Joel S. Larson

Influence of Individual Characteristics on Outcome of Glycemic Control in Intensive Care Unit Patients With or Without Diabetes Mellitus

OBJECTIVE To clarify the relationship of patient and critical illness characteristics (including any history of diabetes mellitus) to glycemic control with insulin and hospital mortality. PATIENTS AND METHODS A case-control descriptive study was performed of patients admitted to a tertiary-care center multidisciplinary closed intensive care unit (ICU) at Mayo Clinic Hospital in Phoenix, Ariz, between January 1, 1999, and December 31, 2003, after implementation of a glycemic management protocol. Hospital mortality, the primary outcome, was examined in nondiabetic and diabetic ICU patients receiving insulin and in patients not requiring insulin (control group). RESULTS Of 7285 patients, 2826 (39%) required insulin, 1083 of whom (15% of total) had a history of diabetes mellitus. The control group had a median (10th-90th percentile) glucose level of 118 mg/dL (range, 97-153 mg/dL) and a 5% mortality rate. The median glucose level was 134 mg/dL (range, 110-181 mg/dL) in nondiabetic patients and 170 mg/dL (121-238 mg/dL) in diabetic patients (P<.001), whereas mortality rates were 10% and 6%, respectively (P<.001). Compared with nondiabetic survivors, nondiabetic nonsurvivors had longer periods with glucose levels greater than 144 mg/dL. Diabetic nonsurvivors vs diabetic survivors had longer periods with glucose levels greater than 200 mg/dL. Poor glycemic control in nondiabetic patients was associated with increased insulin requirement and increased mortality. Critical illness characteristics that predicted poor glycemic control were advanced age, history of diabetes, cardiac surgery, postoperative complications, severity of illness, nosocomial infections, prolonged mechanical ventilation, or concurrent medications. CONCLUSIONS Critical illness characteristics determined glycemic control and clinical outcome in ICU patients. Acute insulin resistance was associated with worse outcomes in nondiabetic patients. Although critical illness characteristics influenced glycemic control, future evaluation of the effect of insulin administration and optimal glycemic control in ICU patients is necessary.

Corticosteroids influence the mortality and morbidity of acute critical illness

IntroductionUse of corticosteroids for adrenal supplementation and attenuation of the inflammatory and immune response is widespread in acute critical illness. The study hypothesis was that exposure to corticosteroids influences the mortality and morbidity in acute critical illness.MethodsThis case–control retrospective study was performed in a single multidisciplinary intensive care unit at a tertiary care institution and consisted of 10,285 critically ill patients admitted between 1 January 1999 and 31 December 2004. Demographics, comorbidities, acute illness characteristics including severity measured by Sequential Organ Failure Assessment, concurrent medications, therapeutic interventions and incidence of infections were obtained from electronic medical records, were examined with multiple regression analysis and were adjusted for propensity of corticosteroid exposure. The primary outcome was hospital death, and the secondary outcome was transfer to a care facility at hospital discharge.ResultsCorticosteroid exposure in 2,632 (26%) patients was characterized by younger age, more females, higher Charlson comorbidity and maximal daily Sequential Organ Failure Assessment scores compared with control patients. Corticosteroids potentiated metabolic and neuromuscular sequels of critical illness with increased requirements for diuretics, insulin, protracted weaning from mechanical ventilation, need for tracheostomy and discharge to a care facility. Early exposure to corticosteroids predisposed to recurrent and late onset of polymicrobial and fungal hospital-acquired infections. Corticosteroids increased the risk for death or disability after adjustments for comorbidities and acute illness characteristics.ConclusionCorticosteroids increased the risk for death or disability in critical illness. Hospital-acquired infections and metabolic and neuromuscular sequels of critical illness were exacerbated by corticosteroids. Careful appraisal of the indications for use of corticosteroids is necessary to balance the benefits and risks from exposure in acute critical illness.

Portal hypertension due to a splenic arteriovenous fistula : A case report

We present an unusual case of portal hypertension due to splenic arteriovenous fistula. The patient was a multiparous woman who presented with portal hypertension manifested by variceal bleeding with no evidence of liver disease. Mesenteric angiography confirmed the presence of a 3.5-cm distal splenic artery aneurysm and a high-flow arteriovenous fistulous communication from the aneurysm into the splenic vein. Arteriovenous fistula should be suspected in a patient who presents with portal hypertension but without liver disease, especially in a multiparous woman who presents with variceal bleeding after a delivery. Surgical ligation of the fistula and angiographic embolization has been reported to be equally successful for this condition. Angiographic coil embolization, done in our patient, is a safe alternative to surgery for the treatment of splenic AVF in unstable patients.

Therapeutic hypothermia for severe traumatic brain injury: a critically appraised topic.

Background: Traumatic brain injury (TBI) is common and confers a high rate of disability and mortality. Current treatments are primarily supportive. Therapeutic hypothermia has been proposed for severe TBI because of its ability to reduce intracranial pressure and putative neuroprotective effects. Objective: To critically appraise the current evidence concerning the efficacy of therapeutic hypothermia in the treatment of severe TBI. Methods: The objective was addressed through the development of a structured, critically appraised topic. This incorporated a clinical scenario, background information, a structured question, literature search strategy, critical appraisal, results, evidence summary, commentary, and bottom line conclusions. Participants included consultant and resident neurologists, a medical librarian, clinical epidemiologists, and critical care and neurocritical care content experts. Results: A recent multicenter randomized controlled trial was selected for critical assessment; meta-analyses were also reviewed. Subjects with severe TBI were randomized to either rapid cooling to 33°C for 48 hours (treatment, n=52) or normothermia (control, n=45). Outcome assessments included mortality and disability at 6 months as measured by the Glasgow Outcome Scale. Initiation of hypothermia began within 2.5 hours of injury and patients were rewarmed over a mean of 17.2 hours. The study was terminated for futility; no difference in outcome or mortality was detected between treatment groups. Post hoc subgroup analysis showed that among subjects who required hematoma evacuation, hypothermia was associated with a lower rate of poor clinical outcome (number needed to treat=2.8; 95% confidence interval, 1.4-78.3, P=0.02) and a trend toward a decrease in mortality (P=0.16). Conclusions: Current cumulative evidence does not support general use of therapeutic hypothermia for acute severe TBI. However, further investigation of the role of therapeutic hypothermia may be warranted for specific TBI subgroups.

Adult venovenous extracorporeal membrane oxygenation for severe respiratory failure: Current status and future perspectives

Extracorporeal membrane oxygenation (ECMO) for severe acute respiratory failure was proposed more than 40 years ago. Despite the publication of the ARDSNet study and adoption of lung protective ventilation, the mortality for acute respiratory failure due to acute respiratory distress syndrome has continued to remain high. This technology has evolved over the past couple of decades and has been noted to be safe and successful, especially during the worldwide H1N1 influenza pandemic with good survival rates. The primary indications for ECMO in acute respiratory failure include severe refractory hypoxemic and hypercarbic respiratory failure in spite of maximum lung protective ventilatory support. Various triage criteria have been described and published. Contraindications exist when application of ECMO may be futile or technically impossible. Knowledge and appreciation of the circuit, cannulae, and the physiology of gas exchange with ECMO are necessary to ensure lung rest, efficiency of oxygenation, and ventilation as well as troubleshooting problems. Anticoagulation is a major concern with ECMO, and the evidence is evolving with respect to diagnostic testing and use of anticoagulants. Clinical management of the patient includes comprehensive critical care addressing sedation and neurologic issues, ensuring lung recruitment, diuresis, early enteral nutrition, treatment and surveillance of infections, and multisystem organ support. Newer technology that delinks oxygenation and ventilation by extracorporeal carbon dioxide removal may lead to ultra-lung protective ventilation, avoidance of endotracheal intubation in some situations, and ambulatory therapies as a bridge to lung transplantation. Risks, complications, and long-term outcomes and resources need to be considered and weighed in before widespread application. Ethical challenges are a reality and a multidisciplinary approach that should be adopted for every case in consideration.

Early extubation after abdominal aortic reconstruction

OBJECTIVE To assess the safety of early (<2 hrs) extubation after elective infrarenal aortic surgical procedures. DESIGN A retrospective chart review of 192 consecutive elective infrarenal aortic surgical procedures from January 1990 to March 1994 at Mayo Clinic Scottsdale was undertaken. MEASUREMENTS AND MAIN RESULTS Combined general and epidural anesthesia was used extensively (187 patients; 97.4%). Early extubation was accomplished in 166 (86.5%) patients. Time to extubation was dependent on clinical factors and not by protocol. All early extubations occurred in the operating room or recovery room with a median time from skin closure of 12 minutes. Ten patients were extubated from 2 to 12 hours after the procedure, 14 patients more than 12 hours after the procedure, and 2 patients were not extubated and subsequently expired. Of the 166 patients extubated within 2 hours, 8 (4.8%) required reintubation. Factors found univariantly to be significantly associated with failure of early extubation include obesity, abnormal chest x-ray postoperatively, prior myocardial infarction, and prior coronary revascularization (p < 0.05). CONCLUSION Early extubation (<2 hrs) after elective infrarenal aortic procedures may be performed safely and should be undertaken unless clinical features suggest failure of extubation.

Paraneoplastic coma and acquired central alveolar hypoventilation as a manifestation of brainstem encephalitis in a patient with ANNA-1 antibody and small-cell lung cancer.

IntroductionParaneoplastic neurological disorders are a well recognized complication of malignancy.MethodsA case report to expand the currently described clinical manifestations of type 1 antineuronal antibody (ANNA-1)-associated paraneoplastic encephalomyelitis to include coma.ResultsWe present an unusual case of fluctuating coma and rapid fulminant progression to acute respiratory failure from central alveolar hypoventilation caused by ANNA-1 paraneoplastic encephalomyelitis associated with small-cell lung carcinoma. Paraneoplastic infiltration of the brainstem and cerebellum, including respiratory and arousal centers, was documented on autopsy.ConclusionsParaneoplastic encephalomyelitis should be considered as a possible cause of coma and central alveolar hypoventilation.

Mechanical circulatory assist devices: a primer for critical care and emergency physicians

Mechanical circulatory assist devices are now commonly used in the treatment of severe heart failure as bridges to cardiac transplant, as destination therapy for patients who are not transplant candidates, and as bridges to recovery and “decision-making”. These devices, which can be used to support the left or right ventricles or both, restore circulation to the tissues, thereby improving organ function. Left ventricular assist devices (LVADs) are the most common support devices. To care for patients with these devices, health care providers in emergency departments (EDs) and intensive care units (ICUs) need to understand the physiology of the devices, the vocabulary of mechanical support, the types of complications patients may have, diagnostic techniques, and decision-making regarding treatment. Patients with LVADs who come to the ED or are admitted to the ICU usually have nonspecific clinical symptoms, most commonly shortness of breath, hypotension, anemia, chest pain, syncope, hemoptysis, gastrointestinal bleeding, jaundice, fever, oliguria and hematuria, altered mental status, headache, seizure, and back pain. Other patients are seen for cardiac arrest, psychiatric issues, sequelae of noncardiac surgery, and trauma. Although most patients have LVADs, some may have biventricular support devices or total artificial hearts. Involving a team of cardiac surgeons, perfusion experts, and heart-failure physicians, as well as ED and ICU physicians and nurses, is critical for managing treatment for these patients and for successful outcomes. This review is designed for critical care providers who may be the first to see these patients in the ED or ICU.

Mild induced hypothermia after out-of-hospital cardiac arrest: persisting doubts about patient safety.

In a study of the endovascular cooling system Alsius CoolGard™ combined with the Icy™ venous catheter, Pichon and colleagues concluded the effectiveness and safety of mild induced hypothermia (MIH) after out-of-hospital cardiac arrest resuscitation [1]. We are troubled because the study has reproduced several safety concerns about MIH that have not been confronted. First, the sixfold increase of the nosocomial bloodstream infection rate (13% versus control 2%) is most probably related to insertion of endovascular catheters for MIH [1]. Bloodstream infection in patients with endovascular catheters can become a significant cause of preventable morbidity and mortality [2]. Second, it is unclear why hypokalemia (75% of MIH cases) was dismissed as a factor for the incidence of cardiac dysrhythmia [1]. Temperature changes induce electrolyte shifts and thus influence the depolarization and repolarization times and the conduction velocity of action potentials within the myocardium, promoting aberrant conduction pathways. Electrolyte abnormalities associated with MIH can influence electrophysiological parameters of the myocardium, triggering dysrhythmia [3].

A comparison of intensive care unit physician staffing costs at the 3 Mayo Clinic sites

OBJECTIVES To determine the provider cost of administering intensive care unit (ICU) services, comparing 3 different staffing models for ICU coverage, and to compare the costs of using house staff vs nonphysician providers (NPPs). METHODS Data were collected on total staff composition and number of beds In ICUs from January 1, 2004, through December 31, 2004, at the 3 Mayo Clinic sites: Rochester, Minn; Jacksonville, Fla; and Scottsdale, Ariz. Institutional or national average staff salaries were used to determine total staffing costs per ICU bed per year at each site. Medicare medical education reimbursements were also taken into account. RESULTS Costs per ICU bed for physician staffing were