Comparison of accuracy of two uncalibrated pulse contour cardiac output monitors in off-pump coronary artery bypass surgery patients using pulmonary artery catheter-thermodilution as a reference.

BACKGROUND: Cardiac output (CO) is a key measure of adequacy of organ and tissue perfusion, especially in critically ill or complex surgical patients. CO monitoring technology continues to evolve. Recently developed CO monitors rely on unique algorithms based on pulse contour analysis of an arterial blood pressure (ABP) waveform. The objective of this investigation was to compare the accuracy of two monitors using different methods of pulse contour analysis - the Retia Argos device and the Edwards Vigileo-FloTrac device - with pulmonary artery catheter (PAC)-thermodilution as a reference. METHODS: Fifty-eight patients undergoing off-pump coronary artery bypass surgery formed the study cohort. A total of 572 triplets of CO measurements from each device - Argos, Vigileo-FloTrac (third generation), and thermodilution - were available before and after interventions (e.g., vasopressors, fluids, and inotropes). Bland-Altman analysis accounting for repeated measurements per subject and concordance analysis were applied to assess the accuracy of the CO values and intervention-induced CO changes of each pulse contour device against thermodilution. Cluster bootstrapping was employed to statistically compare the root-mean-squared-errors (RMSE = √(µ2 + σ2), where µ and σ are the Bland-Altman bias and precision errors) and concordance rates of the two devices. RESULTS: The RMSE (mean (95% confidence intervals)) for CO values was 1.16 (1.00-1.32) L/min for the Argos device and 1.54 (1.33-1.77) L/min for the Vigileo-FloTrac device; the concordance rate for intervention-induced CO changes was 87 (82-92)% for the Argos device and 72 (65-78)% for the Vigileo-FloTrac device; and the RMSE for the CO changes was 17 (15-19)% for the Argos device and 21 (19-23)% for the Vigileo-FloTrac device (p < 0.0167 for all comparisons). CONCLUSIONS: In comparison with CO measured by the PAC, the Argos device proved to be more accurate than the Vigileo-FloTrac device in CO trending and absolute CO measurement in patients undergoing off-pump coronary artery bypass surgery.

Acute intentional caffeine overdose treated preemptively with hemodialysis.

Caffeine is the most commonly used central nervous system stimulant. While it has a high LD50 (150-200 mg/kg), when ingested in significant quantity, caffeine can lead to severe and even lethal side effects. Manifestation of toxicity include tachyarrhythmias, seizures, and metabolic derangements which can eventually lead to cardiovascular collapse and death. Studies have shown that lethal doses of caffeine (80-100 µg/mL) can be seen with the ingestion of approximately 10 g of caffeine. Due to the low number of reported cases, there is no consensus on the standard of care for treatment of suspected caffeine overdose. This case details a 39-year-old male who presented to the emergency department (ED) after having ingested 50 g of caffeine. Despite a high dose esmolol infusion, the patient exhibited worsening tachyarrhythmias. Hemodialysis was started empirically given the known amount ingested and ongoing hemodynamic perturbations. Initial pre-dialysis caffeine level was found to be 254 µg/ml. After treatment with two sessions of hemodialysis the patient's caffeine level decreased dramatically. We believe this is the first case report to demonstrate the success of preemptive hemodialysis, prior to cardiovascular collapse and/or renal failure, in a case of caffeine overdose and should be considered very early in patients presenting with recent toxic ingestion.

Telemedicine coverage for post-operative ICU patients.

Introduction There is an increased demand for intensive care unit (ICU) beds. We sought to determine if we could create a safe surge capacity model to increase ICU capacity by treating ICU patients in the post-anaesthesia care unit (PACU) utilizing a collaborative model between an ICU service and a telemedicine service during peak ICU bed demand. Methods We evaluated patients managed by the surgical critical care service in the surgical intensive care unit (SICU) compared to patients managed in the virtual intensive care unit (VICU) located within the PACU. A retrospective review of all patients seen by the surgical critical care service from January 1st 2008 to July 31st 2011 was conducted at an urban, academic, tertiary centre and level 1 trauma centre. Results Compared to the SICU group ( n = 6652), patients in the VICU group ( n = 1037) were slightly older (median age 60 (IQR 47-69) versus 58 (IQR 44-70) years, p = 0.002) and had lower acute physiology and chronic health evaluation (APACHE) II scores (median 10 (IQR 7-14) versus 15 (IQR 11-21), p < 0.001). The average amount of time patients spent in the VICU was 13.7 + /-9.6 hours. In the VICU group, 750 (72%) of patients were able to be transferred directly to the floor; 287 (28%) required subsequent admission to the surgical intensive care unit. All patients in the VICU group were alive upon transfer out of the PACU while mortality in the surgical intensive unit cohort was 5.5%. Discussion A collaborative care model between a surgical critical care service and a telemedicine ICU service may safely provide surge capacity during peak periods of ICU bed demand. The specific patient populations for which this approach is most appropriate merits further investigation.

Coexisting Cardiac and Hematologic Disorders.

Patients with concomitant cardiac and hematologic disorders presenting for noncardiac surgery are challenging. Anemic patients with cardiac disease should be approached in a methodical fashion. Transfusion triggers and target should be based on underlying symptomatology. The approach to anticoagulation management in patients with artificial heart valves, cardiac devices, or severe heart failure in the operative setting must encompass a complete understanding of the rationale of a patient's therapy as well as calculate the risk of changing this regimen. This article focuses common disorders and discusses strategies to optimize care in patients with coexisting cardiac and hematologic disease.

A 61-year-old woman develops polyuria after hip revision.

A 61-year-old previously healthy woman developed progressive hearing and visual loss over a period of 2-3 months prior to admission. Her medical/surgical history was remarkable for a left hip arthroplasty 11 years ago requiring revision approximately 6 months prior to admission. After dislocating the revised hip, she re-presented to her surgeon and underwent a closed reduction. Several weeks following the reduction, the patient began having polyuria and symptoms of hearing and vision loss along with numbness in her extremities and abdominal region.

Critical care telemedicine: evolution and state of the art.

OBJECTIVES: To review the growth and current penetration of ICU telemedicine programs, association with outcomes, studies of their impact on medical education, associations with medicolegal risks, identify program revenue sources and costs, regulatory aspects, and the ICU telemedicine research agenda. DATA SOURCES: Review of the published medical literature, governmental documents, and opinions of experts from the Society of Critical Care Medicine ICU Telemedicine Committee. DATA SYNTHESIS: Formal ICU telemedicine programs now support 11% of nonfederal hospital critically ill adult patients. There is increasingly robust evidence of association with lower ICU (0.79; 95% CI, 0.65-0.96) and hospital mortality (0.83; 95% CI, 0.73-0.94) and shorter ICU (-0.62 d; 95% CI, -1.21 to -0.04 d) and hospital (-1.26 d; 95% CI, -2.49 to -0.03 d) length of stay. Physicians in training report experiences with telemedicine intensivists that are positive and increased patient safety. Early studies suggest that implementation of ICU telemedicine programs has been associated with lower numbers of malpractice claims and costs. The requirements for Medicare reimbursement and states with legislation addressing providing professional services by telemedicine are detailed. CONCLUSIONS: The inclusion of an ICU telemedicine program as a major part of their critical care delivery paradigm has been implemented for 11% of critically ill U.S. adults as a solution for the problem of access to adult critical care services. Implementation of an ICU telemedicine program is one practical way to increase access and reduce mortality as well as length of stay. ICU telemedicine research including comparative effectiveness studies is urgently needed.

There's no place like home: boarding surgical ICU patients in other ICUs and the effect of distances from the home unit.

BACKGROUND: Intensive care units (ICUs) function frequently at capacity, requiring incoming critically ill patients to be placed in alternate geographically distinct ICUs. In some medical ICU populations, "boarding" in an overflow ICU has been associated with increased mortality. We hypothesized that surgical ICU patients experience more complications when boarding in an overflow ICU and that the frequency of these complications are greatest in boarders farthest from the home unit (HU). METHODS: A 5-year (June 2005 to June 2010) retrospective review of a prospectively maintained ICU database was performed, and demographics, severity of illness, length of stay, and incidence of ICU complications were extracted. Distances between boarding patients' rooms and the HU were measured. Complications occurring in patients located in the same floor (BUSF) and different floor (BUDF) boarding units were compared and stratified by distance from HU to the patient room. Logistic regression was used to develop control for known confounders. RESULTS: A total of 7,793 patients were admitted to the HU and 833 to a boarding unit (BUSF, n = 712; BUDF, n = 121). Boarders were younger, had a lower length of stay, and Acute Physiology and Chronic Health Evaluation II and were more often trauma/emergency surgery patients. Compared with in-HU patients, the incidence of aspiration pneumonia (2.2% vs. 3.6%, p < 0.01) was greater in BUSF patients and highest in those farthest from the HU (odds ratio [OR], 2.39; p = 0.01). Delirium occurred less often in HU than in BUDF patients (3.3% vs. 8.3 %, p < 0.01), and both delirium (OR, 6.09, p < 0.01) and ventilator-associated pneumonia (OR, 4.49, p < 0.05) were more frequent in patients farther from the HU. CONCLUSION: Certain ICU complications occur more frequently in boarding patients particularly if they are located on a different floor or far from the HU. When surgical ICU bed availability forces overflow admissions to non-home ICUs, greater interdisciplinary awareness, education, and training may be needed to ensure equivalent care and outcomes. LEVEL OF EVIDENCE: Epidemiologic study, level III. Therapeutic study, level IV.

Incidental moderate mitral regurgitation in patients undergoing aortic valve replacement for aortic stenosis: review of guidelines and current evidence.

Recent evidence has shown that moderate mitral regurgitation is common and clinically relevant in patients presenting for surgical and transcatheter aortic valve replacement for aortic stenosis. Prospective multicenter clinical trials are now indicated to resolve the clinical equipoise about whether or not mitral valve intervention also is indicated at the time of aortic valve intervention. Advances in three-dimensional transesophageal echocardiography, transcatheter mitral interventions, and surgical aortic valve replacement, including the advent of sutureless valves, likely will expand the therapeutic possibilities for moderate mitral regurgitation in the setting of aortic valve interventions for severe aortic stenosis.

The year in cardiothoracic and vascular anesthesia: selected highlights from 2013.

This article reviewed selected research highlights of 2013 that pertain to the specialty of cardiothoracic and vascular anesthesia. The first major theme is the commemoration of the sixtieth anniversary of the first successful cardiac surgical procedure with cardiopulmonary bypass conducted by Dr Gibbon. This major milestone revolutionized the practice of cardiovascular surgery and invigorated a paradigm of mechanical platforms for contemporary perioperative cardiovascular practice. Dr Kolff was also a leading contributor in this area because of his important contributions to the refinement of cardiopulmonary bypass and mechanical ventricular assistance. The second major theme is the diffusion of echocardiography throughout perioperative practice. There are now guidelines and training pathways to guide its generalization into everyday practice. The third major theme is the paradigm shift in perioperative fluid management. Recent large randomized trials suggest that fluids are drugs that require a precise prescription with respect to type, dose, and duration. The final theme is patient safety in the cardiac perioperative environment. A recent expert scientific statement has focused attention on this issue because most perioperative errors are preventable. It is likely that clinical research in this area will blossom because this is a major opportunity for improvement in our specialty. The patient care processes identified in these research highlights will further improve perioperative outcomes for our patients.

Intravenous GLP-1 (7-36) amide for prevention of hyperglycemia during cardiac surgery: a randomized, double-blind, placebo-controlled study.

OBJECTIVE: The authors sought to evaluate the efficacy of an intravenous glucagon-like peptide-1 (GLP-1) infusion, compared with placebo, to mitigate intraoperative hyperglycemia. DESIGN: Prospective, double-blinded, randomized, placebo-controlled. SETTING: University hospital. PARTICIPANTS: Diabetic (non-insulin dependent) and non-diabetic patients undergoing elective cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Patients were randomized in a 1:1 fashion to GLP-1 (7-36) amide infusion (1.5 pmol/kg/min) or placebo. Insulin was administered intraoperatively to both groups per a standardized protocol. MEASUREMENTS AND MAIN RESULTS: A total of 77 patients were included for analysis (GLP-1, n = 37; placebo, n = 40). Mean blood glucose during cardiopulmonary bypass was 127.5 mg/dL and 142.5 mg/dL (p = 0.002) in the GLP-1 and placebo groups, respectively. Mean blood glucose values during the entire intraoperative course were 12.2 mg/dL lower for subjects given GLP-1 (95% CI 2.3, 22, p = 0.015), independent of time. During the period of cardiopulmonary bypass, mean blood glucose values in subjects given GLP-1 were 14.1 mg/dL lower than those who received placebo (95% CI 3.5, 24.8, p = 0.009), independent of time. The incidence of hypoglycemia did not differ significantly between the 2 groups. CONCLUSIONS: Administration of intravenous GLP-1 (7-36) amide to patients undergoing cardiac surgery significantly reduced their plasma glucose levels intraoperatively and may represent a novel therapeutic strategy to prevent perioperative hyperglycemia.

Clinical risk factors for primary graft dysfunction after lung transplantation.

RATIONALE: Primary graft dysfunction (PGD) is the main cause of early morbidity and mortality after lung transplantation. Previous studies have yielded conflicting results for PGD risk factors. OBJECTIVES: We sought to identify donor, recipient, and perioperative risk factors for PGD. METHODS: We performed a 10-center prospective cohort study enrolled between March 2002 and December 2010 (the Lung Transplant Outcomes Group). The primary outcome was International Society for Heart and Lung Transplantation grade 3 PGD at 48 or 72 hours post-transplant. The association of potential risk factors with PGD was analyzed using multivariable conditional logistic regression. MEASUREMENTS AND MAIN RESULTS: A total of 1,255 patients from 10 centers were enrolled; 211 subjects (16.8%) developed grade 3 PGD. In multivariable models, independent risk factors for PGD were any history of donor smoking (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2-2.6; P = 0.002); FiO2 during allograft reperfusion (OR, 1.1 per 10% increase in FiO2; 95% CI, 1.0-1.2; P = 0.01); single lung transplant (OR, 2; 95% CI, 1.2-3.3; P = 0.008); use of cardiopulmonary bypass (OR, 3.4; 95% CI, 2.2-5.3; P < 0.001); overweight (OR, 1.8; 95% CI, 1.2-2.7; P = 0.01) and obese (OR, 2.3; 95% CI, 1.3-3.9; P = 0.004) recipient body mass index; preoperative sarcoidosis (OR, 2.5; 95% CI, 1.1-5.6; P = 0.03) or pulmonary arterial hypertension (OR, 3.5; 95% CI, 1.6-7.7; P = 0.002); and mean pulmonary artery pressure (OR, 1.3 per 10 mm Hg increase; 95% CI, 1.1-1.5; P < 0.001). PGD was significantly associated with 90-day (relative risk, 4.8; absolute risk increase, 18%; P < 0.001) and 1-year (relative risk, 3; absolute risk increase, 23%; P < 0.001) mortality. CONCLUSIONS: We identified grade 3 PGD risk factors, several of which are potentially modifiable and should be prioritized for future research aimed at preventative strategies. Clinical trial registered with www.clinicaltrials.gov (NCT 00552357).

Implementation of an intraoperative glycemic control protocol for cardiac surgery in a high-acuity academic medical center: an observational study.

STUDY OBJECTIVE: To examine the effect on morbidity and mortality of an established intraoperative insulin protocol in cardiac surgical patients. DESIGN: Retrospective observational study. SETTING: Single-center, 782 bed, metropolitan academic hospital. PATIENTS: 1,616 adult patients undergoing cardiac surgical procedures with cardiopulmonary bypass (CPB). INTERVENTIONS: An intraoperative, intravenous (IV) insulin protocol designed to maintain blood glucose values less than 150 mg/dL was implemented. MEASUREMENTS: Blood glucose was evaluated on entry to the operating room, every 30 minutes during CPB, and at least once after discontinuation of CPB. Blood glucose values were followed postoperatively, as dictated by institutional policy. MAIN RESULTS: Intraoperative predictors of 30-day mortality using multivariate logistic regression included hyperglycemia on initiation of CPB (OR 1.0, P = 0.05). The strongest predictor of 30-day mortality was the development of postoperative renal failure requiring hemodialysis (OR 3.26, P = 0.001). CONCLUSIONS: Implementation of an intraoperative IV insulin protocol, while associated with improved glycemic control, was not associated with improved outcomes. While improved glycemic control on initiating CPB was associated with decreased 30-day mortality, the effect was small. Implementation of our insulin protocol was highly associated with decreased renal failure postoperatively. Further prospective studies are warranted to better establish causality.

Use of telemedicine for the identification and treatment of sulfamethoxazole-induced methaemoglobinemia.

Telemedicine can be used in intensive care units (ICUs) with linked electronic medical records to enable remote clinicians to assess patients and focus on those who are deviating from their expected course. We report the case of a woman admitted to our ICU with apparent hypoxaemia, whose pulse oximetry readings were not believed by the treating team. The intensivist at the telemedicine centre was consulted and instituted treatment on the assumption that methaemoglobinemia was present. Without rapid therapy, ongoing tissue ischaemia and shock was inevitable. Within 60 min of methylene blue administration, the patient's oxygen saturation improved dramatically. The methaemoglobin level was eventually reported as 9.9% (normal value <1%). This case report demonstrates how, with the aid of a tele-intensivist, a rare diagnosis was made rapidly and successful therapy was provided.

The effect of ICU telemedicine on mortality and length of stay.

We conducted a retrospective, observational study of patient outcomes in two intensive care units in the same hospital. The surgical ICU (SICU) implemented telemedicine and electronic medical records, while the medical ICU (MICU) did not. Medical charts were reviewed for a one-year period before telemedicine and a one-year period afterwards. In the SICU, records were obtained for 246 patients before and 1499 patients after implementation; in the MICU, records were obtained for 220 patients and 285 patients in the same periods. The outcomes of interest were ICU length of stay and mortality, and hospital length of stay and mortality. Outcome variables were severity-adjusted using APACHE scoring. A bootstrap method, with 1000 replicates, was used to assess stability of the findings. The adjusted ICU length of stay, ICU mortality, and hospital mortality for the SICU patients all decreased significantly after the implementation of telemedicine. There was no change in adjusted outcome variables in the MICU patients. Implementation of telemedicine and electronic records in the surgical ICU was associated with a profound reduction in severity-adjusted ICU length of stay, ICU mortality, and hospital mortality. However, it is not possible to conclude definitively that the observed associations seen in the SICU were due to the intervention.

Elevated pulmonary artery pressure is a risk factor for primary graft dysfunction following lung transplantation for idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is often associated with elevations in pulmonary artery pressures. Although primary pulmonary arterial hypertension (PAH) has been associated with primary graft dysfunction (PGD), the role of secondary PAH in mediating PGD risk in patients with IPF is incompletely understood. The purpose of this study was to evaluate the relationship between mean pulmonary artery pressure (mPAP) and PGD among patients with IPF. METHODS: We performed a multicenter prospective cohort study of 126 lung transplant procedures performed for IPF between March 2002 and August 2007. The primary outcome was grade 3 PGD at 72 h after lung transplant. The mPAP was measured as the initial reading following insertion of the right-sided heart catheter during lung transplant. Multivariable logistic regression was used to adjust for confounding variables. RESULTS: The mPAP for patients with PGD was 38.5 ± 16.3 mm Hg vs 29.6 ± 11.5 mm Hg for patients without PGD (mean difference, 8.9 mm Hg [95% CI, 3.6-14.2]; P = .001). The increase in odds of PGD associated with each 10-mm Hg increase in mPAP was 1.64 (95% CI, 1.18-2.26; P = .003). In multivariable models, this relationship was independent of confounding by other clinical variables, although the use of cardiopulmonary bypass partially attenuated the relationship. CONCLUSIONS: Higher mPAP in patients with IPF is associated with the development of PGD.

Glycemic control and weight reduction without causing hypoglycemia: the case for continued safe aggressive care of patients with type 2 diabetes mellitus and avoidance of therapeutic inertia.

Diabetes mellitus (DM) is a major and growing concern in the United States, in large part because of an epidemic of obesity in America and its relation to type 2 DM. In affected patients, postprandial glucose may be an early indicator of glucose intolerance or a prediabetes condition, which may be a better predictor of cardiovascular risk than impaired fasting glucose level. Treating patients who have early signs of hyperglycemia, including elevated postprandial glucose level, with intensive glucose control that does not lead to weight gain, and ideally may be associated with weight reduction, may be vital to preventing or reducing later cardiovascular morbidity and mortality. Because hypoglycemia is an important complication of current DM treatments and may cause acute secondary adverse cardiovascular outcomes, not causing hypoglycemia is mandatory. Given that weight loss can significantly lower cardiovascular risk and improve other cardiovascular risk factors in patients with type 2 DM and that medications are available that can result in weight reduction without leading to hypoglycemia, the successful treatment of patients with type 2 DM should be individualized and should address the complete pathophysiologic process. This review is a hypothesis article that presents arguments against general approaches to the treatment of type 2 DM. An algorithm is presented in which the goal for managing patients with type 2 DM is to lower the blood glucose level as much as possible for as long as possible without causing hypoglycemia. In addition, body weight should ideally be improved, reducing cardiovascular risk factors and avoiding therapeutic inertia.