Arterial trauma during central venous catheter insertion: Case series, review and proposed algorithm.

BACKGROUND: Percutaneous catheterization is a frequently-used technique to gain access to the central venous circulation. Inadvertent arterial puncture is often without consequence, but can lead to devastating complications if it goes unrecognized and a large-bore dilator or catheter is inserted. The present study reviews our experience with these complications and the literature to determine the safest way to manage catheter-related cervicothoracic arterial injury (CRCAI). METHODS: We retrospectively identified all cases of iatrogenic carotid or subclavian injury following central venous catheterization at three large institutions in Montreal. We reviewed the French and English literature published from 1980 to 2006, in PubMed, and selected studies with the following criteria: arterial misplacement of a large-caliber cannula (>/=7F), adult patients (>18 years old), description of the method for managing arterial trauma, reference population (denominator) to estimate the success rate of the therapeutic option chosen. A consensus panel of vascular surgeons, anesthetists and intensivists reviewed this information and proposed a treatment algorithm. RESULTS: Thirteen patients were treated for CRCAI in participating institutions. Five of them underwent immediate catheter removal and compression, and all had severe complications resulting in major stroke and death in one patient, with the other four undergoing further intervention for a false aneurysm or massive bleeding. The remaining eight patients were treated by immediate open repair (six) or through an endovascular approach (two) for subclavian artery trauma without complications. Five articles met all our inclusion criteria, for a total of 30 patients with iatrogenic arterial cannulation: 17 were treated by immediate catheter removal and direct external pressure; eight (47%) had major complications requiring further interventions; and two died. The remaining 13 patients submitted to immediate surgical exploration, catheter removal and artery repair under direct vision, without any complications (47% vs 0%, P = .004). CONCLUSION: During central venous placement, prevention of arterial puncture and cannulation is essential to minimize serious sequelae. If arterial trauma with a large-caliber catheter occurs, prompt surgical or endovascular treatment seems to be the safest approach. The pull/pressure technique is associated with a significant risk of hematoma, airway obstruction, stroke, and false aneurysm. Endovascular treatment appears to be safe for the management of arterial injuries that are difficult to expose surgically, such as those below or behind the clavicle. After arterial repair, prompt neurological evaluation should be performed, even if it requires postponing elective intervention. Imaging is suggested to exclude arterial complications, especially if arterial trauma site was not examined and repaired.

Pharmacokinetic variability of extended interval tobramycin in burn patients.

BACKGROUND: Aminoglycosides are mandatory in the treatment of severe infections in burns. However, their pharmacokinetics are difficult to predict in critically ill patients. Our objective was to describe the pharmacokinetic parameters of high doses of tobramycin administered at extended intervals in severely burned patients. METHODS: We prospectively enrolled 23 burned patients receiving tobramycin in combination therapy for Pseudomonas species infections in a burn ICU over 2 years in a therapeutic drug monitoring program. Trough and post peak tobramycin levels were measured to adjust drug dosage. Pharmacokinetic parameters were derived from two points first order kinetics. RESULTS: Tobramycin peak concentration was 7.4 (3.1-19.6)microg/ml and Cmax/MIC ratio 14.8 (2.8-39.2). Half-life was 6.9 (range 1.8-24.6)h with a distribution volume of 0.4 (0.2-1.0)l/kg. Clearance was 35 (14-121)ml/min and was weakly but significantly correlated with creatinine clearance. CONCLUSION: Tobramycin had a normal clearance, but an increased volume of distribution and a prolonged half-life in burned patients. However, the pharmacokinetic parameters of tobramycin are highly variable in burned patients. These data support extended interval administration and strongly suggest that aminoglycosides should only be used within a structured pharmacokinetic monitoring program.

Single rooms may help to prevent nosocomial bloodstream infection and cross-transmission of methicillin-resistant Staphylococcus aureus in intensive care units.

OBJECTIVE: Nosocomial infections remain a major problem in intensive care units. Several authorities have recommended housing patients in single rooms to prevent cross-transmission of potential pathogens, but this issue is currently debated. The aim of the present study was to compare the rate of nosocomial cross-contamination between patients hosted in single rooms versus bay rooms. DESIGN: Prospective observational data acquisition over 2.5 years. SETTING: A 14-bed medico-surgical ICU, composed of six single-bed rooms plus a six-bed and a two-bed bay room served by the same staff. PATIENTS AND PARTICIPANTS: All patients admitted from 1 July 2002 to 31 December 2004. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in admitted patients was 1.1% and acquisition rate 2.4%. The incidence density of MRSA acquisition was 4.1 [95% CI 2.7-6.3]/1,000 patient-days in bay rooms versus 1.3 [0.5-3.4]/1,000 patient-days in single rooms (p<0.001). Pseudomonas spp. acquisition rate was 3.9 [2.5-6.1]/1,000 patient-days in bay rooms versus 0.7 [0.2-2.4]/1,000 patient-days in single rooms (p<0.001), and Candida spp. colonization was 38.4 [33.3-44.1]/1,000 patient-days in bay rooms versus 13.8 [10.2-18.6]/1,000 patient-days (p<0.001). By multivariate analysis, the relative risk of MRSA, Pseudomonas aeruginosa and Candida spp. acquisition in single rooms or cubicles versus bay rooms was 0.65, 0.61 and 0.75 respectively. CONCLUSIONS: These data suggest that in an institution where MRSA is not hyperendemic, infection control measures may be more effective to prevent cross-transmission of microorganisms in patients housed in single rooms.

Epidural anesthesia improves outcome and resource use in cardiac surgery: a single-center study of a 1293-patient cohort.

Thoracic epidural anesthesia (TEA) combined with general anesthesia in cardiac surgery has the potential to initiate earlier spontaneous ventilation and extubation, improved hemodynamics, less arrhythmia or myocardial ischemia, and an attenuated neurohormonal response. The aim of the current study was to characterize the correlation between TEA and postoperative resource use or outcome in a consecutive-patient cohort. The study was performed in a tertiary care, 3-surgeon, university-affiliated hospital that performs 350 to 400 cardiac surgeries per year. All 1293 adult patients who underwent cardiac surgery between July 1, 2002, and February 1, 2006, were included. Patients were assigned to anesthesiologists practicing TEA (TEA group, n = 506) or not (control group, n = 787) for cardiac surgery. The preoperative parameter values and Parsonnet scores for the 2 groups were similar. The 2 groups had the same distribution of surgery types. The TEA group presented with fewer intensive care unit (ICU) complications, such as delirium, pneumonia, and acute renal failure, and presented with better myocardial protection. The TEA group presented with a higher proportion of immediately postoperative extubations and with shorter ventilation times and ICU stays. Total ICU costs decreased from US $18,700 to $9900 per patient. Combining TEA and general anesthesia for cardiac surgery allows a significant change in anesthesia strategy. This change improves immediate postoperative outcomes and reduces the use and costs of ICU resources.

Albumin administration for fluid resuscitation in burn patients: A systematic review and meta-analysis.

OBJECTIVE: The objective was to systematically review the literature summarizing the effect on mortality of albumin compared to non-albumin solutions during the fluid resuscitation phase of burn injured patients. DATA SOURCES: We searched MEDLINE, EMBASE and CENTRAL and the content of two leading journals in burn care, Burns and Journal of Burn Care and Research. STUDY SELECTION: Two reviewers independently selected randomized controlled trials comparing albumin vs. non-albumin solutions for the acute resuscitation of patients with >20% body surface area involvement. DATA EXTRACTION: Reviewers abstracted data independently and assessed methodological quality of the included trials using predefined criteria. DATA SYNTHESIS: A random effects model was used to assess mortality. We identified 164 trials of which, 4 trials involving 140 patients met our inclusion criteria. Overall, the methodological quality of the included trials was fair. We did not find a significant benefit of albumin solutions as resuscitation fluid on mortality in burn patients (relative risk (RR) 1.6; 95% confidence interval (CI), 0.63-4.08). Total volume of fluid infusion during the phase of resuscitation was lower in patients receiving albumin containing solution -1.00ml/kg/%TBSA (total body surface area) (95% CI, -1.42 to -0.58). CONCLUSION: The pooled estimate demonstrated a neutral effect on mortality in burn patients resuscitated acutely with albumin solutions. Due to limited evidence and uncertainty, an adequately powered, high quality trial could be required to assess the impact of albumin solutions on mortality in burn patients.

Clinical trials of immunomodulatory therapies in severe sepsis and septic shock.

Sepsis remains one of the leading causes of mortality in critically ill patients. Increased insight into the complexities of this disease process has resulted in the targeting of various aspects of the inflammatory response as offering potential therapeutic benefits. There have been encouraging results in the past few years. Some of the tested agents have been shown to improve mortality rates in large randomized controlled trials involving patients with severe sepsis. In this article, we discuss the positive and negative results of trials in this field; some of the possible reasons for the negative results are examined, and directions for the future are suggested.

Microvascular alterations in patients with acute severe heart failure and cardiogenic shock.

BACKGROUND: Microvascular blood flow alterations may impair tissue oxygenation and may participate in the development of multiple organ failure in patients with severe heart failure. We hypothesized that microvascular blood flow alterations are present in patients with severe heart failure and cardiogenic shock. METHODS: We used an orthogonal polarization spectral imaging technique to investigate the sublingual microcirculation in 40 patients with acute severe heart failure, including 31 patients with cardiogenic shock, and in a control group of 15 patients who were examined the day before cardiac surgery. The effects of topical application of acetylcholine (10-2M) were also tested in 5 patients with cardiogenic shock. Five sublingual areas were recorded, allocated a random number, and later analyzed semiquantitatively. Data were analyzed with non-parametric tests and presented as medians (percentiles 25-75). RESULTS: The density of all the vessels was similar in the 3 groups. The proportion of perfused small (<20 microm) vessels was lower in patients with cardiac failure and cardiogenic shock than in control patients (63% [46%-65%] and 49% [38%-64%] vs 92% [90%-93%], P <.001). The perfusion of large vessels was preserved in all groups. The proportion of perfused vessels was higher in patients who survived than in patients who did not survive in all vessels (90% [84%-93%] vs 81% [74%-87%], P <.05) and in small vessels (64% [49%-68%] vs 43% [37%-62%], P <.05). The topical application of acetylcholine totally reversed these alterations CONCLUSIONS: Microvascular blood flow alterations are frequently observed in patients with severe heart failure and are more severe in patients who do not survive.

Do all nonsurvivors of cardiogenic shock die with a low cardiac index?

STUDY OBJECTIVES: To characterize the hemodynamic course of cardiogenic shock and to relate the cause of death to ongoing cardiac failure or multiple organ dysfunction. DESIGN: Retrospective study. SETTING: A 31-bed department of intensive care in a university hospital. PATIENTS: All patients admitted for cardiogenic shock from January 1999 to December 2000. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Charts were reviewed for demographic, clinical, hemodynamic, oxygen transport, inflammation, and organ dysfunction data. Of 62 patients with cardiogenic shock, 40 (65%) did not survive. Eight patients (20%) died from fatal arrhythmia, 14 patients (35%) died with low cardiac index (CI) [ie, < 2.2 L/min/m(2)], and 18 patients (45%) died with normalized CI (ie, > 2.2 L/min/m(2)) and a higher CI/oxygen extraction ratio. Of these 18 patients, 9 had evidence of infection. The patients with normalized CI were younger and stayed longer in the ICU than patients with low CI. CONCLUSION: A substantial number of patients with cardiogenic shock die with a normalized CI, suggesting a distributive defect, in the absence of obvious infection. These patients are younger and have a longer ICU course. The release of mediators may be secondary to gut hypoperfusion.

Intra-operative graft blood flow measurements for composite and sequential coronary artery bypass grafting.

OBJECTIVES: Intraoperative assessment of coronary artery bypass grafts (CABG) anastomotic quality can be performed using transit-time flowmetry (TTF). The aim of this study was to compare on- versus off-pump coronary graft TTF and early postoperative outcomes. MATERIALS AND METHODS: Between January 2009 and January 2010, 521 distal graft flows were assessed using TTF measurements in 253 consecutive patients undergoing primary isolated CABG surgery. Data were analyzed using multilevel models accounting for clustering among surgeons and grafts performed in the same patient. RESULTS: Mean age was 66 ± 10 years and 22% were female (n = 55) with 34% diabetics (n = 86) and 40% preoperative myocardial infarction (MI) (n = 101). The surgeries were performed off-pump in 67% (n = 170) with sequential vein grafts in 57% (n = 144) of patients. Off-pump patients had higher pre-operative left ventricular ejection fractions (LVEF), fewer urgent surgeries, fewer distal anastomoses, and fewer sequential vein grafts (all p<0.001). Intra-operative coronary graft TTF measurements were lower in sequential vein grafts performed off-pump versus on-pump. More patients in the on-pump group needed milrinone or dobutamine 24-48 h postoperatively (p = 0.005). Independent predictors of lower TTF included female gender and off-pump surgery, whereas predictors of better TTF were preoperative MI, larger coronary diameter at the site of the distal anastomosis, and sequential vein grafting. CONCLUSIONS: Lower intra-operative TTF measurements were found in sequential vein grafts in off-pump CABG. However, off-pump patients experienced similar short-term outcomes compared to on-pump patients.

Hypoalbuminemia in the first 24h of admission is associated with organ dysfunction in burned patients.

OBJECTIVE: Hypoalbuminemia is a common finding in burned patients, but its association with increased morbidity and mortality has not been well established. We assessed whether hypoalbuminemia in the first 24h of admission is associated with organ dysfunction in patients with severe burns. METHODS: For a two year period (2008-2009), we reviewed the records of burn adult patients with a total body surface area 20% admitted in our unit within the first 24h of injury. A multiple linear regression analysis was conducted to assess hypoalbuminemia as an independent predictor of organ dysfunction. RESULTS: 56 subjects were analyzed. Multiple linear regression analysis showed that hypoalbuminemia in the first 24h of admission was an independent predictor of organ dysfunction. Serum albumin concentration ≤ 30 g/L was associated with a two-fold increase in organ dysfunction [SOFA scores at day 0 (p=0.005), day 1 (p=0.005) and first week mean values (p=0.004)], but not with mortality (p=0.061). CONCLUSION: Hypoalbuminemia is associated with organ dysfunction in burned patients. Unlike unmodifiable predictors such as age, burn surface and inhalation burn, correction of hypoalbuminemia might represent a goal for a future trial in burn patients.

Microcirculatory alterations in cardiac surgery: effects of cardiopulmonary bypass and anesthesia.

BACKGROUND: Heterogeneity in microvascular perfusion is associated with impaired tissue oxygenation. We hypothesized that cardiac surgery with or without cardiopulmonary bypass (CPB) could induce microvascular alterations. METHODS: We used an orthogonal polarization spectral imaging technique to evaluate the sublingual microcirculation in patients undergoing cardiac surgery with (n = 9) or without (n = 6) CPB. We also included, as a control group, 7 patients undergoing thyroidectomy with the same anesthetic procedure. Hemodynamic and microcirculatory variables were obtained the day before surgery, after induction of anesthesia, during CPB, on admission to the intensive care unit or the recovery room, and 6 and 24 hours after the end of the surgical procedure. Data are presented as median (25th to 75th percentile). RESULTS: No differences in hemodynamic variables were observed between the two cardiac surgery groups. The proportion of perfused vessels was similar in all three groups at baseline (89% [87% to 90%]), and decreased similarly after induction of anesthesia to 71% (69% to 74%). It decreased further during CPB to 53% (50% to 56%). On admission to the intensive care unit or recovery room, alterations were more severe in CPB than in off-pump patients (60% [59% to 62%] versus 64% [61% to 65%]; p = 0.03), whereas they had already normalized in thyroidectomy patients (89% [86% to 90%]; p = 0.0005 versus cardiac surgery). In both cardiac surgery groups these microcirculatory alterations decreased with time, but persisted at 24 hours. The severity of microvascular alterations correlated with peak lactate levels after cardiac surgery (y = 11.5 - 0.15x; r(2) = 0.65; p < 0.05). CONCLUSIONS: Microcirculatory alterations are observed in cardiac surgery patients whether or not CPB is used. Anesthesia contributes to these alterations, but its effects are transient.

Microvascular response to red blood cell transfusion in patients with severe sepsis.

OBJECTIVES: Microvascular alterations may play a role in the development of multiple organ failure in severe sepsis. The effects of red blood cell transfusions on microvascular perfusion are not well defined. We investigated the effects of red blood cell transfusion on sublingual microvascular perfusion in patients with sepsis. DESIGN: Prospective, observational study. SETTING: A 31-bed, medical-surgical intensive care unit of a university hospital. PATIENTS: Thirty-five patients with severe sepsis requiring red blood cell transfusions. INTERVENTIONS: Transfusion of one to two units of leukocyte-reduced red blood cells. MEASUREMENTS AND MAIN RESULTS: The sublingual microcirculation was assessed with an Orthogonal Polarization Spectral device before and 1 hr after red blood cell transfusion. Red blood cell transfusions increased hemoglobin concentration from 7.1 (25th-75th percentile, 6.7-7.6) to 8.1 (7.5-8.6) g/dL (p < .01), mean arterial pressure from 75 (69-89) to 82 (75-90) mm Hg (p < .01), and oxygen delivery from 349 (278-392) to 391 (273-473) mL/min.M (p < .001). Microvascular perfusion was not significantly altered by transfusion, but there was considerable interindividual variation. The change in capillary perfusion after transfusion correlated with baseline capillary perfusion (Spearman-rho = -.49; p = .003). Capillary perfusion was significantly lower at baseline in patients who increased their capillary perfusion by >8% compared with those who did not (57 [52-64] vs. 75 [70-79]; p < .01), while hemodynamic and global oxygen transport variables were similar in the two groups. Red blood cell storage time had no influence on the microvascular response to red blood cell transfusion. CONCLUSIONS: The sublingual microcirculation is globally unaltered by red blood cell transfusion in septic patients; however, it can improve in patients with altered capillary perfusion at baseline.

The effects of dobutamine on microcirculatory alterations in patients with septic shock are independent of its systemic effects.

OBJECTIVE: To evaluate the effects of dobutamine on microcirculatory blood flow alterations in patients with septic shock. DESIGN: Prospective, open-label study. SETTING: A 31-bed, medico-surgical intensive care unit of a university hospital. PATIENTS: Twenty-two patients with septic shock. INTERVENTIONS: Intravenous administration of dobutamine (5 mug/kg.min) for 2 hrs (n = 22) followed by the addition of 10 M acetylcholine (topically applied, n = 10). MEASUREMENTS AND MAIN RESULTS: Complete hemodynamic measurements were obtained before and after dobutamine administration. In addition, the sublingual microcirculation was investigated with an orthogonal polarization spectral imaging technique before and after dobutamine administration and after topical application of acetylcholine. Dobutamine significantly improved capillary perfusion (from 48 +/- 15 to 67 +/- 11%, p = .001), but with large individual variation, whereas capillary density remained stable. The addition of topical acetylcholine completely restored capillary perfusion (98 +/- 1%, p = .001) and capillary density. The changes in capillary perfusion during dobutamine administration were not related to changes in cardiac index (p = .45) or arterial pressure (p = .29). Interestingly, the decrease in lactate levels was proportional to the improvement in capillary perfusion (y = 0.07 - 0.02x, r = .46, p = .005) but not to changes in cardiac index (p = .55). CONCLUSIONS: The administration of 5 mug/kg.min dobutamine can improve but not restore capillary perfusion in patients with septic shock. These changes are independent of changes in systemic hemodynamic variables.

Albumin administration improves organ function in critically ill hypoalbuminemic patients: A prospective, randomized, controlled, pilot study.

OBJECTIVE: To test the hypothesis that administration of albumin to correct hypoalbuminemia might have beneficial effects on organ function in a mixed population of critically ill patients. DESIGN: : Prospective, controlled, randomized study. SETTING: Thirty-one-bed, mixed medicosurgical department of intensive care. PATIENTS: All adult patients with a serum albumin concentration < or =30 g/L were assessed for eligibility. Principal exclusion criteria were expected length of stay <72 hrs, life expectancy <3 months or a do-not-resuscitate order, albumin administration in the preceding 24 hrs, or evidence of fluid overload. INTERVENTIONS: The 100 patients were randomized to receive 300 mL of 20% albumin solution on the first day, then 200 mL/day provided their serum albumin concentration was <31 g/dL (albumin group), or to receive no albumin (control group). MEASUREMENTS AND MAIN RESULTS: The primary outcome was the effect of albumin administration on organ function as assessed by a delta Sequential Organ Failure Assessment score from day 1 to day 7 (or the day of intensive care discharge or death, whichever came first). The two groups of 50 patients were comparable at baseline for age, gender, albumin concentration, and Acute Physiology and Chronic Health Evaluation II score. Albumin concentration did not change over time in the control group but increased consistently in the albumin group (p < .001). Organ function improved more in the albumin than in the control group (p = .026), mainly due to a difference in respiratory, cardiovascular, and central nervous system components of the Sequential Organ Failure Assessment score. Diuretic use was identical in both groups, but mean fluid gain was almost three times higher in the control group (1679 +/- 1156 vs. 658 +/- 1101 mL, p = .04). Median daily calorie intake was higher in the albumin than in the control group (1122 [935-1158] vs. 760 [571-1077] kcal, p = .05). CONCLUSIONS: Albumin administration may improve organ function in hypoalbuminemic critically ill patients. It results in a less positive fluid balance and a better tolerance to enteral feeding.

Use of albumin in the intensive care unit.

Recent publications have renewed interest in albumin use in the ICU. Meta-analyses have been published that demonstrate the safety of albumin administration and even potential benefits. Hypoalbuminemia, which has long been considered a marker of disease, has been causally linked to the development of complications. Finally, advances have been made in our knowledge of the unique and potentially beneficial properties of albumin.

Delirium in critically ill patients.

Delirium in the intensive care unit is a serious problem that has recently attracted much attention. User-friendly and reliable tools, such as the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU), offer the clinician the opportunity to identify delirium in patients better. Diagnosis of delirium in a critical care population is often a difficult task because classical psychiatric evaluation is impossible for a number of reasons. The CAM-ICU makes use of nonverbal assessments to evaluate the cardinal features of delirium (i.e. acute or fluctuating onset, inattention, disorganized thinking and altered level of consciousness). Its development for use in the critical care setting represents a significant advance that could lead to better care for such patients.

Hypoalbuminemia in acute illness: is there a rationale for intervention? A meta-analysis of cohort studies and controlled trials.

OBJECTIVE: To determine whether hypoalbuminemia is an independent risk factor for poor outcome in the acutely ill, and to assess the potential of exogenous albumin administration for improving outcomes in hypoalbuminemic patients. SUMMARY BACKGROUND DATA: Hypoalbuminemia is associated with poor outcomes in acutely ill patients, but whether this association is causal has remained unclear. Trials investigating albumin therapy to correct hypoalbuminemia have proven inconclusive. METHODS: A meta-analysis was conducted of 90 cohort studies with 291,433 total patients evaluating hypoalbuminemia as an outcome predictor by multivariate analysis and, separately, of nine prospective controlled trials with 535 total patients on correcting hypoalbuminemia. RESULTS: Hypoalbuminemia was a potent, dose-dependent independent predictor of poor outcome. Each 10-g/L decline in serum albumin concentration significantly raised the odds of mortality by 137%, morbidity by 89%, prolonged intensive care unit and hospital stay respectively by 28% and 71%, and increased resource utilization by 66%. The association between hypoalbuminemia and poor outcome appeared to be independent of both nutritional status and inflammation. Analysis of dose-dependency in controlled trials of albumin therapy suggested that complication rates may be reduced when the serum albumin level attained during albumin administration exceeds 30 g/L. CONCLUSIONS: Hypoalbuminemia is strongly associated with poor clinical outcomes. Further well-designed trials are needed to characterize the effects of albumin therapy in hypoalbuminemic patients. In the interim, there is no compelling basis to withhold albumin therapy if it is judged clinically appropriate.