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Generalized Weakness in a 23-Year-Old Woman


Generalized Weakness in a 23-Year-Old Woman


حالة سريرية

الوصف الكامل Background
A 23-year-old woman presents to the emergency department (ED) with a 3-day history of progressively worsening, generalized muscle weakness and nonbilious emesis. She has been vomiting 1-2 times a day, mostly upon awakening. The emesis does not seem to be associated with oral intake. She also admits to intermittent hematuria, without any flank pain or dysuria. She denies having any fever, diarrhea, chills, headache, abdominal pain, visual disturbances, or paresthesias. Before the onset of symptoms, the patient was in good health, with a past medical history significant only for renal colic 8 months prior to presentation. She had a cosmetic rhinoplasty 2 years ago, but otherwise she has not had any prior major surgery. She has no known allergies and is not taking any medications. Her last menstrual period was 1 month ago. She recently moved to the United States from Mexico, works as a waitress, and denies any tobacco or illicit drug use.

On physical examination, her oral temperature is 99.0°F (37.2°C). Her pulse is regular, with a rate of 75 bpm. Her blood pressure is 112/60 mm Hg, and she has a respiratory rate of 18 breaths/min with an oxygen saturation of 98% while breathing room air. She appears uncomfortable and generally fatigued, but is alert and oriented. The extraocular muscles are intact, with no nystagmus. Her pupils are symmetric and equally reactive to light, and the optic discs appear normal. Her mucous membranes are moist, and the remainder of the head, ears, nose, and throat examination is normal. Her lungs are clear to auscultation and she exhibits normal respiratory effort. The heart rhythm is regular and without murmurs, rubs or gallops. Her abdomen is nontender, without masses, and there is no appreciable costovertebral angle tenderness. The extremities are without edema and the radial pulses are strong bilaterally. The skin is clear and without any rash, petechiae, or ecchymoses. Cranial nerves II-XII are normal and symmetric. Otherwise, the neurologic examination reveals 2/5 strength throughout both upper and lower extremities, with 1/3 patellar, triceps, and Achilles reflexes bilaterally. She has negative Babinski and Hoffmann signs. Finger-to-nose coordination and gait could not be assessed as a result of her weakness.

Urine analysis, urine pregnancy test, and basic metabolic panel are completed soon after arrival. The pregnancy test comes back positive. She has a serum glucose concentration of 97 mg/dL (5.38 mmol/L), a hemoglobin level of 13.4 g/dL (134 g/L), and a potassium level of 1.6 mEq/L (1.6 mmol/L; normal range, 3.6-5.0 mEq/L). As a result of a low bicarbonate finding on the metabolic panel, an arterial blood gas is subsequently performed; this shows a pH of 7.25, a partial pressure of carbon dioxide (pCO2) of 22 mm Hg, a partial pressure of oxygen (pO2) of 100 mm Hg, and a bicarbonate (HCO3) of 9 mEq/L (9 mmol/L). The urine analysis shows a pH of 7.0, with moderate blood, negative nitrates, and small leukocytes. A renal ultrasound is completed prior to admission

كتابة حرة وطرح موضوع النقاش!
What disorder is the most likely primary disorder in this patient?

Cushing syndrome
Addison disease
Bartter syndrome
Distal renal tubular acidosis (RTA type I)

السؤال سهل و مباشر.

المرجع

Medscape CME

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Al Durra
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Distal renal tubular acidosis (RTA type I)

lonely
طبيب مقيم


وأنا كمان بمشي مع الحماض الأنبوبي من النمط الأول

PH = 7.25 أقل من 7.35 --> حماض
ال HCO3 أقل من 23 --> حماض استقلابي
ال PCO2 أقل من 35 --> حماض استقلابي معاوض
لحتى لنعرف إذا معاوض بشكل كافي بدها حسابات --> بلاها هلأ Cool
ولحتى نعرف إذا ال NAGMA كمان بدها شوارد .. بس ما في بالقصة شي بدل على ارتفاع الكيتون أو اللاكتات --> منعتبر فجوة الصواعد طبيعية
من الأسباب الشائعة الحماض الأنبوبي الكلوي، والإسهال (أشيع اتنين)
الحماض الأنبوبي مع نقص بوتاسيوم --> RTA type I أو II
ما في شي بالقصة بيوجه للتاني متل MM أو acetazolamide
هو اكتر نمط اول
أحلى الشي يطلع خطأ بعد كل هالكلام Cool
------
فينا نعتبر أنه الإقياء اللي صار عند المريضة كان من وسائل المعاوضة للحماض Rolling Eyes ؟ .. أول شي فكرت سبب انخفاض البوتاسيوم هو الإقياء
-----
بقيت الخيارات سهل نفيها Eye-wink
عالقليلة ما معها ارتفاع ضغط .. وما في شي بالفحص السريري
وبارتر بدو يكون معها مشكلة عصبية حسب ما بذكر

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Dr.TH

Quote:
فينا نعتبر أنه الإقياء اللي صار عند المريضة كان من وسائل المعاوضة للحماض

أنا ما هيك فسرتها!
نتيجة فحص الحمل---> ايجابية
الحمل ممكن هو يلي سبب الاقياء و بالتالي انكسرت المعاوضة بالنتيجة صار في نقص البوتاسيوم و هالشي أدى للاعراض المذكورة Rolling Eyes

lonely
طبيب مقيم


بعرف أنه الحمل سبب الإقياء وأكيد مو قصدي أنه صار الإقياء بهدف التعويض .. قصدي أنه المريضة ما معها فرط تهوية (18 مرة بالدقيقة) فكيف عاوضت Rolling Eyes ؟

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Dr.TH

Quote:
فكيف عاوضت Rolling Eyes

Rolling Eyes

lonely
طبيب مقيم

Quote:
الحمل ممكن هو يلي سبب الاقياء و بالتالي انكسرت المعاوضة بالنتيجة صار في نقص البوتاسيوم و هالشي أدى للاعراض المذكورة

تماما

ما يميز النمط الأول قصة الحصيات الكلوية أيضاً
غالبا المعاوضة الرئوية بهالحالة هي مزمنة و ليست حادة لذلك الPCO2 منخفض لدرجة المعاوضة دون وجود تسرع حاد في التنفس

The diagnosis of distal renal tubular acidosis was made on the basis of the patient's presentation of profound weakness, history of renal colic, ECG findings consistent with severe hypokalemia, renal ultrasound showing nephrocalcinosis, and arterial blood gas showing a profound metabolic acidosis. Initial laboratory testing revealed a sodium of 138 mEq/L (138 mmol/L; normal range, 135-145 mEq/L), potassium of 1.6 mEq/L (1.6 mmol/L; normal range, 3.6-5.0 mEq/L), chloride of 116 mEq/L (116 mmol/L; normal range, 98-109 mEq/L), bicarbonate of 10 mEq/L (10 mmol/L; normal range, 22-31 mEq/L), anion gap of 12 mEq/L (12 mmol/L; normal range, 6-16 mEq/L), blood urea nitrogen (BUN) of 12 mg/dL (4.3 mmol/L; normal range, 7-21 mg/dL) and a creatinine of 0.83 mg/dL (73.4 µmol/L; normal range, 0.6-1.2 mg/dL). These values were consistent with a nonanion gap metabolic acidosis, with associated hypokalemia and no evidence of chronic kidney disease. Her pregnancy-induced hyperemesis gravidarum was undoubtedly the inciting factor for the progression of hypokalemia to such a critical level.

The ECG (see Figure 1) from the patient showed very prominent "U" waves, which are classically associated with hypokalemia; in cases where the U wave is taller than the T wave, severe hypokalemia is usually present. The chest radiograph (not shown) showed subtle diffuse osteopenia. The patient's prior history of renal colic would be consistent with a history of urinary stones that often occurs in RTA patients resulting from alkaline urine and hypercalciuria. The renal ultrasound (see Figure 2) showed hyperechoic regions in the renal medulla consistent with nephrocalcinosis. The arterial blood gas demonstrated a profound metabolic acidosis with a pH of 7.25, further confirming the diagnosis. It was possible to characterize the type of RTA by looking at the urine pH, which in this patient was 7.0. This is consistent with renal tubular acidosis (RTA) type I, also known as distal renal tubular acidosis.

Distal RTA (RTA type I) is a rare renal disorder characterized by a nonanion gap hyperchloremic acidosis and hypokalemia. In this condition, the alpha intercalated cells of the cortical collecting duct of the distal nephron fail to secrete acid into the urine. This failure of acid secretion leads to an inability to acidify the urine to a pH <5.5. Because renal excretion is the primary means of eliminating acid from the body, there is consequently a tendency towards systemic acidemia. This leads to the clinical features of RTA type I, which include:

Normal anion gap hyperchloremic metabolic acidosis
Hypokalemia (from multiple mechanisms, but often severe during periods of stress)[1]
Nephrocalcinosis[2]
Nephrolithiasis (related to an inability to acidify urine, hypercalciuria, and low urinary citrate)
Loss of calcium from bones (which can cause rickets in children and osteomalacia in adults)
During periods of stress caused by illness, or in this particular case the vomiting of hyperemesis gravidum, patients can have episodes of profound hypokalemia resulting in flaccid paralysis, rhabdomyolysis, cardiac arrest, and even death.

RTA type I is either inherited or acquired. Inherited RTA type I can be either autosomal-dominant or autosomal-recessive. Autosomal-recessive RTA type I often presents in infancy, whereas autosomal-dominant RTA type I may not present until adolescence or young adulthood.[3] Some patients with autosomal recessive distal RTA have associated sensorineural hearing loss.[4] Mutations in the genes encoding carbonic anhydrase (CA) II, kidney anion exchanger-1 (kAE1), and subunits of the H+-ATPase have been identified in patients with distal RTA.[5] Some genetic disorders, such as Ehler-Danlos syndrome, Fabry disease, or Wilson disease, have also been associated with RTA type I.[6] In the acquired form, the disorder can be caused by drugs, autoimmune diseases, or by infection.[6] Some of the more common acquired forms are caused by Sjögren syndrome, lupus, hepatitis, treatment with amphotericin B,[7] toluene toxicity,[8] and chronic pyelonephritis.

The clinical manifestations of RTA type I depend upon the disease severity and whether it is acquired or inherited. The inherited form of RTA type I causes similar metabolic abnormalities, but it is more likely to result in decreased bone mineralization and growth retardation.[9] Both forms, however, have hypokalemia, which results in muscle soreness, flaccid paralysis, and electrical cardiac disturbances. The most common cause of death related to RTA type I is hypokalemia-induced cardiac dysrhythmia.

The diagnostic studies used to diagnose RTA type I include serum electrolytes, renal electrolytes, urine analysis, and 24-hour urine citrate and calcium. In a patient with a borderline acidosis and hypokalemia, an acid load test can often be diagnostic. This test entails giving an acid load of 0.1 g/kg of ammonium chloride or fludrocortisone/furosemide and then checking the urine pH 4-6 hours later.[17] The test is considered positive if the urine pH remains above 5.5. The acid load test, however, is not advisable during periods of profound acidosis, and it should be used only among stable patients in otherwise nondiagnostic cases. An ECG should be done if there is suspicion for severe hypokalemia, which often presents as muscle weakness. Renal imaging can often show evidence of nephrolithiasis or nephrocalcinosis.

The cornerstone of medical treatment for RTA type I first entails addressing the underlying metabolic derangements. This is accomplished by replenishing potassium with oral and intravenous potassium chloride or potassium citrate. The latter is often more beneficial in patients with recurrent renal stones.[13] In addition, oral sodium bicarbonate (1-2 mEq/kg/day) can often help meet the alkali requirements and compensate for the lost bicarbonate. In inherited RTA type I, early medical therapy can mitigate growth retardation and bone demineralization.

The patient in this case was treated with large amounts of oral and intravenous potassium chloride and admitted to the medical intensive care unit (ICU) for further management. During her 1-week hospitalization, nephrology and obstetrics were both consulted. Obstetrics performed a transabdominal ultrasound, which demonstrated an intrauterine 8-week embryo with normal cardiac motion. She was initiated on a regular regimen of oral potassium citrate, bicarbonate, folate, and prenatal vitamins. On the day of discharge, the patient's electrolyte derangements had corrected with oral therapy, and her nausea was controlled with oral odansetron. The patient was discharged to home on hospital day 7, and she had a normal basic metabolic panel 3 weeks after discharge.

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لأن المريضة عندها الحالة منذ فترة ( الحماض الأنبوبي مع المعاوضة التنفسية ) و لكن حدوث الحمل ---> إقياءات ----> نقص بوتاسيوم فوق ما هو ناقص من أساسه ----->ظهور أعراض التعب العضلي بشكل صارخ

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مممم .. حلو .. شكراً دكتور Eye-wink

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حلو .. شكراً دكتور
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