Chronic dyspnea and hyperventilation in an awake patient with small subcortical infarcts

Management of Neurogenic Respiratory Alkalosis and Concomitant Lactatemia After Resection of a Posterior Fossa Meningioma: A Case Report

Central neurogenic hyperventilation (CNH) is a rare disease, caused by chemical or mechanical disturbance of respiratory centers. It is characterized by the absence of extracerebral respiratory stimuli. A woman developed severe respiratory alkalosis and lactatemia after resection of a posterior fossa meningioma despite lack of cardio-respiratory or metabolic alterations. Cerebral computed tomography (cCT) revealed edema of the pontomedullary area. Treatment with mannitol and dexamethasone reestablished normal breathing patterns. Lactatemia was likely due to reduced splanchnic lactate utilization. Intracranial pathologies should be suspected in case of hyperventilation without overt reasons. cCT to confirm edema or ischemia and prompt treatment is suggested.

Central neurogenic hyperventilation in conscious patients due to CNS neoplasm: a case report and review of the literature on treatment

Background

Central neurogenic hyperventilation (CNH) is increasingly reported in conscious patients with a CNS neoplasm. We aimed to synthesize the available data on the treatment of this condition to guide clinicians in their approach.

Methods

We describe the case of a 39-year-old conscious woman with CNH secondary to glioma brainstem infiltration for whom hyperventilation was aborted with hydromorphone, dexamethasone, and brainstem radiotherapy. We then performed a review of the literature on the treatment of CNH in conscious patients due to a CNS neoplasm.

Results

A total of 31 studies reporting 33 cases fulfilled the selection criteria. The underlying neoplasm was lymphoma in 15 (45%) and glioma in 13 (39%) patients. Overall, CNH was aborted in 70% of cases. Opioids and sedatives overall seemed useful for symptom relief, but the benefit was often of short duration when the medication was administered orally or subcutaneously. Methadone and fentanyl were successful but rarely used. Chemotherapy was most effective in patients with lymphoma (89%), but not glioma (0%) or other neoplasms (0%). Patients with lymphoma (80%) and other tumors (100%) responded to radiotherapy more frequently than patients with glioma (43%). Corticosteroids were moderately effective. Subtotal surgical resection was successful in the 3 cases for which it was attempted.

Conclusion

Definitive treatment of the underlying neoplasm may be more successful in aborting hyperventilation. Variable rates of palliation have been observed with opioids and sedatives. Treatment of CNH is challenging but successful in a majority of cases.

Successful Use of Ketamine for Central Neurogenic Hyperventilation: A Case Report

This report describes the use of ketamine in a patient with central neurogenic hyperventilation following intracerebral hemorrhage. A 41-year-old man was admitted with right thalamic intracerebral hemorrhage with intraventricular extension requiring emergent external ventricular drain placement. After aggressive management of his neurologic status and other associated complications, the patient subacutely developed an altered respiratory pattern characterized by shallow, rapid breaths. After the use of multiple sedative agents to control respiratory drive had failed, a single 2 mg/kg bolus dose of intravenous ketamine was administered. In the 6 hours prior to ketamine dosing, respiratory rate ranged from 24 to 40 breaths per minute. Within minutes of ketamine administration, respiratory patterns improved and primarily ranged from 16 to 20. Twenty-four hours after ketamine administration, the patient was successfully extubated following 12 days of mechanical ventilation. Further research is needed to determine the widespread applicability of this strategy.

The Association Between Spontaneous Hyperventilation, Delayed Cerebral Ischemia, and Poor Neurological Outcome in Patients with Subarachnoid Hemorrhage

BACKGROUND

The frequency and associations of spontaneous hyperventilation in subarachnoid hemorrhage (SAH) are unknown. Because hyperventilation decreases cerebral blood flow, it may exacerbate delayed cerebral ischemia (DCI) and worsen neurological outcome.

METHODS

This is a retrospective analysis of data from a prospectively collected cohort of SAH patients at an academic medical center. Spontaneous hyperventilation was defined by PaCO2 <35 mmHg and pH >7.45 and subdivided into moderate and severe groups. Clinical and demographic characteristics of patients with and without spontaneous hyperventilation were compared using χ (2) or t tests. Bivariate and multivariable logistic regression analyses were conducted to examine the association of moderate and severe hyperventilation with DCI and discharge neurological outcome.

RESULTS

Of 207 patients, 113 (55 %) had spontaneous hyperventilation. Spontaneously hyperventilating patients had greater illness severity as measured by the Hunt-Hess, World Federation of Neurosurgical Societies (WFNS), and SAH sum scores. They were also more likely to develop the following complications: pneumonia, neurogenic myocardial injury, systemic inflammatory response syndrome (SIRS), radiographic vasospasm, DCI, and poor neurological outcome. In a multivariable logistic regression model including age, gender, WFNS, SAH sum score, pneumonia, neurogenic myocardial injury, etiology, and SIRS, only moderate [odds ratio (OR) 2.49, 95 % confidence interval (CI) 1.10-5.62] and severe (OR 3.12, 95 % CI 1.30-7.49) spontaneous hyperventilation were associated with DCI. Severe spontaneous hyperventilation (OR 4.52, 95 % CI 1.37-14.89) was also significantly associated with poor discharge outcome in multivariable logistic regression analysis.

CONCLUSION

Spontaneous hyperventilation is common in SAH and is associated with DCI and poor neurological outcome.

Central Neurogenic Hyperventilation Related to Post-Hypoxic Thalamic Lesion in a Child

Central neurogenic hyperventilation (CNH) is a rare clinical condition, whose mechanism is still unclear. Here, we report a 3-year-old male patient, who had bilateral thalamic, putaminal and globus pallideal infarction resulted in CNH without brainstem involvement. This case may illustrate a possible role for the thalamus in regulating ventilation.

Hyperventilation and cerebrospinal fluid acidosis caused by topiramate

OBJECTIVE

To report a case of hyperventilation caused by topiramate therapy and propose a pathophysiologic mechanism for this disorder.

CASE SUMMARY

A 52-year-old woman with refractory seizure disorder was admitted to the burn care unit with burns over 10% of her body. Her seizure medications, unchanged and well tolerated for several months, included carbamazepine 1200 mg, lamotrigine 500 mg, phenobarbital 80 mg, and topiramate 150 mg per day. During hospitalization, despite a relatively normal arterial pH, the woman developed persistent hyperventilation, with respiratory rates up to 50 breaths/min. Alkalinization did not reduce the hyperventilation. Thoracic contrast-enhanced computed tomographic scan ruled out pulmonary embolism and persistent pneumonia. Salicylate and biguanide screening were negative; results of repeated thyroid and liver function tests were normal. Cerebral magnetic resonance imaging excluded a cerebral pathology. After cerebrospinal fluid (CSF) analysis showed acidosis (pH 7.14), topiramate was withdrawn and the patient's general condition rapidly improved. Forty-eight hours later, the CSF pH had increased to 7.26. The woman was discharged from the burn care unit on the 42nd hospital day.

DISCUSSION

Hyperchloremic normal anion gap metabolic acidosis, which can lead to hyperventilation, has been reported as an adverse effect of topiramate treatment. However, our patient had respiratory alkalosis. Concurrent etiologies of peripheral hyperventilation were excluded, leaving central neurogenic hyperventilation as the remaining etiology. Such central neurogenic hyperventilation associated with topiramate has previously been reported in intensive care. Our case report demonstrates CSF acidosis. Withdrawing topiramate reduced both CSF acidosis and hyperventilation. The mechanism of topiramate-induced CSF acidosis remains unclear. According to the Naranjo probability scale, the relationship of hyperventilation to administration of topiramate in our patient was probable.

CONCLUSIONS

Normal doses of topiramate may provoke central neurogenic hyperventilation, as a result of CSF acidosis. The acid-base status of critically ill patients receiving topiramate should be monitored carefully.

Central neurogenic hyperventilation treated with intravenous fentanyl followed by transdermal application

Central neurogenic hyperventilation (CNH) is a rare clinical condition that is sometimes difficult to treat. We report a 51-year-old female patient who was successfully treated with intravenous fentanyl followed by transdermal fentanyl. She had a transient epileptic episode with a temporary loss of consciousness. Immediately before her admission to the intensive care unit (ICU), her Pa(CO2) and pH were 6.7 mmHg and 7.64, respectively. Rebreathing from a paper bag and the intravenous administration of diazepam failed to improve the decreased Pa(CO2). Therefore, we administered intravenous fentanyl, at the rate of 50 microg x h(-1). Two days after her admission to the ICU, the Pa(CO2) had increased gradually to 22.9 mmHg, and the pH to 7.50. Although infiltration of recurrent lymphoma to the brain became apparent, she remained active, without epilepsy or loss of consciousness, in a general ward for 1 month with transdermal fentanyl, treatment until she again became drowsy; she died on hospital day 58. Transdermal fentanyl seems to be a good palliative measure to treat CNH in patients who have advanced neoplasms.

[Primary central nervous system lymphoma presenting with central neurogenic hyperventilation. A case report and review of the literature]

INTRODUCTION

Central neurogenic hyperventilation (CNH) in an awake patient is a rare entity.

OBSERVATION

We report here a 54-year-old patient who developed central neurogenic hyperventilation as the initial presentation of a primary central nervous system lymphoma located in the brainstem.

CONCLUSION

The patient's hyperventilation resolved completely with chemotherapy for primary CNS lymphoma. Most of the cases reported in the literature are related to a diffuse tumor of the brainstem with an intriguing overrepresentation of primary CNS lymphoma. The pathogenesis of CNH is discussed.

Central neurogenic hyperventilation in a conscious man with CSF dissemination from a pineal glioblastoma

A 40-year old conscious man developed central neurogenic hyperventilation (CNH). He had tumor dissemination to the brainstem 10 months after undergoing partial removal of a pineal glioblastoma. To the best of our knowledge, this is the first report of CNH caused by the cerebrospinal fluid dissemination of a tumor. The authors suggest that multiple lesions from an infiltrative tumor in the brainstem may give rise to CNH and further our understanding of the pathogenesis of CNH.