Endobronchial pseudo-tumour caused by herpes simplex.

Herpes simplex virus (HSV) causes tracheobronchitis and pneumonitis; however, to date, there has only been one report of an endobronchial mass caused by HSV type II. This case study describes a 68-yr-old female with severe kyphoscoliosis who was intubated for acute on chronic hypercapnic respiratory failure and developed blood-tinged endotracheal secretions. Fibreoptic bronchoscopy demonstrated an endobronchial mass in the right middle lobe. Cultures grew HSV type I and biopsy specimens demonstrated cytopathological changes consistent with HSV infection. This is the first reported case of HSV type I presenting as an endobronchial tumour.

Predictors of extubation outcome in patients who have successfully completed a spontaneous breathing trial.

BACKGROUND: After patients recovering from respiratory failure have successfully completed a spontaneous breathing trial (SBT), clinicians must determine whether an artificial airway is still required. We hypothesized that cough strength and the magnitude of endotracheal secretions affect extubation outcomes. METHODS: We conducted a prospective study of 91 adult patients treated in medical-cardiac ICUs who were recovering from respiratory failure, had successfully completed an SBT, and were about to be extubated. A number of demographic and physiologic parameters were recorded with the patient receiving full ventilatory support and during the SBT, just prior to extubation. Cough strength on command was measured with a semiobjective scale of 0 to 5, and the magnitude of endotracheal secretions was measured as none, mild, moderate, or abundant by a single observer. In addition, patients were asked to cough onto a white card held 1 to 2 cm from the endotracheal tube; if secretions were propelled onto the card, it was termed a positive white card test (WCT) result. All patients were then extubated from T-piece or continuous positive airway pressure breathing trials. If 72 h elapsed and patients did not require reintubation, they were defined as successfully extubated. RESULTS: Ninety-one patients with a mean (+/- SE) age of 65.2 +/- 1.6 years, ICU admission APACHE (acute physiology and chronic health evaluation) II score of 17.7 +/- 0.7, and duration of mechanical ventilation of 5.0 +/- 0.5 days were studied over 100 extubations. Sixteen patients could not be extubated, and 2 patients underwent two unsuccessful extubation attempts, for a total of 18 unsuccessful extubations. Age, severity of illness, duration of mechanical ventilation, oxygenation, rapid shallow breathing index, and vital signs during SBTs did not differ between patients with successful extubations vs patients with unsuccessful extubations. The WCT result was highly correlated with cough strength. Patients with weak (grade 0 to 2) coughs were four times as likely to have unsuccessful extubations, compared to those with moderate-to-strong (grade 3 to 5) coughs (risk ratio [RR], 4.0; 95% confidence interval [CI],1.8 to 8.9). Patients with moderate-to-abundant secretions were more than eight times as times as likely to have unsuccessful extubations as those with no or mild secretions (RR, 8.7; 95% CI, 2.1 to 35.7). Patients with negative WCT results were three times as likely to have unsuccessful extubations as those with positive WCT results (RR, 3.0; 95% CI, 1.3 to 6.7). Poor cough strength and endotracheal secretions were synergistic in predicting extubation failure (Rothman synergy index, 3.7; RR, 31.9; 95% CI, 4.5 to 225.3). Patients with PaO(2)/fraction of inspired oxygen (P:F) ratios of 120 to 200 (receiving mechanical ventilation) were not less likely to be successfully extubated than those with P:F ratios of > 200, but those with hemoglobin levels < or = 10 g/dL were more than five times as likely to have unsuccessful extubations as those with hemoglobin levels > 10 g/dL. CONCLUSIONS: After patients recovering from respiratory failure have successfully completed an SBT, factors affecting airway competence, such as cough strength and amount of endotracheal secretions, may be important predictors of extubation outcomes. Also, a majority (89%) of medically ill patients with P:F ratios of 120 to 200 (four of five patients with P:F ratios from 120 to 150), values sometimes used to preclude weaning, were extubated successfully.

Lactic acidosis in status asthmaticus : three cases and review of the literature.

Lactic acidosis is a frequent laboratory finding in patients with severe exacerbations of asthma. The pathogenesis of lactic acidosis in asthma is not well understood, but it has been presumed, by some, to be generated by fatiguing respiratory muscles. We herein report the cases of three patients with status asthmaticus and lactic acidosis despite pharmacologic muscle relaxation. No common etiologies were found for lactic acidosis that abated after bronchospasm improved and the intensity of pharmacologic therapies was reduced. We review the literature describing lactic acidosis with asthma and discuss mechanisms by which lactic acidosis may occur in patients with status asthmaticus.

Thyroid storm presenting as multiple organ dysfunction syndrome.

Thyroid storm is a rare disorder characterized by hypertension, hyperthermia, and multiple systems involvement. Early recognition and treatment of thyroid storm are essential in reducing morbidity and mortality from this disorder. We present the case of a patient with an atypical (normothermic, normotensive) presentation of thyroid storm, accompanied by multiple organ dysfunction syndrome, including lactic acidosis and liver dysfunction, both of which are very rare complications. This case highlights both the multiple organ systems that can be involved in thyroid storm and the importance of recognizing atypical presentations of thyroid storm.

Failure of a brief educational program to improve interpretation of pulmonary artery occlusion pressure tracings.

OBJECTIVE: To determine whether a brief educational program can reduce variability of interpretation of pulmonary artery occlusion pressure (PAOP) tracings. DESIGN: Prospective, observational study. PARTICIPANTS: Twenty-three intensive care nurses and 18 physicians. INTERVENTIONS: Participants interpreted PAOP tracings before and 1 week after receiving a single, brief educational session and/or written materials ("in-service") designed to reduce interobserver variability of PAOP interpretation. Differences between two reference values before and after in-service (mean population and Chief of Critical Care's readings) were compared for both groups. RESULTS: There were no significant differences in the variabilities in PAOP interpretations before and after in-service in either group. CONCLUSIONS: We conclude that this specific educational program was ineffective in reducing variability of interpretation of PAOP tracings. These data suggest that more comprehensive educational tools and/or sustained programs may be required to improve performance of critical care personnel in PAOP interpretation.

Risks for developing critical illness with GI hemorrhage.

STUDY OBJECTIVES: To define risk factors, identifiable on initial presentation, that predict subsequent physiologic derangements that are consistent with critical illness in patients presenting to hospital with GI hemorrhage (GIH). DESIGN: Observational, cohort study. SETTING: Fourteen-bed medical ICU in a 300-bed community teaching hospital. PATIENTS: One hundred ninety-three patients were studied during 199 separate hospital admissions for GIH. METHODS AMD MEASUREMENTS: Demographic and physiologic variables were extracted from the medical records of patients admitted with GIH. Comprehensive data, from after 2 h in the emergency department to the time of discharge or death, were used to determine whether patients met established ICU admission criteria. Physiologic and demographic data from the initial 2-h period were then compared for patients who subsequently met and for those who did not meet ICU admission criteria. Independent predictors of meeting ICU admission criteria were identified using multiple logistic regression analyses. Sensitivity and specificity associated with the combined use of these predictors were assessed. RESULTS: Thirty-four patients satisfied ICU admission criteria after the initial 2-h period in the emergency department. Sixty-five patients, including 29 of 34 patients who met ICU admission criteria, were actually admitted to the ICU. Among those who never fulfilled ICU admission criteria, the duration of hospital stay was longer for those admitted to the ICU than for those not admitted to ICU (6.6 +/- 0.6 days vs 5.2 +/- 0.3 days; p = 0.04). The admission prothrombin time (international normalized ratio > 1.2), hypotension (systolic BP < 90 mm Hg), acute neurologic changes, and initial APACHE (acute physiology and chronic health evaluation) II score ( > or =15) were the best independent predictors for meeting the defined criteria for admission to ICU. The presence of one or more of these in the first 2 h of presentation was associated with a sensitivity of 88% and specificity of 74% for predicting subsequent critical instability. The area under the receiver operator characteristic curve for use of these four variables was 86% for predicting whether patients met ICU admission criteria. CONCLUSIONS: Many patients with GIH were admitted to the ICU who never met local criteria for admission, and these patients experienced a significantly longer length of hospital stay than other, similarly ill patients. Coagulopathy, hypotension, neurologic dysfunction, and a higher (> or = 15) APACHE II score in the first 2 h of hospitalization were the best independent predictors of the subsequent development of critical illness.

Summarizing the logistics of liberation from mechanical ventilation.

A goal of critical care clinicians should be to liberate patients from ventilators on the first possible day to avoid the multitude of complications associated with prolonged mechanical ventilation. The past decade has been marked by a deluge of scientific studies that have illuminated methods to expedite successful liberation from mechanical ventilation. This article summarizes the principle themes for this issue of Respiratory Care Clinics of North America and distills the available data to two simple weaning algorithms.

Negative fluid balance predicts survival in patients with septic shock: a retrospective pilot study.

OBJECTIVE: We hypothesized that patients with septic shock who achieve negative fluid balance (< or =-500 mL) on any day in the first 3 days of management are more likely to survive than those who do not. DESIGN: Retrospective chart review. PATIENTS: Thirty-six patients admitted with the diagnosis of septic shock. SETTING: Twelve-bed medical ICU of a 300-bed community teaching hospital. METHODS: Medical records of 36 patients admitted to our medical ICU over a 21-month period were examined. Patients with septic shock who required dialysis prior to hospitalization were not included. A number of demographic and physiologic variables were extracted from the medical records. Admission APACHE (acute physiology and chronic health evaluation) II and daily sequential organ failure assessment (SOFA) scores were computed from the extracted data. Variables were compared between survivors and nonsurvivors and in patients who did vs those who did not achieve negative (< or = 500 mL) fluid balance in > or = 1 day of the first 3 days of management. Survival risk ratios (RRs) were used as the measure of association between negative fluid balance and survival. RRs were adjusted for age, APACHE II scores, SOFA scores on the first and third days, and the need for mechanical ventilation, by stratified analyses. RESULTS: Patients ranged in age from 16 to 85 years with a mean (+/- SE) age of 67.4 +/- 3.3 years. The mean admission APACHE II score was 25.4 +/- 1.4, and the day 1 SOFA score was 9.0 +/- 0.8. Twenty patients did not survive; nonsurvivors had higher mean APACHE II scores than survivors (29.8 vs 20.4, respectively) and higher first day SOFA scores than survivors (10.8 vs 6.9, respectively), and they were more likely to require vasopressors and mechanical ventilation compared to patients who survived. Whereas all 11 patients who achieved a negative balance of > 500 mL on > or = 1 of the first 3 days of treatment survived, only 5 of 25 patient who failed to achieve a negative fluid balance of > 500 mL by the third day of treatment survived (RR, 5.0; 95% CI, 2.3 to 10.9; p = 0.00001). At least 1 day of net negative fluid balance in the first 3 days of treatment strongly predicted survival across the strata of age, APACHE II scores, first- and third-day SOFA scores, the need for mechanical ventilation, and creatinine levels measured at admission. CONCLUSION: These results suggest that at least 1 day of negative fluid balance (< or = -500 mL) achieved by the third day of treatment may be a good independent predictor of survival in patients with septic shock. These findings suggest the hypothesis "that negative fluid balance achieved in any of the first 3 days of septic shock portends a good prognosis," for a larger prospective cohort study.

The pathogenesis of respiratory failure: an overview.

Respiratory failure, defined as inability to breathe without a mechanical ventilator, results from failure of the cardiopulmonary system to maintain adequate oxygenation, even in the face of high inspired concentrations of oxygen or to eliminate carbon dioxide that is a product of metabolism. Thus, respiratory failure may be conceptualized as "a broken system." A thorough knowledge of the pathogenesis of respiratory failure empowers the clinician to define the processes contributing to the "breakdown" and to formulate therapeutic responses designed to expedite recovery and liberation from mechanical ventilation.

Myocardial ischemia and weaning failure in patients with coronary artery disease: an update.

OBJECTIVE: To determine the frequency and effects of weaning-related myocardial ischemia on weaning outcomes in patients with coronary artery disease. DESIGN: Prospective cohort study. SETTING: Medical and cardiac intensive care units of a 300-bed teaching community hospital. MEASUREMENTS AND MAIN RESULTS: Three-lead ST segments, heart rate-systolic blood pressure products, and respiratory rate/tidal volume ratios were obtained for patients with coronary artery disease just before and during their initial trials of weaning from mechanical ventilation. ST segments were interpreted by a blinded cardiologist. Eighty-three patients with a mean age of 72.4 +/- 1.1 years (mean +/- SEM), a mean Acute Physiology and Chronic Health Evaluation II score of 16.4 +/- 0.8, and a mean duration of mechanical ventilation of 4.6 +/- 0.9 days were studied. Eight patients showed electrocardiographic evidence of ischemia during weaning, and seven of these patients failed to be liberated on their first day of weaning. The presence of ischemia significantly increased the risk of weaning failure (risk ratio, 2.1; 95% confidence interval, 1.4-3.1). The rate-pressure product for the group as a whole increased significantly during weaning, from 11.9 +/- 0.4 to 13.5 +/- 0.5 mm Hg x beats/min x 10(3) (p < .01). The increase in rate-pressure product tended to be greater in patients who became ischemic (12.8 +/- 0.9 to 17.3 +/- 2.0 mm Hg x beats/min x 10(3)) than in patients who were not ischemic during weaning (11.8 +/- 0.4 to 13.0 +/- 0.5 mm Hg x beats/min x 10(3); p = .05). The rate/volume ratio did not change significantly during weaning, but the rate/volume ratios after both 1 min (65.6 +/- 4.6 vs. 98.0 +/- 9.4 breaths/min/L; p < .05) and 30 mins (68.6 +/- 4.3 vs. 91.1 +/- 8.9 breaths/min/L; p < .05) of unassisted breathing were lower in successful than in unsuccessful patients. CONCLUSION: Electrocardiographic evidence of myocardial ischemia occurs frequently and is associated with significantly increased risk of first-day weaning failure in patients with coronary artery disease.

Analysis of observer variability in measurement of pulmonary artery occlusion pressures.

The goal of this study was to determine inter- and intraobserver variability in measurement of pulmonary artery occlusion pressure (Ppao), comparing values recorded by critical care nurses and those measured by physician specialists. Critical care nurses (CCNs) obtained contiguous pulmonary artery and occlusion pressure paper tracings, up to twice a day, between June 1997 and March 1998. All tracings were interpreted on two separate occasions, in blinded fashion, by our Chiefs of Critical Care (CCMD) and Cardiology (CARD). Their values of Ppao were compared with those that had been recorded by CCNs. One hundred and forty-seven measurements of Ppao were performed on 40 patients with a mean age of 62.5 +/- 2.2 yr and a mean APACHE II score of 21.5 +/- 0.8. Either or both physician readers found 34 tracings as not satisfactory for Ppao interpretation. Intraobserver agreement of Ppao measurements, determined by correlation coefficients, was 0.91 for the CCMD and 0. 87 for the CARD. Correlation coefficients for interobserver comparisons were 0.83 for CCMD-CARD, 0.66 for CARD-CCN, and 0.67 for CCMD-CCN. Clinically significant differences were observed between CCMD-CARD (range of differences, -11 to 12 mm Hg), CARD-CCN (-13 to 15 mm Hg), and CCMD- CCN (-11 to 15 mm Hg). When Ppao readings were categorized as low (< 5 mm Hg), normal (5-15 mm Hg), and high (> 15 mm Hg), kappa values were 0.57 for CARD-CCMD, 0.51 for CARD-CCN, and 0.41 for CCMD-CCN comparisons. Interobserver variability was not explained by positive pressure ventilation or by the presence of (> 4 mm Hg) ventricular waves. The absolute values of interobserver differences in tracings with respiratory phasic variations (RPV) >/= 8 mm Hg were significantly greater than for tracings with variations < 8 mm Hg (p < 0.05, except CCMD-CCN, p = 0.10). Intraobserver differences also tended to be higher for tracings with RPV >/= 8 mm Hg (p = 0.06 and 0.05). When selected tracings were presented to 23 CCNs and 18 physicians, variability of Ppao interpretation was twice as great for tracings with large RPVs as compared with those with minimal RPVs. These data suggest that observer variability of Ppao interpretation is of potential clinical importance and that the degree of variability is associated with the magnitude of respiratory phasic variation of intrathoracic pressures. Although this could represent a local aberration, this study highlights a factor (respiratory phasic variation of Ppao) responsible for significantly increased intra- and interobserver variabilities.

Erythema nodosum after smoke inhalation-induced bronchiolitis obliterans organizing pneumonia.

Bronchiolitis obliterans organizing pneumonia and erythema nodosum are immunologic diseases that have not been reported to occur together. We report the case of a lady who developed bronchiolitis obliterans organizing pneumonia and erythema nodosum simultaneously, several weeks after smoke inhalation in a house fire.

Noninvasive ventilation: experience at a community teaching hospital.

OBJECTIVE: To describe our hospital's experience with noninvasive positive pressure ventilation (bilevel positive airway pressure; BiPAP) for patients with respiratory failure (RF). DESIGN: Retrospective, observational study. SETTING: A 300-bed community teaching hospital. METHODS: Medical records were analyzed for physiologic and outcome variables for all patients who received BiPAP for RF between January 1994 and December 1996. RESULTS: Eighty patients with a mean (+/- S.E.) age of 71.5+/-1.3 years and APACHE II score of 17.2+/-0.6 received BiPAP for RF during the study period. Thirty-one patients received BiPAP for hypoxemic RF, 25 for acute hypercapnic RF, 9 for chronic hypercapnic RF, 10 for postextubation RF and 5 could not be categorized. BiPAP success was defined as no need for invasive ventilation. BiPAP was successful in 47 of 75 cases that could be classified; all BiPAP successes lived whereas 18 of 28 BiPAP failures died. In the overall cohort, BiPAP success was associated with a lower ICU length of stay (5.8+/-0.9 versus 10.6+/-1.4 days, p < 0.01). The duration of BiPAP dependency in successful cases was 35.3+/-6.7 h. BiPAP was successful in 20 of 25 patients with acute hypercapnic RF and in 15 of 31 patients with hypoxemic RF. The risk of BiPAP failure was significantly greater (risk ratio = 2.6, 95% CI = 1.1-6.1) for patients with hypoxemic than for those with hypercapnic RF. BiPAP success was marked by increased PaO2/FIO2 in patients with hypoxemic RF and by increased pH and reduced PCO2 in patients with hypercapnic RF. BiPAP use was also successful in 8 of 10 patients who developed RF within 48 h of endotracheal extubation. CONCLUSIONS: BiPAP is highly effective in selected patients with RF during routine use in a community teaching hospital. The success rate is higher amongst patients presenting with hypercapnic than amongst those with hypoxemic RF and BiPAP failure is associated with an increased likelihood of in-hospital mortality. BiPAP may also be used successfully to temporize patients who develop RF in the period following endotracheal extubation. The duration of BiPAP dependency (35 h in this study) was shorter than in previous trials, and, though this is speculative, may have been minimized by our performing a trial of unassisted breathing each day.

Accuracy of an infrared tympanic thermometer.

BACKGROUND: The use of infrared thermometry to measure temperatures in hospitalized patients is increasing. Although infrared thermometers have been proven to be accurate when they are used by well-trained personnel, no previous studies have examined their accuracy during routine hospital use. OBJECTIVE: To determine the accuracy and observer variability of temperatures measured with an infrared tympanic thermometer (TT). DESIGN: Prospective, observational study. SETTING: ICUs of a 300-bed teaching community hospital. PATIENTS: Fifty-one critically ill patients. MEASUREMENTS: The mean of three tympanic temperatures measured with the infrared TT (tempTTs) was compared to temperatures simultaneously measured with the thermistor of right heart catheters and rectal mercury thermometers for the following three groups of observers who had been certified in the use of the infrared TT: a single critical care nurse (CCN)/educator (Ed); CCNs, and floor nurses (FNs)/clinical care practitioners (CCPs). RESULTS: Two rounds of measurements were given to 51 patients by 153 observers. Temperatures of the pulmonary artery (PA) measured with the thermistor of right heart catheters (tempPAs) ranged from 96.5 to 102.6 degrees F, with a mean (-/+ SD) of 99.3+/-1.1 degrees F. The intraobserver variabilities (correlation coefficients) of the tempTTs ranged from 0.90 for those measured by FNs/CCPs, to 0.92 for those measured by CCNs, to 0.98 for those measured by the CCN/Ed. Accuracy, arbitrarily defined as within a deviation of -/+0.5 degrees F of the tempPA, was 100% for the rectal mercury thermometer and 98.0% for the infrared TT when used by the CCN/Ed. The accuracy of the infrared TT was 80% when measured by CCNs and 61% when measured by FNs/CCPs. Differences between tempPAs and tempTTs measured by the CCN/Ed ranged from 0 to 0.7 degrees F, with a mean of 0.2 degrees F. Similarly, differences between tempPAs and tempTTs measured by CCNs ranged from 0 to 2.4 degrees F, with a mean difference of 0.3 degrees F. However, differences between tempPAs and tempTTs measured by FNs/CCPs ranged from 0 to 3.0 degrees F, with a mean of 0.6 degrees F (greater differences than those obtained by the CCNs; p < 0.01). The accuracy of rectal mercury thermometry was 100%. If a temperature > or = 101.0 degrees F had been considered as the threshold at which a fever is present, and if the mean of three measurements had been used to designate temperature, workups that were either inappropriately performed or omitted would have resulted from 2% of tempTTs measured by the CCN/Ed, 1% of those measured by CCNs, and 4% of those measured by FNs/CCPs. CONCLUSION: When used properly, both tympanic and rectal thermometry are very accurate. However, the infrared TT produced measurements that were both less accurate and less reproducible when used by nurses who routinely used it in clinical practice.