Patterns of lymphadenopathy in thoracic malignancies

There are different lymphatic drainage pathways in the thorax that are relevant in the staging of lung cancer, breast cancer, lymphoma, esophageal cancer, and malignant mesothelioma. To properly search for metastatic spread, it is important to carefully evaluate the specific nodal stations that drain the thoracic structures from which a primary tumor originates. Because size criteria have limitations in the prediction of nodal status, pathologic confirmation is essential for accurate staging. Computed tomography (CT) is useful in helping the surgeon or interventional radiologist determine the most appropriate approach for nodal sampling. Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) has an increasing role in detection of diseased lymph nodes that appear normal at CT alone, particularly when FDG PET images are fused with CT images. However, the role of radiologic imaging extends beyond initial staging and the guidance of interventions to include posttreatment assessment and the detection of recurrent disease. Therefore, at all levels of cancer imaging, it is essential to identify the relevant lymph node regions and their relations to the primary tumor.

Effect of gabapentin-like compounds on development and maintenance of morphine-induced conditioned place preference

RATIONALE

Psychological dependence to the opioid analgesic morphine is attributable to the rewarding properties of the drug, and its evolution can be divided into two distinct phases: development and maintenance. Both phases can be studied using conditioned place preference (CPP).

OBJECTIVES

To determine whether the two phases can be influenced by pre-treatment with gabapentin-like compounds.

METHODS

CPP to morphine was used to demonstrate the rewarding properties of morphine in the presence or absence of gabapentin-like compounds. In-vivo microdialysis in the nucleus accumbens was used to determine the effects of gabapentin or pregabalin on morphine-induced dopamine release.

RESULTS

Pretreatment with either gabapentin (10-100 mg/kg p.o.) or pregabalin (3-30 mg/kg p.o.) attenuated CPP induced by a submaximal dose of morphine (0.75 mg/kg). Neither gabapentin nor pregabalin had any effect alone in the CPP test. Both gabapentin-like compounds blocked the effect of morphine (0.75 mg/kg s.c.) to increase the release of dopamine in the nucleus accumbens. Studies of the maintenance of CPP to morphine showed CPP was maintained for at least 4 days after the initial test. In a second experiment, it was found that pregabalin (injected once, 24 h after CPP had been demonstrated) was able to reverse morphine-induced CPP.

CONCLUSIONS

Neither gabapentin nor pregabalin induced CPP, but both compounds blocked the development of CPP to morphine and also blocked morphine's effects on dopamine release. Furthermore, pregabalin blocked the maintenance of morphine-induced CPP. It is concluded that gabapentin-like compounds, which have no intrinsic rewarding properties, may have some therapeutic use in the treatment of opioid dependence.

Effects of caffeinated coffee consumption on intraocular pressure, ocular perfusion pressure, and ocular pulse amplitude: a randomized controlled trial

PURPOSE

To examine the effects of caffeinated coffee consumption on intraocular pressure (IOP), ocular perfusion pressure (OPP), and ocular pulse amplitude (OPA) in those with or at risk for primary open-angle glaucoma (POAG).

METHODS

We conducted a prospective, double-masked, crossover, randomized controlled trial with 106 subjects: 22 with high tension POAG, 18 with normal tension POAG, 20 with ocular hypertension, 21 POAG suspects, and 25 healthy participants. Subjects ingested either 237 ml of caffeinated (182 mg caffeine) or decaffeinated (4 mg caffeine) coffee for the first visit and the alternate beverage for the second visit. Blood pressure (BP) and pascal dynamic contour tonometer measurements of IOP, OPA, and heart rate were measured before and at 60 and 90 min after coffee ingestion per visit. OPP was calculated from BP and IOP measurements. Results were analysed using paired t-tests. Multivariable models assessed determinants of IOP, OPP, and OPA changes.

RESULTS

There were no significant differences in baseline IOP, OPP, and OPA between the caffeinated and decaffeinated visits. After caffeinated as compared with decaffeinated coffee ingestion, mean mm Hg changes (± SD) in IOP, OPP, and OPA were as follows: 0.99 (± 1.52, P<0.0001), 1.57 (± 6.40, P=0.0129), and 0.23 (± 0.52, P<0.0001) at 60 min, respectively; and 1.06 (± 1.67, P<0.0001), 1.26 (± 6.23, P=0.0398), and 0.18 (± 0.52, P=0.0006) at 90 min, respectively. Regression analyses revealed sporadic and inconsistent associations with IOP, OPP, and OPA changes.

CONCLUSION

Consuming one cup of caffeinated coffee (182 mg caffeine) statistically increases, but likely does not clinically impact, IOP and OPP in those with or at risk for POAG.

Prioritizing back injury risk in hospital employees: application and comparison of different injury rates

To identify high risk areas for back injury in a large teaching hospital, we calculated standard injury rates and newly developed composite statistics for nursing and non-nursing work groups. Data were extracted from the hospital's workers' compensation database. The hospital-wide total injury rate was 4.6 reports per 100 full-time equivalents (FTE); Compensation Case Rate, 1.4 cases per 100 FTE; Compensation Severity Rate, 76 days lost per 100 FTE; and the Cost Rate, $3742 per 100 FTE. The Total Injury Reports Rate for nursing varied from 14.2 per 100 FTE for Intensive Care Unit (ICU) Nursing to 3.8 per 100 FTE for Pediatric Nursing. Non-nursing areas also demonstrated increased rates for back injury. Individual statistical rates ranked areas differently in risk, whereas composite statistical measures consistently ranked ICU Nursing, Buildings and Grounds, and Orthopedics/Neurological Nursing as the top three. Patient handling was the precipitating event in the majority of nursing back injuries, indicating the need for ergonomic intervention. The use of combined statistical measures provided a more integrative measure for describing and following back injury risk over time.

Source and direction of thoracic lymphatics: Part I--upper thorax

The purpose of this set of two articles is to illustrate the source and direction of lymphatic drainage in the thorax on axial CT schematics. The first article describes the upper thorax. The second article will describe the lower thorax. The nodal groups are given conventional anatomic names and the corresponding terminology of the American Thoracic Society. Arrows indicate the direction of the flow. The region or organ drained is color-coded, and nodes that receive lymph from each area are assigned appropriately colored boxes. Major drainage patterns are also described. This information can be used to assess a suggestive lymph node by tracing it to the region of drainage and looking for pathological lesions. Alternatively, one may extrapolate the potential drainage routes of a tumor and scrutinize specific sites for nodal metastases.

An ex vivo comparison of cuffed endotracheal tubes and self-sealing baffled endotracheal tubes

AIMS To compare cuffed silicone endotracheal tubes with self-sealing baffled silicone endotracheal tubes in an ex vivo canine tracheal model, to determine whether the tubes differed in their maintenance of a seal and their effectiveness in removing fluid from the tracheal lumen, and whether the self-sealing endotracheal tubes would release pressure when a closed anaesthetic circuit reached ≥30 cm H₂O. METHODS Twelve cadaver tracheae were randomly selected to be intubated with either cuffed or self-sealing baffled endotracheal tubes. To test tracheal seal efficacy, the tracheae were positioned vertically, 5 mL of water was instilled proximal to the tube cuff or baffles and they were monitored for leakage at 0, 15, 30, 45, and 60 minutes, recording the total volume leaked. To test fluid removal at extubation, the tracheae were intubated, then 5.6 g of 60% barium sulphate suspension was instilled proximal to the seal and left undisturbed for 5 minutes. The tubes were then extubated, with the cuffed endotracheal tubes being partially deflated before extubation, and the amount of barium recovered was weighed. These procedures were repeated on the same tracheae using the other endotracheal tubes. To test whether self-sealing baffled endotracheal tubes would release pressure at ≥30 cm H₂O, the tracheae were intubated, connected to an anaesthetic machine and pressurised to 30 cm H₂O for 5 minutes and then 50 cm H₂O for 5 minutes. Release of pressure was defined as a decrease in pressure within the closed anaesthetic circuit. RESULTS More cuffed (7/12) than baffled (0/12) endotracheal tubes leaked water after 60 minutes (p=0.016). The mean amount of barium removed by the self-sealing baffled endotracheal tubes (4.9 (95% CI=3.8-4.4) g) was greater than that removed by the partially deflated cuffed endotracheal tubes (0.4 (95% CI=0.14-0.66) g) (p<0.001). None of the self-sealing baffled endotracheal tubes released pressure at ≥30 cm H₂O in a closed anaesthetic circuit. CONCLUSIONS AND CLINICAL RELEVANCE Self-sealing baffled endotracheal tubes were more effective than cuffed endotracheal tubes at both preventing fluid leakage at the tracheal seal and removing fluid from the lumen of the trachea in cadaver tracheae. However they did not release pressure when the closed-circuit system was at ≥30 cm H₂O in a canine cadaver model. The self-sealing baffled endotracheal tubes may be a suitable substitute for cuffed endotracheal tubes.

The source and direction of thoracic lymphatics, part II: The lower thorax

The purpose of this set of 2 articles is to illustrate the source and direction of lymphatic drainage in the thorax on axial computed tomographic (CT) schematics. The first article describes the upper thorax. This article describes the lower thorax. The nodal groups are given conventional anatomic names and the corresponding terminology of the American Thoracic Society. Arrows indicate the direction of the flow. The region or organ drained is color-coded, and nodes that receive lymph from each area are assigned appropriately colored and numbered boxes. Major drainage patterns are also described. This information can be used to assess a suspicious lymph node by tracing it to the region of drainage and looking for pathology. Alternately, one may extrapolate the potential drainage routes of a tumor and scrutinize specific sites for nodal metastases.