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PubMed1992

Effectors of hypercarbia during experimental pneumoperitoneum.

Hypercarbia occurs during laparoscopy with carbon dioxide (CO2) insufflation. This may be due to increased ventilatory dead space after expansion of the peritoneal cavity with impairment of diaphragmatic excursion, or to increased absorption of CO2 from the peritoneum. To separate these effects, the authors examined the consequences of different insufflating gases and of diminished tissue perfusion on hypercarbia and dead space during pneumoperitoneum. Helium was chosen as an alternate insufflating gas because it is both inert and minimally absorbed. Eight swine (18 to 20 kg) were anesthetized, paralyzed, and mechanically ventilated at constant minute volume. Pneumoperitoneum with helium was maintained at 15 mm Hg for 45 minutes. After desufflation and stabilization for 1 hour, pneumoperitoneum was repeated with CO2. The sequence was again repeated after hemorrhagic shock to constant mean arterial pressure of 50 mm Hg. Data was analyzed by analysis of variance; significance levels are P < 0.01 unless otherwise listed. Arterial PCO2 increased significantly with CO2 insufflation within 15 minutes in normotensive animals and within 30 minutes during hypotension. Arterial pH decrease with CO2 pneumoperitoneum was significant in both groups at 30 minutes. Mixed venous PCO2 also increased with CO2 pneumoperitoneum within 30 minutes. Hypotension did not alter these changes. No significant changes were seen with helium pneumoperitoneum. Neither helium nor CO2 pneumoperitoneum significantly altered dead space. The authors make the following conclusions: 1) Absorption of CO2 from the abdomen during CO2 pneumoperitoneum produces respiratory acidosis, which is not seen with helium insufflation; 2) Pneumoperitoneum does not significantly increase dead space with either gas; 3) Transperitoneal absorption of CO2 is only partly related to perfusion because significant hypercarbia occurs during hemorrhagic shock.

Absorption↗
PubMed1975

[Combined effects of hypoxia and hypercapnia on the functional state of the respiratory center].

Experiments were conducted on cats under nembutal anesthesia; a study was made of pulse activity of bulbar respiratory neurons, electrical activity of the diaphragm and of the intercostal muscles; pO2, pCO2, pH, arterial blood oxygen saturation were determined in combined action of hypoxia and hypercapnia. When hypoxic gaseous mixture was given for respiration the developing hypocapnia disturbed the discharge rhythmic activity of the respiratory neurons, the respiration acquiring a pathological character of the Cheyne--Stokes type. After addition to the hypoxic gaseous mixture of 2% CO2 the gaseous composition of the arterial blood approached the initial values; this addition prevented the development of hypercapnia and disturbances of rhythmic discharge activity of the respiratory neurons. Addition of 5% CO2 to the hypoxic gaseous mixture produced a negative effect: at first it intensified and then depressed the pulse activity of the respiratory neurons, caused metabolic and respiratory acidosis, and promoted asphyxia.

Animals↗
PubMed2006

Ventilatory Management of ALI/ARDS.

Acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS) describe syndromes of diffuse parenchymal lung injury resulting from a variety of inflammatory triggers. The pathophysiological consequences include stiff, low-compliance lungs with impaired gas exchange. Importantly, there is often marked heterogeneity of disease. Positive pressure ventilation must therefore not only focus on recruiting and ventilating diseased units but must also avoid injuring healthy units. To this end, the goals of mechanical ventilatory support of ALI and ARDS have shifted over the last decade to providing smaller (and thus less injurious) tidal volumes and accepting consequently lower arterial values for PaO(2) and the development of respiratory acidosis. This has resulted in significant improvements in outcomes. Future developments will need to further refine this lung protective concept.

Humans↗
PubMed1990

Prostaglandin F2 alpha inhibits the ammoniagenic response to acute acidosis in LLC-PK1 cells.

A kidney epithelial cell line, LLC-PK1, which does not synthesize prostaglandins, provides an ideal in vitro model system to investigate the effect of prostaglandins in the regulation of renal ammoniagenesis. Previous studies from our laboratory have demonstrated significant increases in glutamine-dependent ammonia and alanine production by rocked cultures of LLC-PK1 cells subjected to either acute metabolic or respiratory acidosis. In the study presented here, experiments were conducted to investigate the role of prostaglandin F2 alpha (PGF2 alpha) and prostaglandin E2 (PGE2) in the response of ammonia metabolism to acute metabolic acidosis by LLC-PK1 cells. A low dose of PGF2 alpha (0.1 ng/mL) dramatically inhibited the stimulatory effect of a low pH (pH 6.8) on ammonia production. In contrast, the inhibition of cytosolically generated alanine was less dramatic and averaged only 20% of the effect on ammonia production. Furthermore, PGF2 alpha increased cellular alpha-ketoglutarate concentration, suggesting an increase in intramitochondrial pH. Thus, the cellular mechanism of PGF2 alpha action appears to involve either interference with the cytosolic pH signal or its translation to the intramitochondrial compartment. The inhibitory response of PGF2 alpha on pH-stimulated ammoniagenesis was progressively lost at higher concentrations. Both low-dose (0.1 ng/mL) and high-dose (10 ng/mL) PGF2 alpha had no significant effect on the basal rates of ammonia and alanine production at pH 7.4. PGE2, on the other hand, did not exhibit any significant response on ammonia or alanine production at either pH 6.8 or 7.4 when given in a wide range of doses.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis↗
PubMed2003

[Ventilation in special situations. Mechanical ventilation in congenital cardiopathies and pulmonary hypertension].

The cardiovascular and respiratory systems act as a functional unit. Mechanical ventilation modifies pulmonary volumes, which generates changes in autonomic nervous system reactivity and provokes tachy- or brady-cardia (depending on the tidal volume used). Mechanical ventilation also decreases cardiac filling volumes (pre-load) and alters pulmonary vascular resistances. In addition, intrathoracic pressures are enlarged, which usually produces a decrease in right atrium filling and an increase in right ventricle afterload. If coronary flow is impaired, myocardial contractility is reduced. However, if cardiac failure is present, mechanical ventilation is especially beneficial because it corrects hypoxia and respiratory acidosis, decreases the work of breathing, and improves stroke volume. Mechanical ventilation in congenital heart diseases is indicated either as lifesaving support or as physiopathological treatment to modify the ratio between pulmonary and systemic flow. As a general rule, if excessive pulmonary blood flow is present, the aim of respiratory support is to increase pulmonary vascular resistance by using high levels of airway pressure and even by delivering FiO2<21%. When there is low pulmonary flow, the lowest possible intrathoracic pressures should be used, especially in cases of pulmonary hypertension, which will also require high FiO2. However, mechanical ventilation has adverse effects and consequently it must be stopped as early as possible, once the child is stable and requires minimal cardiopulmonary support. Weaning can even be performed in the operating room, when the surgical procedure is finished. When this is not possible, weaning should be performed in the pediatric intensive care unit. Because there are no criteria for successful withdrawal of mechanical support in congenital heart disease, general pediatric criteria should be used.

Child↗
PubMed2005

Sustained oxygenation without ventilation in paralyzed pigs with high-flow tracheal oxygen.

OBJECTIVES: It is generally assumed that ventilation is necessary for oxygenation. This study tested if paralyzed animals without respirations can maintain arterial oxygenation when administered high-flow oxygen delivered by a catheter in the trachea. METHODS DESIGN: Prospective observational study. SETTING: University research laboratory. PARTICIPANTS: 3 anesthetized/paralyzed swine weighing 29.5 +/- 4.2 kg. INTERVENTIONS/OBSERVATIONS: Pigs were intubated, anesthetized with intravenous tiletamine and a pentobarbital drip. A femoral arterial line was placed to record arterial blood gases and vital signs every 5 minutes. Respiratory paralysis was obtained with vecuronium 150 microg/kg and repeated at any sign of movement. A catheter was placed in the trachea to deliver oxygen at 15 L/min. Outflow gas from the endotracheal tube was analyzed for O2 and CO2. O2 was discontinued at 75 minutes. The institutional animal care and use committee approved the protocol. RESULTS: All pigs survived to 75 minutes. PaO2 was more than 100 mm Hg throughout the study period. Mean PaCO2 was 37.4 +/- 2.8 mm Hg at baseline, 146 +/- 59 at 30 minutes, then rose above 200 mm Hg in all pigs by 45 minutes. Mean arterial pH fell from 7.47 +/- 0.04 at onset to 6.75 +/- 0.06 at 75 minutes. When oxygen was terminated at 75 minutes, PaO2 fell to 16.5 +/- 7.6 mm Hg within 5 minutes, and all pigs were sacrificed within 10 minutes. For outflow gas, O2 was more than 98% and expired CO2 less than 1% throughout the study period. CONCLUSIONS: Paralyzed, unventilated pigs receiving high-flow oxygen via a tracheal catheter remained alive after 75 minutes, although a profound respiratory acidosis developed.

Animals↗
PubMed1989

Regulation of intracellular pH in the myocardium; relevance to pathology.

Intracellular pH affects the contractile function of the heart, metabolic reactions, ion exchange and calcium homoeostasis. Numerous studies have concluded that a fall of extracellular pH, by whatever mechanism, causes a fall of contractility by alteration of intracellular pH. Measurement of cytosolic intracellular pH using microelectrodes has confirmed that earlier deduction. Acidosis reduces the slow calcium current and the release of calcium from the sarcoplasmic reticumul but, because the cytosolic calcium does not fall, the major site of action of hydrogen ions appears to be on the calcium sensitivity of the contractile proteins. In man acidosis can be detected 15 s after the occlusion of a coronary artery and is a major mechanism for the simultaneous loss of contractility in ischaemia. A transient alkalosis is not detected in man but has been reported in isolated heart preparations where ATP consumption is low. An imposed mild respiratory acidosis during hypoxia increases the subsequent recovery of mechanical function on reoxygenation whereas a severe acidosis can be harmful. Acidosis in ischaemic may be advantageous due to a cardioplegic effect, inhibition of transsarcolemmal calcium fluxes or a reduction of mitochondrial calcium overload. Calcium uptake on reperfusion or reoxygenation has been linked to an inward movement of sodium in exchange for hydrogen ions on reperfusion and subsequent sodium-calcium exchange. Such a mechanism in its simplest form cannot account for the similar uptake of calcium on reoxygenation and reperfusion. Acidosis is a cause of early contractile failure in ischaemia but the role of acidosis in causing cell necrosis is not established.

Acidosis↗
PubMed1987

Clinical presentation of mitochondrial respiratory chain defects in NADH-coenzyme Q reductase and cytochrome oxidase: clues to pathogenesis of Leigh disease.

Measurement of pyruvate and lactate produced from glucose by confluent skin fibroblast cultures from 95 patients with lactic acidemia revealed 10 in whom the lactate/pyruvate ratio (L/P) was increased (L/P = 57 to 232) compared with that observed in control cell lines (L/P = 18 to 35). Mitochondria prepared from these cells revealed two types of respiratory chain defect. In four patients the deficient activity was present in NADH-coenzyme Q reductase (14% to 21% of controls), and in six the deficiency was in cytochrome c oxidase (21% to 28% of controls). The four patients with NADH-coQ reductase deficiency presented early with lactic acidosis, respiratory failure, anorexia, and hypotonia; all four died within 7 months. The group with cytochrome oxidase deficiency had a somewhat later (18 months to 2 years of age) presentation with milder lactic acidemia, but also with hypotonia and anorexia. They had delayed development, beginning to walk and talk at 18 to 24 months, and then slowly regressed. Although an investigation of central nervous system disorders in this latter group has not been possible, the clinical progression fits into the broad category of Leigh disease. We conclude that in these two groups respiratory chain defects can be detected and localized by the use of skin fibroblast cultures.

Brain Diseases, Metabolic↗
PubMed1996

Noninvasive ventilatory support does not facilitate recovery from acute respiratory failure in chronic obstructive pulmonary disease.

This investigation evaluates, in a prospective, randomized and controlled manner, whether noninvasive ventilatory support (NIVS) with bilevel positive airway pressure (BiPAP) facilitates recovery from acute respiratory failure (ARF) in patients with chronic obstructive pulmonary disease (COPD). Twenty four patients (mean age (+/-SEM) 68 +/- 2 yrs) with COPD (forced expiratory volume in one second (FEV1) at discharge 33 +/- 2% predicted), who attended the emergency room because of ARF (pH 7.33 +/- 0.01; arterial oxygen tension (Pa,O2) 6.0 +/- 0.2 kPa; arterial carbon dioxide tension (Pa,CO2) 7.9 +/- 0.3 kPa), were initially randomized. Four out of the 14 patients (29%) allocated to received NIVS did not tolerate it. Of the remaining 20 patients, 10 received NIVS with BiPAP in a conventional hospital ward during the first 3 days of hospitalization (two daytime sessions of 3 h duration each). All 20 subjects were treated with oxygen, bronchodilators and steroids. On the first and third hospitalization days, before and 30 min after withdrawing oxygen therapy and/or BiPAP ventilatory support, we measured peak expiratory flow, arterial blood gas values, ventilatory pattern, occlusion pressure (P0.1), and maximal inspiratory (MIP) and maximal expiratory (MEP) pressures. All patients were discharged without requiring tracheal intubation and mechanical ventilation. Hospitalization time was similar in both groups (11.3 +/- 1.3 vs 10.6 +/- 0.9 days, control vs BiPAP, respectively). Arterial oxygenation, respiratory acidosis and airflow obstruction improved significantly throughout hospitalization in both groups. By contrast, the ventilatory pattern, P0.1, MIP and MEP did not change. NIVS with BiPAP did not cause any significant difference between groups. We conclude that noninvasive ventilatory support with bilevel positive airway pressure does not facilitate recovery from acute respiratory failure in patients with chronic obstructive pulmonary disease. Furthermore, a substantial proportion of patients (29%) do not tolerate noninvasive ventilatory support under these circumstances. From these results, we cannot recommend the use of noninvasive ventilatory support with bilevel positive airway pressure in the routine management of chronic obstructive pulmonary disease patients recovering from acute respiratory failure.

Aged↗
PubMed1994

Noninvasive mechanical ventilation via face mask in patients with acute respiratory failure who refused endotracheal intubation.

OBJECTIVE: To evaluate the response to noninvasive ventilation in a group of terminally ill patients with acute respiratory failure who refused endotracheal intubation. DESIGN: Case series. SETTING: Medical intensive care units (ICUs) in a university health science center. PATIENTS: Eleven patients, nine with hypercapnic and two with hypoxemic acute respiratory failure. Mean age of patients was 64 yrs. INTERVENTION: Mechanical ventilation was delivered via a face mask. The initial ventilatory setting was continuous positive airway pressure mode, with pressure-support ventilation of 10 to 20 cm H2O, titrated to achieve a respiratory rate of < 25 breaths/min and a tidal volume of 5 to 7 mL/kg. Ventilatory settings were adjusted based on results of arterial blood gases. Mean duration of mechanical ventilation was 44 hrs. MEASUREMENTS AND MAIN RESULTS: Mechanical ventilation via face mask was effective in correcting gas exchange abnormalities in seven of 11 patients, all of whom survived and were discharged from the ICU. Four patients with hypercapnic acute respiratory failure died. Mechanical ventilation via face mask was effective in improving respiratory acidosis in three patients and had no effect in one patient. Two of the four patients could not be weaned from mechanical ventilation and opted for discontinuation of this method. Removal of the ventilator while retaining the mask for oxygen supplementation was a nontraumatic experience to the patient and family. Even when respiratory failure did not resolve, mechanical ventilation via face mask was effective in lessening dyspnea and allowed the patient to maintain autonomy and continuous verbal communication. CONCLUSIONS: We conclude that mechanical ventilation via face mask offers an effective, comfortable, and dignified method of supporting patients with end-stage disease and acute respiratory failure.

Acute Disease↗
PubMed2002

Physiologic factors predisposing to chronic respiratory failure.

V(A)/Q mismatching and load/capacity imbalance are the major physiologic determinants of chronic respiratory failure. The former underlies lung failure and the consequent development of hypoxemia. The latter causes chronic ventilatory failure and hypercapnia. This is the consequence of an inefficient breathing pattern with lower VT and higher respiratory rate, probably due to the "wise choice" of preventing excessive inspiratory effort and eventually respiratory muscle fatigue. In many disorders, V(A)/Q mismatching and the load/capacity imbalance coexist, particularly in COPD, where the interplay between the two pathophysiologically represents the advanced stage of the disease. In other disorders, one of the two mechanisms prevails; for example, V(A)/Q mismatching in pure lung diseases, and chest wall mechanics in thoracic disorders. This has important therapeutic implications because oxygen administration can relieve hypoxemia, whereas mechanical ventilation can prevent excessive hypercapnia and respiratory acidosis. Although the role of oxygen therapy is well established, the role of chronic mechanical ventilation is still a matter of debate, particularly in COPD. A major task for future research is to achieve the best possible understanding of the pathophysiologic factors predisposing to chronic ventilatory failure, to prevent the progression of the respiratory diseases to the stage when chronic respiratory failure eventually develops.

Chronic Disease↗
PubMed1997

Evaluation of renal acidification in HIV-infected patients with hypergammaglobulinemia.

Distal renal tubular acidosis has been reported in several diseases associated with hypergammaglobulinemia, particularly Sjögren's syndrome. Since HIV infection is now a common cause of hypergammaglobulinemia, we evaluated renal acidification under basal and dynamic conditions in 8 asymptomatic HIV-seropositive subjects. Basal acid-base status was normal in all except 1 patient who had respiratory acidosis subsequent to recent pneumonia. Acid-loading tests showed normal acid excretion except for 1 patient who had low acid excretion attributed to non-ingestion of the ammonium chloride capsules. Bicarbonate-loading tests showed normal distal acidification indexes in 7 patients. The only patient with a low acidification defect was diagnosed 2 weeks later as having tuberculosis. Our results suggest that hypergammaglobulinemia per se is not a sufficient condition to induce renal tubular acidosis.

Acidosis, Renal Tubular↗
PubMed1989

[Transient acute respiratory failure and thoracic epidural anesthesia].

A case is reported of acute respiratory failure occurring during upper abdominal surgery in a patient not previously known to have chronic respiratory failure. Preoperatively, this 68 year old patient presented with mild obesity, slight effort dyspnoea and paralysis of the right hemidiaphragm, a sequela of polytrauma she suffered the year before. Respiratory tests were not considered useful with regard to the results of clinical examination. Moreover, she had already several previous general anaesthetics without any problems. A thoracic epidural anaesthesia was performed with a mixture of 150 mg lidocaine, 37.5 mg bupivacaine with adrenaline and 100 micrograms fentanyl, injected in the T8-T9 epidural space via a catheter. Ten minutes after the starting of surgery, the patient became agitated and complained of difficulty in breathing. Blood gas analysis showed hypercapnia, with respiratory acidosis (Pao2: 28.19 kPa; Paco2: 9.2 kPa; pH 7.273). Clinical examination revealed a bilateral Horner syndrome (T1-T4 sympathetic blockade). The patient was intubated and ventilated after adequate sedation. She was extubated 3 h 30 min after the initial epidural injection. Epidural analgesia was maintained during 72 h, with 0.1% bupivacaine, with no recurrence of respiratory failure.

Acute Disease↗
PubMed1997

Hypercarbia during tracheostomy: a comparison of percutaneous endoscopic, percutaneous Doppler, and standard surgical tracheostomy.

OBJECTIVE: Tracheostomy is one of the most commonly performed surgical procedures in the critical care setting. The early use of tracheostomy as a method of primary airway management has been proposed as a means to decrease pulmonary morbidity and to shorten the number of ventilator, intensive care unit, and hospital days. We set out to (1) determine whether hypercarbia occurs during tracheostomy of the critically ill patient and (2) determine the extent to which the partial pressure of carbon dioxide in arterial blood (PaCO2) rises during percutaneous endoscopic, percutaneous Doppler, and standard surgical tracheostomy. DESIGN: Prospective, open clinical trial. SETTING: Surgical intensive care unit and operating room in teaching hospitals. PATIENTS: During mechanical ventilation, patients underwent either percutaneous endoscopic (PET), percutaneous Doppler (PDT), or standard surgical tracheostomy (ST), based on surgeon preference. Arterial blood gas readings were obtained approximately every 4 min throughout each procedure. MEASUREMENTS AND RESULTS: All tracheostomies were successfully performed. No serious complications (including hypoxia) occurred during the study. Significant (p < 0.05 vs PDT and ST) hypercarbia (maximum delta PaCO2 24 +/- 3 mmHg) and acidosis (maximum delta pH -0.16 +/- 0.02) developed during PET. The changes in PaCO2 and pH during PDT (maximum delta PaCO2 8 +/- 2 mmHg; maximum delta pH -0.07 +/- 0.02) and ST (maximum delta PaCO2 3 +/- 1 mmHg; maximum delta pH -0.04 +/- 0.01) were markedly less pronounced. CONCLUSIONS: Continuous bronchoscopy during percutaneous tracheostomy contributes significantly to early hypoventilation, hypercarbia, and respiratory acidosis during the procedure. Percutaneous tracheostomy, when performed using the Doppler ultrasound method to position the endotracheal tube, significantly reduces CO2 retention when compared to PET. Because of a possible rise in intracranial pressure, the potential for hypercarbia should be considered when choosing the method of tracheostomy in the critically ill and/or head-injured patient, where hypercarbia may be detrimental. If PET is to be performed, steps to minimize occult hypercarbia, such as using the smallest bronchoscope available, minimizing suctioning during bronchoscopy, and minimizing the length of time the bronchoscope is in the endotracheal tube, should be undertaken.

Acidosis↗
PubMed1994

Ibuprofen overdose complicated by renal failure, adult respiratory distress syndrome, and metabolic acidosis.

Acute ingestion of ibuprofen commonly results in no symptoms, or minor gastrointestinal or central nervous system manifestations. While most cases of ibuprofen overdose do well, serious toxicity may occur, and is difficult to predict. A case of ibuprofen overdose is presented in which the course was complicated by metabolic acidosis, adult respiratory distress syndrome, and renal failure necessitating prolonged dialysis.

Acidosis↗
PubMed2004

Role of arterial blood gas abnormalities in oedema formation in COPD.

OBJECTIVE: Renal and hormonal abnormalities, manifesting as oedema or hyponatraemia, are often seen in patients with COPD. The aim of this study was to investigate the effect of airflow obstruction and arterial blood gas abnormalities on oedema formation in COPD patients. METHODOLOGY: A total of 58 COPD patients hospitalized for treatment of COPD exacerbation were admitted to the study. Of these, 38 patients had peripheral oedema (group 1) and 20 patients had no oedema (group 2). RESULTS: The mean age was 68 +/- 9 years in group 1 and 68 +/- 8 years in group 2. On the first day of admission, serum urea was 29.18 +/- 12.25 mg/dL and creatinine was 1.62 +/- 0.46 mg/dL in group 1, while urea was 15.50 +/- 4.59 mg/dL and creatinine was 1.07 +/- 0.10 mg/dL in group 2. Hyponatraemia occurred in five patients (13%) in group 1 and one patient (5%) in group 2. There was no difference in severity of airflow obstruction in the two groups; FEV1 was 44 +/- 15% of predicted and FEV1/FVC was 53 +/- 14 in group 1, while FEV1 was 45 +/- 16% of predicted and FEV1/FVC was 54 +/- 20 in group 2. There were statistically significant differences in pH (7.32 vs. 7.39; P= 0.013) and in PaCO2 (62 +/- 10 mmHg vs. 42 +/- 6; P= 0.048) for group 1 compared with group 2. PaO2 (62 +/- 17 mmHg vs. 82 +/- 27) and SaO2 (87 +/- 9%vs. 90 +/- 13) were found to be lower in group 1 compared with group 2 but the difference did not reach statistical significance. CONCLUSION: Alterations in pH and PaCO2 (respiratory acidosis and hypercapnia) appear to have more prominent roles than hypoxaemia in oedema formation in COPD patients.

Aged↗
PubMed2001

Severe respiratory failure secondary to Cushing's myopathy.

We report a 55-year-old woman with typical clinical, biochemical and radiological features of Cushing's disease, who developed a severe respiratory insufficiency as the main symptom. She also complained of proximal muscle weakness over the last year and progressive dyspnea over the last four months. Bronchospasm, respiratory infection or cardiologic dysfunction were excluded. Arterial blood gas analysis showed severe respiratory insufficiency with hypoxemia and hypercapnia, respiratory acidosis and a normal alveolar-arterial oxygen gradient. Spirometry and plethysmography showed a restrictive ventilatory failure and maximum inspiratory and expiratory pressures were reduced. These findings were strongly suggestive of neuromuscular disease. Serum creatine kinase, aldolase, sodium, potassium and thyroid function tests were normal. An electromyogram and a muscle biopsy confirmed myopathic disease. Ketoconazole therapy improved her symptoms and respiratory function tests. In conclusion although proximal myopathy is a frequent presenting symptom of Cushing's syndrome, involvement of respiratory muscles with severe restrictive ventilatory dysfunction has not been previously reported as the main initial feature of Cushing's disease. Medical treatment of hypercortisolism improves muscle strength and resolves the respiratory insufficiency.

Cushing Syndrome↗