Electrical impedance tomography to evaluate air distribution prior to extubation in very-low-birth-weight infants: a feasibility study

OBJECTIVES:

Nasal continuous positive airway pressure is used as a standard of care after extubation in very-low-birth-weight infants. A pressure of 5 cmH₂O is usually applied regardless of individual differences in lung compliance. Current methods for evaluation of lung compliance and air distribution in the lungs are thus imprecise for preterm infants. This study used electrical impedance tomography to determine the feasibility of evaluating the positive end-expiratory pressure level associated with a more homogeneous air distribution within the lungs before extubation.

METHODS:

Ventilation homogeneity was defined by electrical impedance tomography as the ratio of ventilation between dependent and non-dependent lung areas. The best ventilation homogeneity was achieved when this ratio was equal to 1. Just before extubation, decremental expiratory pressure levels were applied (8, 7, 6 and 5 cmH₂0; 3 minutes each step), and the pressure that determined the best ventilation homogeneity was defined as the best positive end-expiratory pressure.

RESULTS:

The best positive end-expiratory pressure value was 6.3±1.1 cmH₂0, and the mean continuous positive airway pressure applied after extubation was 5.2±0.4 cmH₂0 (p = 0.002). The extubation failure rate was 21.4%. X-Ray and blood gases after extubation were also checked.

CONCLUSION:

This study demonstrates that electrical impedance tomography can be safely and successfully used in patients ready for extubation to suggest the best ventilation homogeneity, which is influenced by the level of expiratory pressure applied. In this feasibility study, the best lung compliance was found with pressure levels higher than the continuous positive airway pressure levels that are usually applied for routine extubation.     

Control Analysis

In this paper I present three collections of a patient's words and phrases that I arranged in a particular form. I discuss how I arranged the words in this way as I was struggling to get a sense of what felt “emotionally true” in my work with this patient and how this process helped me to grasp her use of dissociation. I draw on Gergen's work for a cultural perspective on dissociation, on Winnicott's concept of psychesoma dissociation, and on Goldberg's additions to Winnicott's theory. I show how the use of omnipotent, narcissistic structures may mask the use of dissociation (by patient and analyst) and make it quite an elusive phenomenon. My focus is on the process I went through, clinically and in my thinking and writing, as I discovered my own and my patient's dissociated use of mind and emotion and grappled with how to find a reassociation between these psychic functions and their somatic base.     

Genotrim, a DNA-customized nutrigenomic product, targets genetic factors of obesity: hypothesizing a dopamine-glucose correlation demonstrating reward deficiency syndrome (RDS)

Obesity is the second largest cause of preventable death in the United States. Historically, obesity was considered a behavioral problem that could be simply addressed with behavioral modifications in diet and exercise. As scientific advancements have demonstrated in other neurological healthcare conditions such as alcoholism, there are important biological and genetic components that limit the efficacy of behavioral adjustments alone. In light of data suggesting frequent co-morbidities to obesity, including diabetes mellitus, atherosclerosis, osteoporosis, and potentially others, we hypothesize that the biologic and genetic factors, synergistically with behavioral modifications, must be addressed to adequately treat this disease. We hypothesize that one such genetic factor that influences behavior and thus obesity is a predisposition to glucose craving and the overall effect of dopaminergic activity in the reward center of the brain. This defect drives individuals to engage in activities of behavioral excess, which will increase brain dopamine function, for which we have created the term reward deficiency syndrome (RDS) to categorize such biological influences on behavior. Consuming large quantities of alcohol or carbohydrates (carbohydrate bingeing) stimulates the brain's production of and utilization of dopamine. So too does the intake of crack/cocaine and the abuse of nicotine. We are proposing that a novel approach to nutritional supplementation may be required to target the RDS role in obesity. In this regard, Genotrim, a DNA based customized nutraceutical has been designed and is currently under investigation in several clinical studies. This is the first hypothesis paper whereby this new paradigm shift in thinking about obesity is presented.     

Why are fewer medical students in Florida choosing obstetrics and gynecology?

OBJECTIVES: To determine why there has been a decrease in the amount of applicants to Florida-based obstetrics and gynecology (OB/GYN) residency programs, and how this has been affected by the current medical liability climate. METHODS: Fourth year Florida medical students were surveyed about their concerns of a career in OB/GYN. The students were then grouped into three categories: students never interested in OB/GYN, students at one point interested in OB/GYN, and students pursuing a career in OB/GYN. The groups were analyzed for differences in their concerns about OB/GYN and the impact it had on their final career decisions. Finally, we addressed the question of whether or not medical liability played a significant role in their career choice. RESULTS: From September to November of 2005, 198 total students were surveyed. Of those surveyed, 10.8% were applying for OB/GYN, 47.7% had considered OB/GYN but chose another field, and 41.5% never considered OB/GYN as a specialty. The primary and secondary reasons for not choosing OB/GYN were the same in the two groups pursuing different specialties; "more interested in a different specialty" and "desire a specialty with more predictable work hours/lifestyle," respectively. Approximately 27% of those who considered OB/GYN but did not choose it ranked "fear of being sued" first or second, compared with 6.7% of those who never considered it (P < 0.01). Of the 21 students who will pursue careers in OB/GYN, 85.7% stated they are considering leaving Florida because of high malpractice/litigation. CONCLUSIONS: There is a subgroup of students in Florida who were initially interested in OB/GYN but may have been deterred by current medical liability issues. Florida is a state known as being in a professional liability crisis and this survey demonstrates evidence that this has adversely affected students' decisions to pursue OB/GYN.     

Murine typhus: forgotten but not gone.

An occasional patient presents the classical symptoms of a disease that has become uncommon. Typhus is an example of such a disease, since it is now well contained through control of its rodent reservoir. It is readily treated with tetracycline or one of its long-acting analogues, doxycycline or minocycline. Because typhus is infrequently encountered, the physician may not initially include it in his differential diagnosis. Our case serves as a remainder that with the increasingly frequent movement of persons from one geographic area to another, the uncommon rickettsial infection, murine typhus, should continue to be in the differential of a febrile patient. Furthermore, our case underscores the importance of including typhus in the differential of typhoid fever.     

Perinatal development influences mechanisms of bradykinin-induced relaxations in pulmonary resistance and conduit arteries differently

OBJECTIVE: As bradykinin (BYK) relaxes conduit (EPA) and resistance (RPA) pulmonary arteries from both perinatal and adult lungs, we investigated whether this vasodilator's relaxation-mechanisms were altered during perinatal development, differed between EPA and RPA and differed with other endothelium-dependent vasodilators, acetyicholine (ACH) and substance P (SP). METHODS: Arteries from mature foetal (5 days), neonatal (approximately 5 min), newborn (60-84 h) and adult pigs (> or =6 months) were isolated, mounted for in vitro isometric force recording, activated with PGF(2alpha) (30 micromol/l) and relaxed with BYK (10 pmol/l-1 micromol/l), SP (10 pmol/l-0.1 micromol/l) or ACH (1 nmol/l-1 mmol/l). RESULTS: (i) BYK: L-NAME (100 micromol/l) attenuated relaxations in foetal EPA ( approximately 55%) but nearly abolished them in the adult ( approximately 80%). In RPA, L-NAME nearly abolished ( approximately 90%) relaxations in the foetus and this effect diminished progressively with age to approximately 20% in the adult. Indomethacin (IND, micromol/l) attenuated relaxations in neonatal (approximately 25%), new-born and adult EPA (both approximately 45%). Together, L-NAME and IND abolished relaxations in all EPA and in neonatal RPA but not in older RPA. SKF525a (100 micromol/l) attenuated relaxations in foetal RPA ( approximately 4%), diminishing in the adult RPA to approximately 10%. Together, SKF52Sa and L-NAME largely abolished relaxations in postnatal RPA (approximately 80%). Activation with K(+)=125 mmol/l attenuated relaxations in adult EPA (approximately 80%), foetal RPA ( approximately 45%) and neonatal RPA (approximately 75%) and abolished relaxations in RPA from older ages. (ii) ACH: L-NAME abolished relaxations in new-born EPA and RPA. In adult EPA, combined L-NAME and IND moderately attenuated relaxations. (iii) SP: Combined application of L-NAME and IND attenuated relaxations to a similar degree in new-born and adult EPA and RPA. CONCLUSIONS: In postnatal EPA, BYK-relaxations depend completely on prostaglandin- and NO-synthesis whereas those to SP (at all ages) and ACH (in the adult) do not. In RPA, BYK-relaxations develop from being completely dependant on the sole release of NO (foetus) to being almost completely independent of it (adult), a situation mimicked partially by SP but not by ACH, which, in new-born RPA is completely dependent on NO. BYK-relaxations in postnatal RPA depend on the release of a hyperpolarising factor generated through an SKF525a-sensitive pathway in conjunction with NO. The mechanisms of endothelium-dependent BYK-relaxations in the pulmonary vascular bed undergo diverging alterations, depending on the stage of development and arterial size/function. These changes are specific for BYK as they differ from those obtained from ACH or SP.     

A clinical trial to evaluate the worth of preoperative multimodality therapy in patients with operable carcinoma of the rectum

PURPOSE: National Surgical Adjuvant Breast and Bowel Project Protocol R-03 was designed to determine the worth of preoperative chemotherapy and radiation therapy in the management of operable rectal cancer. METHODS: Thus far, 116 patients of an eventual 900 with primary operable rectal cancer have been randomized to receive multimodality therapy to begin preoperatively (59 patients) or identical therapy beginning after curative surgery (57). All patients received seven cycles of 5-fluorouracil (FU)/leucovorin (LV) chemotherapy. Cycles 1 and 4 through 7 used a high-dose weekly FU regimen. In Cycles 2 and 3, FU and low-dose LV chemotherapy was given during the first and fifth week of radiation therapy (5,040 cGy). The preoperative arm (Group 1) received the first three cycles of chemotherapy and all radiation therapy before surgery. The postoperative arm (Group 2) received all radiation and chemotherapy after surgery. Primary study end points included disease-free survival and survival. Secondary end points included local recurrence, primary tumor response to combination therapy, tumor downstaging, and sphincter preservation. RESULTS: Overall treatment-related toxicity was similar in both groups. Although seven preoperative patients had events after randomization that precluded surgery, eight events occurred during an equivalent follow-up period in the postoperative group. No patient was deemed inoperable because of progressive local disease. Sphincter-saving surgery was intended in 31 percent of Group 1 patients and 33 percent of Group 2 patients at the time of randomization. Such surgery was actually performed in 50 percent of the preoperatively treated patients and 33 percent of the postoperatively treated patients. The use of protective colostomy in patients undergoing sphincter-sparing surgery and the development of perioperative complications in all surgical patients were similar in both groups. There was evidence of tumor downstaging in evaluable patients under-going preoperative therapy, with 8 percent of Group 1 patients having had a pathologic complete response. CONCLUSION: These data do suggest that the preoperative chemotherapy and radiation therapy regimen used are, at least, as safe and tolerable as standard postoperative treatment. There is presently a trend to tumor downstaging and sphincter preservation in the preoperative arm. Whether this arm will have greater or lesser survival and long-term toxicity awaits the completion of this relevant study.Supported by National Cancer Institute Grants U10-CA-12027 and U10-CA-37377 and American Cancer Society Grant R-13.Read at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 9 to 14, 1996.