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Biomedical subjects

C L Sprung

Publications and source records attributed to C L Sprung.

At least 91 records · Page 5Linked to original sources

Impact of encephalopathy on mortality in the sepsis syndrome. The Veterans Administration Systemic Sepsis Cooperative Study Group.

Sepsis, an important cause of hospital mortality, continues to be a diagnostic and therapeutic challenge. To define more clearly the impact of encephalopathy on the course of sepsis, the various clinical signs of sepsis, blood culture results, and mortality rates were examined in relation to mental status in septic patients. Patients were classified as having an acutely altered mental status due to sepsis (AAMS), preexisting altered mental status (PAMS), or normal mental status (NMS). Twenty-three (307/1333) percent of the study patients had an acutely altered sensorium secondary to sepsis. Patients with AAMS had a higher mortality (49%) than patients with PAMS (41%) or patients with NMS (26%) (p less than .000001). Multivariate analysis disclosed that altered mental status, hypothermia, hypotension, thrombocytopenia, and the absence of shaking chills were independent predictors of increased mortality in the sepsis syndrome. Patients with Gram-negative bacteremia (28%) were as likely to have AAMS as patients with Gram-positive bacteremia (25%) or patients with negative blood cultures (23%). In summary, alterations in mental status are common in septic patients, and are associated with significantly higher mortality.

Bacterial Infections↗

Lung microvascular transport properties measured by multiple indicator dilution methods in patients with adult respiratory distress syndrome. A comparison between patients reversing respiratory failure and those failing to reverse.

We conducted indicator dilution studies on the lungs of patients in the early phases of adult respiratory distress syndrome (ARDS) to test the hypothesis that capillary permeability was increased in patients with respiratory failure. Indicator dilution studies were performed using 51Cr-erythrocytes, 125I-albumin, 14C-urea, and 3H-water as tracers. The injectate was infused as a bolus into a central venous line. Peripheral arterial blood was collected and counted for radioactivity. Mathematical analysis of the indicator curves yielded cardiac output, measures of the product of capillary permeability and surface area for urea (PS and D1/2S), the intravascular lung volume (Vv), and the extravascular lung water volume (Ve). Permeability was separated from surface area by normalizing PS and D1/2S to Vv. Patients could be divided into 16 in whom blood gas determinations and radiologic criteria for ARDS were reversed and 23 in whom they were not. We examined indicator dilution and other measures of lung function in the two groups to determine whether significant differences in microvascular function existed. PS and PS/Vv were significantly higher in the nonreversal patients. Ve was above normal, but not different between groups. Linear regression analysis showed significant correlations for all of the following in the nonreversal group: Ve and all measures of permeability, pulmonary vascular resistance (PVR), and the inverse of permeability-surface area measures and AaDO2 and PVR. Only measures of Ve and PS correlated in the reversal group. These results support the hypothesis that capillary permeability is increased in patients with early ARDS and continuing respiratory failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Transport↗

Pulmonary edema associated with electrical injury.

The occurrence of cardiogenic pulmonary edema following alternating current electrical injury has not been reported. A patient developing severe pulmonary edema immediately following an electrical injury-induced episode of ventricular fibrillation is described. Evidence that the etiology of the pulmonary edema was cardiogenic is derived from both hemodynamic data and the calculation of the pulmonary edema fluid to serum colloid osmotic pressure ratio.

Accidents, Occupational↗

Clinical antecedents to in-hospital cardiopulmonary arrest.

While the outcome of in-hospital cardiopulmonary arrest has been studied extensively, the clinical antecedents of arrest are less well defined. We studied a group of consecutive general hospital ward patients developing cardiopulmonary arrest. Prospectively determined definitions of underlying pathophysiology, severity of underlying disease, patient complaints, and clinical observations were used to determine common clinical features. Sixty-four patients arrested 161 +/- 26 hours following hospital admission. Pathophysiologic alterations preceding arrest were classified as respiratory in 24 patients (38 percent), metabolic in 7 (11 percent), cardiac in 6 (9 percent), neurologic in 4 (6 percent), multiple in 17 (27 percent), and unclassified in 6 (9 percent). Patients with multiple disturbances had mainly respiratory (39 percent) and metabolic (44 percent) disorders. Fifty-four patients (84 percent) had documented observations of clinical deterioration or new complaints within eight hours of arrest. Seventy percent of all patients had either deterioration of respiratory or mental function observed during this time. Routine laboratory tests obtained before arrest showed no consistent abnormalities, but vital signs showed a mean respiratory rate of 29 +/- 1 breaths per minute. The prognoses of patients' underlying diseases were classified as ultimately fatal in 26 (41 percent), nonfatal in 23 (36 percent), and rapidly fatal in 15 (23 percent). Five patients (8 percent) survived to hospital discharge. Patients developing arrest on the general hospital ward services have predominantly respiratory and metabolic derangements immediately preceding their arrests. Their underlying diseases are generally not rapidly fatal. Arrest is frequently preceded by a clinical deterioration involving either respiratory or mental function. These features and the high mortality associated with arrest suggest that efforts to predict and prevent arrest might prove beneficial.

Female↗

Risk of right bundle-branch block and complete heart block during pulmonary artery catheterization.

The need for the prophylactic insertion of a pacemaker before pulmonary artery catheterization in patients with pre-existing left bundle-branch block (LBBB) is controversial. To determine the incidence of new right bundle-branch block (RBBB) and complete heart block during bedside pulmonary artery catheterization, 293 patients undergoing 307 pulmonary artery catheterizations were prospectively studied. Nine patients had pacemaker rhythms and 19 patients had an RBBB on their precatheterization ECGs and therefore were excluded from analysis. In the remaining 279 pulmonary artery catheterizations, eight (3%) were associated with the development of a new RBBB. None of the 14 patients with a pre-existing LBBB developed complete heart block. The incidence of complete heart block during pulmonary artery catheterization of patients with previous LBBB was not higher than the incidence of RBBB in patients without underlying conduction defects. Because of the rare but grave consequences of RBBB in patients with pre-existing LBBB, we recommend the use of standby external pacemakers and equipment for transvenous pacemaker insertion in these patients during pulmonary artery catheterization. We do not recommend prophylactic pacemaker insertion.

Bundle-Branch Block↗

Informed consent in theory and practice: legal and medical perspectives on the informed consent doctrine and a proposed reconceptualization.

The theoretical, legal, and medical doctrines of informed consent are analyzed. The elements of informed consent include disclosure of information, competency, understanding, voluntariness, and decision-making. The doctrine is ground in deference to individual autonomy and recognition that the exercise of self-determination in matters of health is a liberty interest honored by our history and traditions. The exceptions to informed consent including emergency, incompetency, therapeutic privilege, and waiver are especially important in critically ill patients and reflect a balancing of autonomy values and society's interest in the promotion of health. Legal decisions inevitably are based on atypical physician-patient encounters and focus on a particular problem or procedure rather than on overall medical care. In addition, they often reflect an artificial view of the doctor-patient relationship. Medical decision-making is a complex, evolving pursuit of a diagnosis and proper treatment regimen. Moreover, patients are not always interested in the role assigned to them by law. A reconceptualization of informed consent doctrines utilizing sliding scale standards based on variables pertinent to each individual patient is suggested.

Comprehension↗

Measurement of complement proteins C2 and B in systemic lupus erythematosus and septic shock.

We developed sensitive radioassays to quantitate the homologous complement proteins C2 and B, in intact form, in sera from patients with diseases associated with hypocomplementemia. In a study of systemic lupus erythematosus (SLE) patients, we found a subset of patients (6/40) with low C2 concentrations, though overall, C2 concentration was not related to disease activity. Protein B concentration was increased in 23/40 SLE patients, apparently not due to a generalized acute phase response. Among patients with both gram-negative and gram-positive septic shock, C2 and B concentrations were low in a subset of patients with pre-existing cirrhosis, suggesting hepatic hyposynthesis of these proteins may be important in their prognosis and predisposition to severe infections.

Biomarkers↗

Modification of bronchial blood flow during allergic airway responses.

Ascaris suum antigen effects on mean airflow resistance (RL) and bronchial arterial blood flow (Qbr) were studied in allergic anesthetized sheep with documented airway responses. Qbr was measured with electromagnetic flow probes, and supplemental O2 prevented antigen-induced hypoxemia. Aerosol challenge with this specific antigen increased RL and Qbr significantly. Cromolyn sodium aerosol pretreatment prevented antigen-induced increases in RL but not in Qbr. Intravenous cromolyn, however, prevented increases in Qbr and RL, suggesting a role for mast cell degranulation in both bronchomotor and bronchovascular responses to antigen. Antigen-induced increases in Qbr were not solely attributable to histamine release. Indomethacin pretreatment attenuated the antigen-induced increase in Qbr, thus suggesting that vasodilator cyclooxygenase products contribute to the vascular response. Antigen challenge significantly decreased Qbr after indomethacin and metiamide pretreatment, which suggests that vasoconstrictor substances released after antigen exposure also modulate Qbr; however, released vasodilators overshadow vasoconstrictor effects. Thus antigen challenge affects Qbr by locally releasing histamine and vasodilator prostaglandins as well as vasoconstrictor substances. These effects were independent of antigen-induced changes in systemic and pulmonary hemodynamics.

Airway Resistance↗

High-dose corticosteroids in patients with the adult respiratory distress syndrome.

Corticosteroids are widely used as therapy for the adult respiratory distress syndrome (ARDS) without proof of efficacy. We conducted a prospective, randomized, double-blind, placebo-controlled trial of methylprednisolone therapy in 99 patients with refractory hypoxemia, diffuse bilateral infiltrates on chest radiography and absence of congestive heart failure documented by pulmonary-artery catheterization. The causes of ARDS included sepsis (27 percent), aspiration pneumonia (18 percent), pancreatitis (4 percent), shock (2 percent), fat emboli (1 percent), and miscellaneous causes or more than one cause (42 percent). Fifty patients received methylprednisolone (30 mg per kilogram of body weight every six hours for 24 hours), and 49 received placebo according to the same schedule. Serial measurements were made of pulmonary shunting, the ratio of partial pressure of arterial oxygen to partial pressure of alveolar oxygen, the chest radiograph severity score, total thoracic compliance, and pulmonary-artery pressure. We observed no statistical differences between groups in these characteristics upon entry or during the five days after entry. Forty-five days after entry there were no differences between the methylprednisolone and placebo groups in mortality (respectively, 30 of 50 [60 percent; 95 percent confidence interval, 46 to 74] and 31 of 49 [63 percent; 95 percent confidence interval, 49 to 77]; P = 0.74) or in the reversal of ARDS (18 of 50 [36 percent] vs. 19 of 49 [39 percent]; P = 0.77). However, the relatively wide confidence intervals in the mortality data make it impossible to exclude a small effect of treatment. Infectious complications were similar in the methylprednisolone group (8 of 50 [16 percent]) and the placebo group (5 of 49 [10 percent]; P = 0.60). Our data suggest that in patients with established ARDS due to sepsis, aspiration, or a mixed cause, high-dose methylprednisolone does not affect outcome.

Clinical Trials as Topic↗

Distribution of proteins in pulmonary edema. The value of fractional concentrations.

Pulmonary edema fluid (PEF) and serum (S) were obtained from 14 patients with cardiac pulmonary edema (CPE) and 25 noncardiac pulmonary edema (NCPE) patients. The type of pulmonary edema was based on a clinical classification. The protein content of PEF was not significantly different between CPE (3.89 +/- 0.25 g/dl, mean +/- SEM) and NCPE (4.35 +/- 0.34 g/dl) patients, but the protein content of serum was different (7.18 +/- 0.27 versus 5.13 +/- 0.23, respectively, p less than 0.001). As expected then, the PEF/S ratio was greater in NCPE than in CPE (0.85 +/- 0.06 versus 0.54 +/- 0.03, respectively, p less than 0.05). Thus, differences in the PEF/S ratios in CPE as compared with those in NCPE are independent of mean edema fluid protein content and dependent on differences in serum protein content. PEF and S proteins were separated into 9 fractions of increasing molecular radius by electrophoresis, and fractional concentrations (percent of total protein content) were calculated. The fractional concentrations of these combined fractions of serum proteins were not different between CPE and NCPE. Fractional PEF/S ratios were significantly greater for combined fractions I-III (p less than 0.01) in CPE than in NCPE and significantly less in fractions VII-IX (p less than 0.01). In CPE, a higher percentage of proteins with smaller molecular radii (45 A) enter the airway compartment in part because of higher hydrostatic pressures, whereas in NCPE, larger proteins enter the airways consequent to increased permeability to proteins with molecular radii greater than 72 A.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Complement activation and corticosteroid therapy in the development of the adult respiratory distress syndrome.

Fifty-nine patients in septic shock were observed for the development of the adult respiratory distress syndrome (ARDS) prior to and after receiving either 30 mg/kg methylprednisolone sodium succinate, 6 mg/kg dexamethasone sodium phosphate or no steroid. Serum levels of C3, C4 and Factor B allowed classification of 42 patients by activation of complement pathways. Despite a trend toward patients with severe septic shock who activate the alternative pathway being protected from the development of ARDS, complement pathway determination did not allow prediction of the development of ARDS and steroid pretreatment did not influence complement levels or prevent ARDS.

Complement Activation↗

Complement activation in septic shock patients.

To evaluate the status of the complement system and to determine the effects of corticosteroids on complement component levels in septic shock, C3, C4, and Factor B were measured in 42 patients with severe late septic shock. Serum levels of C4 and Factor B correlated with C3 levels (r = 0.48 and 0.64, respectively; p less than .01) in patients in shock for more than 4 h, but only Factor B correlated with C3 (r = 0.85; p less than .01) in patients in shock for 4 h or less. C3 and Factor B levels were significantly (p less than .05) lower in patients who died (12,174 +/- 1,524 CH50 U/ml and 14 +/- 1 mg/dl, respectively) than in patients who survived (18,418 +/- 2,833 CH50 U/ml and 21 +/- 2 mg/dl, respectively). Corticosteroids did not alter complement component levels. The alternative pathway appears to be activated early in septic shock, whereas the classical pathway is activated later. C3 and Factor B levels may predict survival of patients in septic shock. In this study, corticosteroids did not change the complement component levels of patients in late severe septic shock.

Complement Activation↗

ICU survival of patients with the acquired immunodeficiency syndrome.

The ICU records of 31 patients with the acquired immunodeficiency syndrome were reviewed. Of 23 (74%) patients admitted for respiratory failure requiring intubation and mechanical ventilation, 20 (87%) patients had Pneumocystis carinii and/or cytomegalovirus pneumonia. Of the eight patients admitted without respiratory failure, five (63%) were monitored after brain biopsy. Respiratory failure patients remained in the ICU for 10 +/- 1 days, compared to 5 +/- 1 days for those without respiratory failure (p less than .05). Overall mortality was 24 patients (77%); 21 (91%) of 23 respiratory failure patients died, compared to three (38%) of the eight without respiratory failure (p less than .01). All seven ICU survivors lived to hospital discharge.

Acquired Immunodeficiency Syndrome↗