[Association of type 1 neurofibromatosis and primary hyperparathyroidism]

INTRODUCTION

The combination of neurofibromatosis type I with hyperparathyroidism is classical but rare.

OBSERVATION

Our report is on the original observation of a patient affected with Von Recklinghausen's disease complicated by chronic restrictive breathing deficiency. After an intense breathing decompensation and a spreading convulsive attack, hyperparathyroidism was diagnosed.

DISCUSSION

The similarity of the bone lesions seen in type I neurofibromatosis and in hyperparathyroidism strongly suggests a genetic link between these two pathologies. Hence, hyperparathyroidism should be searched for in all patients affected with Von Recklinghausen's disease, since the adjustment of hypercalcemia can lead to partial reversibility of the bone abnormalities.

Comparison of B-mode ultrasound and computed tomography in the diagnosis of maxillary sinusitis in mechanically ventilated patients

OBJECTIVE

To compare B-mode ultrasound with sinus computed tomograph (CT) scan in the diagnosis of sinusitis in intubated patients undergoing mechanical ventilation.

DESIGN

Prospective, clinical investigation.

SETTING

Medical intensive care unit of a university hospital.

PATIENTS

Fifty patients undergoing intubation and mechanical ventilation more than 2 days, with a clinical suspicion of paranasal sinusitis with purulent nasal discharge.

INTERVENTIONS

One hundred paranasal sinuses were examined. A paranasal CT scan and a B-mode ultrasound were performed the same day. Radiologic maxillary sinusitis (RMS) was defined as complete opacification of the sinus or as the presence of an air-fluid level. Absence of RMS was defined as normal sinus or as the presence of mucosal thickening. Important RMS was defined by total opacity or air-fluid level larger than half of the sinus area. Moderate RMS was defined by air-fluid level inferior than half of the sinus area. For ultrasonographic procedure, the image defined as normal was an acoustic shadow arising from the front wall. Two levels of positive echography were described: 1) a moderate lesion was defined as the visualization only of the hyperechogenic posterior wall of the sinus; 2) an important lesion was defined as the hyperechogenic visualization of posterior wall and the extension by the internal wall of the sinus outlining the hypoechogenic sinus cavity.

MEASUREMENTS AND MAIN RESULTS

Sensibility, specificity, positive predictive value, and negative predictive value of B-mode ultrasound compared with CT were, respectively: 100% (95% confidence intervals [95% CI] = 94.9-100.0), 96.7% (95% CI = 82.8-99.9), 98.6% (95% CI = 92.4-99.9), and 100% (95% CI = 88.1-100). The concordance between a moderate B-mode ultrasound lesion and a moderate RMS on CT, and between an important B-mode ultrasound lesion and an important RMS on CT, assessed using kappa statistics was 93%. The concordance between B-mode ultrasound's results and CT's results assessed using weighted kappa statistics was 97%.

CONCLUSION

B-mode ultrasound may be proposed first-line in a ventilated patient with suspicion of maxillary sinusitis.

Noninvasive ventilation in immunosuppressed patients with pulmonary infiltrates, fever, and acute respiratory failure

BACKGROUND

Avoiding intubation is a major goal in the management of respiratory failure, particularly in immunosuppressed patients. Nevertheless, there are only limited data on the efficacy of noninvasive ventilation in these high-risk patients.

METHODS

We conducted a prospective, randomized trial of intermittent noninvasive ventilation, as compared with standard treatment with supplemental oxygen and no ventilatory support, in 52 immunosuppressed patients with pulmonary infiltrates, fever, and an early stage of hypoxemic acute respiratory failure. Periods of noninvasive ventilation delivered through a face mask were alternated every three hours with periods of spontaneous breathing with supplemental oxygen. The ventilation periods lasted at least 45 minutes. Decisions to intubate were made according to standard, predetermined criteria.

RESULTS

The base-line characteristics of the two groups were similar; each group of 26 patients included 15 patients with hematologic cancer and neutropenia. Fewer patients in the noninvasive-ventilation group than in the standard-treatment group required endotracheal intubation (12 vs. 20, P=0.03), had serious complications (13 vs. 21, P=0.02), died in the intensive care unit (10 vs. 18, P=0.03), or died in the hospital (13 vs. 21, P=0.02).

CONCLUSIONS

In selected immunosuppressed patients with pneumonitis and acute respiratory failure, early initiation of noninvasive ventilation is associated with significant reductions in the rates of endotracheal intubation and serious complications and an improved likelihood of survival to hospital discharge.

Bronchoscopy with bronchoalveolar lavage via the laryngeal mask airway in high-risk hypoxemic immunosuppressed patients

OBJECTIVE

Fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) are major tools in the diagnosis of pulmonary complications in immunocompromised patients. Nevertheless, severe hypoxemia is an accepted contraindication to FOB in nonintubated patients. The purpose of this study was to evaluate the feasibility and safety of laryngeal mask airway (LMA)-supported FOB with BAL in immunosuppressed patients with suspected pneumonia and severe hypoxemia.

DESIGN

Prospective, clinical investigation.

SETTING

Medical intensive care unit of a university hospital.

PATIENTS

Forty-six immunosuppressed patients admitted to our intensive care unit with suspected pneumonia and Pao2/Fio2 < or = 125.

INTERVENTIONS

After the administration of 0.3 mg x kg(-1) of etomidate, the patients were ventilated manually while receiving 1.0 Fio2. After the administration of 2.5 mg x kg(-1) of propofol, followed by an infusion of 9.1 +/- 2.3 mg x kg(-1) x hr(-1) of propofol, the LMA (size 3 or 4) was placed and connected to a bag-valve unit to allow manual ventilation with 1.0 Fio2. The FOB was introduced through a T-adapter attached to the LMA, and BAL was carried out with 150 mL of sterile 0.9% saline solution by sequential instillation and aspiration of 50-mL aliquots.

MEASUREMENTS AND MAIN RESULTS

Three patients developed transient laryngospasm during passage of the bronchoscope via the LMA, which resolved with deepening of anesthesia. Changes in mean blood pressure, heart rate, Pao2/Fio2, and Paco2 values induced by the procedure did not reach significance. Seven patients (15%) presented hypotension (mean blood pressure, <60 mm Hg) maintained for 120 +/- 40 secs, which required plasma expanders in three cases. Oxygen desaturation to <90% occurred in six patients (13%) during BAL. Nevertheless, the lowest Sao2 during the procedure was significantly higher than the initial Sao2 (94% +/- 4% vs. 90% +/- 2%). No patient required tracheal intubation during the 8 hrs after the procedure. BAL had an overall diagnostic yield of 65%. Because of the results obtained by using the BAL analysis, treatment was modified in 33 (72%) cases.

CONCLUSION

Application of the LMA appears to be a safe and effective alternative to intubation for accomplishing FOB with BAL in immunosuppressed patients with suspected pneumonia and severe hypoxemia.

Noninvasive ventilation for acute respiratory failure. Quite low time consumption for nurses

Methods of noninvasive pressure support ventilation (NIPSV) are not always easy to apply in patients with acute exacerbations of chronic obstructive pulmonary disease (COPD). The assistance time spent by nurses in relation to ventilatory time was prospectively studied, when NIPSV was used, in a sequential mode, in COPD patients with either acute exacerbations (58 patients, group I) or postextubation hypercapnic respiratory insufficiency (42 patients, group II) in a medical intensive care unit. During the first 24 h after enrolment, NIPSV was used for 6.7+/-3.2 h (mean+/-SD) in group I and 5.6+/-3.1 h in group II; the duration of NIPSV sessions and the nurse time consumption per session were respectively 47+/-12 and 11+/-7 min in group 1, and 46+/-12 and 11+/-6 min in group II. After the first 24 h of the study, the duration of NIPSV was 4.7+/-3.2 h x day(-1) in group I and 4.9+/-3.5 h x day(-1) in group II, and the nurse time consumption dropped significantly: the duration of NIPSV sessions and the nurse time consumption per session were respectively 44+/-10 and 7+/-4 min in group I, and 47+/-14 and 7+/-3 min in group II. Between the first 24 h and the subsequent period of 24 h, the nursing time dropped significantly (98 versus 59 min in group I (p<0.05), and 85 versus 52 min in group II (p<0.05)). There was no difference in the duration of NIPSV sessions, or in the overall assistance time per session, between the two groups of patients. In conclusion, the study seems to favour a quite low assistance time spent by nurses in relation to ventilatory time when noninvasive pressure support ventilation is used in chronic obstructive pulmonary disease patients with either acute exacerbations or postextubation hypercapnic respiratory insufficiency.

Rotation and restricted use of antibiotics in a medical intensive care unit. Impact on the incidence of ventilator-associated pneumonia caused by antibiotic-resistant gram-negative bacteria

To test the hypothesis that a new program of antibiotic strategy control can minimize the incidence of ventilator-associated pneumonia (VAP) caused by potentially antibiotic-resistant microorganisms, we performed a prospective before-after study in 3, 455 patients admitted to a single intensive care unit over a 4-yr period. Regarding the bacterial ecology and the increasing antimicrobial resistance in our medical intensive care unit (MICU), we decided to vary our choice of empiric and therapeutic antibiotic treatment, with a supervised rotation, and a restricted use of ceftazidime and ciprofloxacin, which were widely prescribed before this scheduled change. For all patients, VAP was diagnosed based on the results of quantitative culture of bronchoalveolar lavage specimens (>/= 10(4) cfu/ml). We studied 1,044 and 1,022 patients requiring more than 48 h of mechanical ventilation (MV), respectively, in the before-period (2 yr: 1995-1996) and the after-period (2 yr: 1997-1998). We observed a decrease from 231 consecutive episodes of VAP in the before-period to 161 episodes of VAP in the after-period (p < 0.01), particularly for VAP occurring before 7 d of MV. The total number of potentially antibiotic-resistant gram-negative bacilli responsible for VAP such as Pseudomonas aeruginosa, Burkholderia cepacia, Steno-trophomonas maltophilia, and Acinetobacter baumanii decreased from 140 to 79 isolated bacilli. The susceptibilities of these bacteria to the antibiotics regimen increased significantly, especially for P. aeruginosa and B. cepacia. The percentage of methicillin-sensitive Staphylococcus aureus increased significantly from 40% to 60% of S. aureus responsible for VAP. These results suggest that a new strategy of antibiotics use could be an efficient means to reduce the incidence of VAP caused by antibiotic-resistant bacteria. Nevertheless, further studies are needed to validate these data.

Noninvasive continuous positive airway pressure in neutropenic patients with acute respiratory failure requiring intensive care unit admission

OBJECTIVE

To evaluate the tolerance and the efficacy of noninvasive continuous positive airway pressure (CPAP) in severe acute respiratory failure occurring in intensive care unit (ICU) neutropenic patients with hematologic malignancies, and to establish predictive variables of efficacy of this method.

DESIGN

Prospective study over a 5-yr period.

SETTING

Hematologic and medical intensive care unit of a teaching hospital.

METHODS

Among 129 neutropenic patients admitted to the ICU, 64 patients presented with febrile acute hypoxemic normocapnic respiratory failure (PaO2/FIO2 ratio <200) and were enrolled. In addition to standard therapy, patients received CPAP with a facial mask. The initial settings of the CPAP were 6 cm H2O positive end-expiratory pressure and FIO2 0.8 (80%). Physiologic measurements were performed at the end of 45 mins of ventilation with first adjustments. CPAP was used with a sequential mode (45 mins/3 hrs). CPAP was efficient if intubation was avoided.

RESULTS

The setting of CPAP, after adjustments, was as follows: positive end-expiratory pressure 7 +/- 1 cm H2O and FIO2 0.7 +/- 0.1 (70% +/- 10%). For the 64 patients, CPAP was administered for a total of 6 +/- 2 hrs during the first 24 hrs. The mean duration of CPAP was 7 +/- 3 days. A reduction in respiratory rate to less than 25 breaths/min was achieved in 53% of patients. PaO2/FIO2 ratio increased from 128 +/- 32 to 218 +/- 28. CPAP was successful in avoiding endotracheal intubation in 16/64 patients. A total of 16 responders and four nonresponders survived. Hepatic failure was a criterion indicating the failure of CPAP: 1/16 vs. 26/48 (p = .001). In multivariate analysis, two variables were predictive of failure of CPAP: Simplified Acute Physiology Score II (58 +/- 14 vs. 41 +/- 11) and a hepatic failure at the entry into the study.

CONCLUSION

CPAP was efficient in 25% of cases. All the responders survived. This noninvasive method was used as a way to avoid mechanical ventilation, which is well correlated with a poor prognosis in neutropenic ICU patients. Further controlled studies are needed to confirm the efficacy of noninvasive CPAP and to evaluate the most appropriate selection of immunocompromised patients.

Impact of colony-stimulating factor therapy on clinical outcome and frequency rate of nosocomial infections in intensive care unit neutropenic patients

OBJECTIVES

To determine whether the use of recombinant human granulocyte colony-stimulating factor (G-CSF, filgrastim) reduces the mortality rate and the frequency rate of nosocomial infections in neutropenic patients requiring intensive care unit (ICU) admission.

DESIGN

Retrospective consecutive case series analysis.

SETTING

Medical ICU of a teaching hospital.

PATIENTS

We compared two groups of patients, according to whether or not they received G-CSF. In the ICU, 28 leukopenic patients received filgrastim (5 microg of body weight per day intravenously). In all these patients, G-CSF was continued until recovery from leukopenia, defined as a leukocyte count >1,000/mm3. A total of 33 ICU leukopenic patients did not receive G-CSF. End points included leukocyte count, bone marrow recovery, frequency of ICU nosocomial infections (pneumonia, urinary tract, and catheter-related infections), and mortality rate.

MEASUREMENTS AND MAIN RESULTS

There were no differences in number of patients who recovered from leukopenia or in whom blood leukocyte count increased. Nosocomial infections occurred in the same percentage in both groups. The percentage of patients who died was identical in both groups. The percentage of patients with and without filgrastim therapy who recovered from leukopenia but died, was 86% and 78%, respectively.

CONCLUSION

In the ICU, clinical outcome of neutropenic patients was not changed by G-CSF therapy. It is possible that G-CSF therapy may not be helpful in improving the ICU clinical outcome of neutropenic patients. Additional controlled studies designed to address this question are warranted.

Utility of fiberoptic bronchoscopy in neutropenic patients admitted to the intensive care unit with pulmonary infiltrates

OBJECTIVE

To analyze the impact of fiberoptic bronchoscopy and bronchoalveolar lavage (BAL) on guiding the treatment and intensive care unit (ICU) clinical outcome in neutropenic patients with pulmonary infiltrates admitted to the ICU.

DESIGN

Prospective collection of data.

SETTING

Medical ICU in a teaching hospital.

PATIENTS

During a 6-yr period, we analyzed the results of 93 fiberoptic bronchoscopies plus BALs performed in 93 consecutive neutropenic ICU patients. We separated the patients into two groups according to the cause of neutropenia (high-dose chemotherapy [n = 41] or stem cell transplantation [SCT; n = 52]).

RESULTS

Of the 93 BALs, 53 were performed to evaluate diffuse infiltrates and 42 were performed on mechanically ventilated patients. Forty-nine percent of BALs (46 patients) were diagnostic, with a significantly better yield in ICU patients with high-dose chemotherapy-induced neutropenia (26 of 41 BALs). The number of cases of proven infectious pneumonia was significantly higher in this group of ICU neutropenic patients. In patients who underwent SCT, diffuse infiltrates were statistically correlated with a negative result of BAL. Twenty-six patients who underwent diagnostic BALs changed therapy. Sixteen complications (17%) occurred with only two intubations. The overall mortality rate in the ICU and the mortality rate in mechanically ventilated neutropenic patients were 71% and 93%, respectively. In neutropenic patients who underwent SCT, the mortality rate was statistically higher in patients in whom no diagnosis was established. Patients who had a diagnostic BAL that changed therapy did not have an increased probability of survival compared with patients who had a BAL that did not change therapy.

CONCLUSIONS

The use of routine diagnostic BAL in ICU neutropenic patients with pulmonary infiltrates is difficult to establish, even if BAL is helpful in the management of these critically ill patients. BAL in our ICU neutropenic patient population had an acceptable overall diagnostic yield (49%), which was higher in ICU patients with chemotherapy-induced neutropenia. Nevertheless, in the ICU, if BAL had a low complication rate, it had infrequently led to changed treatment and was not associated with improved patient survival.

Inexcitability of nerves in a fulminant case of Guillain-Barré syndrome

A 45-year-old woman presented with a recent sensorimotor deficiency in all 4 limbs, and the next day she was totally paralyzed. A slight motor improvement began on day 27. The cerebrospinal fluid had normal cellularity, but the protein varied from 90 mg/dL on the first day to 800 mg/dL on day 15, and then 290 mg/dL on day 33. Electrophysiologic studies performed on days 15 and 23 revealed a universal peripheral nerve inexcitability. A superficial peroneal nerve biopsy was performed on day 23. Nine fascicles were examined on semi-thin sections and myelinated fiber damage varied greatly from one fascicle to another. At ultrastructural examination, certain axons were severely damaged, but the others were quite well preserved and were naked or wrapped in a myelin sheath presenting a multivesicular degeneration. A few fibers had a better-preserved myelin sheath that was sometimes dissociated by elongated processes from an invading histiocyte. Six cases of fulminant Guillain-Barré syndrome with inexcitability of nerves and ultrastructural examination of nerve fragments have been reported. Electrophysiologic study is often ambiguous and cannot determine the precise origin of such an axonal degeneration. Therefore, ultrastructural analysis of a nerve biopsy is mandatory in this setting.

Fulminant Guillain-Barré syndrome mimicking cerebral death: case report and literature review

A 45-year-old woman was admitted to the intensive care unit (ICU) for respiratory arrest. One day prior to admission, she had been nauseated and in a state of total exhaustion. On the night of admission she was unresponsive and developed gasping respiration. The patient was comatose with absent brainstem reflexes and appeared brain dead. Blood chemistry findings and brain magnetic resonance imaging were normal. Electroencephalogram revealed an alpha rhythmical activity unresponsive to painful or visual stimuli. The cerebrospinal fluid showed an albuminocytological dissociation. Guillain-Barré syndrome (GBS) was suspected. The electrophysiological evaluation revealed an inexcitability of all nerves. The pathological findings of the sural nerve biopsy indicated an axonal degeneration secondary to severe demyelination. GBS can very rarely present with coma and absent brainstem reflexes. This case illustrates the importance of electrophysiological tests and laboratory and imaging studies in patients with suspected brain death where a cause is not clearly determined.

Critical illness polyneuropathy. A 2-year follow-up study in 19 severe cases

Critical illness polyneuropathy (CIP) is a reported cause of varying degrees of neuromuscular weakness in patients with multiple organ failure. Little is known concerning predictive factors of neurological recovery. The critical care conditions, neurological explorations and 2-year clinical follow-up of 19 patients who suffered from severe forms (quadriplegia or quadriparesis) of CIP were analyzed. Characteristics of patients who recovered clinically were compared with those of patients who did not. Two patients died within 2 months, 11 recovered completely, 4 remained quadriplegic and 2 remained quadriparetic. All patients suffered from sepsis, multiple organ dysfunction syndrome and a catabolic state before the onset of CIP. Outcome appears difficult to predict with clinical or electrophysiological data. Three parameters were significantly correlated with poor recovery: longer length of stay in the critical care unit, longer duration of sepsis and greater body weight loss. A relationship seems to exist between the severity of CIP and that of sepsis and its associated hypercatabolism. The favorable outcome usually attributed to CIP must be reconsidered. The authors recommend aggressive measures against sepsis to limit CIP and its sequelae.

Severe respiratory failure requiring ICU admission in bone marrow transplant recipients

Two groups of bone marrow transplant (BMT) recipients with febrile noncardiogenic respiratory failure requiring intensive care unit (ICU) admission, in the early phase of bone marrow transplantation were compared: those who had proven infectious pneumonia and those in whom bronchoalveolar lavage (BAL) failed to establish a diagnosis. Thirty-eight consecutive neutropenic BMT recipients admitted to an ICU with febrile noncardiogenic respiratory failure were enrolled. All of them underwent a BAL with viral, fungal, bacterial, and histopathological examinations. Lung biopsies were performed in nonsurviving patients in order to compare with BAL results. Haematological, biological, respiratory failure and other organ failure parameters, infectious results, outcome, and lung biopsy results were evaluated. BAL allowed an infectious diagnosis to be established in 16 BMT recipients. No aetiology was proven in 22 patients. Without a significant difference in respiratory failure parameters on ICU admission, noninvasive continuous positive airway pressure ventilation, which was given to 11 patients in each group, was significantly more successful in patients with proven infectious pneumonia (6 of 11 versus 0 of 11 patients) and enabled endotracheal intubation to be avoided in significantly more patients with infectious disease (10 of 16 versus 22 of 22 patients). The evolution of patients without diagnosis was significantly different with more frequent renal failure, hepatic failure, and death (20 of 22 versus 9 of 16 patients). Post mortem biopsies confirmed the absence of micro-organisms, but endothelial damage and fibrosis was found in 14 of the 22 patients. In conclusion, in the early phase of bone marrow transplantation the recipients without proven aetiology of pneumonia have a worse outcome than grafted patients with proven infectious pneumonia.

Malignant hyperthermia and neuroleptic malignant syndrome in a patient during treatment for acute asthma

Acute asthma is well known to provoke complications. We report the case of a patient who needed intubation and mechanical ventilation for acute asthma. Despite a treatment with corticosteroids, bronchodilators, neuromuscular blocking drugs and magnesium sulfate, the situation remained uncontrolled and as a last resort, halothane became necessary. The patient then developed an episode of malignant hyperthermia with fever at 40 degrees C and rhabdomyolysis. At this time, halothane could be stopped and all the symptoms disappeared without modifying the rest of the treatment. Eight days later, he presented with a neuroleptic malignant syndrome following an injection of droperidol. Temperature rose to 42 degrees C, associated with muscle rigidity, sweating, tachycardia and severe circulatory collapse. The use of dantrolene in association with a symptomatic treatment of the collapse led to a favourable outcome in. Unfortunately, in vitro contracture test could not be performed in this case. The links between malignant hyperthermia and neuroleptic malignant syndrome remain unclear. Although these two pathologies share the same physiopathology, symptomatology and treatment, they are clearly individualized. This case seems to be the first description of their occurrence in the same patient.

Early infectious complications after bone marrow transplantation requiring medical ICU admission

The objective of this study was to define the type, the incidence and the outcome of early infectious complications (mean interval between day 1 post-BMT and the onset of fever was 9+/-3 days) occurring in granulocytopenic bone marrow transplant recipients, requiring medical intensive care unit admission. Over a five-years period, forty-one patients with microbiologically confirmed infection were enrolled, with a statistically significant higher frequency of allogeneic marrow transplant recipients (51%, p < 0.02). Infectious pneumonia occurred in 24 patients (59%), septicemia with septic shock in ten patients (24%), catheter-related infection in 5 patients (12%) and meningitis in 2 patients (5%) (p < 0.001). Twenty-six patients died (63%). Among the patients with confirmed infectious pneumonitis, which occurred most frequently in allogeneic marrow recipients (p < 0.02), 16 died (67%). This poor outcome was related to the requirement of mechanical ventilation. Eight patients (80%) with septicemia and septic shock and the two patients with meningitis died. Bacteria (Pseudomonas aeruginosa and Staphylococcal species) were the most common isolated in bronchoalveolar lavage fluid and blood cultures. We found a lower incidence of fungal or viral infections compared to previous studies. Empiric antimicrobial therapy in the cases of patients admitted in ICU may be included antibiotics anti-Pseudomonas and anti-Staphylococcus, as the ecology of hematology unit. The requirement of mechanical ventilation is the main adverse prognostic factor in transplanted patients. At ICU admission, patients with hepatic failure combined with respiratory failure represented a subgroup with a dismal prognosis.

Airway occlusion pressure at 0.1 s (P0.1) after extubation: an early indicator of postextubation hypercapnic respiratory insufficiency

OBJECTIVE

To examine variables associated with postextubation respiratory distress in chronic obstructive pulmonary disease (COPD) patients.

DESIGN

Prospective, clinical investigation.

SETTING

Intensive care unit of a university hospital.

PATIENTS

Forty COPD patients, considered ready for extubation.

MEASUREMENTS AND MAIN RESULTS

We recorded, from the digital display of a standard ventilator, breathing frequency (f), tidal volume (VT) and f/VT for the respiratory pattern, airway occlusion pressure at 0.1 s (P0.1) for the respiratory drive and measured blood gases: i) before extubation, following 30 min of a 6 cm H2O pressure support (PS) ventilation trial, ii) 1 h after extubation, at the 30th min of a face mask 4 cm H2O PS ventilation trial. According to the weaning outcome, the patients were divided into two groups: respiratory distress, and non-respiratory distress within 72 h of the discontinuation of mechanical ventilation. The respiratory distress was defined as the combination of f more than 25 breaths/min, an increase in PaCO2 of at least 20% compared with the value measured after extubation, and pH lower than 7.35. We determined whether those patients who developed respiratory distress after extubation differed from those who did not. Respiratory pattern data and arterial blood gases recorded, either before or after extubation, and P0.1 recorded before extubation, were inadequate to differentiate the two groups. Only P0.1 recorded 1 h after the discontinuation of mechanical ventilation differentiated the patients who developed respiratory distress from those who did not (4.2+/-0.9 vs 1.8+/-0.8, p < 0.01).

CONCLUSIONS

P0.1 recorded after extubation may be a good indicator of postextubation respiratory distress. Measuring P0.1 and/or the analysis of the evolution of this parameter could facilitate decisions during the period following extubation.

Characteristics and survival of patients prescribed long-term oxygen therapy outside prescription guidelines

Criteria for the prescription of long-term oxygen therapy (LTOT) have been published by academic societies and regulatory bodies, but many prescriptions for LTOT do not fulfil these criteria. Demographic, functional data and survival were compared in chronic obstructive pulmonary disease (COPD) patients with different levels of oxygenation, i.e. arterial oxygen tension (Pa,O2) < 8 kPa or > or = 8 kPa (60 mmHg), at the time of initial registration in the ANTADIR Observatory. Data were collected between 1984-1995. Selection criteria were a diagnosis of COPD or emphysema with forced expiratory volume in one second (FEV1) < 80% pred, FEV1/vital capacity (VC) < 70% and age between 18-75 yrs. Of 7,700 patients prescribed LTOT 18.5% had stable Pa,O2 > or = 8 kPa. While the FEV1 was the same they differed from the patients with more severe hypoxaemia in having a higher rate of diagnosis of primary emphysema and a lower arterial carbon dioxide tension (Pa,CO2). In this group of patients LTOT was more frequently administered as liquid oxygen than in other patients on LTOT. The survival of these patients was reduced compared to the general population of the same age and sex but comparable to that of patients with a Pa,O2 between 6.7-8 kPa (50-60 mmHg). Patients prescribed long-term oxygen therapy with an arterial oxygen tension > or = 8 kPa (60 mmHg) in the ANTADIR network were shown to have severe chronic obstructive pulmonary disease on the basis of spirometry and their survival was similar to that of more hypoxaemic patients. Randomized controlled trials of the effect of long-term oxygen therapy in patients with arterial oxygen tension > or = 8 kPa are needed.

[Guillain-Barré syndrome in the adult: therapeutic aspects]

The Guillain-Barré syndrome is the most common cause of acute flaccid paralysis. The current mortality is 5%, while severe motor sequelae persist after one year in 10%. Multidisciplinary teams, trained in all specific treatments, are required to treat these patients. Oral and intravenous steroids have proved ineffective. Two large randomized clinical trials comparing plasma exchange (PE) with no treatment have shown a short-term and a 1-year benefit. The appropriate number of exchanges and the indications are now more precisely known. In the mild form (walking possible) patients should receive two PEs; a further two exchanges should be done in the event of deterioration or in advanced forms (loss of walking ability, mechanical ventilation). More exchanges are not beneficial. Recently two new randomized trials have produced evidence that intravenous immunoglobulin (IVIg) (0.4 g/kg/day for 5 days) was as effective as 5 PEs in advanced forms. The combination of PE with IVIg did not confer a significant advantage but increased the costs and risks. In advanced forms the choice between PE and IVIg depends on the contraindications for each treatment.

Optimal pressure support level for beginning weaning in patients with COPD: measurement of diaphragmatic activity with step-by-step decreasing pressure support level

PURPOSE

The study objective was to determine an "optimal" individual pressure support (PS) level for beginning weaning with PS ventilation in patients with chronic obstructive pulmonary disease (COPD).

MATERIALS AND METHODS

Eleven COPD patients intubated and ventilated for acute respiratory failure and judged ready for weaning were studied. The technique consisted of lowering the PS level from a point that was characteristic for each patient and measurable under controlled mechanical ventilation, after setting the ventilator as recommended for COPD patients judged ready for weaning, that is, peak inflation pressure (PIP). This determination was based mainly on exploring the diaphragm with an electromyographic technique by defining the optimal PS level as the lowest PS level associated with no EMG evidence of diaphragmatic stress. Diaphragmatic electromyographic activity (diEMG) was recorded by a bipolar esophageal electrode (Disa-Denmark), and the high-frequency electrical component/low-frequency ratio (H/L) was calculated. The reference H/L was determined during a few spontaneous ventilatory cycles. Muscle stress was defined as a greater than 20% reduction in H/L compared with the reference value.

RESULTS

Optimal PS levels ranged from 4 to 24 cm H2O with a mean of 14+/-6 cm H2O. Two patients with optimal PS level at 4 cm H2O did not require weaning and were quickly extubated. For the nine other patients, optimal PS levels were found to be 70% of PIP; in none was it necessary during weaning to use PS levels higher than individual optimal PS levels.

CONCLUSIONS

Optimal PS level established with diEMG monitoring seems to be a useful index for beginning weaning in the PS ventilation mode in COPD patients. The hypothesis of beginning weaning with a PS level equal to 70% of PIP needs to be tested.

Severe infection caused by Stomatococcus mucilaginosus in a neutropenic patient: case report and review of the literature

A 24-year-old female, in neutropenic phase after chemotherapy for acute myelogenous leukemia (on day 15) was admitted in intensive care unit for infectious pneumonia. Two strains of Stomatococcus mucilaginosus were isolated from peripheral blood cultures. No microorganisms were yielded from bronchoalveolar lavage. Patient's condition improved with prompt instigation of effective antibiotic therapy. This was the first case of septicemia and pneumonia, due to Stomatococcus mucilaginosus, in our unit. Only 26 cases occurring in neutropenic patients with underlying hematologic malignancies were reported in the literature and among these, only five cases with pneumonia were described. The complications of this normal inhabitant of the human oral cavity can be serious and fatal: septic shock, meningitis, acute respiratory distress syndrome. This study illustrate the possible virulence of Stomatococcus mucilaginosus in neutropenic patients.

Noninvasive pressure support ventilation in COPD patients with postextubation hypercapnic respiratory insufficiency

Patients with chronic obstructive pulmonary disease (COPD) who have been intubated and mechanically ventilated may prove difficult to wean. Noninvasive ventilation may be used in an attempt to avoid new endotracheal intubation. The efficacy of administration of noninvasive pressure support ventilation was evaluated in 30 COPD patients with postextubation hypercapnic respiratory insufficiency, compared with 30 historically matched control patients who were treated conventionally. Patients were included in the study if, within 72 h postextubation, they presented with respiratory distress, defined as the combination of a respiratory frequency >25 breaths x min(-1), an increase in the arterial carbon dioxide tension (Pa,CO2) of at least 20% compared with the value measured after extubation, and a pH <7.35. Noninvasive pressure support ventilation was effective in correcting gas exchange abnormalities. The use of noninvasive ventilation significantly reduced the need for endotracheal intubation: 20 of the 30 patients (67%) in the control group required endotracheal intubation, compared with only six of the 30 patients (20%) in the noninvasive-ventilation group (p<0.001). In-hospital mortality was not significantly different between the two groups, but the mean duration of ventilatory assistance for the treatment of the postextubation distress, and the length of intensive care unit stay related to this event, were both significantly shortened by noninvasive ventilation (p<0.01). In conclusion, noninvasive ventilation may be used in the management of patients with chronic obstructive pulmonary disease and postextubation hypercapnic respiratory insufficiency.

Sequential use of noninvasive pressure support ventilation for acute exacerbations of COPD

OBJECTIVES

To compare the efficacy of noninvasive pressure support ventilation (NIPSV) in acute decompensation in chronic obstructive pulmonary disease (COPD) by means of a bi-level positive airway pressure support system (BiPAP) in a sequential mode with medical therapy alone; to assess the short-term physiologic effects of the device on gas exchange; and to compare patients successfully ventilated with NIPSV with those in whom NIPSV failed.

DESIGN

A prospective case series with historically matched control study.

SETTING

A general intensive care unit (ICU) of a university hospital.

PATIENTS

We evaluated the efficacy of administration of NIPSV in 42 COPD patients and compared this with standard treatment in 42 matched historical control COPD patients.

INTERVENTIONS

NIPSV was performed in a sequential mode, i.e., BiPAP in the spontaneous mode was used for at least 30 min every 3 h. Between periods of ventilation, patients could be systematically returned to BiPAP when the arterial oxygen saturation was < 0.85 or when the respiratory rate was > 30 breaths/min.

MEASUREMENTS AND RESULTS

Success rate, mortality, duration of ventilatory assistance, and length of ICU stay were recorded. Eleven of the 42 patients (26%) in the NIPSV group needed tracheal intubation compared with 30 of the 42 control patients (71%). The 31 patients in whom NIPSV was successful were ventilated for a mean of 6 +/- 3 days. In-hospital mortality was not significantly different in the treated versus the control group, but the duration of ventilatory assistance (7 +/- 4 days vs 15 +/- 10 days, p < 0.01) and the length of ICU stay (9 +/- 4 days vs 21 +/- 12, p < 0.01) were both shortened by NIPSV. BiPAP was effective in correcting gas exchange abnormalities. The pH values, measured after 45 min of BiPAP with optimal settings, in the success (7.38 +/- 0.04) and failure (7.28 +/- 0.04) patients were significantly different (p < 0.05).

CONCLUSIONS

NIPSV, performed with a sequential mode, may be used in the management of patients with acute exacerbations of COPD.

Survival and long-term follow-up of tracheostomized patients with COPD treated by home mechanical ventilation. A multicenter French study in 259 patients. French Cooperative Study Group

To define more clearly the value of home mechanical ventilation by tracheostomy (HMVT) in patients with advanced COPD, a retrospective French multicenter study group analyzed the prognostic factors and long-term survival of 259 patients with severe COPD, who were tracheostomized for at least 1 year. Seventy-eight percent of the patients died by the end of the observation period. The actuarial survival rate for the overall study population was, therefore, 70 percent at 2 years, 44 percent at 5 years, and 20 percent at 10 years. These results appear to be better than those of the major published series and compare to the prognosis of COPD patients treated by long-term oxygen therapy (LTO) 15 hr/24 hr. The parameters most closely correlated with a survival for more than 5 years were age < 65 years, use of an uncuffed cannula, and a PaO2 > 55 mm Hg in room air during the 3 months after tracheostomy (p < 0.01). This study, therefore, confirmed the feasibility of HMVT in COPD and should lead to a review of the place of permanent tracheostomy in the long-term prognosis of severe COPD patients.

Guillain-Barré syndrome: an ultrastructural study of peripheral nerve in 65 patients

65 biopsies of peripheral nerve from patients suffering from Guillain-Barré syndrome were studied by electron microscopy. In 48 cases there was macrophagic invasion of the Schwann cells of certain myelinated fibers, and in 32 of these cases some myelin sheaths were stripped away by an elongated macrophagic process. Vesicular disruption of the myelin sheath was observed in only 8 cases and in less than 1% of the myelinated fibers. Uncompacted myelin lamellae were observed in a few myelinated fibers. These ultrastructural lesions are analysed and commented on with a view to selecting patients who are to undergo plasma exchange.

Acute inflammatory demyelinating polyneuropathy in a diabetic patient: predominance of vesicular disruption in myelin sheaths

A diabetic woman underwent an incision of the right big toe for an abscess and developed a typical Guillain-Barré syndrome 48 h later. A biopsy of a peripheral nerve, performed 10 days later, showed modifications usually seen in diabetic patients, as well as the characteristic ultrastructural modifications of the Guillain-Barré syndrome (GBS). Moreover, 22% of myelinated fibers exhibited vesicular disruption of the myelin sheaths. This lesion is rarely encountered on the biopsies of peripheral nerve in GBS and concerns only a few myelinated fibers. Such a prominence of myelinic vesicular disruption and its occurrence in a diabetic patient are discussed.

[Problems raised by the technique and supervision of home ventilation of chronic respiratory insufficient patients (author's transl)]

The effectiveness of assisted ventilation at home, especially in the case of tracheostomized patients, has been nearly established at the present time. The experience of various centers in France, having or not the support of an independent structured organization, shows that the setting-up and supervision of such therapy can be effectively carried out. Nevertheless, difficult choices remain. Some indications are still questionable, such as the choice of the respirator if the patient has not been tracheostomized. The type of organization is not univocal and could perhaps depend on the number of patients to be cared for. In any case, in the years to come, the experience of the different teams and the technical progress made will lead to a solution to the problems raised: a decrease in the number of hospitalizations and more comfort for the patients can be hoped for.