Journal of Intensive Care Medicine recent issues

Analytic Review: Mass-Casualty Incidents: How Does an ICU Prepare?

Mahoney, E. J., Biffl, W. L., Cioffi, W. G. — 2008-07-23

Despite the ever-present risk of mass-casualty incidents (MCIs) in all geographical regions, there is a limited body of literature detailing specifically how an intensive care unit (ICU) prepares for such an event. When responding to an overwhelming volume of severely injured victims, the intensivist must make a paradigm shift away from providing complete care to all patients to one of preferentially administering care to those with the greatest likelihood of survival. To do this effectively, ICU directors must possess a detailed understanding of the entire disaster response, including organization, triage, staffing, and treatment. This article provides a comprehensive review of each of these topics, as well as a framework on specific elements of critical care and treatment based on published literature and expert opinion to assist the clinician in directing care to where it is most appropriate.

Cytokines and Brain Injury: Invited Review

Kadhim, H. J., Duchateau, J., Sebire, G. — 2008-07-23

The brain reacts to injury or disease by cascades of cellular and molecular responses. Evidence suggests that immune-inflammatory processes are key elements in the physiopathological processes associated with brain injury or damage. Cytokines are among major mediators implicated in these processes. Cytokine responses in the initial phase of brain injury might have a role in aggravating brain damage. However, in later stages, these molecular mediators might contribute to recovery or repair. Hemodynamic stabilization and optimalization of oxygen delivery to the brain remain cornerstones in the management of acute brain injury. New approaches might use anticytokine therapy to limit progression and halt or attenuate secondary brain damage. Progress toward such novel neuroprotection strategies, however, awaits better understanding of the optimal timing and dosing of those neuromodulatory therapies and better knowledge of the numerous interactions of those mediators. This also requires understanding of how and when precisely immune mechanisms shift from noxious to protective or restorative actions.

Review of A Large Clinical Series: A Microcosting Study of Intensive Care Unit Stay in the Netherlands

2008-07-23

The primary objective of this study was to estimate the actual daily costs of intensive care unit stay using a microcosting methodology. As a secondary objective, the degree of association between daily intensive care unit costs and some patient characteristics was examined. This multicenter, retrospective cost analysis was conducted in the medical-surgical adult intensive care units of 1 university and 2 general hospitals in the Netherlands for 2006, from a hospital perspective. A total of 576 adult patients were included, consuming a total of 2868 nursing days. The mean total costs per intensive care unit day were 1911, with labour (33%) and indirect costs (33%) as the most important cost drivers. An ordinary least squares analysis including age, Nine Equivalent of Nursing Manpower Use score/Therapeutic Intervention Scoring System score, mechanical ventilation, blood products, and renal replacement therapy was able to predict 50% of the daily intensive care unit costs.

Bispectral Index Monitoring Documents Burst Suppression During Pentobarbital Coma

Tobias, J. D. — 2008-07-23

During pentobarbital coma, electroencephalographic monitoring is used to document burst suppression (3-5 episodes of electrical activity/min). The current study evaluates the association of the bispectral index number and suppression ratio with a burst suppression pattern on electroencephalograph. The records of 7 patients (aged 2.9-14 years) who received pentobarbital for elevated intracranial pressure were retrospectively reviewed. The bispectral index number was 7 ± 5, 14 ± 3, and 37 ± 12, whereas the suppression ratio was 93 ± 7%, 75 ± 6%, and 29 ± 18% when the electroencephalograph showed ≤ 2, 3-5, and ≥ 6 bursts/min, respectively. The sensitivity and specificity of a bispectral index value of 10 to 20 were 96% and 92%, respectively, whereas the sensitivity and specificity of a suppression ratio of 65% to 85% were 89% and 88%, respectively, in demonstrating the presence of 3 to 5 bursts/min. Bispectral index monitoring may be easier to perform and may require less technical expertise to interpret.

Role of Transcranial Doppler in Optimizing Treatment of Cerebral Vasospasm in Subarachnoid Hemorrhage

Darwish, R. S., Ahn, E., Amiridze, N. S. — 2008-07-23

This study was undertaken to evaluate the role of transcranial Doppler ultrasonography in arterial blood pressure management during hypervolemia/hypertension/ hemodilution therapy in patients with vasospasm from subarachnoid hemorrhage and correlate this data with neurologic outcome. The study included 18 adult patients, Hunt and Hess grades III-IV. Complete neurologic assessment was performed. Transcranial Doppler indices were calculated by standard formulas. On the basis of our results, resistance area product can be used to estimate the optimal arterial blood pressure in hypervolemia/hypertension/hemodilution therapy. An increase in the cerebral blood flow index was associated with better performance on neurologic examination. Estimated cerebral perfusion pressure from transcranial Doppler data analysis showed poor correlation with cerebral perfusion pressure derived from direct measurement of intracranial pressure in patients with cerebral vasospasm ( = 0.15; 95% CI, 0.11-0.39; P = .2590).

Recognition and Importance of Forced Exhalation on the Measurement of Intraabdominal Pressure: A Subgroup Analysis From a Prospective Cohort Study on the Incidence of Abdominal Compartment Syndrome in Medical Patients

2008-07-23

Intraabdominal pressure is measured conventionally at end-expiration; however, the significance of forced exhalation on this measurement has not been evaluated previously. Using data from a previous prospective cohort study of the incidence of intraabdominal hypertension and abdominal compartment syndrome in medical intensive care unit patients, the authors evaluated 65 strip-chart recordings obtained from 28 patients who had measurements of intraabdominal pressure and airway pressures taken simultaneously. Forced exhalation was identified by a rise in intraabdominal pressure during exhalation. Forced exhalation was observed in 4 patients; with a mean intraabdominal pressure increase of 14.3 ± 1.3 mm Hg at end-exhalation, compared with a decrease of –2.5 ± 1.2 mm Hg in 24 patients without forced exhalation and absolute pressures of 28.0 ± 6.6 versus 13.8 ± 3.9 mm Hg (P < .001). However, there was no difference in end-inspiratory values. Forced exhalation is not uncommon in acutely ill, mechanically ventilated medical intensive care unit patients and may increase intraabdominal pressure significantly to values that exceed the diagnostic threshold for abdominal compartment syndrome.

Acute Respiratory Distress Syndrome From Chlorine Inhalation During a Swimming Pool Accident: A Case Report and Review of the Literature

Babu, R. V., Cardenas, V., Sharma, G. — 2008-07-23

Chlorine inhalation can result in significant morbidity and mortality. The most common clinical ramification is mucosal irritation. Rarely, depending upon the degree of exposure, patients can develop acute respiratory distress syndrome. Management is usually supportive with an unproven role for inhaled or systemic corticosteroids. A case of a young woman who developed respiratory failure secondary to acute respiratory distress syndrome from accidental exposure to chlorine fumes at a community swimming pool is described. The patient suffered a prolonged hospitalization with the need for mechanical ventilation. Despite limited data to support the decision, the patient was started on treatment with corticosteroids. She recovered completely from her illness and was discharged home without supplemental oxygen. A concise discussion of chlorine inhalation injury and a literature review on the utility of inhaled and/or systemic corticosteroids for this clinical entity is presented.

Cyclic Appearance of Left Ventricular Outflow Tract Dynamic Obstruction During Mechanical Ventilation: Evidence for a Preload Dependent Phenomenon

Canivet, J.-L., Lancellotti, P., Radermecker, M., Damas, P. — 2008-07-23

The cyclic appearance of dynamic left ventricular outflow tract obstruction during mechanical ventilation, according to the phasic changes in preload, is described in this article. Hemodialysis-induced fluid removal resulted in preload dependence as evidenced by the pulse pressure variation in a 56-year-old critically ill patient. The clinical picture was suggestive of myocardial failure. Transthoracic echocardiography disclosed dynamic left ventricular outflow tract obstruction associated with systolic anterior motion of the mitral valve. Progressive fluid restitution resulted in a parallel decrease in both the degree of dynamic obstruction and pulse pressure variation. During fluid loading, dynamic obstruction disappeared at first during the inspiratory phase of intermittent positive pressure ventilation corresponding to the phasic increase in left ventricular preload. Further fluid loading resulted in the disappearance of dynamic obstruction during both inspiratory and expiratory phase of intermittent positive pressure ventilation. This is the first reported case clearly relating left ventricular outflow tract dynamic obstruction to preload dependence during mechanical ventilation in a critically ill patient without predisposing anatomical factor.

Intensive Care Unit Disaster Preparation: Keep it Simple

Geiling, J. — 2008-07-23

Book Review: Electrophysiological Disorders of the Heart: By Sanjeev Saksena et al Elsevier, 2005

Spodick, D. H. — 2008-07-23

Analytical Reviews: Antifungal Therapies in the Intensive Care Unit

Chowdhry, R., Marshall, W. L. — 2008-05-11

Fungal infections are increasing nationwide, paralleling increases in the number of immunosuppressed hosts. Most of the candida infections seen in the intensive care unit are likely due to iatrogenic factors such as hyperalimentation, catheters, broad-spectrum antibiotics, and postprocedure complications that are prevalent in intensive care unit patients. Delays in appropriate therapy are common and may compromise care. Fortunately, the recognition of several clinical syndromes in the intensive care unit that require specialized treatment can improve outcomes. The issue of antifungal prophylaxis has to be balanced against issues of resistance, and current guidelines are reviewed here for prophylactic use of fluconazole only in selected intensive care unit patients. Finally, several new antifungal agents are available to treat the emerging resistant fungi, with better toxic/therapeutic ratios than in the past. Thus, there are an increasing number of safer and more effective options for treating fungal infections in the intensive care unit.

Intensive Care Management of the Patient With Cystic Fibrosis

Kremer, T. M., Zwerdling, R. G., Michelson, P. H., O'Sullivan, B. P. — 2008-05-11

Cystic fibrosis was previously thought to be a disease of childhood. With a better understanding of this condition along with improvements in therapy, patients with cystic fibrosis are now living well into adulthood. The aim of this article is to familiarize the intensive care unit physician with cystic fibrosis care, to discuss complications associated with cystic fibrosis specifically related to the intensive care unit, and to detail the current recommendations for the clinical management of the patient with cystic fibrosis. With advancing disease, the most severely affected organs are the lungs. Obstruction, infection, and inflammation contribute to the decline of pulmonary function, ultimately leading to death. Some patients may be eligible for lung transplantation, but choosing wisely will affect posttransplant survival. Because other organs are affected by the genetic defect and associated treatments, serious complications related to the liver, pancreas, intestines, and kidneys must be considered by the intensivist faced with a patient with cystic fibrosis. As practitioners, the fact that not all patients will survive and help our patients and families gracefully through the end-of-life process should be accepted.

Review of A Large Clinical Series: Paroxysmal Atrial Fibrillation in Critically Ill Patients With Sepsis

Salman, S., Bajwa, A., Gajic, O., Afessa, B. — 2008-05-11

The objective of this retrospective cohort study was to describe the incidence of paroxysmal atrial fibrillation and to determine its risk factors and effect on outcome in critically ill patients with sepsis. The study included 81 patients with sepsis admitted to an intensive care unit. In all, 25 patients (31%) developed paroxysmal atrial fibrillation. Advanced age, history of paroxysmal atrial fibrillation, higher severity of illness at intensive care unit admission, and lower left ventricular ejection fraction were risk factors for paroxysmal atrial fibrillation. Multiple logistic regression analysis showed that paroxysmal atrial fibrillation was independently associated with 28-day mortality (odds ratio = 3.284; 95% confidence interval, 1.126-9.574). The incidence of paroxysmal atrial fibrillation is high in critically ill patients with sepsis. It occurs more frequently in patients with advanced age, history of paroxysmal atrial fibrillation, high severity of illness, and lower left ventricular ejection fraction and is associated with increased mortality.

A Prospective Evaluation of Propylene Glycol Clearance and Accumulation During Continuous-Infusion Lorazepam in Critically Ill Patients

2008-05-11

Propylene glycol is a commonly used diluent in several pharmaceutical preparations, including the sedative lorazepam. Fifty critically ill patients receiving continuous-infusion lorazepam for a minimum of 36 hours were prospectively evaluated to determine the extent of propylene glycol accumulation over time, characterize propylene glycol clearance in the presence of critical illness, and develop a pharmacokinetic model that would predict clearance based on patient-specific clinical, laboratory, and demographic factors. In this cohort, the median lorazepam infusion rate was 2.1 mg/h (0.5-18). Propylene glycol concentration correlated poorly with osmolality, osmol gap, and lactate. In all, 8 patients (16%) had significant propylene glycol accumulation (>25mg/dL). When propylene glycol concentrations were >25 mg/dL, the median lorazepam infusion rate before sample collection was higher, 6.4 (1.9-11.3) versus 2.0 (0.5-7.4) mg/h (P =.0003). A linear first-order model with interoccasion variability on clearance adjusted for total body weight and Acute Physiology and Chronic Health Evaluation II score predicted propylene glycol concentration.

Intermittent Hemodialysis Versus Continuous Renal Replacement Therapy for Acute Renal Failure in the Intensive Care Unit: An Observational Outcomes Analysis

2008-05-11

Background: Studies have failed to show a survival difference between intermittent hemodialysis (IHD) and continuous renal replacement therapy (CRRT). Comparative cost analyses are limited and fail to control for differences in patient disease severity and comorbid conditions. The authors retrospectively estimated clinical and economic outcomes associated with CRRT and IHD among critically ill patients experiencing acute renal failure (ARF) in 2 tertiary care hospitals in Rochester, Minnesota, between January 1, 2000, and December 12, 2001. Methods: 161 critically ill patients requiring dialysis for ARF were analyzed. Patient demo-graphics, comorbid conditions, ARF etiology, mode of renal replacement therapy (RRT), renal recovery, and survival were abstracted from medical chart. APACHE II scores at dialysis initiation were calculated. Administrative data tracked length of stay (LOS) and direct medical costs from initiation of RRT to death or intensive care unit (ICU) and hospital discharge. Multivariate modeling was used to adjust outcomes for baseline differences. Results: 84 (52%) of the patients received CRRT and 77 (48%) received IHD. CRRT-treated patients were younger (58 vs 65 years), less likely male (58% vs 77%), had higher APACHE II scores (32 vs 27) with a higher incidence of sepsis (46% vs 30%) and respiratory disease (56% vs 39%), and were less likely to have chronic renal insufficiency (32% vs 49%). With adjustment for differences in baseline patient characteristics, the RRT method did not affect the likelihood of renal recovery, in-hospital survival, or survival during follow-up. Mean adjusted ICU LOS was 9.5 days shorter for IHD-treated than CRRT-treated patients (P < .001), and the adjusted mean difference in hospital and total costs associated with ICU stay was $56 564 and $60 827, in favor of IHD (P < .001). Mean adjusted total costs through hospital discharge were $93 611 and $140 733 among IHD-treated and CRRT-treated patients, respectively (P < .001). Conclusions: This observational study suggests that costs may significantly differ by mode of RRT despite similar severity-adjusted patient outcomes. Future prospective comparisons of renal replacement modalities will need to include both clinical and economic outcomes.

Paradoxical Air Embolism Successfully Treated With Hyperbaric Oxygen

Scruggs, J. E., Joffe, A., Wood, K. E. — 2008-05-11

The use of the central venous catheter may be complicated by air embolism when central venous pressure is subatmospheric and the catheter is open to the surrounding air. Paradoxical air embolus occurs when the gas bubbles are able to traverse a right to left shunt, gaining access to the systemic arterial circulation causing ischemic symptoms in end organs. In this article, a case of a patient with an unknown patent foramen ovale through which air entered the arterial circulation resulting in obtundation and stroke after inadvertent manipulation of a Hickman catheter is presented. The physiology, clinical manifestations, and management strategies are also discussed.

Perioperative Management of a 7-Year-Old Child With Brugada Syndrome

Baty, L., Hollister, J., Tobias, J. D. — 2008-05-11

Brugada syndrome results from abnormalities in the myocardial transmembrane conduction of sodium, resulting in the characteristic electrocardiographic changes of ST segment elevation in the precordial leads and incomplete right bundle branch block in an otherwise structurally normal heart. Affected patients are frequently asymptomatic until their presentation with potentially lethal arrhythmias including ventricular fibrillation. The youngest reported patient with Brugada syndrome to undergo anesthetic management is presented in this article; the pathophysiology of the syndrome is reviewed, and its perioperative implications are discussed.

Book Review: Heart Disease Diagnosis and Therapy. M. Gabriel Khan. Humana Press. 2005. $99.50 Humana Press, Totowa, New Jersey

Ferullo, J. A. — 2008-05-11

Analytic Review: Pituitary Tumor Apoplexy: A Review

Nawar, R. N., AbdelMannan, D., Selman, W. R., Arafah, B. M. — 2008-03-27

Pituitary tumor apoplexy is an uncommon syndrome resulting often spontaneously from hemorrhage or infarction of a pre-existing pituitary adenoma. As the primary event involves the adenoma, the syndrome should be referred to as pituitary tumor apoplexy and not as pituitary apoplexy. The sudden increase in sellar contents compresses surrounding structures and portal vessels, resulting in sudden, severe headache, visual disturbances, and impairment in pituitary function. Initial management of patients with pituitary tumor apoplexy includes supportive therapy (intravenous fluids and corticosteroids), following which many patients exhibit clinical improvement. Because those patients can be effectively managed with supportive measures, many who remain clinically and neurologically unstable might benefit from urgent surgical decompression by an experienced neurosurgeon. All patients presenting with this syndrome require long-term follow-up to treat any residual tumor and/or pituitary dysfunction. Close interaction between members of the management team is necessary for optimal patients' outcome.

Medication-Related Complications in the Trauma Patient

Corbett, S. M., Rebuck, J. A. — 2008-03-27

Trauma patients are twice as likely to have adverse reactions to medication as nontrauma patients. The need for medication in trauma patients is high. Surgery is often necessary, and immunosuppression and hypercoagulability may be present. Adverse drug events can be caused in part by altered pharmacokinetics, drug interactions, and polypharmacy. Medications may also have serious long-term adverse effects, which must be considered. It is not the purpose of this review article to discuss all adverse effects of all medications. This article will discuss the more common adverse effects of medications for trauma patients in the acute care setting, in the following categories: pain control, sedation, antibiotics, seizure prophylaxis in head trauma, atrial fibrillation, deep vein thrombosis and pulmonary embolism prophylaxis, hemodynamic support, adrenal insufficiency, factor VIIa.

Transfusion-Related Acute Lung Injury

Jawa, R. S., Anillo, S., Kulaylat, M. N. — 2008-03-27

Transfusion-related acute lung injury (TRALI) refers to a clinical syndrome of acute lung injury that occurs in a temporal relationship with the transfusion of blood products. Because of the difficulty in making its diagnosis, TRALI is often underreported. Three not necessarily mutually exclusive hypotheses have been described to explain its etiogenesis: antibody mediated, non-antibody mediated, and two hit mechanisms. Treatment is primarily supportive and includes supplemental oxygen. Diuretics are generally not indicated, as hypovolemia should be avoided. Compared with many other forms of acute lung injury, including the acute respiratory distress syndrome, TRALI is generally transient, reverses spontaneously, and carries a better prognosis. A variety of prevention strategies have been proposed, ranging from restrictive transfusion strategies to using plasma derived only from males.

Anion Gap, Anion Gap Corrected for Albumin, and Base Deficit Fail to Accurately Diagnose Clinically Significant Hyperlactatemia in Critically Ill Patients

2008-03-27

Anion gap, anion gap corrected for serum albumin, and base deficit are often used as surrogates for measuring serum lactate. None of these surrogates is postulated to predict hyperlactatemia in the critically ill. We prospectively collected data from September 2004 through August 2005 for 1381 consecutive admissions. Patients with renal disease, ketoacidosis, or toxic ingestion were excluded. Anion gap, anion gap corrected for albumin, and base deficit were calculated for all patients. We identified 286 patients who met our inclusion or exclusion criteria. The receiver-operating characteristic area under the curve for the prediction of hyperlactatemia for anion gap, anion gap corrected for albumin, and base deficit were 0.55, 0.57, and 0.64, respectively. Anion gap, anion gap corrected for albumin, and base deficit do not predict the presence or absence of clinically significant hyperlactatemia. Serum lactate should be measured in all critically ill adults in whom hypoperfusion is suspected.

Experience in the Management of Eighty-Two Newborns With Congenital Diaphragmatic Hernia Treated With High-Frequency Oscillatory Ventilation and Delayed Surgery Without the Use of Extracorporeal Membrane Oxygenation

2008-03-27

The aim of this study is to analyze neonatal outcome of isolated congenital diaphragmatic hernia and to identify prenatal and postnatal prognosis-related factors. A retrospective single institution series from January 2000 to November 2005 of isolated congenital diaphragmatic hernia neonates was reviewed. Respiratory-care strategy was early high-frequency oscillatory ventilation, nitric oxide in pulmonary hypertension, and delayed surgery after respiratory and hemodynamic stabilization. Survival rate at 1 month was 65.9%. None of the prenatal factors were predictive of neonatal outcome, except an intra-abdominal stomach in left diaphragmatic hernia. Preoperative pulmonary hypertension was more severe in the nonsurvivor group and was predictive of length of ventilation in the survivors. During the first 48 hours of life, the best oxygenation index above 13 and the best PaCO₂ above 45 were predictive of poor outcome. When treating isolated congenital diaphragmatic hernia with early high-frequency ventilation and delayed surgery but excluding extracorporeal membrane oxygenation, survival rates compare favorably with other reported series, and the respiratory morbidity is low.

Measurement of Central Venous Pressure From a Peripheral Intravenous Catheter Following Cardiopulmonary Bypass in Infants and Children With Congenital Heart Disease

Baty, L., Russo, P., Tobias, J. D. — 2008-03-27

The current study evaluates the feasibility and accuracy of measuring central venous pressure from a peripheral intravenous catheter following cardiopulmonary bypass in infants and children. Central venous pressure was simultaneously measured from a right atrial catheter and from a peripheral intravenous cannula. The continuity of the peripheral intravenous cannula with the central venous system was evaluated by noting the change in the pressure during a sustained inspiratory effort and during occlusion of the vessel above (proximal to) the catheter. The cohort for the study included 29 infants and children. In 5 of the 29 patients (17%), there was no increase in the peripheral venous pressure in response to a Valsalva maneuver or occlusion of the extremity proximal to the intravenous site. The difference between peripheral venous pressure and central venous pressure in these patients was 11 ± 3 mm Hg versus 2 ± 1 mm Hg in the patients in whom the peripheral venous pressure increased with these maneuvers (P < .0001). No clinically significant variation in the accuracy of the technique was noted based on the actual CVP value, size of the PIV, its location, or the patient's weight. Provided that the peripheral venous pressure increases to a sustained inspiratory breath and occlusion above the intravenous site, there is a clinically useful correlation between the peripheral venous pressure and the central venous pressure following cardiopulmonary bypass in infants and children with congenital heart disease.

Cardiac Arrest Following Massive Pulmonary Embolism During Mechanical Declotting of Thrombosed Hemodialysis Fistula: Successful Resuscitation With tPA

Toosy, K., Saito, S., Patrascu, C., Jean, R. — 2008-03-27

Percutaneous declotting of a thrombosed fistula or graft is standard of care and is a safe procedure. Subclinical pulmonary embolism (PE) during this procedure occurs commonly, but symptomatic PE is extremely rare. The authors report a case of declotting-associated massive PE with cardiopulmonary arrest and successful resuscitation. The patient developed a new right-axis deviation and right-bundle branch block. Diagnosis of PE was confirmed with a computed tomography (CT) angiogram, and the patient received tissue plasminogen activator (tPA) and heparin. She required norepinephrine and dobutamine temporarily and was subsequently extubated successfully. Massive PE is a very rare complication of this procedure. Given the grave outcome, the clinical signs and symptoms should be recognized immediately and treatment instituted early.

Pituitary Tumor Apoplexy: A Review

Laws, E. R. — 2008-03-27

Analytic Reviews: Cardiac Surgery as a Cause of Acute Kidney Injury: Pathogenesis and Potential Therapies

Rosner, M. H., Portilla, D., Okusa, M. D. — 2008-01-29

Cardiopulmonary bypass surgery occurs in nearly 1 million patients per year. Acute kidney injury requiring dialysis can occur in up to 1% of these patients. The development of acute kidney injury is associated with substantial morbidity and mortality independent of all other factors, and many patients are left dependent on dialysis therapies. The pathogenesis of acute kidney injury involves multiple pathways. Hemodynamic, inflammatory, and nephrotoxic factors are involved and overlap each other in leading to kidney injury. Clinical studies have identified risk factors for acute kidney injury that can be used to effectively determine the risk of acute kidney injury in patients undergoing bypass surgery. These high-risk patients can then be targeted for renal protective strategies. Thus far, no single strategy has conclusively demonstrated its ability to prevent renal injury post-bypass surgery. Novel anti-inflammatory agents are in development and offer hope as potential therapies.

Nonventilatory Interventions in the Acute Respiratory Distress Syndrome

Schuster, K. M., Alouidor, R., Barquist, E. S. — 2008-01-29

Acute respiratory distress syndrome was first described in 1967. Acute respiratory distress syndrome and acute lung injury are diseases the busy intensivist treats almost daily. The etiologies of acute respiratory distress syndrome are many. A significant distinction is based on whether the insult to the lung was direct, such as in pneumonia, or indirect, such as trauma or sepsis. Strategies for managing patients with acute respiratory distress syndrome/acute lung injury can be subdivided into 2 large groups, those based in manipulation of mechanical ventilation and those based in nonventilatory modalities. This review focuses on the nonventlilatory strategies and includes fluid restriction, exogenous surfactant, inhaled nitric oxide, manipulation of production, or administration of eicosanoids, neuromuscular blocking agents, prone position ventilation, glucocorticoids, extracorporeal membrane oxygenation, and administration of beta-agonists. Most of these therapies either have not been studied in large trials or have failed to show a benefit in terms of long-term patient mortality. Many of these therapies have shown promise in terms of improved oxygenation and may therefore be beneficial as rescue therapy for severely hypoxic patients. Recommendations regarding the use of each of these strategies are made, and an algorithm for implementing these strategies is suggested.

Fetal Surgery

Kunisaki, S. M., Jennings, R. W. — 2008-01-29

Fetal surgery has emerged from the realm of medical curiosity into an exciting, multidisciplinary specialty now capable of improving patient outcomes for a wide variety of diseases. Recent advances allow prenatal providers to both accurately diagnose and treat many fetal anomalies while maintaining maternal safety. As the initial postnatal health care providers to the majority of these newborns, neonatologists need to be familiar with some of the more recent state-of-the-art procedures currently being used. In this review, the authors discuss the prenatal evaluation process and various operative approaches (ie, open hysterotomy, fetoscopy, and percutaneous) to conduct fetal surgery. They then analyze the effectiveness of some of the more established and experimental prenatal therapies that are being performed for a number of fetal anomalies, including twin—twin transfusion syndrome, thoracic malformations, airway obstruction, congenital diaphragmatic hernia, myelomeningocele, and aortic valve stenosis.

Minute Ventilation Recovery Time Measured Using a New, Simplified Methodology Predicts Extubation Outcome

Seymour, C. W., Halpern, S., Christie, J. D., Gallop, R., Fuchs, B. D. — 2008-01-29

Extubation failure is associated with poor intensive care unit and hospital outcomes. Minute ventilation recovery time, an integrative measure of a patient's respiratory reserve, has been shown in a pilot study to predict extubation outcome; however, the methodology is subjective and impractical for routine use. The authors hypothesize that minute ventilation recovery time, measured using an objective and simpler method, would predict extubation outcome. A prospective cohort study was performed in adult medical and surgical intensive care unit patients intubated for >24 hours who were weaning from mechanical ventilation. Minute ventilation recovery time was measured using a new, simplified, and objective method following the final spontaneous breathing trial prior to extubation. The primary outcome was extubation failure, defined as reintubation within 7 days. The study cohort comprised 88 patients, of whom 22 (25%) failed extubation after a median of 3 days. Demographic data, weaning parameters, and the proportion of patients who passed an extubation screen were similar between groups (P > .05). Minute ventilation recovery time was significantly longer in patients who failed extubation (15 [5-15] vs 2 [1-5] minutes, P < .001), consistent in both medical and surgical subgroups. Operating characteristics for a preliminary threshold (minute ventilation recovery time ≥5 minutes) for prediction of extubation failure were sensitivity = 0.78, specificity = 0.71, positive predictive value = 0.47, negative predictive value = 0.90, correctly classified = 0.72. Adjustment for significant covariates did not alter the relationship between minute ventilation recovery time ≥5 minutes and extubation failure (odds ratio = 4.9, 95% confidence interval 1.45-16.2, P < .02). C statistic was 0.79 ± 0.17. It was concluded that minute ventilation recovery time, measured using a feasible methodology, can predict extubation outcome in medical and surgical intensive care unit patients.

Efficacy of Magnesium-Amiodarone Step-Up Scheme in Critically Ill Patients With New-Onset Atrial Fibrillation: A Prospective Observational Study

2008-01-29

Amiodarone is considered a first-choice antiarrhythmic drug in critically ill patients with new-onset atrial fibrillation (AF). However, evidence supporting the use of this potentially toxic drug in critically ill patients is scarce. Magnesium sulphate (MgSO₄) has shown to be effective for both rate and rhythm control, to act synergistically with antiarrhythmic drugs, and to prevent proarrhythmia. Treatment with MgSO₄ may reduce the need for antiarrhythmic drugs such as amiodarone in critically ill patients with new-onset atrial fibrillation. The efficacy of a new institutional protocol was evaluated. Patients were treated with a new institutional protocol for new-onset atrial fibrillation in critically ill patients. An MgSO₄ bolus (0.037 g/kg body weight in 15 minutes) was followed by continuous infusion (0.025 g/kg body weight/h). Intravenous amiodarone (loading dose 300 mg, followed by continuous infusion of 1200 mg/24 h) was given to those not responding to MgSO₄ within 1 hour. Clinical response was defined as conversion to sinus rhythm or decrease in heart rate <110 beats/min. Sixteen of the 29 patients responded to MgSO₄ monotherapy, whereas the addition of amiodarone was needed in 13 patients. Median (range) time until conversion to sinus rhythm after MgSO₄ was 2 (1-45) hours. Median (range) conversion time in patients requiring amiodarone was 4 (2-78) hours, and median (range) conversion time in all patients was 3 (1-78) hours. The 24-hour conversion rate was 90%. Relapse atrial fibrillation was seen in 7 patients. The magnesium-amiodarone step-up scheme reduces the need for amiodarone, effectively converts new-onset atrial fibrillation into a sinus rhythm within 24 hours, and seems to be safe in critically ill patients.

Fetal Surgery: Coming to a Center Near You?

Olutoye, O. O. — 2008-01-29

Nonventilatory Interventions in ALI/ARDS: Recent Work

Tidswell, M. — 2008-01-29