Effect of acetazolamide on post-NIV metabolic alkalosis in acute exacerbated COPD patients.

OBJECTIVE: Non-invasive ventilation (NIV) is an effective treatment in patients with acute exacerbation of COPD (AECOPD). However, it may induce post-hypercapnic metabolic alkalosis (MA). This study aims to evaluate the effect of acetazolamide (ACET) in AECOPD patients treated with NIV. PATIENTS AND METHODS: Eleven AECOPD patients, with hypercapnic respiratory failure and MA following NIV, were treated with ACET 500 mg for two consecutive days and compared to a matched control group. Patients and controls were non invasively ventilated in a bilevel positive airway pressure (BiPAP) mode to a standard maximal pressure target of 15-20 cmH2O. RESULTS: ACET intra-group analysis showed a significant improvement for PaCO2 (63.9 ± 9.8 vs. 54.9 ± 8.3 mmHg), HCO3- (43.5 ± 5.9 vs. 36.1 ± 5.4 mmol/L) and both arterial pH (7.46 ± 0.06 vs. 7.41 ± 0.06) and urinary pH (6.94 ± 0.77 vs 5.80 ± 0.82), already at day 1. No significant changes in endpoints considered were observed in the control group at any time-point. Inter-group analysis showed significant differences between changes in PaCO2 and HCO3- (delta), both at day 1 and 2. Furthermore, the length of NIV treatment was significantly reduced in the ACET group compared to controls (6 ± 8 vs. 19 ± 19 days). No adverse events were recorded in the ACET and control groups. CONCLUSIONS: ACET appears to be effective and safe in AECOPD patients with post-NIV MA.

Intrarenal hemodynamic and oxidative stress in patients with obstructive sleep apnea syndrome.

BACKGROUND: Oxygen desaturation and reoxygenation, related to intermittent hypoxia cycles due to upper airway obstruction, are major pathophysiologic features of obstructive sleep apnea syndrome (OSAS) and are thought to be responsible for an increased risk of cardiovascular diseases. Continuous positive airway pressure (CPAP) is therefore considered the gold standard in the management of OSAS. Further data demonstrated a high prevalence of OSAS in patients with altered renal function despite the underlying pathophysiological mechanisms that have not been clarified. This study aims to provide evidence on the reported high prevalence of endothelial dysfunction and alterations of the intrarenal hemodynamic in patients affected by OSAS. Furthermore, we evaluated the effect of a CPAP therapy on these endpoints. METHODS: Twenty patients were enrolled in a prospective study and underwent ultrasound examination to assess endothelial dysfunction, by collecting brachial flow-mediated dilation (FMD) and intrarenal artery stiffness, pre- and post a 30-day treatment with CPAP. RESULTS: Endothelial dysfunction and intrarenal artery stiffness significantly improved in all patients after a month of CPAP. In particular, we observed a significant reduction in the renal resistance index (RI) (p < 0.001) and systolic/diastolic ratio (S/D) ratio (p < 0.001) and a significant increase of FMD (p < 0.001). The apnea-hypopnea index (AHI) showed a negative correlation with Δ FMD (p < 0.05, r = -0.46). Conversely, a positive correlation exists between Δ RI and the oxygen desaturation index (ODI) (specificare la sigla) (p < 0.05, r = 0.46). CONCLUSIONS: Our study firstly showed a significant effect of CPAP on renal perfusion and endothelial function in OSAS patients without concomitant cardiovascular comorbidities.

Exercise tolerance in systemic sclerosis patients without pulmonary impairment: correlation with clinical variables.

OBJECTIVES: In systemic sclerosis (SSc) patients pulmonary vasculopathy (PV) is present in the early stage of disease and impairs dilation of affected pulmonary blood vessels, impeding pulmonary blood flow during exercise. Abnormal gas exchange findings were early investigated by cardiopulmonary exercise test (CPET). METHODS: A total of 34 female and 6 male [median age 49 (20-63) years] SSc patients with normal chest imaging and pulmonary function tests were enrolled. Twenty healthy controls age and sex matched [16 female and 4 male; median age 51 (35-73) years] were also recruited. All subjects underwent a full clinical examination, including a nailfold video capillaros copy (NVC). An incremental symptom-limited CPET was performed with estimation of minute ventilation (VE), workload (WR), peak oxygen uptake (pVO22), and ventilatory efficiency (VE/VCO2 slope). RESULTS: A reduced exercise tolerance (pVO2<80% of predicted) was documented in 18 out of 40 subjects (45%). Six out of 18 patients with a reduced exercise tolerance showed indirect signs of ventilation perfusion mismatch (VE/ VCO2 slope >34). Patients with digital ulcers (DUs) history showed VE/VCO2slope values significantly higher [31.4 (18-39.6)] than in patients without DUs history [26.9 (22-29.4)] (p<0.0001). VE/VCO2slope values also significantly differed between the three capillaroscopic groups: early [26.3 (18-29.4)], active [28 (26.8-39.6)], and late [32.9 (22.4-39)] (p<0.0001). A positive correlation was found between the VE/ VCO2slope and both Disease Activity Index (p<0.0001, r=0.59) and Disease Severity Scale (p<0.0001, r=0.73). CONCLUSIONS: In SSc patients without evidence of pulmonary and cardiac involvement, CPET might be useful in disclosing an early PV.

Safety and infectious prophylaxis of intravenous immunoglobulin in elderly patients with membranous nephropathy.

A variety of infections has been recognized as an important cause of morbidity and mortality in patients with nephrotic syndrome, and membranous nephropathy is a common cause of this in the elderly. The reasons for infection risk are due to oedema complications, urinary loss of factor B and D of the alternative complement pathway, cellular immunity, granulocyte chemotaxis, hypogammaglobulinemia with serum IgG levels below 600 mg/dL, and secondary effects of immunosuppressive therapy. Many different prophylactic interventions have been used for reducing the risks of infection in these patients but recommendations for routine use are still lacking. We report two membranous nephropathy cases in the elderly in which Intravenous immunoglobulin were useful in long-term infectious prophylaxis, showing safety in renal function. During immunosuppressant therapy in membranous nephropathy, intravenous immunoglobulin without sucrose are a safe therapeutic option as prophylaxis in those patients with nephrotic syndrome and IgG levels below 600 mg/dL. The long-term goal of infection prevention in these patients is to reduce mortality, prolong survival and improve quality of life.

Hydroxyurea-induced interstitial pneumonitis: case report and review of the literature.

Hydroxyurea is a cytotoxic agent widely used in the treatment of myeloproliferative disorders. It is considered a-well-tolerated antineoplastic drug, with a dose-related bone marrow suppression as main adverse effect. This report describes a patient with essential thrombocythemia who developed an interstitial pneumonitis and respiratory failure within 4 years from beginning therapy with hydroxyurea (HU). After discontinuing of HU. both clinical and radiological resolution of pneumonitis occurred. In conclusion, HU-induced pulmonary toxicity is a potentially life-threatening side effect.

Nephrotic syndrome and stroke.

The hypercoagulability of patients with nephrotic syndrome could be an important trigger for arterial and venous thrombotic events. Arterial thromboses are less frequent than venous thromboses and the most common locations are femoral arteries. The association of stroke and nephrotic syndrome is extremely rare. Here we report the case of a patient with stroke as first manifestation of nephrotic syndrome. Ischemic stroke can be the first manifestation of nephrotic syndrome and should be considered as a possible complication of the syndrome, when the commonest causes of ischemic stroke are excluded and especially in presence of pre-existing glomerular disease.

Giant cyst of the cavum septi pellucidi, cavum Vergae and veli interpositi.

The authors report a case study of a giant cyst of the cavum septi pellucidi, cavum Vergae and veli interpositi spreading to the posterior fossa, and initially treated elsewhere by ventriculoperitoneal shunt, with no resolution of the symptomatology. A few months later the patient was successfully treated by fenestration into the ventricular system through a neuroendoscopic technique, at the Pediatric Neurosurgical Center of the Meyer Children's Hospital in Florence. Symptomatic midline cysts are quite rare and different techniques have been proposed for their treatment, i. e., direct craniotomy, conventional shunting, stereotactic approaches as well as endoscopic fenestration. In such cases neuroendoscopy obtains a good symptom resolution level, avoiding at the same time the risks of damage to endoventricular structures and often eliminates the need for a definitive ventriculoperitoneal shunt. In the present research the authors analyze the anatomy of the midline cavities and the mechanism through which a cyst may become symptomatic. The surgical endoscopic technique and the clinical and radiological assessments which confirmed the patency of the fenestration are also discussed. The authors conclude that endoscopic ventricular fenestration may represent the treatment of choice for this pathology.

Peduncular hallucinations associated with large posterior fossa meningiomas.

Peduncular hallucinosis may be observed in patients with thalamic or brain stem ischemia or hemorrhage, while it has been less often described in association with brain stem or cerebellar tumors. We report in this paper two cases associated with large posterior fossa meningiomas. In the first patient hallucinosis appeared preoperatively as a result of brain stem compression and ceased after the tumor removal. In the second patient hallucinosis occurred after the surgery, as a result of surgical trauma with local brain stem edema, and ceased 4 days after treatment with desamethasone and carbamazepine.

Dural arteriovenous malformation associated with recurrent subdural haematoma and intracranial hypertension.

An unusual case of intracranial hypertension and symptoms of a left parieto-occipital mass lesion due to a dural arteriovenous malformation (AVM) with a large and dilated draining vein is reported. The patient also had a history of homolateral recurrent subdural haematoma, 11 years before. Subdural haematoma is rarely associated to a dural AVM. We suggest that the recurrent subdural haematoma was due to the very slow and intermittent venous bleeding from the preexisting dural malformation, which progressively enlarged in the following years to become very large. The symptoms of intracranial hypertension and papilloedema may be explained by the increased pressure in the dural sinus and the cerebral venous system. On the other hand, focal neurological symptoms in our case resulted from the mass effect due to an aneurysmally dilated draining vein in the left parieto-occipital region.

Endoscopic surgery for large posterior fossa arachnoid cysts.

The authors report two cases of large arachnoid cysts of the posterior fossa treated by endoscopic surgery. One patient underwent a successful endoscopic cyst fenestration by burr hole approach after several procedures of shunt revision. In another an endoscope-assisted microsurgical intervention was necessary. Lateral (cerebellar or cerebellopontine angle) cysts, as two reported cases, may be treated through a lateral retromastoid approach by fenestration into the prepontine cistern and eventually into the cisterna magna. We advise to start the operation through a burr hole and to try to realize the fenestration by endoscopy only. If this attempt fails, an endoscope-assisted microsurgical technique may be performed by enlarging the craniectomy. In this last instance the endoscope is useful particularly deeply to fenestrate the anterior cyst wall in the prepontine or ambient cisterns, where it provides more illumination and helps to identify the nervous and vascular structures.

Schwannomas of the brachial plexus--diagnostic and surgical problems.

OBJECTIVE: This paper reports four cases of schwannomas of the brachial plexus operated upon with good outcome and discusses the CT and MRI findings and the best surgical treatment of these lesions. DESIGN: All patients had large schwannomas (more than 4 cm in diameter) presenting as painless masses in the supraclavear region, explored by CT and MRI. A homogeneous mass, hypo-isointense in T1- and hyperintense in T2-weighted images, with well-defined margins, is in favor of a schwannoma. The nerve of origin, external to the tumor mass, may be defined on MRI. INTERVENTION: All patients have been operated upon using microsurgical technique: enucleation of the tumor content, piecemal removal of the capsule, identification and preservation of the neural elements were the main goals of the operation in all cases. OUTCOME: Postoperatively, one patient experienced transient deficit of the deltoid muscle (two weeks). Actually, all four patients are symptom-free with no tumor recurrence, 6 months to 7 years after the operation. CONCLUSIONS: A correct preoperative diagnosis of schwannoma of the brachial plexus may be obtained by MRI, which shows a rather typical aspect; on the other hand, needle aspiration histology and open biopsies should be avoided. The microsurgical treatment with preservation of the neural structures, as for schwannomas of the cranial and spinal nerves, results in good outcome without recurrences.

Connections of sympathetic fibres inside the cavernous sinus: a microanatomical study.

A microanatomical study has been designed to investigate the pattern of arrangement of the sympathetic fibres inside the cavernous sinus. The course of these fibres has been examined in 60 fresh specimens of parasellar region from autopsy cadavers. Apart from the thin branches arising at different intervals along its course, the sympathetic plexus of the carotid artery gives rise to a large division that usually joins the abducens nerve and leaves it to combine with the ophthalmic branch of the fifth. In 10% of specimens we have found a direct connection between sympathetic fibres and the ophthalmic branch of the trigeminal nerve. We did not recognise similar connections with oculomotor and trochlear nerves.

Endoscopic surgery for intracranial cerebrospinal fluid cyst malformations.

Endoscopic surgery represents a new and very useful modality of treatment for intracranial cysts. The authors review the cases of 19 patients with intracranial malformative CSF cysts (seven intraventricular, six paraventricular, and six arachnoid) who underwent endoscopic fenestration by using a burr-hole approach. The various endoscopic approaches and techniques of fenestration, according to the type and location of the cyst, and the causes of unsuccessful outcome are critically discussed. The authors recommend endoscopic fenestration as the treatment of choice for patients with para- and intraventricular cysts, in whom the procedure may help to avoid the microsurgical approach and shunt placement in nearly all patients. In patients with arachnoid cysts, the endoscopic procedure, although associated with a lower rate of successful outcome, may be performed as the primary procedure in most cases because it is a minimally invasive procedure; the traditional surgical treatment may be performed without additional risk in which endoscopic surgery has failed.

Olfactory groove meningioma with paranasal sinus and nasal cavity extension: removal by combined subfrontal and nasal approach.

A very unusual case of olfactory groove meningioma with recurrence extending into the paranasal sinuses and nasal cavities, 15 years after the first transcranial operation, is described. The patient was successfully treated by a combined subfrontal and nasal approach. Large downward extension of an olfactory groove meningioma into the nasal cavities is a rare event, with no or isolated cases reported even in large series of these tumours. The nasal extent of these meningiomas is more often asymptomatic, although signs of sinus obstruction and epistaxis have been described. Although small paranasal sinus extensions of the meningioma may be removed by the transcranial route, a combined subfrontal and nasal approach is necessary in cases with large tumour masses extending into the nasal cavities, as in our own one.

Tryptic peptide mapping of sequence 1-298 of human serum albumin by high-performance liquid chromatography and fast-atom bombardment mass spectrometry.

The determination of the tryptic peptide mapping of sequence 1-298 of human serum albumin (HSA) by chemical and enzymatic cleavage and combined use of high-performance liquid chromatography (HPLC) and fast-atom bombardment mass spectrometry (FAB-MS) is described. A total coverage of about 75% of the entire sequence was obtained. Unidentified fragments included some peptides which were not present in the chromatograms because of their extreme hydrophobic or hydrophilic character, as indicated by the calculated retention times. Due to the high reproducibility of the experiments and to the satisfactory yield of the tryptic fragments identified, the combined use of HPLC and FAB-MS appears to possess great potential for structural investigation of HSA.