The effect of sedation with propofol and fentanyl during epidural catheter insertion on intraoperative temperatures

General anesthesia inhibits thermoregulation by suppressing tonic vasoconstriction and facilitates a core-to-peripheral redistribution of body heat, which is the major cause of core hypothermia during the first hour of anesthesia. We randomly assigned 16 patients to two groups; 1) patients who received fentanyl (1 microgram.kg-1, i.v.) and propofol (1.5 mg.kg-1.h-1) during insertion of epidural catheters (P group), and 2) no drug (control) group (C group). We measured tympanic (Ttym) and skin temperatures at the time of admission to operating rooms, after dural catheter insertion, before induction of anesthesia, just after induction of anesthesia, and one hour after induction. After dural catheter insertion, forearm-finger tip skin temperature gradient of P group was significantly smaller than C group. One hour after induction of anesthesia, Ttym of P group was significantly higher than C group. We can conclude that a sedative dose of propofol and fentanyl before induction of general anesthesia inhibits redistribution hypothermia during general anesthesia.     

Increasing incidence of midterm and long-term complications after endovascular graft repair of abdominal aortic aneurysms: a note of caution based on a 9-year experience

OBJECTIVE: To analyze the late complications after endovascular graft repair of elective abdominal aortic aneurysms (AAAs) at the authors' institution since November 1992. SUMMARY BACKGROUND DATA: Recently, the use of endovascular grafts for the treatment of AAAs has increased dramatically. However, there is little midterm or long-term proof of their efficacy. METHODS: During the past 9 years, 239 endovascular graft repairs were performed for nonruptured AAAs, many (86%) in high-risk patients or in those with complex anatomy. The grafts used were Montefiore (n = 97), Ancure/EVT (n = 14), Vanguard (n = 16), Talent (n = 47), Excluder (n = 20), AneuRx (n = 29), and Zenith (n = 16). All but the AneuRx and Ancure repairs were performed as part of a U.S. phase 1 or phase 2 clinical trial under a Food and Drug Administration investigational device exemption. Procedural outcomes and follow-up results were prospectively recorded. RESULTS: The major complication and death rates within 30 days of endovascular graft repair were 17.6% and 8.5%, respectively. The technical success rate with complete AAA exclusion was 88.7%. During follow-up to 75 months (mean +/- standard deviation, 15.7 +/- 6.3 months), 53 patients (22%) died of unrelated causes. Two AAAs treated with endovascular grafts ruptured and were surgically repaired, with one death. Other late complications included type 1 endoleak (n = 7), aortoduodenal fistula (n = 2), graft thrombosis/stenosis (n = 7), limb separation or fabric tear with a subsequent type 3 endoleak (n = 1), and a persistent type 2 endoleak (n = 13). Secondary intervention or surgery was required in 23 patients (10%). These included deployment of a second graft (n = 4), open AAA repair (n = 5), coil embolization (n = 6), extraanatomic bypass (n = 4), and stent placement (n = 3). CONCLUSION: With longer follow-up, complications occurred with increasing frequency. Although most could be managed with some form of endovascular reintervention, some complications resulted in a high death rate. Although endovascular graft repair is less invasive and sometimes effective in the long term, it is often not a definitive procedure. These findings mandate long-term surveillance and prospective studies to prove the effectiveness of endovascular graft repair.     

Ultrasonographic detection of very thin percutaneous central venous catheter in neonates

To assess the ability of ultrasonography to detect the tip of a very thin (0.4 mm outer diameter) percutaneous central venous catheter (PCVC) in neonates, the PCVC tip location was assessed by ultrasonography (US) and compared to the location estimated by standard radiography for 57 PCVCs in 44 neonates. Of 57 occasions, the examiner could not find the PCVC tip in three cases (5%). In the remaining 54 instances, in 87% of cases, the PCVC tip position was consistent with the location implied by skeletal landmarks on standard radiographs. On 24 occasions we also assessed catheter tip dislodgement according to flexion and extension of the infant's arm. US could detect 78% of cases of catheter tip dislodgement. The PCVC tip was sometimes visualized as a dot and parallel lines as well as mere parallel lines. In a large population of cases, US is a reliable method for detection of a thin PCVC tip. US provides precise information about the PCVC tip position in relation to vascular structure and contributes to safer positioning of the PCVC than traditional radiography alone.     

Comparative analysis of CD80 and CD86 on human Langerhans cells: expression and function

Abstract Although both CD80 (B7–1) and CD86 (B7–2/B70) have been recently identified in cultured human Langerhans cells (LC), little is known of the role and regulatory properties of CD80 and CD86 on human LC. We present here the results of a study comparing the expression and function of CD80 and CD86 in human LC using the T-helper type-1 cytokines IL-2 and interferon γ (IFN)-γ, and the T-helper type-2 cytokines IL-10, IL-4 and granulocyte/macrophage colony-stimulating factor (GM-CSF). Freshly isolated human LC expressed little CD80 and CD86 in vitro, but the expression of both molecules was rapidly induced during a 72-h incubation with cytokines and the expression of CD86 occurred much earlier and more strongly than that of CD80. The expression of both CD80 and CD86 was upregulated by GM-CSF and downregulated by IL-10, and the expression of CD86, but not that of CD80, was upregulated by both IL-4 and IFN-γ. Finally, pretreatment of LC with GM-CSF and IFN-γ, but not with IL-4, enhanced the alloreactive T-cell proliferation induced by the LC, and IL-10 pretreatment of LC decreased their capacity for alloreaction. These results indicate that the expression of both CD80 and CD86 on human LC may be regulated by these cytokines (IL-2, IL-4, GM-CSF, IFN-γ and IL-10) secreted from helper T cells infiltrating into the inflammatory microenvironment. Received: 4 December 1997     

Malignant fibrous histiocytoma of the thoracic region

A clinicopathological investigation of five malignant fibrous histiocytoma (MFH) in the thoracic region was performed. They were two cases of metastasis to the lung and 1 each of the primary lesion in the lung, chest wall and sternal region. This tumor usually occurs on the extremities, in the abdominal cavity or the retroperitoneal areas, so instances of its arising in the thoracic region, except for metastatic episodes, are considered to be rare. Tumors in 4 cases were excised surgically, while one was inoperable. On light microscopy, the lesions were found to be composed of two types of neoplastic cells, fibroblast-like cells and histiocyte-like cells, showing the characteristic histologic pattern of storiform and pleomorphic. Electron-microscopically, these two types of cells were discriminated according to the quantitative and quantitative differences of the various intracytoplasmic organelles. The histogenesis of malignant fibrous histiocytoma has been commonly considered to be the histiocytic cell derived from the bone marrow. However, more detailed pathological investigations are necessary.     

Absence of proximal neck dilatation and graft migration after endovascular aneurysm repair with balloon-expandable stent-based endografts

OBJECTIVE: Proximal neck dilatation (PND) and/or endograft migration with the subsequent development of type I endoleak is a significant cause of late endograft failure after endovascular abdominal aortic aneurysm repair (EVAR). Although there are numerous reports examining PND in patients receiving endografts that use self-expanding stents (SES) for proximal fixation, there are no such reports for patients treated with endografts that use balloon-expanding stents (BES). The purpose of this study was to investigate PND and endograft migration after EVAR with BES endografts. METHODS: We retrospectively reviewed all charts and all serial computed tomographic scans available for patients who underwent EVAR with a BES endograft (surgeon-made, aortounifemoral polytetrafluoroethylene graft with a proximal Palmaz stent) between August 1997 and October 2002. Only patients with longer than a 12-month follow-up were analyzed. Neck diameter was measured at the level of the lowest renal artery and at 5 mm below it. PND was defined as neck enlargement of 2.5 mm or more. To assess endograft migration, the distance between the superior mesenteric artery and the cranial end of the BES was measured. Stent migration was defined as a change of 5 mm or more. RESULTS: A total of 77 patients received this device during the study period. The technical success rate was 99%. The 1-, 3-, and 5-year survival was 66%, 48%, and 29.5%, respectively. Complete serial computed tomographic scans were available in 41 of the 48 patients who survived 12 months or longer after the operation. The mean follow-up period for these patients was 31 months (range, 12-66 months). The maximum aneurysm diameter was either unchanged or decreased in 35 patients (85%). The immediate postoperative proximal neck diameter was 19 to 29 mm (median, 24 mm). This was unchanged at the latest follow-up. None of the patients had significant PND. The cranial end of the BES was located in the area between 14 mm proximal and 36 mm distal to the superior mesenteric artery (median, 6 mm). None of the patients developed significant endograft migration. CONCLUSIONS: Neither PND nor endograft migration was observed with the BES endograft. The nature of the SES may be responsible for the observed neck dilatation and device migration after EVAR with SES endografts. This study suggests that BES may be a better fixation method for EVAR.     

Behavior of new type of rock wool (HT wool) in lungs after exposure by nasal inhalation in rats

Objectives Previous types of rock wool has been recently replaced with high-temperature wool (HT wool). HT wool is characterized by a chemical composition with a higher concentration of Al₂O₃ and a lower concentration of SiO₂, lower biopersistence, and a higher melting point than previous types of rock wool. To evaluate the safety of HT wool, an asbestos substitute, we examined the biopersistence of HT wool in the lungs, based on changes in fiber count according to the length and fiber size (length and width), by performing a nose-only inhalation exposure study in rats. Methods Male Fischer 344 rats were exposed to fibers at the target exposure concentration of 30 mg/m³ continuously for 3 hours daily for 5 consecutive days. Rats were sacrificed shortly after exposure, and 1, 2, and 4 weeks after exposure, and their lung tissues were incinerated at a low temperature. Then, fiber counts and sizes in the lungs were analyzed using a phase contrast microscope. Results The fiber count in the lungs 4 weeks after exposure significantly decreased from the baseline value (shortly after exposure). The half-life of fibers calculated from the approximation curve was 34 days for all fibers and 11 days for fibers longer than 20 μm. Conclusions Both the length and width significantly decreased 4 weeks after exposure, probably because fibers were ingested by alveolar macrophages, discharged to outside of the body by mucociliary movement, or lysed by body fluid. In future studies, it is necessary to examine the long-term persistence of fibers in the lungs.     

Extended observation of the nasal cycle using a portable rhinoflowmeter

OBJECTIVE: Nasal patency varies owing to the effects of humidity, temperature, and exercise. In addition, periodic cycles of congestion and decongestion that alternate between the right and the left side of the nose, which are termed the "nasal cycle," have been observed. The physiologic mechanisms underlying this cycle are not clear. Sympathetic nerves that supply the nose are regulated by the hypothalamus and the vasomotor areas of the brainstem. It is possible that the nasal cycle could be involved in protection against respiratory infection or allergies. Conventional methods of studying the nasal cycle, including rhinomanometry and acoustic rhinometry, impose limitations on the location and timing of evaluation. We studied the nasal cycle using a new portable device for relatively long-term rhinoflowmetry. METHODS: Twenty normal subjects aged 24 to 77 years were fitted with the portable rhinoflowmeter (Rhinocycle, Rhinometrics, Lynge, Denmark) to continuously measure nasal air flow via each nostril over 12 daytime hours. RESULTS: No subject complained of discomfort owing to the device, and 14 of them showed a detectable nasal cycle. The mean nasal cycle duration was 110 minutes, although variation was considerable, even in a single subject. CONCLUSIONS: The portable device proved useful for observing the nasal cycle, and it should be valuable for the general investigation of nasal physiology.