Lean Six Sigma Methodologies to Reduce the Cardiac Troponin Turnaround Time in the Core Laboratory

OBJECTIVE

Measurement of cardiac biomarker troponin T plays a vital role in the diagnosis of myocardial infarction. A quick turnaround time (TAT) for cardiac troponin T is crucial in managing patients in the emergency department and critical care unit. The goal of the study was to implement Lean Six Sigma methods to improve stat troponin T TAT compliance rate (the time specimen received in the laboratory to the reporting of results through the laboratory information system [LIS]) from 86% to 95% in an 8-month period.

METHODS

We conducted a quality and process improvement project to reduce stat troponin T TAT in the core laboratory. We used a 5-stage Six Sigma methodology to simplify the laboratory work process and decrease the TAT by eliminating non-value-added steps. Data from April 2021 (baseline) and January 2022 (improved) are included in the analysis.

RESULTS

In the core laboratory, we improved the TAT for the preanalytical and analytical process by eliminating the batch processing and prioritizing the stat samples. We improved the TAT for the postanalytical process by replacing manual result verification with auto result verification via an LIS. Improved stat troponin T TAT compliance rate has the potential to enhance the overall quality of patient care, especially in the emergency and critical care departments.

CONCLUSION

Using Lean Six Sigma methodologies in the core laboratory, we successfully improved the stat troponin T TAT compliance rate from 86% to 95% in an 8-month period.

Isolated Metastasis to the Brain From Upper Tract Urothelial Carcinoma

Isolated brain metastasis from cancers of urothelial origin are rare, especially after a long recurrence-free interval with few reports in the literature. We herein present the case of a 62 year old male with history of recurrent bladder cancers treated in 2004 and 2005 and a left distal ureteral high grade pT3aN1M0 urothelial cancer treated with distal ureterectomy and reimplant followed by adjuvant chemotherapy in 2014 who presented after a 5 year recurrence-free interval with tonic-clonic seizure. Further workup revealed an isolated 12.0 mm x 18.0 mm x 8.0 mm mass overlying the left parietal lobe with no other metastatic sites. The patient was treated with resection of the mass and adjuvant radiation therapy with pathology confirming metastatic carcinoma of urothelial origin. Though prognosis for patients with such a presentation remains poor, we provide a review of the current literature with respect to incidence, presentation and therapeutic considerations for such patients.

Risk of severe serotonin toxicity following co-administration of methylene blue and serotonin reuptake inhibitors: an update on a case report of post-operative delirium

In a previous case report, published in this journal, we described a postoperative delirium in a patient during recovery from parathyroidectomy. We noted that the delirium resembled serotonin toxicity and that the patient had been taking paroxetine until 2 days before surgery. We offered several tentative explanations for this event, including an adverse interaction between paroxetine and other agent(s) used in the course of the anaesthesia. Recent developments in characterisation of serotonin toxicity have prompted us to re-examine the clinical details surrounding this life-threatening event. It is now known to be important that the patient was given methylene blue, pre-operatively, to enable visualisation of the parathyroid glands. Methylene blue has been found to be a potent inhibitor of monoamine oxidase (MAO), and several cases of serotonin toxicity have been reported recently following its administration. All these cases are consistent with the well-known risk of serotonin toxicity when drugs that augment serotonergic transmission are given in combination with an MAO inhibitor. Methylene blue is used in a variety of surgical settings as well as for treatment of various types of hypotensive shock and methemoglobinaemia. It is also being studied for treatment of Alzheimer's disease and malaria. In this paper, we outline the pharmacology of methylene blue and the aetiology of serotonin toxicity to help prevent further unintentional co-administration of drugs that risk precipitating this life-threatening drug interaction.

Postoperative delirium indicating an adverse drug interaction involving the selective serotonin reuptake inhibitor, paroxetine?

We report a postoperative delirium expressed by a 49-year-old female patient during recovery from anaesthesia. Prominent features of the delirium, which lasted for nearly 2 days, included agitation, confusion, uncontrolled limb movements, abnormal ocular function, hypertension, pyrexia, brisk reflexes, ankle clonus and raised creatine kinase. The delirium did not respond to naloxone, diazepam or flumazenil. The patient had not been prescribed neuroleptics but, before surgery, she had been taking the selective serotonin reuptake inhibitor, paroxetine, to relieve her depression. During surgery, she was given morphine, which increases release of the neurotransmitter, serotonin, and ondansetron, which blunts neuronal release of dopamine. Although there is no clear explanation for the delirium, it had many features in common with problems associated with paroxetine withdrawal, the serotonin syndrome and the malignant neuroleptic syndrome. We offer several alternative explanations for this event, all of which rest on disruption of serotonergic and/or dopaminergic transmission and which could also involve inhibition by paroxetine of the P450 enzyme, CYP2D6, which metabolizes ondansetron.

Analgesic benefit of locally injected bupivacaine after hemorrhoidectomy

The analgesic efficacy of locally injected bupivacaine was studied in 40 patients undergoing hemorrhoidectomy. After a standard Milligan-Morgan hemorrhoidectomy, 40 age- and sex-matched patients were randomized to receive either 0.5 percent bupivacaine (1.5 mg/kg) in adrenaline solution (1:200,000) injected into the perianal area, or equivalent volumes of adrenaline solution. Intramuscular opiate was available on demand during the postoperative period, and the amount and timing of analgesia given was recorded. All patients noted their pain on a daily basis using a linear analogue scale, and all patients answered a questionnaire assessing analgesic efficacy. Although the median time interval between surgery and first analgesic demand was nearly four times greater for patients receiving bupivacaine compared with adrenaline solution, there was no difference in the levels of pain recorded or in the overall opiate requirements. Local injection of bupivacaine after hemorrhoidectomy provides initial pain relief, but patients do not obtain an overall analgesic benefit.

Effect of doxapram on postoperative oxygenation in obese patients

A infusion of doxapram in 5% dextrose at a rate of 2 mg/kg/hour for 6 hours, or of 5% dextrose alone, was given to 20 grossly obese patients who had undergone upper abdominal surgery. There was no statistically significant difference in the degree of hypoxaemia or the incidence of chest infections between the two groups.

Morbidity after day-case gynaecological surgery. Comparison of enflurane with halothane

In 105 patients undergoing day-case surgery recovery of consciousness was significantly faster after enfluane compared with halothane anaesthesia. There was no difference in postoperative morbidity between the two anaesthetic groups.

Morbidity of day-case gynaecological surgery. A comparison of thiopentone and Althesin

To compare two anaesthetic techniques, morbidity following day-case gynaecological surgery in 170 patients was assessed by means of a questionnaire at the time of leaving hospital. A further questionnaire sought information for the evening of the operation, and the 1st and 2nd days after operation. Ninety-four per cent of patients returned the latter questionnaire. There was a high frequency of morbidity extending into the 2nd day after operation. An anaesthetic technique using Althesin and nitrous oxide in oxygen offered no advantage over a technique with thiopentone and nitrous oxide in oxygen and halothane.