Majetschak M, Christensen B, Obertacke U, et al. Sex differences in posttraumatic cytokine release of endotoxin-stimulated whole blood: relationship to the development of severe sepsis. J Trauma. 2000;48:832-839.
Oberholzer A, Keel M, Zellweger R, et al. Incidence of septic complications and multiple organ failure in severely injured patients is sex specific. [editorial] J Trauma. 2000;48:932-937.

Detection of small lung cancer tumors may have no impact on survival, according to a study by Patz et al. The researchers believe that by the time a lesion has grown to 5 mm (close to the detectable range of a computed tomography [CT] scan), the cancer is already late in the biology of the disease.

The study involved 510 patients with surgically resected pathological stage IA non--small-cell lung cancer. Of this group, 38% had squamous cell carcinoma, 46% had adenocarcinoma, 9% had bronchoalveolar cell carcinoma, and 7% had large cell carcinoma.

As shown in Table 2, tumor size did not influence survival. Even when the authors divided tumor size into deciles, the groups had similar survival rates. Thus, it appears that the size of lung cancer nodules does not necessarily correspond to the biological behavior of the disease.

In an accompanying editorial, William C. Black, MD, noted that the findings "force us to think hard about screening with CT and remind us that survival statistics can be very misleading." He also believes that "we should not rush headlong into screening before its effectiveness has been demonstrated by randomized clinical trials."

Patz EF Jr, Rossi S, Harpole DH Jr, et al. Correlation of tumor size and survival in patients with stage IA non--small cell lung cancer. Chest. 2000;117:1568-1571.
Black WC. Unexpected observations on tumor size and survival in stage IA non--small cell lung cancer. [editorial] Chest. 2000; 117:1532-1534.

Indirect calorimetry is more accurate than the Fick method for measuring whole body oxygen consumption (VO2) among patients receiving mechanical ventilation, new findings suggest. Use of indirect calorimetry may help achieve an optimal balance between oxygen delivery and consumption in these patients.

Epstein et al prospectively studied 38 mechanically ventilated adults with multiple injuries who received a pulmonary artery catheter within 24 hours of admission to a surgical intensive care unit. VO2 was measured simultaneously by the reverse Fick equation and indirect calorimetry every four to six hours for 24 hours as long as the patients were normothermic. (Patients who were hypothermic were warmed until normothermia was achieved.)

At each time point, the mean VO2 value was significantly higher when calculated by indirect calorimetry than by the Fick method. Overall, the mean difference was 41 mL/min/m2.

Although the Fick method is convenient and relatively inexpensive, this study confirms concerns about its accuracy and precision. "While neither method of measuring VO2 is free from measurement error, the bias and the confidence intervals were far too wide for these methods to be considered interchangeable," Epstein et al concluded.

Epstein CD, Peerless JR, Martin JE, Malangoni MA. Comparison of methods of measurements of oxygen consumption in mechanically ventilated patients with multiple trauma: the Fick method versus indirect calorimetry. Crit Care Med. 2000;28:1363-1369.

Reluctance to admit cancer patients to the intensive care unit (ICU) is not justified, according to data from a retrospective cohort study. While the findings suggest that ICU admission is associated with a poor prognosis in these patients, the rate of ICU mortality in cancer patients is comparable with that in severely ill patients without cancer.

Staudinger et al followed 414 cancer patients admitted to an ICU as well as two control groups: 2,772 cancer patients not admitted to the ICU and 1,362 patients admitted to the ICU with noncancer diagnoses. The subjects were followed for one to 5.5 years after ICU admission.

The cancer patients treated in the ICU had the highest one-year crude mortality rate (77% vs 44% for cancer patients not admitted and 37% for noncancer patients). However, according to the authors, the 77% mortality rate is similar to or lower than that found in studies involving severely ill patients with pneumonia, respiratory distress syndrome, sepsis, or renal or multiple organ failure, as well as patients who require cardiopulmonary resuscitation.

Age, neutropenia, and underlying disease were not significant predictors of outcome. APACHE III scores correlated positively with mortality but were not accurate predictors of individual outcome. "Scoring systems alone should not be used to make decisions about prolongation of resource-consuming treatment; rather, they serve to define patients at high risk who should be treated intensively and early," Staudinger et al believe.

Staudinger T, Stoiser B, MŸllner M, et al. Outcome and prognostic factors in critically ill cancer patients admitted to the intensive care unit. Crit Care Med. 2000;28:1322-1328.

A relatively high prevalence of cocaine use was found among patients with asthma exacerbations in a recent study. The actual prevalence may be much higher, Rome et al noted, because 29% of the total group refused to submit urine samples.

Of 163 adults who presented to an inner-city emergency department with acute asthma exacerbations, 37 patients refused to participate; an additional 10 were excluded because of language barriers, psychiatric illness, or other logistical problems. Of the 116 remaining patients, complete urine samples were available for 103.

In 13 patients, urine samples were positive for cocaine; in six, they were positive for opiates. Patients with evidence of cocaine use had a greater frequency of hospital admissions than did those with negative urine samples (38% vs 20%), but the difference was not statistically significant. Among those who were admitted to the hospital, cocaine-positive patients had a significantly longer length of stay than did cocaine-negative patients (5 vs 2.5 days). Furthermore, two of three patients who required intubation were cocaine-positive.

These findings suggest that cocaine use may be associated with more severe asthma exacerbations. Rome et al admitted that they were unable to control for potentially confounding factors, such as access to health care, tobacco smoking, and appropriate use of medications. The researchers also explained that it would have been helpful to compare the prevalence of cocaine use in this cohort with that among nonasthmatic control subjects.

Rome LA, Lippmann ML, Dalsey WC, et al. Prevalence of cocaine use and its impact on asthma exacerbation in an urban population. Chest. 2000;117:1324-1329.

A metered-dose inhaler (MDI) with a metal spacer was as effective as aerosol nebulization in the delivery of albuterol (salbutamol) to small children in a study by Mandelberg et al.

Forty-two children (age 10 months to 4 years) who presented to an emergency department with acute wheeze were randomized to 2.5 mg nebulized albuterol or four puffs (400 mg) of inhaled albuterol delivered through an MDI with a metal, nonelectrostatic spacer and a face mask. All patients received a total of three treatments given at 20-minute intervals.

The overall percent fall in the respiratory rate from baseline was similar in the MDI and nebulizer groups (17.9% and 18.6%, respectively). In fact, the groups showed similar rates of decline at each 20-minute time interval. In addition, the percent fall in clinical scores did not differ at any time point. Overall, these scores fell 23.2% and 24.7%, respectively.

Furthermore, the method of delivery did not affect the hospitalization rate, the pulse rate, or the saturation of oxyhemoglobin while the patient was breathing room air. No adverse effects were reported in either group. The researchers reported similar findings in a study of adults treated for severe airflow limitation.

"Wet nebulization is more expensive and time-consuming for patients and practitioners, with little or no added benefit," noted Charles W. Callahan, DO, in an accompanying editorial. He added that clinical and physiologic evidence supports the use of MDI therapy in the place of nebulization.

Mandelberg A, Tsehori S, Houri S, et al. Is nebulized aerosol treatment necessary in the pediatric emergency department? Chest. 2000;117:1309-1313.
Callahan CW. Wet nebulization in acute asthma. The last refrain? [editorial] Chest. 2000;117:1226-1227.

Patients who appear to have developed asthma in adulthood may actually have congenital vascular rings compressing the trachea or esophagus, researchers reported in a recent case review. Particularly at risk for this condition are people with an abnormally flattened expiratory loop who have a reduced peak expiratory flow (PEF) rate.

Parker et al diagnosed four cases of symptomatic vascular rings in adults who had been unsuccessfully treated for asthma. These anomalies are caused by abnormal development of the primitive aortic arch. For example, in two of the patients, the vascular ring was formed by a right aortic arch with a persistent ligamentum arteriosum.

"Spirometric values were deceptively normal, except for reduced PEF," the researchers found. The key to the diagnosis was that all of the patients had an abnormally truncated expiratory flow loop. In each case, chest films showed a right aortic arch, and computed tomography or magnetic resonance imaging scans confirmed the diagnosis of a vascular ring.

While congenital vascular rings are well recognized in infants and children, this condition is not often considered as an alternative diagnosis to asthma in adults because adults are usually evaluated by physicians who are less familiar with congenital abnormalities. "Failure to consider this possibility may result in a misdiagnosis of asthma, with the use of ineffective and expensive medications," the researchers concluded.

Parker JM, Cary-Freitas B, Berg BW. Symptomatic vascular rings in adulthood: an uncommon mimic of asthma. J Asthma. 2000;37:275-280.