Muscular Respiratory Failure Research Articles

Short-lived survival of severe hypercapnia from chronic respiratory failure in motor neuron disease

Surviving extreme hypercapnia from muscular respiratory failure has been only rarely reported. A 66-year-old male developed slowly progressive weakness of the lower limbs since one year resulting in recurrent falls and later dysarthria, weakness of the left intrinsic hand muscles, general wasting, brisk tendon reflexes, and symmetric stocking type pall-hypaesthesia. Electromyograms of various muscles were neurogenic. Cerebral MRI showed diffuse atrophy, leucaraiosis, spot-like hyperintensities subcortically and in the basal ganglia and a diffuse hypersignal in the pons. Probable amyotrophic lateral sclerosis (ALS) was diagnosed. Four months later he was admitted for respiratory insufficiency, impaired consciousness, exsiccosis, and cachexia. Blood pH was 6.9 and blood pCO2 was 235 mmHg (n, 35 - 45 mmHg). Within six hours under mechanical ventilation he recovered completely from hypercapnia and actively extubated himself two days after admission. This case shows that severe hypercapnia from weakness of the respiratory muscles may be survived if respiratory failure develops slowly, and if adequately treated.

Cardiopulmonary Support in Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is an X-linked, rapidly progressive myopathy affecting the limb muscles, the respiratory muscles, the heart, the intestines, and the brain. Since about 90% of DMD patients die from muscular respiratory failure or cardiomyopathy, early and adequate therapy is essential. Ventilatory failure from muscle weakness requires mechanical support for ventilation and coughing as soon as there is symptomatic nocturnal hypoventilation. Today noninvasive positive-pressure ventilation (NIPPV) is the method of choice for supportive long-term mechanical ventilation in DMD. For assisted coughing, various methods are available, among which the mechanical in-exsufflator is the most widely used device. There is large nonrandomized clinical trial evidence that NIPPV improves quality of life and prolongs the lives of DMD patients if medical, social, economic, and ethical issues, raised by the availability of long-term NIPPV, are adequately addressed. Cardiac involvement in DMD manifests as impulse generation or impulse conduction abnormalities or cardiomyopathy. Cardiac abnormalities in DMD respond well to adequate therapy. Though DMD is ultimately a fatal disease, quality of life and life expectancy can be markedly improved if cardiopulmonary manifestations are adequately treated.

Acquired noncompaction in Duchenne muscular dystrophy

Acquired left ventricular hypertrabeculation/noncompaction (LVHT) is rare and has been described in patients with mitochondriopathy, Barth syndrome, and Becker muscular dystrophy. Here we report acquired LVHT in a 28-year-old man with Duchenne muscular dystrophy who required non-invasive, positive-pressure ventilation for muscular respiratory failure since age 16 years. Transthoracic echocardiography at age 22 years revealed enlarged left atrium and ventricle and reduced fractional shortening, but no LVHT. Transthoracic echocardiography at age 27 years revealed enlarged left atrium and ventricle, systolic dysfunction, mitral insufficiency, and, surprisingly, LVHT. The cause and pathomechanism of acquired LVHT in this patient remained speculative.

Hypothyroidism and Muscular Respiratory Failure Successfully Treated With Liothyronine

After total thyroidectomy because of hyperthyroidism, hypothyroidism developed in a 78-year-old woman. Despite replacement therapy with levothyroxine sodium in continuously increasing doses, worsening hypothyroidism led to respiratory failure, necessitating artificial ventilation. The addition of liothyronine resulted in complete recovery. Impaired conversion of thyroxine to triiodothyronine by the dejodase was responsible for the manifestations of hypothyroidism.

Hypothyroidism and Muscular Respiratory Failure Successfully Treated With Liothyronine

After total thyroidectomy because of hyperthyroidism, hypothyroidism developed in a 78-year-old woman. Despite replacement therapy with levothyroxine sodium in continuously increasing doses, worsening hypothyroidism led to respiratory failure, necessitating artificial ventilation. The addition of liothyronine resulted in complete recovery. Impaired conversion of thyroxine to triiodothyronine by the dejodase was responsible for the manifestations of hypothyroidism.