Factors affecting mortality in Hong Kong patients with upper limb necrotising fasciitis.

OBJECTIVE: To identify predictive factors for mortality of patients with upper limb necrotising fasciitis. DESIGN: Retrospective study. SETTING: Six hospitals in Hong Kong. PATIENTS: Clinical records of 29 patients treated in the hospitals were traced and analysed. MAIN OUTCOME MEASURES: Possible predictive factors for mortality as evaluated by application of Fisher's test. RESULTS: Overall mortality was 28%. Digital infections conferred a lower mortality, but progressive necrosis necessitated amputation. Vibrio vulnificus was the commonest organism identified in association with marine injury and in patients with cirrhosis. Prognostic indicators with decreasing significance include deranged renal and liver function, thrombocytopaenia, proximal involvement (elbow or above) initially, and presence of hypotension upon admission. CONCLUSION: With a P value of less than 0.05, deranged renal and liver function, thrombocytopaenia, initial proximal involvement, and hypotension on admission were predictors of mortality in necrotising fasciitis affecting the upper limbs. The ALERTS (Abnormal Liver function, Extent of infection, Renal impairment, Thrombocytopenia, and Shock) score with a cutoff of 3 appeared to predict mortality.

Hand numbness and carpal tunnel syndrome after volar plating of distal radius fracture.

We report the incidence of late onset post-operative carpal tunnel syndrome (late carpal tunnel syndrome) and late median nerve neuropathy after volar plating of distal radius fracture by conducting a retrospective study on volar plating for distal radius fracture performed during 2002 to 2006. Two hundred eighty-two volar plating were performed for acute distal radius fracture after exclusion. Post-operative hand numbness occurred in 24 patients of which nine had carpal tunnel syndrome. Thus, the incidence of late carpal tunnel syndrome was 3.2% (9/282). Of the eight (8/24, 33%) patients with post-operative hand numbness that failed to respond to conservative treatment, five had carpal tunnel release and three had neurolysis of median nerve at distal forearm. All had clinical improvement except in one patient. The incidence of late carpal tunnel syndrome after volar plating of distal radius in the present series is similar to the prevalence of carpal tunnel syndrome in general population. The incidence is low compared with other series, regardless of treatment method (conservative treatment, volar or dorsal plating). The outcome of post-operative hand numbness is generally favourable.

Efficacy of mirtazapine in preventing intrathecal morphine-induced nausea and vomiting after orthopaedic surgery*.

Nausea and vomiting are frequent complications of intrathecal morphine. In this randomised, double-blind trial, we tested the efficacy of mirtazapine, an antidepressant that blocks receptors associated with vomiting, on the incidence of nausea and vomiting after intrathecal morphine. One hundred patients receiving spinal anaesthesia for lower limb surgery were assigned equally to take either an orally disintegrating form of 30 mg mirtazapine or matching placebo 1 h before surgery. Spinal anaesthesia was performed by injection of 15 mg isobaric bupivacaine 0.5% along with 0.2 mg preservative-free morphine. Nausea and vomiting were evaluated 3, 6, 12, 18 and 24 h after intrathecal morphine administration. The incidence of nausea and vomiting was significantly lower in patients receiving mirtazapine compared with placebo (26.5% vs 56.3%, respectively; p = 0.005). The mean (SD) onset time of postoperative nausea and vomiting was significantly delayed in mirtazapine patients: 9.4 (2.5) vs 5.2 (1.8) h, respectively; p < 0.0001. The severity of nausea and vomiting was also decreased after mirtazapine at the 3-6 h and 6-12 h periods. Our data indicate that pre-operative mirtazapine decreases the incidence, delays the onset and reduces the severity of nausea and vomiting induced by intrathecal morphine in patients undergoing spinal anaesthesia.

Multi-level multi-thermal-electron FDTD simulation of plasmonic interaction with semiconducting gain media: applications to plasmonic amplifiers and nano-lasers.

Interactions between a semiconducting gain medium and confined plasmon-polaritons are studied using a multilevel multi-thermal-electron finite-difference time-domain (MLMTE-FDTD) simulator. We investigated the amplification of wave propagating in a plasmonic metal-semiconductor-metal (MSM) waveguide filled with semiconductor gain medium and obtained the conditions required to achieve net optical gain. The MSM gain waveguide is used to form a plasmonic semiconductor nano-ring laser(PSNRL) with an effective mode volume of 0.0071 microm3, which is about an order of magnitude smaller than the smallest demonstrated integrated photonic crystal based laser cavities. The simulation shows a lasing threshold current density of 1kA/cm2 for a 300 nm outer diameter ring cavity with 80 nm-wide ring. This current density can be realistically achieved in typical III-V semiconductor, which shows the experimental feasibility of the proposed PSNRL structure.

Mycobacterium chelonae and Mycobacterium fortuitum infection following open fracture: a case report and review of the literature.

We report a case of dual nontuberculous mycobacterial infections complicating an open distal radius and ulna fracture after polytrauma in a 35-year-old man. There was persistent wound discharge after definitive fixation of this fracture, but microbiological cultures did not yield any organism. The patient underwent multiple debridement, and subsequent tissue grew Mycobacterium chelonae and Mycobacterium fortuitum. Despite appropriate chemotherapy and surgical debridement the infection persisted until radical bone excision and tissue debridement were done. This case indicates that nontuberculous mycobacterial infections should be considered when conventional microbiological assays fail to identify the infecting agent in suspected osteomyelitis following open fracture. A combination of radical debridement, including removal of infected bone, and prolonged antimicrobial therapy are required to eradicate the infection completely.

Osteonecrosis of the jaw after oral bisphosphonate for osteoporosis.

Bisphosphonates are a common treatment for osteoporosis. Osteonecrosis of the jaw has been associated with the use of bisphosphonates, usually when they have been used parenterally to treat malignancies. Cases associated with oral bisphosphonate as a treatment for osteoporosis are less frequent. We describe two patients exhibiting the clinical manifestations of bisphosphonate-associated osteonecrosis of the jaw. A brief review of the literature on the incidence, possible risk factors, and practice guidelines is also presented.

Relative reliability of the auditory evoked potential and Bispectral Index for monitoring sedation level in surgical intensive care patients.

Sedation is an important adjunct therapy for patients in the intensive care unit. The objective of the present study was to observe correlation between an established subjective measure, the Ramsay Sedation Scale, and two objective tools for monitoring critically ill patients: the Bispectral Index (BIS) and auditory evoked potential. Ninety patients undergoing major surgery scheduled for postoperative mechanical ventilation and continuous sedation with propofol and fentanyl were selected. Electrodes for determining BIS and auditory evoked potential were placed on the foreheads of all patients according to manufacturer's specifications at least six hours after patients' arrival at the intensive care unit. Ramsay Sedation Scale, BIS, signal quality index, composite A-line autoregressive index (AAI) and electromyographic activities were recorded every five minutes for 30 minutes. BIS and AAI showed good correlation amongst readings (r(s)=0.697, P <0.01). Both were significantly influenced by electromyographic activities (BIS, r(s)=0.735, P <0.01; AAI, r(s)=0.856, P <0.01). Comparison of BIS and AAI revealed an acceptable correlation between electroencephalogram variables and the Ramsay Sedation Scale (BIS, tau=-0.689; AAI, tau=-0.621; P <0.01). In conclusion, the auditory evoked potential and BIS monitors revealed an acceptable correlation with the Ramsay Sedation Scale. However, the BIS and auditory evoked potential monitors do not perform adequately as a substitute in the assessment of sedated intensive care unit patients. These monitors could be used as part of an integrated approach for the evaluation of those patients especially when the subjective scales do not work well in the setting of neuromuscular blockade or may not be sufficiently sensitive to evaluate very deep sedation.

Prophylactic mirtazapine reduces intrathecal morphine-induced pruritus.

BACKGROUND: Activation of the serotonergic system is an important factor in the pathogenesis of intrathecal morphine-induced pruritus. Mirtazapine is a new antidepressant that selectively blocks 5-HT(2) and 5-HT(3) receptors. We therefore tested the hypothesis that preoperative mirtazapine would reduce the incidence of intrathecal morphine-induced pruritus. METHODS: One hundred and ten ASA I patients undergoing lower limb surgery under spinal anaesthesia were randomly allocated into two equal groups and received either mirtazapine 30 mg or an orally disintegrating placebo tablet 1 h before operation in a prospective, double-blinded trial. All patients received an intrathecal injection of 15 mg of 0.5% isobaric bupivacaine and 0.2 mg preservative-free morphine. The occurrence and the severity of pruritus were assessed at 3, 6, 9, 12, and 24 h after intrathecal morphine. RESULTS: Pruritus was significantly more frequent in the placebo group compared with the mirtazapine group (75% vs 52%, respectively; P=0.0245). The time to onset of pruritus in the two groups was also significantly different. The patients who experienced pruritus in the placebo group had a faster onset time than that in the mirtazapine group [mean (sd): 3.2 (0.8) vs 7.2 (4.1) h, P<0.0001]. CONCLUSIONS: Mirtazapine premedication prevents pruritus induced by intrathecal morphine in patients undergoing lower limb surgery with spinal anaesthesia.

Squamous cell carcinoma arising from an epidermal cyst.

There are few case reports in the English literature concerning malignant transformation of an epidermal cyst into squamous cell carcinoma. We report a case of squamous cell carcinoma arising from a 40-year epidermal cyst in the proximal left thigh of a 74-year-old man. The epidermal cyst had increased in size in the previous 3 years. The patient presented with a discharge from the lesion. Ultrasonography and magnetic resonance imaging of the lesion suggested malignancy. An intra-operative frozen section of an incisional biopsy of the lesion found it to be an epidermal cyst with suspected malignant change, so a marginal excision of the lesion was performed. Squamous cell carcinoma arising from the epidermal cyst was confirmed histologically. A wide excision was done in order to obtain an adequate resection margin. A computed tomographic scan of the thorax and abdomen found no evidence of metastases. No evidence of recurrence was noted in the latest follow-up, 2 years postoperatively.

Antinociceptive effect of a novel long-acting nalbuphine preparation.

BACKGROUND: A long-acting analgesic may be particularly desirable in patients suffering from long-lasting pain. The aim of the study was to evaluate the antinociceptive effect of a novel nalbuphine preparation and to determine its duration of action. METHODS: The antinociceptive effects of i.m. nalbuphine HCl in saline and nalbuphine base in sesame oil were evaluated in rats. The in vitro drug-releasing profiles of nalbuphine HCl and base in different preparations were also evaluated. RESULTS: We found that i.m. nalbuphine HCl 25, 50 and 100 micromol kg(-1) produced dose-related antinociceptive effects with a duration of action of 1.5, 2 and 3 h, respectively. i.m. nalbuphine base 100, 200 and 400 micromol kg(-1) also produced dose-related antinociceptive effects but with longer durations of action: 27, 49 and 55 h, respectively. In vitro studies demonstrated that nalbuphine base in sesame oil had the slowest drug-releasing profile of the different preparations. CONCLUSIONS: i.m. injection of an oil formulation of nalbuphine base produced a long-lasting antinociceptive effect.

Pharmacokinetics of desflurane uptake into the brain and body.

The aim of this study was to investigate the pharmacokinetics of desflurane uptake into the brain and body by comparing desflurane concentrations in internal jugular-bulb blood (Jdes), arterial blood (Ades) and pulmonary arterial blood (PAdes) at a fixed inspired desflurane concentration. Thirteen patients (aged 42-72 years) undergoing coronary artery bypass grafting surgery were enrolled in this study. They were anaesthetised using a constant 5% inspired desflurane concentration (CIdes) during the first hour of anaesthesia. Under constant volume-controlled ventilation, CIdes and end-tidal desflurane (CEdes) were measured with an infrared analyser. The desflurane concentration in the blood was analysed using gas chromatography, and cardiac output was measured using an Opti-Q pulmonary artery catheter. It took 24 min for the Jdes to equilibrate with Ades. Both CIdes-CEdes and Ades-PAdes gradients persisted during the study period. There was no further uptake of desflurane into the brain after 24 min but there was near-constant uptake into the body.

High prevalence of asymptomatically poor muscle perfusion of lower extremities measured in systemic lupus erythematosus patients with abnormal myocardial perfusion.

Patients with systemic lupus erythematosus (SLE) may develop premature atherosclerosis, notably peripheral vascular disease (PVD) presenting with intermittent claudication or gangrene. Therefore, it is important to investigate if high prevalence of poor muscle perfusion of lower extremities in SLE patients with abnormal myocardial perfusion is related to more cardiovascular risk factors. We used a well-established and noninvasive radionuclide method (xenon 133 muscle washout) to evaluate objectively the anterior tibial muscle perfusion of 34 SLE female patients without symptoms/signs of PVD in the lower extremities. The patients were separated into two groups according to myocardial perfusion imaging results. Meanwhile, 30 normal female controls with matched age distribution were also included for comparison. The muscle perfusion differed significantly ( P <0.05) between patients (1.90+/-0.41 ml/100 g per min) and controls (2.91+/-0.50 ml/100 g per min), as well as between 18 SLE patients with abnormal myocardial perfusion (1.33+/-0.43 ml/100 g per min) and 16 with normal myocardial perfusion (2.26+/-0.45 ml/100 g per min). Based on the xenon 133 muscle washout method, we conclude that muscle perfusion in the lower extremities of SLE patients without symptoms/signs of PVD is significantly decreased and related to abnormal myocardial perfusion.

Using technetium-99m tetrofosmin chest imaging to predict taxol-based chemotherapy response in non-small cell lung cancer but not related to lung resistance protein expression.

In vitro studies have shown that technetium-99m tetrofosmin (Tc-99m TF) is a transport substrate for the P-glycoprotein (Pgp) pump. Therefore, Tc-99m TF uptake of tumors can be used to predict chemotherapy response in lung cancers. However, whether lung resistance-related protein (LRP) expression affects tumor accumulation and efflux of Tc-99m TF in lung cancers is not known. Our aim was to use Tc-99m TF uptake of tumors to predict paclitaxel-based chemotherapy response of non-small cell lung cancer (NSCLC) and to compare Pgp or LRP expression. Twenty patients with advanced NSCLC received Tc-99m TF chest images before Taxol-based chemotherapy was used in this study. The chemotherapy response was evaluated by clinical and radiological methods in the third month after completion of treatment. No significant differences of prognostic factors (age, sex, body weight loss, performance status, tumor size, tumor stage, and tumor cell type) were found between the patients with good and those with poor responses. Early and delayed tumor/normal lung (T/L) uptake ratios were calculated on Tc-99m TF chest images. Immunohistochemical analyses were performed on multiple nonconsecutive sections of the biopsy specimens to detect Pgp and LPR expressions. The early and delayed T/L uptake ratios of 10 patients with good response were significantly higher than those of the other 10 patients with poor response. Significantly higher early and delayed T/L uptake ratios were found in patients with negative than those with positive Pgp expression ( p < 0.05). However, no significant differences of early and delayed T/L uptake ratios were found between patients with negative and positive LRP expressions ( p > 0.05). We found that Tc-99m TF imaging could accurately predict Taxol-base chemotherapy response. In addition, the Tc-99m TF tumor uptake was related to Pgp but not LPR expression in NSCLC.

Pharmacokinetics of sevoflurane uptake into the brain and body.

The aim of this study was to investigate the pharmacokinetics of sevoflurane uptake into the brain and body by comparing sevoflurane concentrations in internal jugular-bulb blood (Jsev), arterial blood (Asev) and pulmonary arterial blood (PAsev) over a fixed inspired sevoflurane concentration. Ten patients (aged 51-73 years), undergoing coronary artery bypass grafting surgery were enrolled in this study. They were anaesthetised using a constant 3.5% inspired sevoflurane concentration (CIsev) during the first hour of anaesthesia. During constant volume-controlled ventilation, we measured CIsev and end-tidal sevoflurane (CEsev) using infrared analysis. The sevoflurane concentration in the blood was analysed using gas chromatography, and cardiac output was measured using an Opti-Q pulmonary artery catheter. We found that it took 40 min for the brain concentration to equilibrate with arterial blood (Asev). Both CIsev-CEsev and Asev-PAsev gradients persisted during the study period. There was no further uptake of sevoflurane into the brain after 40 min; however, there was near-constant uptake into the body.

Correlations of extractable heavy metals with organic matters in contaminated river sediments.

In southern Taiwan, almost all the main rivers have been contaminated by anthropogenic heavy metals and organic matters. The main pollution sources include agricultural, industrial, and domestic activities. River sediments potentially have large capacities to accumulate heavy metals and organic matters when the river water flows through it. The sediments sampled from high contaminated river (the Yenshui River) and moderately contaminated rivers (the Tsengwen, Chishui, Potzu, and Peikang Rivers) were used to realize correlations between each kind of aqua regia extractable heavy metals (Co, Cr, Cu, Zn, Ni, Pb, Mn, and Fe) and organic matters in vertical sediment cores. Organic matters and aqua regia extractable heavy metal concentrations, analyzed by strong acid-digested extraction, were determined in vertical profile segments from downstream sediments of the five rivers. Sum of six aqua regia extractable heavy metals (Co, Cr, Cu, Zn, Ni, and Pb) were below 3,000 mg/kg in sediments of the Yenshui River, and below 500 mg/kg in the other four rivers' sediments. Strongly positive correlations (r = 0.83-0.95) between each kind of aqua regia extractable heavy metals and organic matters (concentration range between 0.6 to 3.8%) were observed in sediments of the Yenshui River. The slopes of the linear regressive lines approximated the average metal complexation ratios with organic matters in the sediments. In sediments of the other four rivers, smaller positive correlation coefficients between aqua regia extractable heavy metals and organic matters (below 2.6%) were observed. The complexation ratios derived from the four moderately polluted river sediments were smaller than those derived from the highly contaminated river sediments, indicating that the importance of organic matters in the accumulation of heavy metals in river sediments.

Usefulness of Tc-99m ECD brain SPECT to evaluate the effects of methylprednisolone pulse therapy in lupus erythematosus with brain involvement: a preliminary report.

Methylprednisolone pulse therapy (MPT) was introduced to avoid life-threatening complications in systemic lupus erythematosus (SLE) with brain manifestations. However, its efficacy in SLE patients remains uncertain and needs to be objectively evaluated. In this study, technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect regional cerebral blood flow (rCBF) in SLE patients with normal brain magnetic resonance imaging (MRI) findings. Twelve female SLE patients with neuropsychiatric symptoms were enrolled in this study. All patients had normal brain MRI and abnormal Tc-99m ECD brain SPECT findings. The Tc-99m ECD brain SPECT studies were performed 2 weeks after MPT. Pre- and post-MPT serum levels of anticardiolipin antibodies (ACA) and antiribosomal P antibodies (anti-P) were also measured. Before MPT, four patients had positive ACA and seven had positive anti-P. After MPT, all 12 patients demonstrated negative serologic findings and no neuropsychiatric symptoms. After MPT, ten patients showed complete recovery and two showed partial recovery of rCBF in the follow-up Tc-99m ECD brain SPECT images. This imaging is a logical and objective tool for measuring the effects of MPT in SLE patients with brain involvement by the determination of rCBF changes.

Evaluating the changes in alveolar permeability and lung ventilation in patients with chronic renal failure after haemodialysis using 99mTc-DTPA radioaerosol inhalation lung scan.

Hypoxaemia occurring in patients with chronic renal failure (CRF) during haemodialysis (HD) has long been known. Several mechanisms of pathogenesis have been proposed. Before and after regular HD, lung ventilation (LV) and alveolar permeability (AP) were measured in 24 male patients with CRF (age, 61-75 years). LV and AP were determined by 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) radioaerosol inhalation lung scan (99mTc-DTPA lung scan). The LV images were visually interpreted according to established criteria, including the presence or absence of an inhomogeneous distribution, inverted base to apex gradient and segmental hypoventilation. The degree of AP in the total right lung was presented as the clearance rate (K; %.min-1) of the time-activity curve from dynamic total right lung images. Ten male normal controls (age, 62-76 years) were enrolled in the study for comparison. Ten of 24 (42%) cases showed an inhomogeneous distribution and eight of 24 (33%) cases showed hypoventilation on equilibrium LV images. After regular HD for 5 h, no significant changes in the LV images were found. Before HD, the CRF patient group (K=1.14+/-0.36%.min-1) had a significantly faster clearance rate than that of normal controls (0.75+/-0.14%.min-1, P<0.05). Moreover, the clearance rate after HD was significantly slower (0.87+/-0.15%.min-1, P<0.05) than that before HD. CRF can predispose patients to LV change and AP damage. After HD, the damage to AP is significantly improved. However, after HD, the change in LV is not significant.

Predicting chemotherapy response to paclitaxel-based therapy in advanced non-small-cell lung cancer with P-glycoprotein expression.

BACKGROUND: It was reported that multidrug resistance gene 1 (MDR1) encoding human P-glycoprotein (Pgp) may play an important role in multidrug resistance of lung cancer. Therefore, before initiating chemotherapy, it is important to accurately determine the presence of Pgp in lung cancer, to achieve a satisfactory chemotherapy response. OBJECTIVES: The aim of this study was to compare immunohistochemical analyses of Pgp expression and response to paclitaxel in non-small-cell lung cancer (NSCLC). METHODS: Before chemotherapy with paclitaxel, 50 patients with stage IIIb or IV NSCLC were enrolled in this study. Immunohistochemical analyses were performed on multiple nonconsecutive sections of the biopsy specimens to determine Pgp expression. Chemotherapy response was evaluated in the 3rd month after completion of treatment by clinical and radiological methods. RESULTS: All of the 28 (100%) cases with good response had negative Pgp expression and 15 of the 22 (68%) cases with poor response had positive Pgp expression (p < 0.05). No significant differences were found for other prognostic factors (age, sex, body weight loss, performance status, tumor cell type, and tumor stage) between good response and poor response groups. CONCLUSIONS: Although Pgp expression in NSCLC does not fully predict chemotherapy response to paclitaxel-based therapy, detection of Pgp expression will aid in planning paclitaxel-based therapy for patients with advanced NSCLC. Further studies with a larger number of patients and a longer time of follow-up are necessary to confirm our findings.

Comparing the relationship of Taxol-based chemotherapy response with P-glycoprotein and lung resistance-related protein expression in non-small cell lung cancer.

Our aim was to compare Taxol-based chemotherapy response of non-small cell lung cancer (NSCLC) with P-glycoprotein (Pgp) or lung resistance protein expression (LRP). Immunohistochemical analyses were performed on multiple nonconsecutive sections of the biopsy specimens to detect Pgp and LPR expressions in 40 patients with advanced NSCLC before Taxol-based chemotherapy. The chemotherapy response was evaluated by clinical and radiological methods in the third month after completion of treatment. No significant differences of prognostic factors (age, sex, body weight loss, performance status, tumor size, tumor stage, and tumor cell type) were found between the 20 patients with good and the 20 patients with poor responses. The incidence difference of positive Pgp expressions between good and poor responses was significant, however, the difference of LRP expression was not. We concluded that Taxol-based chemotherapy response of patients with NSCLC was related to Pgp but not LPR expression.

Monitoring cytokeratin fragment 19 (CYFRA 21-1) serum levels for early prediction of recurrence of adenocarcinoma and squamous cell carcinoma in the lung after surgical resection.

The purpose of this study was to evaluate the markers' clinical usefulness for early prediction of recurrence, by serial and simultaneous measurements of serum cytokeratin fragment 19 (CYFRA 21-1), before and after surgery on patients with non-small cell lung cancers (NSCLC). The 48 patients enrolled in this study had adenocarcinoma of the lung (adenoCa) (including 24 patients with recurrence and 24 patients without recurrence 1 year after surgery) and 48 patients with squamous cell carcinoma of the lung (SCC) (including 24 cases with recurrence and 24 without recurrence 1 year after surgery). Serial serum levels of CYFRA 21-1 were measured before the operation and 1 week, 1 month, 3 months, 6 months, 9 months, and 12 months after surgery for the early detection of recurrence. The results revealed that (1) the mean serum values of CYFRA 21-1 were significantly higher beginning at 1 month after surgery in the 24 patients with recurrent adenoCa compared with the 24 patients without recurrent adenoCa, (2) mean serum values of CYFRA 21-1 were significantly higher beginning at 1 month after surgery in 24 patients with recurrent SCC when compared with 24 patients without recurrent SCC, and (3) mean serum values of CYFRA 21-1 were significantly higher beginning at 1 month after operation in the total 48 patients with recurrent NSCLC when compared with 48 patients without recurrent NSCLC. We conclude that CYFRA 21-1 is not a good marker for early prediction of NSCLC recurrence including adenoCa and SCC after surgery.