50例高血钾症临床心电图诊断价值的探讨

目的 探讨心电图对诊断高血钾的临床价值。方法 对50例高血钾症者的心电图与血清钾浓度进行对照分析。结果 血清钾高低与心电图改变并不绝对平行，排钾困难所致的高血钾症心电图改变与血清钾测定有较好的一致性。不同程度的高血钾在心电图上有不同的特征表现．而细胞内钾外移所致的高血钾在心电图上无高血钾改变。结论 心电图对高血钾改变的反映比血清钾测定更准确，可作为诊断、判定程度和观察疗效的重要指标。     

心电图在高钾血症临床诊断价值中的研究

目的 探讨心电图对诊断高血钾的临床价值。方法 对59例高钾血症患者的心电图与血清钾浓度进行对照分析。结果 不同程度的高钾血症在心电图上有不同的特征表现，但血清钾高低与心电图改变并不呈绝对平行关系，排钾困难所致的高血钾心电图改变与血清钾测定有较好的一致性，而细胞内钾外移所致的高血钾在心电图上无高血钾改变。结论 随着血清钾浓度的升高，心电图改变程度加重，心电图鉴别诊断高钾血症较假性高血钾测定更具有重要的临床价值。     

心电图在高血钾急诊诊断中的临床价值

目的探讨心电图（ECG）对诊断高血钾急诊的临床价值，尽早诊断与治疗高血钾这一临床急症。方法对46例高血钾病人的ECG与血清钾浓度进行对比分析。结果血清钾浓度高低与ECG改变并不呈平行关系，排钾困难所致的ECG改变与血清钾测定一致性。不同程度的高血钾在ECG上有不同的特征表现，而细胞内钾外移所致的高血钾在ECG上无高血钾表现。结论ECG时高血钾改变的反应比血清钾测定更准确，可作为诊断高血钾判定其程度和观察疗效的重要指持。     

心电图在高血钾临床诊断价值中的研究

目的为了探讨心电图对诊断高血钾的临床价值，尽早诊断、治疗高血钾这一l临床急症。方法对48例高血钾患者的心电图与血清钾浓度进行对照分析。结果显示血清钾高低与心电图改变并不呈绝对平行关系，排钾困难所致的高血钾心电图改变与血清钾测定有较好的一致性。不同程度的高血钾在心电图上有不同的特征表现，而细胞内钾外移所致的高血钾在心电图上无高血钾改变。结论心电图对高血钾改变的反应比血清钾测定更准确，可作为诊断高血钾，判定其程度和观察疗效的重要指标。     

高血钾心电图与血清钾浓度对照分析

为深入了解高血钾与心电图改变的关系,对76例高血钾患者的心电图与血清钾浓度改变进行对比分析。结果显示:排钾困难所致的高血钾心电图的异常改变与血钾测定有较好的一致性,不同程度的高血钾在心电图上有不同的特征性表现,而细胞内钾外移所致的高血钾则心电图上无高血钾表现。认为心电图对高血钾改变的反映比血清钾测定更准确。     

心电图对高血钾的诊断价值

为探讨心电图对高血钾的诊断价值.对80例高血钾患者的心电图改变与临床病因及血清钾浓度进行对比分析.结果显示;对排钾困难而导致的不同程度的高血钾在心电图上有不同的特征性表现;因细胞内钾外移所致的高血钾.心电图上则无高血钾表现。认为心电图对高血钾改变的反映比血清钾测定更准确。     

高钾血症56例心电图分析

目的通过对高钾血症心电图特征及其与血清钾浓度进行分析，探讨心电图对高钾血症的临床价值。方法将56例高钾血症患者的心电图特征及血清钾浓度对比分析。结果心电图改变和血清钾浓度高低并不是呈绝对平行关系，对肾功能不全所致排钾困难的高钾血症有较好的一致性，而细胞内钾外移所致的血清钾升高则无明显的心电图改变。随着血清钾浓度的升高，心电图异常的发生率递增。结论高钾血症的心电图改变比血清钾测定更具有临床价值，对观察疗效和判断预后有重要意义。     

心电图诊断高钾血症的临床价值

目的探讨心电图诊断高钾血症的临床意义。方法对60例高钾血症患者的心电图改变与血清钾浓度进行对比分析。结果①心电图诊断高钾血症32例，与血清钾测定的符合率为53．3％，主要病因为肾功能不全，其次是肝功能不全和糖尿病。②血清钾5．5～7．0mmol／L时。心电图诊断高钾血症的符合率为37．1％，表现为T波高尖呈帐篷状；〉7．0mmol/L时，心电图诊断高钾血症的符合率为76．0％，表现为T波高尖、QRS时间增宽、电压降低、P波低平或消失、房室传导阻滞和窦-室传导；两组符合率差异有非常显著性意义（χ^2=8．84，P〈0．01）。〉10．0mmol/l时，出现心室扑动和颤动。结论随着血清钾浓度的升高，心电图改变程度加重，心电图鉴别诊断高血钾与假性高血钾较血清钾测定更具有重要的临床价值。     

175例低钾血症心电图检查与血清钾检测结果对比研究

目的探讨心电图对低血钾的临床诊断价值。方法对于175例低血钾患者的心电图与血清钾浓度进行回顾性对照分析。结果心电图诊断低钾血症准确率为89.1%,优于血清钾测定(68.0%)。血清钾高低与心电图改变程度并不绝对一致,但心电图低血钾改变发生率和室性心律失常发生率与血清钾浓度均呈负相关(rs=-0.54,P<0.01),随血钾浓度的降低而递增。结论心电图对低血钾改变的反映比血清钾测定更准确,可作为诊断低血钾,判定其严重程度和观察疗效的重要指标。     

高血钾心电图时序性变化特征及临床意义

目的探讨高血钾心电图的时序性变化特征和临床意义。方法对53例高钾血症患者的临床资料进行回顾性分析,根据血钾浓度将其分为轻、中、重、极重4个阶段,观察各个阶段心电图特征与血清钾浓度变化之间的相关联系。结果心电图异常改变和高血钾程度具备良好的相关性,大部分表现为正相关关系,随着血钾浓度的逐步升高,心电图依次表现为T波高耸、QRS波增宽、P波消失、窦室传导、多部位传导障碍、QRS波与T波形成正弦曲线、心室颤动等,死亡率也随之上升。结论正确识别高血钾不同时期时序性心电图改变,可以为高血钾的早期发现、正确评估病情和及时纠治提供有益的帮助。     

The ability of physicians to predict hyperkalemia from the ECG

STUDY OBJECTIVE: To determine whether physicians blinded to the serum potassium level can predict hyperkalemia (potassium concentration of more than 5.0 mmol/L) from the ECG. DESIGN: ECGs of patients at high risk for hyperkalemia were interpreted retrospectively by two physicians blinded not only to the specific clinical diagnosis of the patient and to their serum potassium measurement but also to each other's interpretation. The physicians predicted the presence or absence of hyperkalemia as well as the severity of hyperkalemia on a nominal scale (mild, moderate, or severe). SETTING: The emergency department of a university-affiliated urban county hospital. PATIENTS: Two hundred twenty consecutive patients admitted to the hospital from the ED with a diagnosis of renal failure or hyperkalemia. Eighty-seven patients had hyperkalemia, and 133 did not. RESULTS: The sensitivities of the readers for predicting hyperkalemia were .43 and .34, respectively (best positive predictive value, .65). The respective specificities for detecting hyperkalemia were .85 and .86 (best negative predictive value, .69). When only patients with moderate-to-severe hyperkalemia (potassium of more than 6.5 mmol/L) were analyzed, sensitivities were .62 and .55. The readers' ability to predict the severity of hyperkalemia was equally poor. CONCLUSION: The ECG is not a sensitive method of detecting hyperkalemia, even in high-risk patients. The specificity of the ECG is better for hyperkalemia, but empiric treatment of hyperkalemia based on the ECG alone will lead to mistreatment of at least 15% of patients.     

Survival of Extreme Hyperkalemia

ABSTRACT. Hylander B (Department of Internal Medicine, Karolinska Hospital, Stockholm, Sweden). Survival of extreme hyperkalemia. Acta Med Scand 1987; 221:121–3. Severe hyperkalemia has been reported to lead to typical ECG changes, often reflecting cardiac abnormalities which finally lead to death in arrythmias. The present report describes a 77-year-old male, who developed extreme hyperkalemia because of treatment with a potassium saving diuretic in combination with potassium supplementation and subsequent development of urinary retention. In spite of a maximal potassium value of 10.1 mmol/1 only non-specific ECG-changes were found. The patient survived after an uneventful dialysis. Thus, extreme hyperkalemia may occur without typical ECG changes and serum potassium values exceeding 10 mmol/1 may be survived. Hyperkalemia is a well-known feature of acute renal failure. The most important toxic effects are cardiac arrythmias. In Harrison's Principle of Internal Medicine, severe hyperkalemia is defined as plasma potassium exceeding 8 mekv/l or if electrocardiographic abnormalities include absent P waves, widened QRS complexes or ventricular arrythmia (1). The following case report describes extreme hyperkalemia due to a combination of potassium saving diuretics, potassium supplementation and post-renal failure but without specific effects on the ECG.     

Recurrent life-threatening hyperkalemia without typical electrocardiographic changes

Hyperkalemia is generally associated with electrocardiographic (ECG) changes and these changes have been used to follow the effects of high serum potassium (K +) levels on the heart. It is known that chronic renal impairment may diminish the toxic effects of hyperkalemia on ECG abnormality formation. ^{,  and}  Here, we report a case of recurrent severe hyperkalemia without any significant ECG changes in a patient with normal baseline renal function.     

Retrospective Review of the Frequency of ECG Changes in Hyperkalemia

Background and objectives: Experimentally elevated potassium causes a clear pattern of electrocardiographic changes, but, clinically, the reliability of this pattern is unclear. Case reports suggest patients with renal insufficiency may have no electrocardiographic changes despite markedly elevated serum potassium. In a prospective series, 46% of patients with hyperkalemia were noted to have electrocardiographic changes, but no clear criteria were presented.Design, setting, participants, & measurements: Charts were reviewed for patients who were admitted to a community-based hospital with a diagnosis of hyperkalemia. Inclusion criteria were potassium ≥6 with a concurrent electrocardiogram. Data were abstracted regarding comorbid diagnoses, medications, and treatment. Potassium concentrations were documented along with other electrolytes, pH, creatinine, and biomarkers of cardiac injury. Coincident, baseline, and follow-up electrocardiograms were examined for quantitative and qualitative changes in the QRS and T waves as well as the official cardiology readings.Results: Ninety patients met criteria; two thirds were older than 65, and 48% presented with renal failure. Common medications included β blockers, insulin, and aspirin; 80% had potassium <7.2. The electrocardiogram was insensitive for diagnosing hyperkalemia. Quantitative assessments of T-wave amplitude corroborated subjective assessments of T-wave peaking; however, no diagnostic threshold could be established. The probability of electrocardiographic changes increased with increasing potassium. The correlation between readers was moderate.Conclusions: Given the poor sensitivity and specificity of electrocardiogram changes, there is no support for their use in guiding treatment of stable patients. Without identifiable electrocardiographic markers of the risk for complications, management of hyperkalemia should be guided by the clinical scenario and serial potassium measurements.Hyperkalemia is a common and a potentially life-threatening electrolyte disorder in patients in the hospital setting. Exact incidence varies between surveys, with estimates ranging between 1.1 and 10% of hospitalized patients (1–4). Such estimates are reinforced by reports that in patients who are treated with at least prophylactic doses of heparin, now standard of care for most hospitalized patients, the incidence of hyperkalemia is between 7 and 8% (5). Although severe cases may be associated with paralysis and cardiac arrest, in the majority of cases, symptoms are most often nonspecific and may include muscle twitching, nausea, vomiting, and abdominal pain (6).In experimental settings, hyperkalemia has been associated with a defined series of electrocardiogram (ECG) abnormalities, including shortening of QT interval, peaking of T waves, QRS prolongation, shortening of PR interval, reduction in amplitude of the P wave, loss of sinoatrial conduction with onset of a wide-complex “sine-wave” ventricular rhythm, and ultimately asystole (7). Although no uniform threshold has been documented in animal models, the most severe cardiac manifestations have been shown to occur with serum potassium concentrations >9 mEq/L (7). On the basis of these experimental observations, commonly used clinical references recommend ECG assessment as an integral part of the evaluation of patients with hyperkalemia (8).In clinical series, the relationship between serum potassium concentration and cardiac manifestations is less clear. In one published series of 127 patients with serum potassium concentrations ranging between 6 and 9.3 mEq/L, no serious arrhythmias were documented (9). Only 46% of ECG were noted to have changes suggestive of hyperkalemia, including QRS widening, conduction deficits, and peaking of T waves (9). There are multiple case reports of patients with renal failure who presented without significant ECG changes despite markedly elevated potassium levels (10,11). Other, less typical ECG presentations of hyperkalemia include ST elevations mimicking acute myocardial infarction and rate-dependent bundle branch blocks (12–17). Given the high prevalence of cardiovascular disease in the surveyed population and the nonspecific nature of most of the observed ECG changes, the potential for confounding in any case series is significant.Given the variability in the ECG presentation of hyperkalemia, it is not surprising that in the absence of formal criteria, the sensitivity of physician readers in the ECG diagnosis of hyperkalemia has been estimated to be as low as 0.34 to 0.43 (6). Significantly, the specificity in the same series was higher at 0.85 with a κ between readers of 0.73, indicating a high degree of correlation. When the sample was limited to ECGs with a potassium >6.5, the sensitivity was higher (between 0.55 and 0.62), suggesting that the majority of missed diagnoses occurred with potassium in the range of 5.0 to 6.4.Attempts have been made to quantify the ECG changes associated with hyperkalemia in both experimental and clinical series. Wrenn et al. (6), in a study of patients who were on hemodialysis, examined the mean precordial T-wave amplitude and the mean ratio of precordial T-wave to R-wave amplitude as a reflection of the peaking of T waves. Given the lack of validation of this method, it is unclear whether the lack of documented correlation with serum potassium concentration reflects the inadequacy of the measurement or a physiologic difference in patients with ESRD. Porter et al.(18) used a combination of electrocardiographic markers incorporated into a neural network algorithm to diagnose hyperkalemia in dogs with high sensitivity (89%) and specificity (77%). Although compelling, these results have not been reproduced in human clinical settings, and the use of a neural network makes their application to patient care logistically more complicated. Given these uncertainties, we undertook a retrospective review of ECG parameters associated with laboratory diagnosis of hyperkalemia in an inpatient setting.     

血液透析患者高钾血症季节分布特征研究北大核心CSCD

目的分析血液透析患者高钾血症的发生率及其季节分布特征和不同检测次数的高钾检出率,为高钾血症的防治及研究提供重要参考依据。方法纳入四川省2018年至2020年血液透析患者资料,以血钾≥5.0 mmol/L定义为高钾血症,计算高钾血症发生率及时间分布特征。结果(1)共纳入6618例至少有一次血钾检测记录的患者,包含24885次血钾结果,高钾血症发生率为28.2%。(2)第一至第四季度高钾血症发生率分别为30.9%、29.2%、23.7%、28.6%。(3)血钾检测次数越多,高钾血症检出率越高。结论血液透析患者高钾血症发生率较高,存在季节差异,增加检测频率可以显著增加高钾血症患者检出率。     

ECG changes under hyperkalemia with nephrectomy in the rat.

Electrolyte abnormalities have become an increasingly important cause of arrhythmias. Although the electrocardiographic (ECG) changes under hyperkalemia in the rat are poorly understood, it is conceivable that excess plasma potassium may also alter the cardiac excitations in the rat. Further, effects of hyperkalemia on ECG in the rat may differ from other species that have ST-segment and longer QT intervals in ECG. The present study was designed to determine the diagnostic criteria for ECG manifestations to various levels of plasma potassium concentration. For this purpose, hyperkalemia was induced by nephrectomy with and without infusions. Because it was difficult to produce various levels of plasma potassium concentration by only nephrectomy, we used two kinds of infusions to obtain especially moderate levels of nephrectomy-induced hyperkalemia. ECGs were recorded 24, 36, and 48 hours after nephrectomy. Plasma potassium concentration and number of abnormal ECGs were increased time-dependently. Increased T wave amplitude was present with mild hyperkalemia. The typical T wave change observed with so-called sinoventricular conduction levels of potassium concentration in species with long QT intervals did not occur in the rat. PR interval and QRS duration became slightly shorter within moderate hyperkalemia. P wave disappeared in most rats at potassium levels above 8.0 mEq/l. In advanced hyperkalemia (plasma potassium concentration above 7.5 mEq/l), conduction in all parts of the heart was suppressed. Moreover, sinoventricular conduction appeared. Thus, the diagnostic criteria for ECG manifestations to various levels of plasma potassium concentration in the rat were demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hiperpotasemia transitoria del lactante sin pérdida salina,enfoque fisiopatológico de tres casos

Two types of early-childhood hyperkalemia had been recognized, according to the presence or absence of urinary salt wasting. This condition was attributed to a maturation disorder of aldosterone receptors and is characterized by sustained hyperkalemia, hyperchloremic metabolic acidosis due to reduced ammonium urinary excretion and bicarbonate loss, and normal creatinine with growth delay. We present three patients of the type without salt wasting, which we will call transient early-childhood hyperkalemia without salt wasting, and discuss its physiopathology according to new insights into sodium and potassium handling by the aldosterone in distal nephron. In three children from 30 to 120-day-old admitted with bronchiolitis and growth delay hyperkalemia was found in routine laboratory. Further studies revealed a normal creatinine with inappropriately normal or low fractional excretion of potassium, accompanied by inadequately normal serum aldosterone and plasma renin activity for their higher plasma potassium levels, but without urine salt wasting. They also presented hyperchloremic metabolic acidosis with fractional excretion of bicarbonate 0.58–2.2%, positive urinary anion gap during metabolic acidosis and normal ability to acidify the urine. Based on these findings a diagnosis of transient early-childhood hyperkalemia without salt wasting was made and they were treated sodium bicarbonate and hydrochlorothiazide with favorable response. The condition was transient in all cases leading to treatment discontinuation. Given that transient early-childhood hyperkalemia without salt wasting is a tubular disorder of transient nature with mild symptoms; it must be keep in mind in the differential diagnosis of hyperkalemia in young children.