Metformin-associated lactic acidosis (MALA) is a rare but potentially lethal complication. The first case of MALA with acute renal failure after colonoscopy was reported. Further study is needed to review whether metformin should be withheld before procedures associated with dehydration. A community-dwelling 86-year-old woman was admitted for dizziness and vomiting for 2 days. She had a history of type 2 diabetes mellitus (NIDDM) with a glycated hemoglobin of 7.3%. She was taking gliclazide (modified-release formulation) 120 mg/d and metformin 1 g three times daily for NIDDM. Two days before this admission, a colonoscopy had been performed to investigate rectal bleeding. Polyethylene glycol was used for bowel preparation. The colonoscopy revealed a 5-cm tumor in the rectum. Biopsy of the tumor showed it was adenocarcinoma. She was afebrile with a blood pressure of 133/60 mmHg and pulse rate of 101/minute on admission. Examination of respiratory, cardiovascular, and gastrointestinal systems was unremarkable. Her blood glucose level was 34.2 mg/dL. She was oliguric, with urine output of less than 10 mL/hour. Laboratory investigations revealed acute renal failure, with serum creatinine level rising from a baseline of 0.88 to 5.83 mg/dL and serum urea from 17.6 to 63 mg/dL. High anion gap metabolic acidosis was detected, with a pH of 6.74, a serum bicarbonate of 2 mEq/L, and an anion gap of 52.6 mEq/L. Serum lactate was high (24 mEq/L). Urgent noncontrast computed tomography revealed no urinary tract obstruction. The patient was treated for MALA and acute renal failure and transferred to the intensive care unit for emergency hemodialysis. Intravenous cefuroxime and metronidazole were given for Klebsiella urinary tract infection. After 5 days, there was marked improvement in renal function and acid-based disturbance. Urine output increased, and serum lactate fell. She was transferred to a convalescent hospital for rehabilitation after stabilization. MALA is an uncommon but potentially fatal complication. Incidence has been estimated to be 9 per 100,000 person-years of exposure.1 Mortality with MALA has been reported to be 45%.2 MALA after colonoscopy due to bowel preparation with polyethylene glycol has not been reported. To the best of the knowledge of the authors of this letter, this is the first case reported in literature. Accumulation of metformin can occur in individuals with renal impairment as it is excreted from the kidney. According to National Clinical Guidelines and American Diabetes Association consensus, metformin should be discontinued in individuals whose serum creatinine is greater than 1.5 mg/dL and estimated glomerular filtration rate (eGFR) is less than 30 mL/min per 1.73 m2.3, 4 It is worthwhile to calculate creatinine clearance (CrCl) or eGFR in elderly adults, especially those who have low muscle mass because creatinine production is low in these individuals. In the woman discussed in this letter, baseline serum creatinine was within the normal range. CrCl calculated using the Cockcroft-Gault equation was 34.61 mL/min and eGFR using the Modification of Diet in Renal Disease (MDRD) study equation was 58.35 mL/min per 1.73 m.2 According to the above guidelines, metformin was safe in this woman, but she was on a high dose of metformin, amounting to 3 g/d. Circulatory compromise can trigger the development of MALA. Being isomotic in nature, polyethylene glycol causes minimal fluid shift across colonic membrane, but recent studies have shown that polyethylene glycol is associated with risk of acute renal failure.5 Fatal dehydration has also been reported, arising through the interaction of multiple factors.6 Previous studies could not show an obvious relationship between dose of metformin and risk of MALA.7 The authors of the current letter believe that the potential culprit in acute renal failure and MALA in this woman was dehydration after bowel preparation for colonoscopy. Nausea and vomiting, a well-known side effect of polyethylene glycol, worsened the dehydration process. The above factors resulted in low effective circulatory volume and tissue hypoperfusion. The interplay of the above factors resulted in acute renal failure and MALA in this older woman with satisfactory baseline renal function. This case illustrates an important principle in managing older adults. Although objective parameters suggested that it was safe for this woman to take metformin, the presence of unexpected coexisting conditions can lead to dehydration, renal failure, and ultimately MALA. Because older adults are prone to iatrogenesis because of poor organ function and low reserve, clinicians need to pay particular attention whenn ordering investigations and prescribing drugs. Clinicians should beware of MALA in procedures that could lead to dehydration in older adults. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: All the authors contributed in managing the woman. WC Kwok was the main author. TC Chan, JKH Luk, and FHW Chan reviewed this letter and provided opinions and comments. Sponsor's Role: No sponsor.
To the Editor: A 73-year-old Chinese woman complained of slowly progressive patchy scalp itchiness and redness associated with hair loss for longer than 10 years. She had seen many doctors, including dermatologists, and had been diagnosed with scalp dermatitis and psoriasis and given multiple courses of topical corticosteroids and tar shampoo with mild improvement. Scalp biopsy in February 2012 was compatible with psoriasis. She later developed a left breast nodule with erosion, worsening scalp condition despite good drug adherence, and multiple ill-defined erythematous patches on her limbs and trunk for 1 month in May 2012. Incisional biopsy of the nodule showed acute inflammation, and ultrasound and mammogram of her left breast reported benign findings. Regular wound dressing and antibiotics were initiated for presumably infective mastitis, but her condition continued to deteriorate, with a repeat biopsy showing a dense infiltration of small and medium-sized lymphoid cells throughout the dermis, extending to the subcutaneous layer. These cells were predominantly CD3-positive (T-cells) with retention of CD5, some loss of CD2, and prominent loss of CD7 (signifying immaturity). Lymphoid disease was suspected, so biopsies were repeated in the breast and thigh and revealed isolated single-haloed lymphocytes and groups of lymphocytes in the epidermis. Early Pautrier microabscesses, epidermotropism, and clonal T-cell receptor gene rearrangements were present, confirming the diagnosis of mycosis fungoides (MF). A staging positron emission tomography–computed tomography scan showed diffuse skin thickening and multicompartmental hypermetabolic lymph nodes in the right cervical, left axillary, and bilateral inguinal regions. Her bone marrow was not involved. She received 10 cycles of alemtuzumab, with initially good clinical response of her skin, but treatment was stopped in November 2012 because of pneumonia and reinitiated 6 months later. In July 2013, she relapsed while on alemtuzumab, presenting with a fungating tumor in her anterior abdomen (Figure 1A). A cycle of cisplatin, gemcitabine, ifosfamide, etoposide, and l-asparaginase was given, with prompt improvement (Figure 1B). She was subsequently discharged after a course of rehabilitation care. MF is a rare skin disease, with an incidence of 0.044 per 100,000 over 10 years in Hong Kong.1 It mainly affects the middle-aged to elderly adults, with elderly adults having a poorer prognosis.2 MF presents slowly and indolently, beginning as itchy scaly patches and elevated plaques and progressing to tumors (dome-shaped, solid skin lesion >1 cm in diameter). Other manifestations include alopecia, dyspigmentation, and erythroderma (particularly in Sézary syndrome). When MF presents with skin patches or plaques, it is often misdiagnosed clinically and histologically as psoriasis or eczema, as in this woman. The condition often improves initially with topical corticosteroids, which are used to treat early MF,3 leading to reduced vigilance among doctors. This woman later developed "mastitis," which is uncommon with MF. Fortunately, a high degree of clinical suspicion and repeated biopsies led eventually to the correct diagnosis and treatment. This case reminds us not to be complacent with older adults when they seemingly have minor complaints such as scalp itchiness with hair loss. These complaints are often overlooked as a "natural" aging process without serious consequences and may delay diagnosis in the background of heightened probability and mortality of malignances in elderly adults. Careful examination of the scalp and skin is needed, particularly to look for evidence of serious illnesses such as MF and systemic lupus erythematosus. Crusted scabies is another important differential in any elderly adult with an itchy, psoriasiform scalp eruption. Individuals at higher risks include those who are bedbound with multiple medical comorbidities and poor mobility. The prognosis in MF is worse in men, older adults, at a higher stage of disease, and with the folliculotropic variant of MF.2 This woman had at least T3N1M0B0 disease, compatible with Stage IIB, which is advanced.4 Overall survival at this stage is 37.8% to 63.2% at 5 years after diagnosis and 19.8% to 53.2% at 10 years.2 Systemic therapy is indicated because of extensive skin and lymph node involvement. Choices include retinoid (bexarotene), interferon, histone deacetylase inhibitors (e.g., romidepsin, vorinostat), chemotherapy (e.g., methotrexate, doxorubicin, gemcitabine, cyclophosphamide, chlorambucil, fludarabine, etoposide), and biologic agents (e.g., bortezomib, alemtuzumab).5, 6 Because these treatments are expensive and not readily available, this woman was fortunate to receive the biological treatment and chemotherapy free of charge and had a good outcome. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that the authors have no financial or any other kind of personal conflicts with this paper. Author Contributions: Ngan: acquisition of patient information, analysis and interpretation of data, preparation of manuscript. Chan: preparation of manuscript and dermatological discussion of case. Hwang: preparation of manuscript and hematological discussion of case. Luk: preparation of manuscript, revision of draft, and geriatric discussion of case. Sponsor's Role: No sponsor was involved.
The efficacy of influenza vaccination in older nursing home residents is frequently overestimated due to frailty selection bias. Limited data exist to examine this issue.We conducted a prospective cohort study from December 2009 to November 2010 to evaluate the efficacy of influenza vaccination in old nursing home residents with respect to their functional status. Participants were stratified according to the Barthel Index (BI) into good functioning (GF; BI > 60), intermediate functioning (IF; BI = 5-60), and poor functioning (PF; BI = 0). Participants were vaccinated by monovalent H1N1 2009 and trivalent seasonal influenza vaccinations (H1N1-TIV), TIV alone, or remained unvaccinated by choice. The associations between all-cause mortality, vaccination efficacy, and functional status were examined.A total of 711 older nursing home residents were enrolled (GF group: N = 230; IF group: N = 246; PF group: N = 235). At 12 months, H1N1-TIV recipients had the lowest all-cause mortality, whereas unvaccinated residents had the highest all-cause mortality in all three functional status groups. In the comparison between H1N1-TIV recipients and TIV alone recipients, the hazard ratios (HRs) of all-cause mortality were lower in the GF group and higher in the PF group (GF group: HR 0.30 [0.07-0.95], p < .05; IF group: HR 0.40 [0.18-0.86], p < .05; PF group: HR 0.53 [0.28-0.99], p < .05). The same observation was found in comparison between other vaccination statuses (H1N1-TIV vs unvaccinated and TIV alone vs unvaccinated).Influenza vaccination was associated with reduced all-cause mortality in older nursing home residents with different functional statuses. Vaccine efficacy in reducing mortality declined with increasingly impaired functional status.
The effects of natriuretic peptides in kidney are blunted in congestive heart failure (CHF). The aim of this study is to examine the changes of atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) second messenger productions in CHF. Experiments were conducted on 300-day-old normal and cardiomyopathic hamsters. Blood was collected for ANF measurement. cGMP accumulation studies were done in glomeruli upon ANF and BNP stimulation, and in inner medullary collecting duct (IMCD) cells upon ANF stimulation. Higher plasma ANF levels were found in cardiomyopathic hamsters (811.3 ± 124.6 vs. 166.6 ± 13pg/ml, p < 0.01). ANF-stimulated cGMP accumulations in glomeruli and IMCD cells were higher in cardiomyopathic hamsters. Increased BNP-stimulated cGMP accumulations were also observed in cardiomyopathic hamster glomeruli. These results suggest that the renal hyporesponsiveness to natriuretic peptides in CHF is not due to attenuated ANF and BNP second messenger productions.
There are at present more than 78800 places in residential care home for elderly (RCHEs) in Hong Kong and more than half of the residents have cognitive impairment. A longitudinal cohort study was conducted using convenience sampling in 66 RCHEs in Hong Kong. Residents aged 65 years or more with advanced cognitive impairment were recruited and were followed up for 12 months. Adopting an interpretive systemic framework with purposeful sampling, six service users, six resident care home staffs, nine medical professionals and nine administrators were recruited to participate in 4 focus groups interviews. 312 residential care home residents (71 men and 241 women) with advanced cognitive impairment were studied. Their mean age was 88 (standard deviation, 8) years and their mean Barthel Index 20 score was 1.5 (standard deviation, 2.0). 164 (53%) were receiving enteral feeding. Nearly all of them had double incontinence. Apart from Community Geriatric Assessment Team clinics, 119 (38%) of the residents attended other specialist clinics outside their residential care homes. 107 (34%) died within 1 year; those who died within 1 year used significantly more emergency and hospital services (P≤0.001), and utilized more services from community care nurses for wound care (P=0.001), enteral feeding tube care (P=0.018), and urinary catheter care (P≤0.001). Ten themes have emerged to elucidate the systemic factors required for the successful implementation of end-of-life care path, which can be categorized into 1) regulatory empowerment, 2) family-centred care and 3) collective compassion. Residents of residential care homes for the elderly with advanced cognitive impairment were frail, exhibited multiple co-morbidities and high mortality. They were frequent users of out-patient, emergency, and in-patient services. Our findings high-lighted the importance of organizational structure, social disclosure and shared meaning in the planning, provision and delivery of end-of-life care path in the Chinese context. An Interpretive-System Framework for End-of-Life Integrated Care Pathway in Hong Kong
To assess the effectiveness of partially hydrolyzed guar gum (PHGG) in improving constipation and reducing the use of laxatives among long term care facility (LTCF) residents.
<i>Background:</i> The predicting value of age on stroke rehabilitation has been controversial. There is a lack of large-scale studies in the Chinese population to examine the effect of age on stroke rehabilitation outcomes. This study examines the predictors of a good outcome after rehabilitation in Chinese stroke patients with special attention to age as a factor. <i>Patients and</i><i>Methods:</i> This retrospective cohort study includes stroke patients receiving a standard inpatient multidisciplinary rehabilitation program in a neuro-rehabilitation ward of a convalescence hospital in Hong Kong from January 2000 to December 2003. Functional independence measure (FIM) ≧90 was used to define a good outcome. Multivariate regression analysis was used to assess the independent predictors of a good outcome. <i>Results:</i> There were important differences in clinical characteristics and complications of stroke among patients of three age groups: <65, ≧65 and <80, and ≧80 years. The total FIM scores both upon admission and at discharge were lower in the older age groups. No significant difference was observed in the changes in FIM scores across these age groups. Age was not an independent predictor for a good outcome. FIM upon admission was an independent predictor for a good outcome (discharge FIM ≧90) in all patients and in individual age groups. Having employment before stroke was a predictor for good outcome in all patients. Living at home prior to stroke was a predictor for the total population and the ≧65 and <80 years group. The length of stay predicted a good outcome in the group ≧80 years. <i>Conclusions:</i> Admission functional status, employment and living at home before stroke but not age per se are predictors of a good outcome following stroke rehabilitation. As older patients show comparable improvement during rehabilitation, intensive rehabilitation should not be withheld in stroke patients simply because of advanced age.
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