Urinary retention: a cause of hyponatremia?

BACKGROUND: Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common cause of hyponatremia in elderly hospitalized patients; however in many patients the etiology remains unclear even after routine investigations. OBJECTIVE: To report our experience of the association of hyponatremia and urinary retention in elderly hospitalized patients. PATIENTS: Six patients with hyponatremia and urinary retention who were admitted to the geriatric department in our hospital during a four-year period (2001-2004). RESULTS: The mean age of the patients was 85 years. The mean serum sodium level was 120 mEq/l, average volume of retained urine was 933 ml (range 500-1,500 ml). All patients underwent a comprehensive work-up seeking a possible cause for the hyponatremia. The diagnostic work-up was negative. In 5 of the patients the laboratory findings fulfilled the criteria for SIADH. In all patients hyponatremia resolved following urinary catheterization and fluid restriction. All patients made a complete recovery. CONCLUSIONS: Potentially, urinary retention by itself may cause hyponatremia. The possible mechanism for this is SIADH, triggered by bladder distention or pain due to bladder distention. Urinary catheterization may be the key to treatment in these cases of hyponatremia.     

Incidence and risk factors for surgical infection after total knee replacement

Surgical site infection (SSI) after total knee replacement (TKR) is a devastating complication. We performed a retrospective study of all consecutive TKRs performed during a 2-y period. Surgical site infection (SSI) was defined by standard criteria. All patients were examined 1 y following surgery. Of 180 patients undergoing TKR, 10 (5.6%) developed a superficial (3, 1.7%) or deep (7, 3.9%) SSI. Two independent risk factors for SSI were detected: left knees became infected more often (9/ 92, 9.8%) than right knees (1/88, 1.1%) (Relative Risk 6.7 +/- 95% CI 1.7-26.8); and 7/72 (9.7%) patients receiving a type-1 prosthesis developed infection versus 3/104 (3.1%) receiving a type-2 prosthesis (RR 4.7, 95% CI 1.18-18.4). Investigation of the operating room revealed 3 problems: there was significant traffic through the door on the left of the patient; a nonstandard horizontal-flow air conditioner had been installed above that door; a tool-washing sink was in use on the other side of that door. Infection control guidelines were rehearsed: the sink was removed, the air conditioner was disconnected, and the door was locked. In a prospective survey performed 2 y later only 1/45 patients (2.2%) undergoing TKR developed a superficial SSI (p = 0.5). Correction of independent risk factors for infection following TKR led to a decrease in SSI rate.     

Evidence for cortical hyperexcitability of the affected limb representation area in CRPS: a psychophysical and transcranial magnetic stimulation study

Functional alterations in noxious, sensory and motor circuits within the central nervous system may play an important role in the pathophysiology of complex regional pain syndrome (CRPS). The aim of the present study was to search for further evidence of hyperexcitability in the hemisphere contralateral to the affected limb in patients with CRPS by employing both psychophysical and transcranial magnetic stimulation (TMS) methods. Twelve patients with CRPS type I, confined to the distal part of a limb (six in an upper-limb and six in a lower-limb), were enrolled in the study. The quantitative thermal, mechanical and 'wind-up' like pain testing was performed at the most painful site in the affected limb and in the ipsilateral limb. Results were then compared to those found at mirror sites in the contralateral limbs. TMS was used to assess the inter-hemispheric difference in parameters of corticospinal excitability, intracortical inhibition, and intracortical facilitation. The quantitative thermal and mechanical testing showed significant differences in cold, heat and mechanical pain thresholds, as well as in the first and last 'wind-up' stimuli between the affected and the contralateral limbs of the CRPS patients. No significant differences between the ipsilateral unaffected limbs and their contralateral pair limbs were found. A significant reduction in the short intracortical inhibition associated with a significant increase of the I-wave facilitation was found in the hemisphere contralateral to the affected side in the upper-limb CRPS group. No significant inter-hemispheric asymmetry between the affected and the non-affected sides was revealed in the lower-limb CRPS group. Taken together, these results suggest that in patients with well-localized CRPS, there is evidence for sensory and motor CNS hyperexcitability, though it seems to involve only corresponding regions within the CNS rather than the entire hemisphere.     

Ventilatory effects of almitrine bismesylate in congenital central hypoventilation syndrome

Patients with congenital central hypoventilation syndrome (CCHS) lack hypercapnic and hypoxic stimulation of ventilation but have demonstrated carotid body function in response to hyperoxia and to pharmacological stimulation with doxapram. This study investigated the ventilatory effects of almitrine bismesylate, a carotid body stimulant, in 12 patients with CCHS. Measurements of minute ventilation, tidal volume (VT), respiratory rate (RR) and transcutaneous PO2 (TCPO2) were taken before and after administration of 4.5 mg/kg and 6 mg/kg of almitrine. Twenty-four hour pharmacokinetic studies were performed in 7 patients who received 4.5 mg/kg and in 6 patients who received 6 mg/kg almitrine. There was no significant improvement in ventilatory and gas exchange parameters at either dose of almitrine despite appropriate peak serum concentration of the drug at the time of the studies. These results suggest that almitrine is not a useful ventilatory stimulant in children with CCHS.     

Relocating the nipple areola complex as a composite graft

Achieving a good shape of the breast is not sufficient to complete a reconstruction. The presence and correct positioning of a nipple areola complex (NAC) is important for a good esthetic result. This is demonstrated by the unsatisfactory result in cases of NAC malposition. Two cases are presented in which revision was performed by transferring the NAC as a composite graft. This approach achieved improvement in the esthetic result and the patient satisfaction. Level of Evidence: Level V, therapeutic study.     

A Biomechanical Foot-Worn Device Improves Total Knee Arthroplasty Outcomes

Background

Biomechanics after total knee arthroplasty (TKA) often remain abnormal and may lead to prolonged postoperative recovery. The purpose of this study is to assess a biomechanical therapy after TKA.