Andrea Gabrielli

Part 9: Post–Cardiac Arrest Care 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

The goal of immediate post-cardiac arrest care is to optimize systemic perfusion, restore metabolic homeostasis, and support organ system function to increase the likelihood of intact neurological survival. The post-cardiac arrest period is often marked by hemodynamic instability as well as metabolic abnormalities. Support and treatment of acute myocardial dysfunction and acute myocardial ischemia can increase the probability of survival. Interventions to reduce secondary brain injury, such as therapeutic hypothermia, can improve survival and neurological recovery. Every organ system is at risk during this period, and patients are at risk of developing multiorgan dysfunction. The comprehensive treatment of diverse problems after cardiac arrest involves multidisciplinary aspects of critical care, cardiology, and neurology. For this reason, it is important to admit patients to appropriate critical-care units with a prospective plan of care to anticipate, monitor, and treat each of these diverse problems. It is also important to appreciate the relative strengths and weaknesses of different tools for estimating the prognosis of patients after cardiac arrest.

A Comparison of Two Antimicrobial-Impregnated Central Venous Catheters

BACKGROUND The use of central venous catheters impregnated with either minocycline and rifampin or chlorhexidine and silver sulfadiazine reduces the rates of catheter colonization and catheter-related bloodstream infection as compared with the use of unimpregnated catheters. We compared the rates of catheter colonization and catheter-related bloodstream infection associated with these two kinds of antiinfective catheters. METHODS We conducted a prospective, randomized clinical trial in 12 university-affiliated hospitals. High-risk adult patients in whom central venous catheters were expected to remain in place for three or more days were randomly assigned to undergo insertion of polyurethane, triple-lumen catheters impregnated with either minocycline and rifampin (on both the luminal and external surfaces) or chlorhexidine and silver sulfadiazine (on only the external surface). After their removal, the tips and subcutaneous segments of the catheters were cultured by both the roll-plate and the sonication methods. Peripheral-blood cultures were obtained if clinically indicated. RESULTS Of 865 catheters inserted, 738 (85 percent) produced culture results that could be evaluated. The clinical characteristics of the patients and the risk factors for infection were similar in the two groups. Catheters impregnated with minocycline and rifampin were 1/3 as likely to be colonized as catheters impregnated with chlorhexidine and silver sulfadiazine (28 of 356 catheters [7.9 percent] vs. 87 of 382 [22.8 percent], P<0.001), and catheter-related bloodstream infection was 1/12 as likely in catheters impregnated with minocycline and rifampin (1 of 356 [0.3 percent], vs. 13 of 382 [3.4 percent] for those impregnated with chlorhexidine and silver sulfadiazine; P<0.002). CONCLUSIONS The use of central venous catheters impregnated with minocycline and rifampin is associated with a lower rate of infection than the use of catheters impregnated with chlorhexidine and silver sulfadiazine.

Central Venous Catheters Coated with Minocycline and Rifampin for the Prevention of Catheter-Related Colonization and Bloodstream Infections: A Randomized, Double-Blind Trial

See related articles on pp 257-266 and 275-280 and editorial comment on pp 304-306. Central venous catheters are indispensable in the treatment of critically and chronically ill patients, but they are the leading cause of primary nosocomial bloodstream infection [1, 2]. A study of hospitals in the National Nosocomial Infection Surveillance System, conducted between 1986 and 1990, showed that rates of bloodstream infection were substantially higher in patients who were in intensive care units and had intravascular devices than in those who did not have such devices [3]. To decrease the risk for catheter colonization and infection, antiseptic and antibiotic agents have been applied topically at the insertion site [4-6]. More recently, the use of antimicrobial flush solutions has been proposed [7]. However, coating venous catheters with antiseptic or antimicrobial agents may have an even more pronounced protective effect against colonization and infection, particularly if both the external and internal surfaces of the device are coated. Since 1990, several types of antiseptic or antimicrobial vascular catheter coatings have been developed and studied [8, 9]. Maki and colleagues [9] investigated central venous catheters coated with chlorhexidine-silver sulfadiazine; the coated catheters seemed less likely than the uncoated catheters to be associated with bloodstream infections. We recently coated vascular catheters with a combination of minocycline and rifampin after treatment with the tridodecylmethyl-ammonium chloride surfactant. In vitro, these catheters were shown to have broad-spectrum antimicrobial inhibitory activity that was significantly superior to the activity of catheters coated with chlorhexidine-silver sulfadiazine [10, 11]. The catheters coated with minocycline and rifampin were also found to be highly efficacious in preventing catheter colonization and subcutaneous infection in a rabbit model [11]. In a double-blind, randomized clinical trial, we studied the efficacy of catheters that were treated with tridodecylmethyl-ammonium chloride and coated with minocycline and rifampin in preventing catheter colonization and bloodstream infection in hospitalized patients. Methods Study Sample Our study was conducted simultaneously at five university-based hospitals in the Texas Medical Center in Houston: The University of Texas M.D. Anderson Cancer Center (518 beds), Veterans Administration Medical Center (1050 beds), Hermann Hospital (600 beds), Ben Taub General Hospital (580 beds), and The Methodist Hospital (904 beds). The study began on 1 September 1994 and ended on 27 March 1995. Hospitalized patients 18 years of age or older who required a triple-lumen polyurethane central venous catheter at a new insertion site were asked to participate. We excluded pregnant women, patients who were allergic to rifampin or tetracycline, patients with dermatitis or a burn over the insertion site, and patients for whom the anticipated duration of catheterization was less than 3 days. All patients gave informed consent. Randomization All catheters were triple-lumen, polyurethane, 7 French, and 20 cm long (Cook Critical Care, Bloomington, Indiana). The coated catheters were pretreated with tridodecylmethyl-ammonium chloride and then coated, 18 hours later, with minocycline and rifampin. The levels of minocycline and rifampin on the external and internal surfaces of coated catheters before insertion, as determined by high-performance liquid chromatography, were 139.3 g/cm and 13.9 g/cm, respectively. Control catheters were untreated and uncoated. All catheters were gas sterilized and placed in identical trays, and each tray was assigned an identification number. The trays were then randomly assigned into blocks of six: three with coated catheters and three with control catheters. Each block of trays was placed in boxes by Cook Critical Care, and the boxes were shipped to the five hospitals. When a patient was determined to be eligible, a tray was removed from the box (trays were removed one at a time, in sequential order from top to bottom), and that catheter was used for the patient. The catheter identification number was recorded on a data entry form and on the patients medical chart; neither the patient nor the clinician who inserted the device knew which catheter (coated or uncoated) had been used. Catheter Insertion and Care Study catheters were inserted into the subclavian vein, internal jugular vein, or femoral vein of patients who had no other indwelling catheter. Study catheters were not exchanged over guidewires. Maximal sterile barrier precautions were taken, including use of a sterile gown, sterile gloves, full sterile drapes, a mask, and a cap. At the time of catheter insertion and at each dressing change, the insertion site was cleaned with chlorhexidine gluconate (at The Methodist Hospital) or 10% povidone-iodine scrub (at all other hospitals). In each case, the preparation was applied to the skin for 2 minutes before catheter insertion. The insertion site was then covered with sterile gauze and taped securely. The insertion site was inspected every 72 hours (during a dressing change) for evidence of infection, such as erythema, purulence, swelling, or tenderness over the catheter. During follow-up, the following information was obtained for all patients: site of catheter insertion; dates of catheter placement and removal; occurrence of difficulties and violations of aseptic technique during insertion or removal, if any; reason for using the catheter (chemotherapy, total parenteral nutrition, administration of blood products, or a combination of these reasons); type of dressing; and reason for catheter removal. In addition, clinical data were obtained on underlying disease, neutrophil and platelet counts, antibiotic therapy administration, other therapeutic interventions administered during the period of catheterization, and the presence or absence of fever and infection during catheterization. The catheter remained in place until it was no longer needed; until a specific event, such as catheter-related infection, necessitated its removal; or for 28 days, whichever occurred first. Microbiological Methods Quantitative Cultures of Central Venous Catheters The entire catheter was removed aseptically, and 4-cm segments were cut from the catheter tip and the subcutaneous section. These segments were semiquantitatively cultured by using the roll-plate method; the same segment was then quantitatively cultured by using the sonication method [12-14]. Organisms recovered by either method were fully identified according to standard microbiological methods. Coagulase-negative staphylococci were classified as gram-positive cocci in clusters that produced catalase but not coagulase and were categorized according to species by using the Staph-Ident System (Analytab Products, Plainview, New Jersey). All hospitals used the same methods for culture. Skin Cultures To determine whether bacteria became resistant to the antibiotics that coated the study catheters, skin samples obtained from the insertion site were cultured at the time of insertion and within 24 hours after catheter removal, as described elsewhere [15]. Organisms recovered from the insertion site were fully identified by using standard microbiological methods. Antimicrobial Resistance We used the modified Kirby-Bauer technique to test the antimicrobial activity of the catheters coated with minocycline and rifampin against all organisms isolated from indwelling coated catheters at the time of catheter removal [16]. The zones of inhibition against staphylococci cultured from coated catheters were compared with those of uncoated catheters. The minimal inhibitory concentration (MIC) of minocycline hydrochloride (Lederle Laboratories, Pearl River, New York) and rifampin (Ciba-Geigy Corp., Summit, New Jersey) against staphylococcal organisms that colonized the catheter tip, subcutaneous segments, and adjacent skin insertion sites of the coated catheters was determined. A microbroth dilution method was used to determine the MIC in accordance with guidelines established by the National Committee for Clinical Laboratory Standards [17]. Definitions The definitions adopted for our study were proposed by the Centers for Disease Control and Prevention [18]. Colonization of a central venous catheter was defined as 1) the isolation from either the tip or the subcutaneous segment of 15 or more colony-forming units of any organism by the rollplate technique or 2) isolation of more than 1000 colony-forming units of any organism by the sonication technique. Catheter-related bloodstream infection was defined as the isolation of microorganisms from the bloodstream (blood was obtained through venipuncture, not through the catheter) of a patient who had concurrent clinical manifestations of sepsis and no source for the bloodstream infection other than the vascular catheter. In addition, the catheter had to be colonized with the same organism (same species and same antibiogram). To confirm the diagnosis of catheter-related bloodstream infection, DNA molecular typing done using pulse-field gel electrophoresis was performed on organisms that were of the same species, had the same antibiogram, and were isolated from the catheter and blood during the period of catheterization. Patients were considered to have fever if the oral body temperature was greater than 38 C. Neutropenia was defined as a polymorphonuclear count of fewer than 1000 cells/mm3. Thrombocytopenia was defined as a platelet count of fewer than 100 000 cells/mm3. Molecular Typing Molecular typing was performed by using pulse-field gel electrophoresis. Identical organisms with similar DNA profiles that were isolated from a segment of the colonized catheter and from the bloodstream confirmed the diagnosis of catheter-related bloodstream infection. However, a mismatch did not rule out such a diagnosis because catheter coloniza

Part 12: Cardiac Arrest in Special Situations 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

This section of the 2010 AHA Guidelines for CPR and ECC addresses cardiac arrest in situations that require special treatments or procedures beyond those provided during basic life support (BLS) and advanced cardiovascular life support (ACLS). We have included 15 specific cardiac arrest situations. The first several sections discuss cardiac arrest associated with internal physiological or metabolic conditions, such as asthma (12.1), anaphylaxis (12.2), pregnancy (12.3), morbid obesity (12.4), pulmonary embolism (PE) (12.5), and electrolyte imbalance (12.6). The next several sections relate to resuscitation and treatment of cardiac arrest associated with external or environmentally related circumstances, such as ingestion of toxic substances (12.7), trauma (12.8), accidental hypothermia (12.9), avalanche (12.10), drowning (12.11), and electric shock/lightning strikes (12.12). The last 3 sections review management of cardiac arrest that may occur during special situations affecting the heart, including percutaneous coronary intervention (PCI) (12.13), cardiac tamponade (12.14), and cardiac surgery (12.15). Asthma is responsible for more than 2 million visits to the emergency department (ED) in the United States each year, with 1 in 4 patients requiring admission to a hospital.1 Annually there are 5,000 to 6,000 asthma-related deaths in the United States, many occurring in the prehospital setting.2 Severe asthma accounts for approximately 2% to 20% of admissions to intensive care units, with up to one third of these patients requiring intubation and mechanical ventilation.3 This section focuses on the evaluation and treatment of patients with near-fatal asthma. Several consensus groups have developed excellent guidelines for the management of asthma that are available on the World Wide Web: ### Pathophysiology The pathophysiology of asthma consists of 3 key abnormalities: Complications of severe asthma, such as tension pneumothorax, lobar atelectasis, pneumonia, and pulmonary edema, can contribute to fatalities. Severe asthma exacerbations are commonly associated with …

Long-term risk of mortality and acute kidney injury during hospitalization after major surgery.

Objective:To determine the relationship between long-term mortality and acute kidney injury (AKI) during hospitalization after major surgery. Summary Background Data:AKI is associated with a risk of short-term mortality that is proportional to its severity; however the long-term survival of patients with AKI is poorly studied. Methods:This is a retrospective cohort study of 10,518 patients with no history of chronic kidney disease who were discharged after a major surgery between 1992 and 2002. AKI was defined by the RIFLE (Risk, Injury, Failure, Loss, and End-stage Kidney) classification, which requires at least a 50% increase in serum creatinine (sCr) and stratifies patients into 3 severity stages: risk, injury, and failure. Patient survival was determined through the National Social Security Death Index. Long-term survival was analyzed using a risk-adjusted Cox proportional hazards regression model. Results:In the risk-adjusted model, survival was worse among patients with AKI and was proportional to its severity with an adjusted hazard ratio of 1.18 (95% confidence interval [CI], 1.08–1.29) for the RIFLE-Risk class and 1.57 (95% CI, 1.40–1.75) for the RIFLE-Failure class, compared with patients without AKI (P < 0.001). Patients with complete renal recovery after AKI still had an increased adjusted hazard ratio for death of 1.20 (95% CI, 1.10–1.31) compared with patients without AKI (P < 0.001). Conclusions:In a large single-center cohort of patients discharged after major surgery, AKI with even small changes in sCr level during hospitalization was associated with an independent long-term risk of death.

Recommended guidelines for uniform reporting of data from drowning: the “Utstein style”

This document presents the consensus of a group of international investigators who met to establish guidelines for the uniform reporting of data from studies of drowning incidents. The consensus process consisted of formal discussions at 3 international meetings as well as expert review, endorsements from multiple organizations, and invited recommendations from other interested parties. The concept of using consensus workshops to formulate guidelines is not new. Similar consensus guidelines for reporting surveillance and resuscitation research have been developed for both adult and pediatric cardiac arrest.1–3 The principal purpose of the recommendations in this advisory is to establish consistency in the reporting of drowning-related studies, both in terms of nomenclature and guidelines for reporting data. These recommendations are intended to improve the clarity of scientific communication and the comparability of scientific investigations. Improved clarity and comparability of future scientific reports will advance the clinical and epidemiological knowledge base. In turn, such studies can help identify appropriate prevention strategies as well as the best treatment for victims of drowning and can ultimately save lives. Laboratory and clinical investigators from many different specialties contribute to the multidisciplinary knowledge base of injury prevention and resuscitation science. Although diversity can be a strength, it can also be an obstacle because of the lack of a common language and communication between investigators from different backgrounds. In response to these problems, in June 1990 an international group of scientists concerned with research involving out-of-hospital cardiac arrest met at the Utstein Abbey in Stavanger, Norway. Participants discussed the lack of standardized nomenclature and definitions as a key problem in research reports. A second meeting, the Utstein Consensus Conference, was held in December 1990 in Brighton, England. Recommendations from this follow-up conference were published simultaneously in American and European journals.4,5 The report included uniform definitions, terminology, and …

Ubiquitin C-terminal hydrolase is a novel biomarker in humans for severe traumatic brain injury

Objective:Ubiquitin C-terminal hydrolase (UCH-L1), also called neuronal-specific protein gene product (PGP 9.3), is highly abundant in neurons. To assess the reliability of UCH-L1 as a potential biomarker for traumatic brain injury (TBI) this study compared cerebrospinal fluid (CSF) levels of UCH-L1 from adult patients with severe TBI to uninjured controls; and examined the relationship between levels with severity of injury, complications and functional outcome. Design:This study was designed as prospective case control study. Patients:This study enrolled 66 patients, 41 with severe TBI, defined by a Glasgow coma scale (GCS) score of ≤8, who underwent intraventricular intracranial pressure monitoring and 25 controls without TBI requiring CSF drainage for other medical reasons. Setting:Two hospital system level I trauma centers. Measurements and Main Results:Ventricular CSF was sampled from each patient at 6, 12, 24, 48, 72, 96, 120, 144, and 168 hrs following TBI and analyzed for UCH-L1. Injury severity was assessed by the GCS score, Marshall Classification on computed tomography and a complicated postinjury course. Mortality was assessed at 6 wks and long-term outcome was assessed using the Glasgow outcome score 6 months after injury. TBI patients had significantly elevated CSF levels of UCH-L1 at each time point after injury compared to uninjured controls. Overall mean levels of UCH-L1 in TBI patients was 44.2 ng/mL (±7.9) compared with 2.7 ng/mL (±0.7) in controls (p <.001). There were significantly higher levels of UCH-L1 in patients with a lower GCS score at 24 hrs, in those with postinjury complications, in those with 6-wk mortality, and in those with a poor 6-month dichotomized Glasgow outcome score. Conclusions:These data suggest that this novel biomarker has the potential to determine injury severity in TBI patients. Further studies are needed to validate these findings in a larger sample.

Inspiratory muscle strength training improves weaning outcome in failure to wean patients: a randomized trial

IntroductionMost patients are readily liberated from mechanical ventilation (MV) support, however, 10% - 15% of patients experience failure to wean (FTW). FTW patients account for approximately 40% of all MV days and have significantly worse clinical outcomes. MV induced inspiratory muscle weakness has been implicated as a contributor to FTW and recent work has documented inspiratory muscle weakness in humans supported with MV.MethodsWe conducted a single center, single-blind, randomized controlled trial to test whether inspiratory muscle strength training (IMST) would improve weaning outcome in FTW patients. Of 129 patients evaluated for participation, 69 were enrolled and studied. 35 subjects were randomly assigned to the IMST condition and 34 to the SHAM treatment. IMST was performed with a threshold inspiratory device, set at the highest pressure tolerated and progressed daily. SHAM training provided a constant, low inspiratory pressure load. Subjects completed 4 sets of 6-10 training breaths, 5 days per week. Subjects also performed progressively longer breathing trials daily per protocol. The weaning criterion was 72 consecutive hours without MV support. Subjects were blinded to group assignment, and were treated until weaned or 28 days.ResultsGroups were comparable on demographic and clinical variables at baseline. The IMST and SHAM groups respectively received 41.9 ± 25.5 vs. 47.3 ± 33.0 days of MV support prior to starting intervention, P = 0.36. The IMST and SHAM groups participated in 9.7 ± 4.0 and 11.0 ± 4.8 training sessions, respectively, P = 0.09. The SHAM groups pre to post-training maximal inspiratory pressure (MIP) change was not significant (-43.5 ± 17.8 vs. -45.1 ± 19.5 cm H2O, P = 0.39), while the IMST groups MIP increased (-44.4 ± 18.4 vs. -54.1 ± 17.8 cm H2O, P < 0.0001). There were no adverse events observed during IMST or SHAM treatments. Twenty-five of 35 IMST subjects weaned (71%, 95% confidence interval (CI) = 55% to 84%), while 16 of 34 (47%, 95% CI = 31% to 63%) SHAM subjects weaned, P = .039. The number of patients needed to be treated for effect was 4 (95% CI = 2 to 80).ConclusionsAn IMST program can lead to increased MIP and improved weaning outcome in FTW patients compared to SHAM treatment.Trial RegistrationClinicalTrials.gov: NCT00419458

αII-Spectrin Breakdown Products (SBDPs): Diagnosis and Outcome in Severe Traumatic Brain Injury Patients

In this study we assessed the clinical utility of quantitative assessments of alphaII-spectrin breakdown products (SBDP145 produced by calpain, and SBDP120 produced by caspase-3) in cerebrospinal fluid (CSF) as markers of brain damage and outcome after severe traumatic brain injury (TBI). We analyzed 40 adult patients with severe TBI (Glasgow Coma Scale [GCS] score <or=8) who underwent ventriculostomy. Patients requiring CSF drainage for other medical reasons served as controls. CSF samples were taken at admission and every 6 h thereafter for a maximum of 7 days and assessed using novel quantitative fragment-specific ELISAs for SBDPs. Outcome was assessed using the 3-month Glasgow Outcome Scale. Mean CSF levels of SBDPs were significantly higher in TBI patients than in controls at all time points examined. Different temporal release patterns of CSF SBDP145 and SBDP120 were observed. SBDP145 provided accurate diagnoses at all time points examined, while SBDP120 release was more accurate 24 h after injury. Within 24 h after injury, SBDP145 CSF concentrations significantly correlated with GCS scores, while SBDP120 levels correlated with age. SBDP levels were significantly higher in patients who died than in those who survived. SBDP145 levels (>6 ng/mL) and SBDP120 levels (>17.55 ng/mL) strongly predicted death (odds ratio 5.9 for SBDP145, and 18.34 for SBDP120). The time course of SBDPs in nonsurvivors also differed from that of survivors. These results suggest that CSF SBDP levels can predict injury severity and mortality after severe TBI, and can be useful complements to clinical assessment.

Clinical and hemodynamic comparison of 15: 2 and 30:2 compression-to- ventilation ratios for cardiopulmonary resuscitation

Objective:To compare cardiopulmonary resuscitation (CPR) with a compression to ventilation (C:V) ratio of 15:2 vs. 30:2, with and without use of an impedance threshold device (ITD). Design:Prospective randomized animal and manikin study. Setting:Animal laboratory and emergency medical technician training facilities. Subjects:Twenty female pigs and 20 Basic Life Support (BLS)-certified rescuers. Interventions, Measurements, and Main Results: Animals:Acid-base status, cerebral, and cardiovascular hemodynamics were evaluated in 18 pigs in cardiac arrest randomized to a C:V ratio of 15:2 or 30:2. After 6 mins of cardiac arrest and 6 mins of CPR, an ITD was added. Compared to 15:2, 30:2 significantly increased diastolic blood pressure (20 ± 1 to 26 ± 1; p < .01); coronary perfusion pressure (18 ± 1 to 25 ± 2; p = .04); cerebral perfusion pressure (16 ± 3 to 18 ± 3; p = .07); common carotid blood flow (48 ± 5 to 82 ± 5 mL/min; p < .001); end-tidal CO2 (7.7 ± 0.9 to 15.7 ± 2.4; p < .0001); and mixed venous oxygen saturation (26 ± 5 to 36 ± 5, p < .05). Hemodynamics improved further with the ITD. Oxygenation and arterial pH were similar. Only one of nine pigs had return of spontaneous circulation with 15:2, vs. six of nine with 30:2 (p < 0.03). Humans: Fatigue and quality of CPR performance were evaluated in 20 BLS-certified rescuers randomized to perform CPR for 5 mins at 15:2 or 30:2 on a recording CPR manikin. There were no significant differences in the quality of CPR performance or measurement of fatigue. Significantly more compressions per minute were delivered with 30:2 in both the animal and human studies. Conclusions:These data strongly support the contention that a ratio of 30:2 is superior to 15:2 during manual CPR and that the ITD further enhances circulation with both C:V ratios.