The overstated risk of preoperative hypokalemia

To examine the relation between preoperative hypokalemia and frequency of intraoperative arrhythmias, Holter monitoring was employed in 447 patients undergoing major cardiac or vascular operations, the group at greatest risk for life-threatening arrhythmias. Based on serum potassium levels measured immediately before surgery, 57% of patients were normokalemic (greater than or equal to 3.6 mEq/L), 34% hypokalemic (3.1-3.5 mEq/L), and 9% severely hypokalemic (less than or equal to 3.0 mEq/L). No arrhythmia occurred at any time in 63% of patients and minor arrhythmias (premature atrial and occasional premature ventricular contractions) occurred in 16%. Frequent or complex ventricular ectopy appeared before and during operation in 92 patients (21%) but was not related to preoperative potassium level or history of long-term diuretic therapy. Frequent and complex ventricular arrhythmias were more common in patients with a history of long-term digoxin therapy or congestive heart failure. Even among these patients, hypokalemia or diuretic therapy did not increase the incidence or severity of ectopy. These data fail to support the common practice of delaying operation for acute potassium replacement in patients whose preoperative serum potassium is less than normal, even in the presence of cardiovascular disease.     

Dehiscent temporomandibular joint

The appearance of an acute effusion in a well-pneumatized temporal bone directs attention to the nasopharynx and skull base. Two patients are described in whom dehiscence of the temporomandibular joint allowed herniation of the contents of the joint posteromedically, where they obstructed the middle ear entrance of the eustachian tube, the protympanum. This is, to the authors' knowledge, a previously unreported cause of an acute middle ear and mastoid effusion.     

40例鼓室成形术临床结果分析

目的研究Ⅲ、Ⅳ型鼓室成形术后听力改善的情况.方法回顾性总结美国匹兹堡大学医学中心眼耳研究所从1992-2000年随访的40例鼓室成形术病人,其中Ⅲ型和Ⅳ型各20例.Ⅲ型中男6例,女14例.平均年龄43.55岁(范围11-79岁).Ⅳ型中男3例,女17例,平均年龄45.11岁(范围12-74岁).Ⅲ型中9例有胆脂瘤.Ⅳ型中7例有胆脂瘤.20例Ⅲ型病人中4例采用金伯格人工听骨,16例采用自体-异体砧骨.20例Ⅳ型病人中10例采用金伯格人工听骨,4例采用理查德人工听骨,6例采用鲁森斯基人工听骨.所有的病人都行Ⅰ期听骨链重建.结果所有的病人在术后3月、6月、12月随访.Ⅲ型术后气骨导差距≤20dB者15例,占75%.Ⅳ型术后气骨导差距≤20dB者12例,占60%.结论Ⅲ、Ⅳ型鼓室成形术都能得到较好的听力改善.     

Enalapril attenuates glomerular hyperfiltration following a meat meal

It has been shown that the glomerular filtration rate increases after a meat meal. We examined in humans whether enalapril, which has been shown to decrease glomerular capillary pressure in rats with chronic renal failure, could attenuate the renal response to a meat meal. Twelve healthy volunteers were studied after an oral protein load, 1.5 g/kg body weight, as lean cooked beef meat, and on a separate day, after eating the same meal with prior oral intake of enalapril. On the control day, creatinine clearance increased from 114.3 +/- 4.7 before the meal to 137.1 +/- 4.7 ml/min/1.73 m2 after the meal (p less than 0.001). On the enalapril intake day, creatinine clearance increased from 113.7 +/- 5.6 before the meal to 128.3 +/- 5.8 ml/min/1.73 m2 after the meal (p less than 0.01). However, the mean increase in creatinine clearance was lower on the enalapril intake than on the control day (14.0 +/- 4.3 vs. 21.0 +/- 4.1%, p less than 0.05). Mean arterial pressure before the meal was lower on the enalapril intake day than on the control day (76.2 +/- 3.5 vs. 84.2 +/- 3.6, p less than 0.01). Likewise, postprandial mean arterial pressure was lower on the enalapril day compared with the control day (69.9 +/- 2.8 vs. 78.5 +/- 3.7, p less than 0.01). We conclude that enalapril blunts the hyperfiltration which follows a meat meal.     

Treatment of chronic subdural collection in infants by subdural peritoneostomy

Between 1980 and 1987, 50 chronics bilateral subdural collections in infants were treated by means of a subdural peritoneal shunt (unilateral in 48 cases, bilateral in 2 cases). In 2 patients with huge macrocranium the drains were left in situ. In the 48 others, the drains were removed after an average of 10 months. In these 48 cases, the drainages either bilateral (2 cases) or unilateral (46 cases) led to the disappearance of the collections; however, in 1 of these 48, a drain had to be reinserted due to the reproduction of the collection following the removal of the initial drainage. High level of C.S.F. protein content did not alter the peritoneal resorption. Obstruction of the catheter by a clot occurred in 3 cases with grossly bloody collections. Unilateral subdural peritoneal drainage for bilateral pericerebral collection is an efficient and safe treatment. The authors should advocate temporary external drainage only in the cases where the collection is grossly bloody.     

Suppression of the humoral response to anti-CD3 monoclonal antibody

Anti-CD3 monoclonal antibodies are used clinically to treat organ allograft rejection. Their administration can result in reversal of rejection even in episodes resistant to other modes of therapy. A major limitation to their use has been the humoral response of the patients against the mAbs, resulting in loss of therapeutic efficacy. We have established an animal model for anti-CD3 treatment using the antimurine CD3 mAb, 145-2C11. Exposure of mice to this mAb, like exposure of humans to its antihuman analog OKT3, results in suppression of graft rejection but also stimulates a strong humoral response that abrogates the efficacy of further treatments. Administration of an additional dose of anti-CD3 mAb did not prolong skin graft survival--and, in some instances, resulted in a lethal anaphylactic reaction. In an attempt to suppress the humoral response against the anti-CD3 mAb, anti-CD4 mAb was administered prior to the anti-CD3 mAb treatment. Pretreatment of mice with anti-CD4 mAb (GK1.5) almost completely suppressed the humoral response to anti-CD3 mAb, and permitted readministration of the anti-CD3 mAB without loss of efficacy as assessed by prolongation of skin graft survival. The data suggest that the use of anti-CD4 mAb to suppress the humoral response against anti-CD3 mAb should be attempted clinically, as it might permit repeated courses of anti-CD3 administration, thus significantly improving the efficacy of these agents in the therapy of organ allograft rejection.     

The natural history of functional morbidity in hospitalized older patients

This study provides data on changes in the functional status of older patients that are associated with acute hospitalization. Seventy-one patients over the age of 74 admitted to the medical service of Stanford University Hospital between February and May 1987 received functional assessments covering seven domains: mobility, transfer, toileting, incontinence, feeding, grooming, and mental status. Assessments were obtained by report from the patient's caregiver (or the patient when he or she lived alone) for 2 weeks before admission; from the patient's nurse on day 2 of hospitalization and on the day before discharge; and again from the caregiver (or patient) 1 week after discharge. The sample had a mean age of 84, covered 37 Diagnostic Related Groups, and had a median length of stay of 8 days. Between baseline and day 2, statistically significant deteriorations occurred for the overall functional score and for the individual scores for mobility, transfer, toileting, feeding, and grooming. None of these scores improved significantly by discharge. In the case of mobility, 65% of the patients experienced a decline in score between baseline and day 2. Between day 2 and discharge, 67% showed no improvement, and another 10% deteriorated further. These data suggest that older patients may experience a burden of new and worsened functional impairment during hospitalization that improves at a much slower rate than the acute illness. An awareness of delayed functional recovery should influence discharge planning for older patients. Greater efforts to prevent functional decline in the hospitalized older patient may be warranted.