Laparoscopy for appendicitis and cholelithiasis during pregnancy: a new standard of care

BACKGROUND

Subsequent to a report from the authors' institution, the laparoscopic management of symptomatic cholelithiasis and appendicitis during pregnancy has become the standard of care at LDS Hospital using institutional guidelines. For comparison with previous outcomes described by the authors, 59 additional laparoscopic cases are reported.

METHODS

Medical records of all pregnant patients at LDS Hospital who underwent open or laparoscopic cholecystectomy or appendectomy between 1998 and 2002 were reviewed. The outcomes were compared with the authors' previous data.

RESULTS

The laparoscopic management of symptomatic cholelithiasis and appendicitis during pregnancy increased from 54% to 97%. No significant differences in preterm delivery rates, birth weights, or 5-min Apgar scores were found between the two periods. No birth defects or uterine injuries occurred.

CONCLUSIONS

With the use of the authors' guidelines, laparoscopy has become the standard of care for managing symptomatic cholelithiasis and appendicitis during pregnancy at LDS Hospital without significant increase in morbidity or mortality.

An evaluation of predictive factors for CD34+ cell harvest yields from patients mobilized with chemotherapy and growth factors

BACKGROUND

Accurately predicting the outcomes of peripheral blood stem cell harvests is important because unproductive collections are expensive and subject the donor to unnecessary toxicity.

STUDY DESIGN AND METHODS

Predictive factors for stem cell mobilization and collection by a retrospective review of 104 consecutive donors were evaluated.

RESULTS

Of several previously suggested measures, the peripheral CD34+ cell concentration on the day of harvest (pCD34DH) correlated best with total numbers of CD34+ collected (r = 0.88). This was followed by the pCD34 on the day before harvest (pCD34Day -1) (r = 0.74). The peripheral WBC count on the day of harvest (pWBC) was inferior (r = 0.39). When ratios of potential predictive factors divided by the previous day's value were examined, pWBC ratio was found to be a significant independent predictive factor for cells collected (r = 0.45). Furthermore, the predictive value of both the pCD34Day -1 and the pWBC can be improved by combining with the pWBC ratio. To examine whether the chosen collection starting days were optimal, serial pCD34 obtained daily during the harvest procedures was examined. Poorly mobilizing donors, who required several days of collection, did not reach maximal harvest yields until the fourth collection day.

CONCLUSIONS

pCD34DH is the optimal predictive factor for harvest yields. If pCD34DH is not available, pCD34Day -1 or pWBC combined with the pWBC ratio may offer the best prediction of harvest outcomes. The best harvest yields on poorly mobilizing donors occur 3 to 4 days after the usual collection starting times.

Rates of disease progression by baseline CD4 cell count and viral load after initiating triple-drug therapy

CONTEXT

Current recommendations for initiation of antiretroviral therapy in patients infected with human immunodeficiency virus type 1 (HIV) are based on CD4 T-lymphocyte cell counts and plasma HIV RNA levels. The relative prognostic value of each marker following initiation of therapy has not been fully characterized.

OBJECTIVE

To describe rates of disease progression to death and AIDS or death among patients starting triple-drug antiretroviral therapy, stratified by baseline CD4 cell count and HIV RNA levels.

DESIGN, SETTING, AND PARTICIPANTS

Population-based analysis of 1219 antiretroviral therapy-naive HIV-positive men and women aged 18 years or older in British Columbia who initiated triple-drug therapy between August 1, 1996, and September 30, 1999.

MAIN OUTCOME MEASURE

Cumulative mortality rates from the initiation of triple-drug antiretroviral therapy to September 30, 2000, determined using various CD4 cell and plasma HIV RNA thresholds.

RESULTS

As of September 30, 2000, 82 patients had died of AIDS-related causes, for a crude AIDS-related mortality rate of 6.7%. The product limit estimate (SE) of the cumulative mortality rate at 12 months was 2.9% (0.5%). In univariate analyses, a prior diagnosis of acquired immunodeficiency syndrome (AIDS), CD4 cell count, use of protease inhibitors, and HIV RNA level were associated with mortality. There was no difference in mortality by age or sex. Only CD4 cell count remained statistically significant in the multivariate analysis. After controlling for AIDS, protease inhibitor use, and plasma HIV RNA level at baseline, patients with CD4 cell counts of less than 50/microL were 6.67 (95% confidence interval [CI], 3.61-12.34) times and those with counts of 50/microL to 199/microL were 3.41 (95% CI, 1.93-6.03) times more likely to die than those with counts of at least 200/microL.

CONCLUSION

Our data demonstrate uniformly low rates of disease progression to death and AIDS or death among patients starting antiretroviral therapy with CD4 cell counts of at least 200/microL. In our study, disease progression to death and AIDS or death was clustered among patients starting therapy with CD4 cell counts less than 200/microL.

CCR5Delta32 and promoter polymorphisms are not correlated with initial virological or immunological treatment response

OBJECTIVE

Natural genetic polymorphisms within the CCR5 gene and promoter have been linked to patterns of HIV-1 clinical disease progression in untreated individuals. The objective of this retrospective study was to assess the influence of the CCR5Delta32 mutation and promoter polymorphisms on virological and immunological treatment outcome in 436 antiretroviral-naive individuals initiating their first therapy, over a mean follow-up time of 22 months.

METHODS

Genotypes for the CCR5Delta32 and promoter were determined by polymerase chain reaction amplification of human DNA from plasma, followed by gel electrophoresis for CCR5Delta32 or DNA sequencing for the promoter polymorphisms. Time to virological failure [defined as the second plasma viral load > or = 400 copies HIV-1 RNA/ml) and immunological failure (defined as time to achieve two successive CD4 cell counts below baseline) were analyzed by Kaplan-Meier methods.

RESULTS

The five most common CCR5 promoter polymorphisms were observed at positions 208(G/T), 303(A/G), 627(C/T), 676(A/G), and 927(C/T). Allele frequencies were 0.24(208T), 0.38(303G), 0.44(627T), 0.35(676G) and 0.18(927T). The CCR5Delta32 allele frequency was 0.08. The promoter polymorphisms existed in strong linkage disequilibrium with each other and the Delta32. No significant effect of the individual CCR5Delta32 or promoter polymorphisms could be demonstrated with respect to time to treatment failure as defined by virological or immunological parameters (P > or = 0.07). Similarly, when combined CCR5Delta32 and promoter genotypes were analyzed in order to account for linkage disequilibrium, no significant effect was observed on time to virological or immunological failure (P > 0.6).

CONCLUSION

CCR5Delta32 and promoter genotypes may not be of clinical relevance in predicting initial virological or immunological response to antiretroviral therapy.

Lipodystrophy-associated morphological, cholesterol and triglyceride abnormalities in a population-based HIV/AIDS treatment database

OBJECTIVE

To provide population-based estimates of the prevalence of lipodystrophy syndrome and constituent symptoms and to identify correlates of prevalent symptomology.

METHODS

Participants in a province-wide HIV/AIDS treatment programme reported morphological and metabolic abnormalities. Probable lipodystrophy was defined as self-report of at least one morphological abnormality or both high cholesterol and triglyceride levels. Explanatory variables investigated included: age; sex; ethnicity; transmission risk group; CD4 cell count; plasma viral load; AIDS diagnosis; duration of infection; alternative therapy use; past, current and duration of use of antiretroviral therapy (ART) by class and specific drug; total duration of ART; and current adherence. Stepwise logistic regression identified possible determinates of lipodystrophy.

RESULTS

Of 1035 participants, 50% appeared to have probable lipodystrophy, with 36% reporting peripheral wasting, 33% abdominal weight gain, 6% buffalo hump, and 10 and 12% increased triglyceride or cholesterol levels, respectively. In multivariate analysis, lipodystrophy was associated with older age (per year) (AOR 1.03; 95% CI 1.01, 1.04), the use of ingested alternative therapies (AOR 1.46; 95% CI 1.06, 2.01), having ever used protease inhibitors (PI) (AOR 2.63; 95% CI 1.89, 3.66), and duration of stavudine treatment (per year) (AOR 1.35; 95% CI 1.15, 1.58). In analysis limited to participants exposed to PI, after similar adjustment, the duration of lamivudine rather than stavudine treatment was associated with lipodystrophy (AOR 1.32; 95% CI 1.13, 1.53).

CONCLUSION

Increased risk of abnormalities is associated with the use of PI, and the duration of stavudine and lamivudine treatment after adjustment for personal characteristics, clinical disease stage, duration of infection and detailed treatment history.

Evaluation of a computerized diagnostic decision support system for patients with pneumonia: study design considerations

Planning the clinical evaluation of a computerized decision support system requires a strategy that encompasses the different aspects of the clinical problem, the technical difficulties of software and hardware integration and implementation, the behavioral aspects of the targeted users, and the discipline of study design. Although clinical information systems are becoming more widely available, only a few decision support systems have been formally evaluated in clinical environments. Published accounts of difficulties associated with the clinical evaluation of decision support systems remain scarce. The authors report on a variety of behavioral, logistical, technical, clinical, cost, and work flow issues that they had to address when choosing a study design for a clinical trial for the evaluation of an integrated, real-time decision support system for the automatic identification of patients likely to have pneumonia in an emergency department. In the absence of a true gold standard, they show how they created a credible, clinically acceptable, and economical reference standard for the diagnosis of pneumonia, to determine the overall accuracy of the system. For the creation of a reference standard, they describe the importance of recognizing verification bias and avoiding it. Finally, advantages and disadvantages of different study designs are explored with respect to the targeted users and the clinical setting.

Carboxyhemoglobin half-life in carbon monoxide-poisoned patients treated with 100% oxygen at atmospheric pressure

STUDY OBJECTIVES

There are large reported differences for the carboxyhemoglobin (COHb) half-life (COHb t(1/2)) in humans breathing 100% atmospheric O(2) following CO inhalation in tightly controlled experiments compared to the COHb t(1/2) observed in clinical CO poisoning (range, 36 to 131 min, respectively). Other reports have suggested that the COHb t(1/2) may be affected by gender differences, age, and lung function. We wished to test the hypothesis that the COHb t(1/2) might also be influenced by CO poisoning vs experimental CO exposure, by a history of loss of consciousness (LOC), concurrent tobacco smoking, and by PaO(2). The purpose of the present study was to measure the COHb t(1/2) in a cohort of CO-poisoned patients and to determine if those listed factors influenced the COHb t(1/2).

DESIGN

Retrospective chart review from 1985 to 1995. We calculated the COHb t(1/2) of CO-poisoned patients who were treated with high-flow supplemental atmospheric pressure O(2) delivered by nonrebreather face mask or endotracheal tube.

SETTING

Hyperbaric medicine department of a tertiary-care teaching hospital.

PATIENTS

Of 240 CO-poisoned patients, 93 had at least two COHb measurements > 2% (upper limit of normal) with recorded times of the measurements, permitting calculation of the COHb t(1/2).

RESULTS

The COHb t(1/2) was 74 +/- 25 min (mean +/- 1 SD) with a range from 26 to 148 min. By stepwise multiple linear regression analysis, the PaO(2) influenced the COHb t(1/2) (R(2) = 0.19; p < 0.001), whereas the COHb t(1/2) was not influenced by gender, age, smoke inhalation, history of LOC, concurrent tobacco smoking, degree of initial metabolic acidosis (base excess), or initial COHb level.

CONCLUSIONS

The COHb t(1/2) of 93 CO-poisoned patients treated with 100% O(2) at atmospheric pressure was 74 +/- 25 min, considerably shorter than the COHb t(1/2) reported in prior clinical reports (approximately 130 +/- 130 min) and was influenced only by the patient's PaO(2).

Dissection plane of the human vocal fold lamina propria and elastin fibre concentration

To determine whether a natural plane of dissection occurs in the normal human vocal fold, semi-blunt instruments (Bouchayer laryngeal dissectors) were used to dissect the lamina propria. The depth of the plane of dissection was correlated with the elastin fibre concentration to determine whether the plane occurred at a predictable point in the elastin concentration as it increased between the superficial and middle layers. Eight human larynges were dissected using an operative microscope. The dissection plane consistently occurred between 23-50% depth into the lamina propria. No consistent correlation was found with the elastin fibre concentration. The depth of the plane of dissection has an interesting association with age: dissection planes occurred more superficially in older specimens.

Systematic nodal dissection in the intrathoracic staging of patients with non-small cell lung cancer

OBJECTIVE

Although systematic nodal dissection is accepted as an important component of the intrathoracic staging of disease in patients undergoing thoracotomy for lung cancer, many surgeons still do not routinely perform it. We reviewed our practice to assess the information provided by its routine application even when lymph node metastases are considered unlikely.

METHODS

The records of 240 patients undergoing thoracotomy for clinically staged cT1-3 N0-1 non-small cell lung cancer were reviewed. In 5 cases (2%) mediastinal dissection was not performed because of specific contraindications and in 8 cases (3%) exploratory thoracotomy was performed. The pathologic findings in the 227 patients who underwent pulmonary resection with systematic nodal dissection were analyzed.

RESULTS

The median number of nodal stations, including N1 and N2, examined and submitted separately for histologic assessment was 7 per patient (range 3-13). N2 disease was disclosed in 46 patients overall (20%), including 41 of the 227 patients undergoing pulmonary resection (18%) and 5 of those undergoing exploratory thoracotomy (62.5%). No subgroup had a 0% incidence of N2 metastases. Multivariate analysis showed that younger age, increasing tumor size, left lower lobe origin, and bronchial origin were significant independent variables for prediction of lymph node metastases at the N1 level, the N2 level, or both.

CONCLUSIONS

Because no clinical or pathologic subset of patients with a negligible incidence of N2 disease could be discriminated, systematic nodal dissection must be routinely employed for accurate intrathoracic staging of non-small cell lung cancer.