Louis Shenkman

Patients in the intensive care unit suffer from severe lack of sleep associated with loss of normal melatonin secretion pattern.

BACKGROUND Patients hospitalized in the intensive care unit (ICU) tend to become agitated and confused, and many even develop temporary psychoses (the ICU syndrome). We wondered whether the regulation of sleep and the secretion of melatonin is abnormal in ICU patients. Therefore, we studied the association of sleep-wake pattern in patients hospitalized in the ICU, their melatonin secretion rates, and profile compared with a control group of patients in general medical wards. METHODS Sleep was assessed by actigraphy. Urine was collected every 3 hours for 24 hours. Melatonin secretion was assessed by measuring the melatonin metabolite 6-sulphatoxymelatonin by enzyme-linked immunosorbent assay. RESULTS Actigraphy suggested that the ICU patients lacked normal sleep behavior for the entire study period, except for occasional short naps. Compared with controls, the nocturnal peak of melatonin secretion was absent, except in two patients in the nonventilated group, and showed a flat curve. CONCLUSIONS Our results suggest that lack of sleep is indeed a severe problem in ICU patients and is accompanied by impairment of normal melatonin secretion. The possibility that melatonin administration may prove useful in improving sleep patterns in ICU patients deserves further study.

Effect of melatonin on sleep quality of COPD intensive care patients: a pilot study.

Sleep deprivation is extremely common in the intensive care unit (ICU), and this lack of sleep is associated with low melatonin secretion. The objective of the current study was to explore the effect of exogenous melatonin administration on sleep quality in patients hospitalized in the pulmonary intensive care unit (ICU). We performed a double-blind, placebo-controlled study in the pulmonary ICU of a tertiary care hospital. Eight adult patients hospitalized in the pulmonary ICU with respiratory failure caused by exacerbation of chronic obstructive pulmonary disease (COPD) or with pneumonia were studied. Patients received either 3 mg of controlled-release melatonin or a placebo at 22:00, and sleep quality was evaluated by wrist actigraphy. Treatment with controlled-release melatonin dramatically improved both the duration and quality of sleep in this group of patients. Our results suggest that melatonin administration to patients in intensive care units may be indicated as a treatment for sleep induction and resynchronization of the “biologic clock.” This treatment may also help in the prevention of the “ICU syndrome” and accelerate the healing process. (Chronobiology International, 17(1), 71–76, 2000)

The effects of coffee consumption on sleep and melatonin secretion

BACKGROUND In this study we examined the effects of caffeine on sleep quality and melatonin secretion. Melatonin is the principal hormone responsible for synchronization of sleep. Melatonin secretion is controlled by neurotransmitters that can be affected by caffeine. METHODS In the first part of the study, six volunteers drank either decaffeinated or regular coffee in a double-blind fashion on one day, and the alternate beverage 7 days later. Sleep parameters were assessed by actigraphy. In the second part of the study, the subjects again drank either decaffeinated or regular coffee, and they then collected urine every 3h for quantitation of 6-sulphoxymelatonin (6-SMT), the main metabolite of melatonin in the urine. RESULTS We found that drinking regular caffeinated coffee, compared to decaffeinated coffee, caused a decrease in the total amount of sleep and quality of sleep, and an increase in the length of time of sleep induction. Caffeinated coffee caused a decrease in 6-SMT excretion throughout the following night. CONCLUSIONS The results of our study confirm the widely held belief that coffee consumption interferes with sleep quantity and quality. In addition, we found that the consumption of caffeine decreases 6-SMT excretion. Individuals who suffer from sleep abnormalities should avoid caffeinated coffee during the evening hours.

Internal jugular vein thrombosis in patients with ovarian hyperstimulation syndrome

OBJECTIVE To describe a case of bilateral internal jugular vein thrombosis complicating ovarian hyperstimulation syndrome (OHSS). DESIGN Case report. SETTING Internal medicine ward in a teaching hospital. PATIENT A 28-year-old nulliparous woman undergoing IVF. INTERVENTION(S) Ultrasonographic Doppler of the neck veins was performed because of pain and swelling in the neck, and bilateral jugular vein thromboses were detected. Laboratory evaluation revealed activated protein C resistance caused by factor V Leiden mutation. Low-molecular-weight heparin (enoxaparin) was administered for the remainder of the pregnancy and for 6 weeks after delivery. MAIN OUTCOME MEASURE Resolution of jugular venous thromboses documented by ultrasonographic Doppler and normal progression of pregnancy. RESULT(S) The patient delivered healthy twins at term. There were no complications arising from the jugular vein thromboses or the low-molecular-weight heparin treatment. CONCLUSION(S) Unusually located venous thrombosis should prompt an evaluation for a hypercoagulable state. The high prevalence (4%-7%) of factor V Leiden mutation in most Western populations and the mutations potential contribution to thrombotic complications in OHSS suggest that screening for this abnormality in women undergoing IVF may be indicated.

Autoimmune thyroid disease and antiphospholipid antibodies

Autoimmune thyroid disease (ATD) is associated with circulating autoantibodies reactive with epitopes on thyroid tissue and that are thought to be pathogenic in the development of these diseases. Antiphospholipid antibodies (APLA) are a family of immunoglobulins that recognize a variety of plasma proteins in association with anionic phospholipids. These antibodies may lead to a number of clinical syndromes including venous and arterial thromboses, thrombocytopaenia, and recurrent fetal loss. We have studied the prevalence of APLA in patients with ATD and have determined the prevalence of the APLA syndrome among APLA‐positive patients.

Contamination of blood cultures during venepuncture: Fact or myth?

Contamination of blood cultures is believed to occur mainly during the venepuncture procedure. Consequently, meticulous preparation of the venepuncture site is widely recommended. To determine whether the contamination rate is indeed affected by the quality of the antiseptic procedure at the venepuncture site, 181 paired cultures were collected from 176 patients during a 6-month period after either strict antiseptic cleansing of skin with alcohol followed by povidone-iodine, or after brief disinfection with alcohol alone. The contamination rate was not influenced by the antiseptic procedure, and corresponded to the accepted percentage reported in most other studies. Eight false positive cultures (4.4%) were obtained after strict antisepsis of the skin and 6 (3.3%) after short simple cleansing with alcohol (P = 0.39). Our results suggest that contamination of blood cultures may not be related to the venepuncture procedure--regardless of the antiseptic technique used--but may be due to later stages of laboratory handling and processing of the specimens. Review of the literature has provided further indirect evidence to support this conclusion.

Prevalence and Evaluation of B12 Deficiency in Patients with Autoimmune Thyroid Disease

Background:Patients with autoimmune thyroid disease (AITD) have a higher prevalence of pernicious anemia compared with the general population. Clinical signs of B12 deficiency may be subtle and missed, particularly in patients with known autoimmune disease. We assessed the prevalence of vitamin B12 deficiency in patients with AITD and whether their evaluation may be simplified by measuring fasting gastrin levels. Methods:Serum B12 levels was measured in 115 patients with AITD (7 men and 108 women), with a mean age of 47 ± 15 years. In patients with low serum B12 levels (≤133 pmol/L), fasting serum gastrin and parietal cell antibodies (PCA) were measured. Results:Thirty-two patients (28%) with AITD had low B12 levels. Fasting serum gastrin was measured in 26 and was higher than normal in 8 patients. PCA were also measured in 27 patients with B12 deficiency and were positive in 8 patients. Five patients with high gastrin levels underwent gastroscopy with biopsy, and atrophic gastritis was diagnosed in all. The prevalence of pernicious anemia as assessed by high serum gastrin levels in patients with low B12 was 31%. Conclusions:Patients with AITD have a high prevalence of B12 deficiency and particularly of pernicious anemia. The evaluation of B12 deficiency can be simplified by measuring fasting serum gastrin and, if elevated, referring the patient for gastroscopy.

Clinical relevance of non-palpable thyroid nodules as assessed by ultrasound-guided fine needle aspiration biopsy

It is known from autopsy data that thyroid nodules are far more common than can be detected by palpation alone. With the wide use of modern non-invasive imaging many nonpalpable thyroid nodules are discovered but the proper approach to these nodules is still debatable. In a retrospective study, we reviewed the data from 186 US-guided FNA biopsies (US-FNAB) performed between May 1995 and March 1997 at the Sapir Medical Center, Israel, a iodine-sufficient urban area. Sixty-one of the 186 US-FNAB of the thyroid were performed in non-palpable nodules. The mean size of these nodules was 2.4±1.0 cm (mean±SD) ranging from 1.1–5.5 cm. Description of the nodule consistency was available in 53 cases; 42/53 were solid and 11/53 were solid-cystic. FNAB was diagnostic in 46 patients and non-diagnostic in 15. Forty-three of the diagnostic cytology reports were benign, one revealed papillary carcinoma, one had suspicious findings and the third was suspicious for a follicular neoplasm. The last two patients were referred to surgery and a follicular adenoma was found in both. Among the 61 non-palpable thyroid nodules, only one was papillary carcinoma, a prevalence of 1.6%. The other two patients referred to surgery had benign lesions. We found a low prevalence of malignancy in relatively large nonpalpable thyroid nodules.

Sweet's syndrome and subacute thyroiditis.

A 63 year old woman developed biopsy documented lesions of acute febrile neutrophilic dermatosis (Sweets syndrome) one week after the onset of subacute thyroiditis. This is only the second reported case of such an association. The role of cytokines in the development of both subacute thyroiditis and Sweets syndrome may be the link between these two conditions.

Comparing the distress of American and Israeli medical students studying in Israel during a period of terror

Introduction  Medical school is a very stressful environment with multiple sources of stress, including academic, social and other issues. International medical students are exposed to additional stressors such as homesickness and culture shock.