Search PubMed⌕ Search

Biomedical subjects

C N Sessler

Publications and source records attributed to C N Sessler.

At least 19 recordsLinked to original sources
PubMed1999

Endotracheal tube narrowing after closed-system suctioning: prevalence and risk factors.

BACKGROUND: Few data exist about buildup of secretions within endotracheal tubes of patients treated with closed-system suctioning in the intensive care unit. OBJECTIVES: To describe the extent, prevalence, and distribution of narrowing of endotracheal tubes related to buildup of secretions and to determine contributing factors. METHODS: Forty endotracheal tubes were examined within 4 hours of extubation, after at least 72 hours of use. Data on patients' daily weight and fluid balance, ventilator humidification temperatures, and nurses' descriptions of secretions during the 3 days preceding extubation were recorded. Any secretion debris in the endotracheal tubes was weighed. At 1-cm intervals along the tube, the debris was described and the depth of the debris was measured to the nearest 0.5 mm. RESULTS: Mean duration of intubation was 6.6 days. Two tubes had no debris. Mean overall depth of debris was 0.64 mm, mean greatest depth was 2.0 mm (range, 0-5 mm), and mean weight was 1.16 g. The entire tube was affected, with the greatest depth of debris at the 6- to 9-cm and 13- to 14-cm markings. Duration of intubation correlated with mean greatest depth of debris (r = 0.37, P = .02), mean overall depth of debris (r = 0.48, P = .002), and mean weight of debris (r = 0.38, P = .02). CONCLUSIONS: Endotracheal tubes are markedly narrowed by the buildup of secretions after closed-system suctioning. Duration of intubation, but not endotracheal tube size or amount of secretions, was associated with the degree of narrowing.

Adolescent↗
PubMed1998

Mechanical ventilation of patients with acute lung injury.

Ventilatory management of patients with acute lung injury (ALI), particularly its most severe subset, acute respiratory distress syndrome (ARDS), is complex. Newer lung protective strategies emphasize measures to enhance alveolar recruitment and avoid alveolar overdistention, thus minimizing the risk of ventilator-induced lung injury (VILI). Key components of such strategies include the use of smaller-than-conventional tidal volumes which maintain peak transpulmonary pressure below the pressure associated with overdistention, and titration of positive end-expiratory pressure to promote maximal alveolar recruitment. Novel techniques, including prone positioning, inverse ratio ventilation, tracheal gas insufflation, and high frequency ventilation, are considerations in severe ARDS. No single approach is best for all patients; adjustment of ventilatory parameters to individual characteristics, such as lung mechanics and gas exchange, is required.

Algorithms↗
PubMed1997

Abbreviated cognitive test for delirium.

The cognitive test for delirium (CTD) was recently developed to identify delirium in an intensive care unit (ICU) setting. Stepwise discriminant analyses using the original validation sample indicated that a total score formed by summing only two of the nine content scores (visual attention span and recognition memory for pictures) maintained good reliability (coefficient alpha = 0.79) and the ability to discriminate delirium from dementia, schizophrenia, and depression (p < 0.0001) and delirium from moderate to severe dementia (p < 0.0002). This abbreviated version of the CTD is more practical for use by ICU clinicians.

Adult↗
PubMed1997

Soluble E-selectin levels in sepsis and critical illness. Correlation with infection and hemodynamic dysfunction.

E-selectin, an early mediator of leukocyte-endothelial adhesion, is expressed on activated endothelium. Soluble E-selectin is present in the supernatant of cytokine-activated endothelial cells and elevated serum levels are found in a variety of inflammatory conditions. We documented elevated E-selectin serum levels in 119 critically ill medical ICU patients (log transformed mean E-selectin level, measured by ELISA, was 5.28 ng/ml) compared to normal volunteers (1 ng/ml). Forty-three patients with culture-positive sepsis had higher (p < 0.05) E-selectin levels (15.39 ng/ml) than 24 patients with culture-negative sepsis (4.87 ng/ml), 44 with noninfectious SIRS (2.33 ng/ml), and eight without SIRS (1.97 ng/ml). E-selectin levels related strongly to the degree of hemodynamic compromise (p < 0.0001). Further analysis demonstrated microbiological status and hemodynamic status to be independent variables related to E-selectin level. Day 1 E-selectin levels correlated positively with peak organ failure score over the course of ICU hospitalization (r = 0.30, p = 0.001) and were higher (p < 0.05) for nonsurvivor (10.61 ng/ml, n = 26) than survivors (4.35 ng/ml, n = 93). We conclude that soluble E-selectin levels are higher in serum of patients with microbiologically documented sepsis than in other critically ill medical ICU patients. Day 1 E-selectin levels correlate highly with hemodynamic compromise and modestly with subsequent organ dysfunction and survival.

APACHE↗
PubMed1996

Current concepts of sepsis and acute lung injury.

Acute respiratory distress syndrome continues to be a vexing clinical problem with no specific therapy. Epidemiologic and basic sciences have advanced our understanding of the clinical syndrome and have brought us to the brink of effective intervention strategies. This article carefully examines the current state of knowledge, with reference to acute lung injury and current efforts, to arrive at effective pharmacologic approaches.

Cytokines↗
PubMed1995

Central venous catheter infections: concepts and controversies.

Central venous catheters (CVCs) are widely used in critically ill patients in intensive care units. However, infectious complications are common and may limit their utility. We critically review the literature to determine the impact of CVC design and composition, insertion site selection, insertion procedures, care and removal of temporary CVCs on infectious complications. Relevant articles were identified and selected for review using a database search (Medline and manual of the English language literature) based upon study design and sample size with an emphasis on prospective randomized trials. To minimize infectious complications and maintain a reasonable cost-benefit ratio, we recommend: i) use a single lumen catheter unless clear indications for a multi-lumen catheter exist; ii) insert the catheter via the subclavian vein if no relative contraindication exists (bleeding diathesis, positive pressure ventilation); iii) disinfect the insertion site employing sterile technique; iv) apply a dry, sterile dressing and change the dressing every other day; v) inspect the insertion site for signs of infection and remove the catheter if pus is present; vi) if a catheter-related infection is suspected, change the catheter over a guidewire and culture the distal segment. The replacement catheter should be removed if an original catheter segment culture is positive.

Bacteremia↗
PubMed1995

Circulating ICAM-1 is increased in septic shock.

Adhesion molecules play a critical role in the interaction of circulating neutrophils with vascular endothelium during inflammation. Increased quantities of soluble, circulating intercellular adhesion molecule-1 (cICAM-1) are present in various inflammatory conditions. The purpose of this investigation was to measure cICAM-1 levels in septic adults, as well as to examine the relationship between this potential marker of endothelial-cell activation and the consequences of sepsis (i.e., multiple organ failure and death). Using a sandwich-type enzyme-linked immunosorbent assay (ELISA), we measured cICAM-1 in blood samples obtained within 12 h of admission to an intensive care unit (ICU) for sepsis and other conditions. We found cICAM-1 levels to be increased in 25 septic patients (1,259 +/- 159 ng/ml, mean +/- SEM) as compared with 12 healthy volunteers (355 +/- 41 ng/ml, p < 0.0001) and four ICU patients without systemic inflammatory response syndrome (SIRS) (585 +/- 76 ng/ml, p < 0.001). Twenty-five patients with SIRS but no evidence of causative infection also had elevated levels of cICAM-1 (937 +/- 144 ng/ml, p = 0.12 versus sepsis). Serial measurements over the first week of sepsis demonstrated persistent elevation in most patients. Day 1 cICAM-1 levels were higher (p = 0.017, ANOVA) in 16 patients with septic shock than in seven with severe sepsis and two with sepsis but without hypotension or hypoperfusion. There was a positive correlation (r = 0.50, p = 0.009) between Day-1 cICAM-1 measurements and severity of shock as determined by the presence of hypotension and vasopressor use.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Unplanned extubation. Clinical predictors for reintubation.

STUDY OBJECTIVE: To examine the incidence, clinical impact, and predictors of reintubation following unplanned extubation (UE) in ICU patients. DESIGN: Retrospective data collection of prospectively identified consecutive cases of UE. SETTING: The adult Medical, Coronary, Surgical, Cardiac Surgery, and Neuroscience ICUs of a University Medical Center. PATIENTS: Eighty-one episodes of UE in 72 adolescent or adult (53 +/- 19 years) ICU patients. MEASUREMENTS AND RESULTS: In 39 (48 percent) of 81 cases, reintubation was performed within 24 h of UE, 33 (85 percent) within the first hour, and 31 (79 percent) as a result of respiratory distress. There were five documented complications of UE and/or reintubation but no deaths. Clinical predictors for reintubation were sought from routinely available demographic, clinical, laboratory, and respiratory factors which had been documented in the medical records for the 24 h period prior to UE. Using univariate analysis followed by stepwise logistic regression in the first 56 cases (model set), the following factors were identified as being associated with reintubation: (1) volume controlled ventilation (synchronous intermittent mandatory ventilation or assist-control ventilation) with rate more than 6/min; (2) most recent arterial pH level prior to UE being 7.45 or more; (3) most recent ratio of PaO2 to fraction of inspired oxygen prior to UE less than 250 mm Hg; (4) highest heart rate in the 24 h prior to UE greater than 120 beats per minute; (5) presence of 3 or more coexisting medical disorders (of 7 possible); (6) mental status other than alert; and (7) indication for intubation other than "preoperative." In the model set, the presence of 4 or more of these 7 factors correctly predicted reintubation in 23 of 25 (92 percent positive predictive value) and presence of 3 or fewer factors correctly predicted no reintubation in 26 of 31 cases (83 percent negative predictive value), with outcome of 88 percent of cases being correctly predicted. The model was tested in the next 24 cases (validation set) in which 18 (75 percent) were correctly predicted. CONCLUSION: Unplanned extubation can result in serious complications; however, about half the patients who have UE can be safely observed without immediate reintubation. Selected clinical factors, which are readily available from standard ICU records for the 24-h period prior to UE, may be useful to predict the likelihood of reintubation.

Adolescent↗
PubMed1991

Platelet-activating factor in porcine Pseudomonas acute lung injury.

We investigated the role of platelet-activating factor (PAF) in acute septic lung injury by examining the effects of the selective PAF antagonist SRI 63-675 and by measuring PAF in lung tissue in the porcine model. Four groups of pigs (15-25 kg) were studied: saline control (C, n = 5); Pseudomonas (Ps, n = 9), given 5 x 10(8) CFU/ml at 0.3 ml/20 kg/min intravenously over 1 hr; SRI (n = 3), given SRI 63-675 in a 40 mg/kg bolus; and SRI + Ps (n = 5). Ps infusion produced a fulminant lung injury characterized by a threefold increase in pulmonary arterial pressure at 30 min and persistent pulmonary hypertension (P less than 0.05 vs C), a significant (P less than 0.05 vs C) decrease in arterial oxygen tension (PaO2) from 60 min, a significant (P less than 0.05 vs C) increase in extravascular lung water (EVLW) from 120 min, and a significant (P less than 0.05 vs C) increase in albumin flux determined scintigraphically as slope index at 150-180 min. Systemic arterial pressure and cardiac index (CI) decreased significantly (P less than 0.05) in the Ps group vs C at 60 and 180 min, respectively. Bolus injection of SRI 63-675 at the time of Ps infusion blocked the early pulmonary hypertension, attenuated the early and late fall in PaO2, ameliorated the increase in EVLW, and prevented the late (150-180 min) increase in albumin flux. SRI 63-675 had minimal effects on Ps-induced hypotension or alterations in CI.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1991

In situ pulmonary vascular perfusion for improved recovery of pulmonary intravascular macrophages.

The microcirculation contains mononuclear phagocytes, with features characteristic of macrophages, adhered to luminal capillary surfaces by intercellular adhesion plaques. These pulmonary intravascular macrophages may play an important role in regulating lung vascular tone and capillary permeability, and may modulate capillary endothelial cell growth and replication by the secretion of soluble mediators (i.e., arachidonate metabolites, cytokines). This study describes a technique which utilizes in situ lung perfusion to remove intravascular macrophages in large numbers from the microcirculation of porcine lung (n = 26). This technique yielded 3.8 +/- 0.5 x 10(8) (mean +/- SEM) mononuclear cells which were highly phagocytic toward particulate carbon (phagocytic index, 80 +/- 6%). Harvested mononuclear phagocytes reestablished intercellular adhesion plaques when placed on small vessel porcine pulmonary artery endothelial cell monolayers and exhibited histochemical characteristics typical of monocyte/macrophage lineage cells. Mononuclear cells obtained from lung microcirculation displayed size heterogeneity varying from 10.4 to 16.5 microns in diameter. Both large and small cell populations phagocytosed particulate carbon. Morphometric studies performed on collagenase-treated lung demonstrated that in situ perfusion removed significant numbers of intravascular macrophages in lung capillaries. The technique described permits the rapid removal of anchored mononuclear phagocytes from lung capillaries with minimal postmortem delay.

Animals↗
PubMed1990

Theophylline toxicity: clinical features of 116 consecutive cases.

PURPOSE: To examine the predisposing factors, clinical and laboratory characteristics, management, course, and outcome of consecutive cases of theophylline toxicity in an outpatient setting. PATIENTS AND METHODS: Toxicology records and hospital charts of consecutive patients with a serum theophylline concentration (STC) greater than 30 mg/L (167 mumol/L) identified in the emergency departments (EDS) of a University Medical Center and a Veterans Administration Medical Center were reviewed. RESULTS: Ten percent and 2.8% of 5,557 consecutive STCs measured in the EDs over 2 years were greater than 20 mg/L (111 mumol/L) and greater than 30 mg/L (167 mumol/L), respectively. One hundred sixteen cases with STC greater than 30 mg/L were identified. Fourteen (12%) and 102 (88%) were due to acute overdose and chronic overmedication, respectively. Principal predisposing factors included patient and/or physician dosing errors and conditions or medications that reduce theophylline clearance. One or more toxic manifestations were present in 109 (94%) cases. Fifty percent of patients had mild toxicity, 38% had moderate toxicity, and 7% had severe or life-threatening toxicity. Seven (6%) patients died when STC was still in the toxic range and/or as a result of toxicity. Acute overdose was associated with higher peak STC (p less than 0.001), younger age (p less than 0.01), and greater mortality (p less than 0.05) than chronic overmedication. Peak STC correlated significantly with the severity of toxicity for patients with acute overdose (p less than 0.01) but not for patients with chronic overmedication. All three patients with acute overdose and fatal toxicity had peak STCs greater than 100 mg/L (555 mumol/L) and fulminant toxicity, whereas the four patients with chronic overmedication who died during toxicity had peak STCs in the 40 to 60 mg/L (222 to 333 mumol/L) range and most died of respiratory failure rather than directly from toxicity. Patients with acute overdose who had the delayed onset of severe or life-threatening toxicity and/or died from toxicity were accurately identified using previously published criteria for prophylactic charcoal hemoperfusion. In contrast, the predictive value of the criteria applied to patients with chronic overmedication was poor. Two patients with acute overdose underwent charcoal hemoperfusion, but died. No patient with chronic overmedication received charcoal hemoperfusion. CONCLUSION: Toxic-range STCs are relatively common in the ED population, occur primarily as a result of patient and physician dosing errors, and cause a broad range of toxic manifestations of varying severity. Peak STC correlates with the severity of toxicity and outcome for acute overdose but not chronic overmedication intoxication. Previously published criteria for prophylactic charcoal hemoperfusion accurately identify patients with acute overdose but not patients with chronic overmedication at risk for serious complications and death.

Adolescent↗
PubMed1990

Cardiac arrhythmias during theophylline toxicity. A prospective continuous electrocardiographic study.

To examine the effects of theophylline toxicity on cardiac rhythm, patients underwent continuous ambulatory ECG recording during acute theophylline toxicity and recovery. The patients, who were recruited form inpatient wards, intensive care units, and emergency departments of a University Medical Center and a Veterans Administration Medical Center, had serum theophylline concentrations (STC) greater than 30 mg/L. There were 14 men and two women with a mean age of 66 years. Fourteen patients had COPD and developed toxicity following long-term theophylline overmedication. Two patients had asthma and ingested an intentional overdose. The STC at the onset of ECG recording ranged from 23 to 67 mg/L. The principal rhythm was sinus in 15 patients; one patient had atrial fibrillation. Sinus tachycardia (heart rate greater than 100/min) was common, and heart rate fell in proportion to STC as toxicity resolved. Supraventricular ectopic beats (SVEs) were noted in seven patients with multiple runs of SVE being present in four. One patient developed multifocal atrial tachycardia (MAT) during toxicity that resolved spontaneously. During the 11 +/- 8 hours of recording during toxicity (STC greater than 20 mg/L), 80 percent of patients had ventricular premature beats (VPBs), 44 percent had paired VPBs, and 25 percent had ventricular runs. One elderly patient with heart disease developed sustained ventricular tachycardia (VT) when STC = 66 mg/L. No other patient had ventricular ectopy that required intervention. During the 10 +/- 6 hours of recording during the "recovery phase" (STC less than 20 mg/L), all patients with VPBs continued to have ectopy; however, the number of VPBs declined significantly. A follow-up 24-hour ECG recording obtained one week after recovery from toxicity in the patient with sustained VT demonstrated marked reduction in the frequency and complexity of VPBs. Patients with frequent (greater than 10/h) or repetitive VPBs were older (p less than 0.05) than those without complex ectopy. There was a trend (p = 0.07) suggesting patients with underlying heart disease were at risk for having complex ventricular ectopy. We conclude that sinus tachycardia, SVE, and VPBs are common among patients with theophylline toxicity; however, sustained ventricular or supraventricular tachyarrhythmias that require antiarrhythmic therapy are uncommon.

Acute Disease↗
PubMed1989

Transient pulmonary perfusion scintigraphic abnormalities in pulmonary air embolism.

A critically ill man suffered a respiratory arrest due to pulmonary air embolism after the exchange of central venous catheters over a guidewire. A pulmonary perfusion lung scan performed 90 min later demonstrated extensive perfusion defects which were interpreted as "high probability" for PTE. Pulmonary angiography 4.5 h later was normal. A second perfusion lung scan performed 24 h after the respiratory arrest was normal. Pulmonary air embolism can produce segmental (and larger) perfusion defects which may be indistinguishable from those caused by PTE. The rapid (24 h) resolution of the perfusion defects may help differentiate the two disorders.

Catheterization, Central Venous↗
PubMed1988

Effects of platelet-activating factor antagonist SRI 63-441 on endotoxemia in sheep.

We investigated whether platelet-activating factor (PAF) mediates endotoxin-induced systemic and pulmonary vascular derangements by studying the effects of a selective PAF receptor antagonist, SRI 63-441, during endotoxemia in sheep. Endotoxin infusion (1.3 micrograms/kg over 0.5 h) caused a rapid, transient rise in pulmonary arterial pressure (Ppa) from 16 +/- 3 to 36 +/- 10 mmHg (P less than 0.001) and pulmonary vascular resistance (PVR) from 187 +/- 84 to 682 +/- 340 dyn.s.cm-5 (P less than 0.05) at 0.5 h, followed by a persistent elevation in Ppa to 22 +/- 3 mmHg and in PVR to 522 +/- 285 dyn.s.cm-5 at 5 h in anesthetized sheep. Arterial PO2 (PaO2) decreased from 341 +/- 79 to 198 +/- 97 (P less than 0.01) and 202 +/- 161 Torr at 0.5 and 5 h, respectively (inspired O2 fraction = 1.0). SRI 63-441, 20 mg.kg-1.h-1 infused for 5 h, blocked the early rise in Ppa and PVR and fall in PaO2, but had no effect on the late phase pulmonary hypertension or hypoxemia. Endotoxin caused a gradual decrease in mean aortic pressure, which was unaffected by SRI 63-441. Infusion of SRI 63-441 alone caused no hemodynamic alterations. In follow-up studies, endotoxin caused an increase in lung lymph flow (QL) from 3.8 +/- 1.1 to 14.1 +/- 8.0 (P less than 0.05) and 12.7 +/- 8.6 ml/h at 1 and 4 h, respectively. SRI 63-441 abolished the early and attenuated the late increase in QL.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Worsening oxygenation in the mechanically ventilated patient. Causes, mechanisms, and early detection.

Hypoxemia or worsening oxygenation is a common problem in the ICU. Ventilator-related problems, patient-related problems, including progression of the underlying disease process or superimposed disorders, and interventions, procedures, and medications can all adversely affect the patient's oxygenation status. Each of these causes should be sought for in a rapid and expeditious manner and appropriate corrective actions taken.

Equipment Failure↗