Lean techniques for the improvement of patients' flow in emergency department.

BACKGROUND: Emergency departments (EDs) face problems with overcrowding, access block, cost containment, and increasing demand from patients. In order to resolve these problems, there is rising interest to an approach called "lean" management. This study aims to (1) evaluate the current patient flow in ED, (2) to identify and eliminate the non-valued added process, and (3) to modify the existing process. METHODS: It was a quantitative, pre- and post-lean design study with a series of lean management work implemented to improve the admission and blood result waiting time. These included structured re-design process, priority admission triage (PAT) program, enhanced communication with medical department, and use of new high sensitivity troponin-T (hsTnT) blood test. Triage waiting time, consultation waiting time, blood result time, admission waiting time, total processing time and ED length of stay were compared. RESULTS: Among all the processes carried out in ED, the most time consuming processes were to wait for an admission bed (38.24 minutes; SD 66.35) and blood testing result (mean 52.73 minutes, SD 24.03). The triage waiting time and end waiting time for consultation were significantly decreased. The admission waiting time of emergency medical ward (EMW) was significantly decreased from 54.76 minutes to 24.45 minutes after implementation of PAT program (P<0.05). CONCLUSION: The application of lean management can improve the patient flow in ED. Acquiescence to the principle of lean is crucial to enhance high quality emergency care and patient satisfaction.

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.

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.

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.

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.

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.

Comparison between technetium 99m hexamethylpropyleneamine oxide labeled white blood cell abdominal scan and abdominal sonography to detect appendicitis in adult patients with atypical clinical presentation.

BACKGROUND: Acute appendicitis is much more serious in the elderly, and early diagnosis is very important. However, the diagnosis of acute appendicitis in older patients is often difficult because these patients may present with atypical clinical manifestations. METHODS: We conducted a prospective study to evaluate and compare the value of technetium 99m hexamethylpropyleneamine oxide (Tc 99m HMPAO) labeled white blood cell (WBC) abdominal scan and abdominal sonography in the diagnosis of acute appendicitis in older patients with an atypical clinical presentation. Forty-nine patients (age > 50 years) with acute abdominal pain and suspected appendicitis, but with atypical findings, were included in this study. RESULTS: Twenty-seven patients received laparotomy for final surgical and pathologic diagnoses. The remaining 22 patients did not receive surgery and showed no evidence of appendicitis after at least 1 month of follow-up. Two patients had false-positive WBC scan findings and two patients had false-negative WBC scan findings. The overall sensitivity, specificity, and accuracy for WBC scans in diagnosing appendicitis were 92.0%, 91.7%, and 91.8%, respectively. The overall sensitivity, specificity, and accuracy for abdominal sonography in diagnosing appendicitis were 84.0%, 95.8%, and 89.8%, respectively. CONCLUSION: The Tc 99m HMPAO WBC scan provides a more sensitive and accurate method for diagnosing appendicitis in older patients with equivocal clinical examinations when compared with abdominal sonography.

Relationship between chemotherapy response of small cell lung cancer and P-glycoprotein or multidrug resistance-related protein expression.

The resistance of small cell lung cancer (SCLC) to anticancer drugs is a serious clinical problem often encountered during chemotherapy. Therefore, how to prevent this drug resistance need to be investigated. Multidrug resistance 1 (MDR1) gene and multidrug resistance-related protein (MRP) gene, two genes known to be associated with the development of drug resistance, are very common in SCLC. The purpose of this study was to evaluate retrospectively the relationship between chemotherapy responses to MDR1 gene encodes 170 kDa P-glycoprotein (Pgp) expression or MRP gene encodes 190 kDa MRP expression in SCLC. Before chemotherapy, multiple nonconsecutive sections of the bronchoscopy biopsy specimens of SCLC from 50 patients were analyzed immunohistochemically to detect Pgp and MRP expressions. Chemotherapy responses of the 50 patients were evaluated in the third month after completion of treatment by clinical and radiological methods. Of the 23 SCLC patients with poor response to chemotherapy, 11 had positive Pgp and MRP expressions, 2 had positive Pgp but negative MRP expressions, 6 had positive MRP but negative Pgp expressions, and 4 patients had negative Pgp and MRP expressions. All 27 SCLC patients with good response had negative Pgp and MRP expression. Immunohistochemical analyses of Pgp or MRP expression are potential tools for predicting patients' chemotherapy response in SCLC.

Increased lung uptake of technetium-99m hexamethylpropylene amine oxime in systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) can affect every organ. Involvement of the lungs in this disease is a significant cause of morbidity and mortality. OBJECTIVES: To assess pulmonary vascular endothelium damage in SLE by lung uptake of technetium-99m hexamethylpropylene amine oxime ((99m)Tc-HMPAO). METHODS: Lung uptake of (99m)Tc-HMPAO was measured in 20 SLE patients and for comparison in 25 controls without SLE, referred for brain imaging due to dementia or stroke. Of the 20 SLE patients, 10 had significant clinical pulmonary manifestations. However, all SLE patients had normal chest X-ray findings. Anterior lung image, including a large part of the liver, was taken 10 min after intravenous injection of 20-25 mCi of (99m)Tc-HMPAO. Regions of interest were calculated over the liver and lung. RESULTS: The mean lung/liver uptake ratio in patients without SLE was 0.36 +/- 0.1. The mean lung/liver uptake ratio in SLE patients was 0.79 +/- 0.58. The difference was significant. CONCLUSIONS: Our results indicated that determining the ratio of lung/liver uptake of (99m)Tc-HMPAO may be a useful complementary method to assess pulmonary injury in SLE patients.

Transition from amplified spontaneous emission to laser action in strongly scattering media

In an active random medium, the combination of multiple scattering with light amplification may lead to random laser action. However, it is crucial but sometimes difficult to distinguish between amplified spontaneous emission and lasing. By varying the amount of scattering in an amplifying random medium, we have observed the transition from amplified spontaneous emission to lasing with coherent feedback. We have found out when the transition occurs through the measurement of the scattering mean free path. Our numerical simulation based on the direct solution to Maxwell equations clearly illustrates the transition from light amplification to laser oscillation due to an increase of the amount of scattering in active random medium.

Spatial confinement of laser light in active random media

We have observed spatial confinement of laser light in micrometer-sized random media. The optical confinement is attributed to the disorder-induced scattering and interference. Our experimental data suggest that coherent amplification of the scattered light enhances the interference effect and helps the spatial confinement. Using the finite-difference time-domain method, we simulate lasing with coherent feedback in the active random medium.