. An immediate use of HFOV.

OBJECTIVE: To report the immediate use of High-Frequency Oscillatory ventilation in an adult acute respiratory distress syndrome. DESIGN: Case report. SETTING: Intensive care unit at the Military Teaching Hospital of Toulon. PATIENT: A 64-yr-old Caucasian male who developed acute respiratory distress syndrome in the course of severe falciparum malaria. INTERVENTION: Initial use of HFO to minimise ventilator-induced lung injury. MEASUREMENT AND MAIN RESULTS: Rapid improvement of PaO2/fraction of inspired oxygen from 172 mmHg (NIV) to 310 mmHg with HFO. No ventilator-induced injury on CT scan after 5 days of invasive ventilation. CONCLUSION: In contrast with previous studies, we successfully used lung protective ventilation with HFO immediately. Further studies, with immediate, rather than rescue use of HFO ventilation, are needed.

A prospective randomized trial of two safety peripheral intravenous catheters.

BACKGROUND: To reduce the risk of accidental needlestick injuries, first active then passive safety devices were developed on IV catheters. However, whether these catheters are easy to implement and really protect personnel from accidental needlestick is untested. METHODS: In this prospective randomized survey, we compared a passive safety catheter with an active safety catheter and a nonsafety classic catheter. The main objective was to evaluate the difficulty of inserting the catheters in terms of the number of insertion failures, difficulties introducing the catheter and withdrawing the needle, and the normality of the blood reflux in the delivery system. The second objective was to determine the degree of exposure to patients' blood evaluated as the number of exposures of the staff and blood splashes of the environment, and the staff's sense of protection. RESULTS: Seven hundred fifty-nine assessment cards were collected. The number of failures for the three catheter groups was similar and not statistically different. Introduction of the catheter was more difficult with the active safety catheter. Needle withdrawal was more difficult with the passive safety catheter. The blood reflux was abnormal more often with the safety catheters. The staff's exposure was more frequent with the active safety catheter. The number of blood splashes was more common with the safety catheters. CONCLUSIONS: Safety catheters are not superior with regard to failure rate in the catheter's placement. Users feel better protected, but find the use of safety catheters more difficult, and their handling generates more splashing of blood into the environment. The passive safety catheter is more efficient than the active safety catheter with regard to ease of introduction of the catheter into the vein and the staff's exposure to the patient's blood.

Hyperventilation and cerebrospinal fluid acidosis caused by topiramate.

OBJECTIVE: To report a case of hyperventilation caused by topiramate therapy and propose a pathophysiologic mechanism for this disorder. CASE SUMMARY: A 52-year-old woman with refractory seizure disorder was admitted to the burn care unit with burns over 10% of her body. Her seizure medications, unchanged and well tolerated for several months, included carbamazepine 1200 mg, lamotrigine 500 mg, phenobarbital 80 mg, and topiramate 150 mg per day. During hospitalization, despite a relatively normal arterial pH, the woman developed persistent hyperventilation, with respiratory rates up to 50 breaths/min. Alkalinization did not reduce the hyperventilation. Thoracic contrast-enhanced computed tomographic scan ruled out pulmonary embolism and persistent pneumonia. Salicylate and biguanide screening were negative; results of repeated thyroid and liver function tests were normal. Cerebral magnetic resonance imaging excluded a cerebral pathology. After cerebrospinal fluid (CSF) analysis showed acidosis (pH 7.14), topiramate was withdrawn and the patient's general condition rapidly improved. Forty-eight hours later, the CSF pH had increased to 7.26. The woman was discharged from the burn care unit on the 42nd hospital day. DISCUSSION: Hyperchloremic normal anion gap metabolic acidosis, which can lead to hyperventilation, has been reported as an adverse effect of topiramate treatment. However, our patient had respiratory alkalosis. Concurrent etiologies of peripheral hyperventilation were excluded, leaving central neurogenic hyperventilation as the remaining etiology. Such central neurogenic hyperventilation associated with topiramate has previously been reported in intensive care. Our case report demonstrates CSF acidosis. Withdrawing topiramate reduced both CSF acidosis and hyperventilation. The mechanism of topiramate-induced CSF acidosis remains unclear. According to the Naranjo probability scale, the relationship of hyperventilation to administration of topiramate in our patient was probable. CONCLUSIONS: Normal doses of topiramate may provoke central neurogenic hyperventilation, as a result of CSF acidosis. The acid-base status of critically ill patients receiving topiramate should be monitored carefully.