Optic Nerve Sheath Diameter Ultrasound Evaluation in Intensive Care Unit: Possible Role and Clinical Aspects in Neurological Critical Patients' Daily Monitoring.

Background. The increase of the optic nerve sheath diameter (ONSD) is a reliable, noninvasive sonographic marker of intracranial hypertension. Aim of the study was to demonstrate the efficacy of ONSD evaluation, when monitoring neurocritical patients, to early identify malignant intracranial hypertension in patients with brain death (BD). Methods. Data from ultrasound ONSD evaluation have been retrospectively analyzed in 21 sedated critical patients with neurological diseases who, during their clinical course, developed BD. 31 nonneurological controls were used for standard ONSD reference. Results. Patients with neurological diseases, before BD, showed higher ONSD values than control group (CTRL: RT 0.45 ± 0.03 cm; LT 0.45 ± 0.02 cm; pre-BD: RT 0.54 ± 0.02 cm; LT 0.55 ± 0.02 cm; p < 0.000) even without intracranial hypertension, evaluated with invasive monitoring. ONSD was further significantly markedly increased in respect to the pre-BD evaluation in neurocritical patients after BD, with mean values above 0.7 cm (RT 0.7 ± 0.02 cm; LT 0.71 ± 0.02 cm; p < 0.000), with a corresponding dramatic raise in intracranial pressure. Logistic regression analysis showed a strong correlation between ONSD and ICP (R 0,895, p < 0.001). Conclusions. ONSD is a reliable marker of intracranial hypertension, easy to be performed with a minimal training. Routine ONSD daily monitoring could be of help in Intensive Care Units when invasive intracranial pressure monitoring is not available, to early recognize intracranial hypertension and to suspect BD in neurocritical patients.

Current practice of brain death determination and use of confirmatory tests in an Italian University hospital: a report of 66 cases.

BACKGROUND: Time to final brain death (BD) determination is fundamental to rapidly identify donors without organ deterioration. Guidelines for BD determination are different from country to country and, through years, they have been subjected to several revisions, to simplify the procedure. The aim of this study was to describe a one-year experience according to the latest Italian Guidelines for BD in our University hospital and to focus on timing of final BD declaration according to the ancillary tests executed. METHODS: Sixty-six consecutive inpatients with BD diagnosis were enrolled. Etiological factors, ancillary tests and timing to final declaration were analyzed. RESULTS: Electroencephalogram (EEG) could be performed without artifacts in all the patients. Time to BD procedure starting depended on whether the demonstration of cerebral circulatory arrest was required, being shorter with EEG only (40±17 min), longer with cerebral blood flow evaluation (175±95 min), minimal with transcranial Doppler (83±32 min), maximal with angiography (165±20 min). None of the patients who initiated BD procedure were found to recover cerebral or brainstem function at the second observation. CONCLUSIONS: In Italy, the same guidelines ensure the same approach in every hospital, with multi-specialist cooperation. The EEG is mandatory and prompt recognition of the first, flat EEG is fundamental to reduce time to the final procedure. A multimodal neurophysiological approach with trained specialists, neurosonologists and monitoring devices in intensive care units may represents a valid help to further reduce time for BD diagnosis.

Transcranial Doppler for brain death in infants: the role of the fontanelles.

OBJECTIVE: Transcranial Doppler (TCD) is a sensitive technique for circulatory arrest diagnosis in brain death when patterns such as reverberant flow and short systolic spikes are observed. In infants, the nonossified fontanelles compensate for intracranial hypertension. We describe TCD patterns in infants with brain death, different from adults, with the hemodynamic modifications induced by anterior fontanelle compression. METHOD: TCD was performed in 2 infants with diagnosed brain death admitted to the neonatal intensive care unit. RESULTS: TCD showed a large peak 'reverberant' flow, with a high peak systolic velocity and a consistent retrograde component, away from the brain. Compression of the anterior fontanelle induced, at first, a reduction in systolic flow with the subsequent appearance of the characteristic short systolic spikes. Upon compression removal, a brief increase in the systolic flow was observed before the prompt reappearance of the reverberant flow. CONCLUSION: TCD for brain death diagnosis should be done cautiously in infants. In these cases, reverberating flow may be indicative of circulatory arrest even if with a large peak and with a high peak systolic velocity. Heavy fontanelle compression may reproduce the classical adult TCD patterns of brain death, thus supporting the diagnosis of cerebral circulatory arrest.

Noninvasive vs. conventional mechanical ventilation in patients with chronic obstructive pulmonary disease after failure of medical treatment in the ward: a randomized trial.

OBJECTIVE: We conducted a randomized prospective study comparing noninvasive positive pressure ventilation (NPPV) with conventional mechanical ventilation via endotracheal intubation (ETI) in a group of patients with chronic obstructive pulmonary disease who failed standard medical treatment in the emergency ward after initial improvement and met predetermined criteria for ventilatory support. DESIGN AND SETTING: Prospective randomized study in a university hospital 13-bed general ICU. PATIENTS: Forty-nine patients were randomly assigned to receive NPPV (n=23) or conventional ventilation (n=26). RESULTS: both NPPV and conventional ventilation significantly improved gas exchanges. The two groups had similar length of ICU stay, number of days on mechanical ventilation, overall complications, ICU mortality, and hospital mortality. In the NPPV group 11 (48%) patients avoided intubation, survived, and had a shorter duration of ICU stay than intubated patients. One year following hospital discharge the NPPV group had fewer patients readmitted to the hospital (65% vs. 100%) or requiring de novo permanent oxygen supplementation (0% vs. 36%). CONCLUSIONS: The use of NPPV in patients with chronic obstructive pulmonary disease and acute respiratory failure requiring ventilatory support after failure of medical treatment avoided ETI in 48% of the patients, had the same ICU mortality as conventional treatment and, at 1-year follow-up was associated with fewer patients readmitted to the hospital or requiring for long-term oxygen supplementation. An editorial regarding this article can be found in the same issue (http://dx.doi.org/10.1007/s00134-002-1503-3).

Lipid peroxidation, circulating cytokine and endothelin 1 levels in healthy volunteers undergoing hyperbaric oxygenation.

BACKGROUND: The aim of the present study was to evaluate the effects of hyperbaric oxygenation on lipid peroxidation, on the release of circulating cytokines (TNFa, IL6, IL1b) and endothelin-1 (ET1). EXPERIMENTAL DESIGN: single arm, prospective study. SETTING: ICU hyperbaric division of a University Hospital. PATIENTS: fifteen healthy volunteers (10 male and 5 female, mean age 32+/-7 years) studied during hyperbaric oxygenation divided at random into two groups: group A (7 subjects) and group B (8 subjects). INTERVENTIONS: Both groups were consecutively pressurized at 2 atmospheres (2 atm abs) and 2.8 atm abs, with a constant descending rate of 1 m/min; in accordance with the experimental design, group A breathed pure oxygen continuously through facial masks and group B breathed chamber air during pressurization. MEASURES: Twenty millilitres of blood were drawn from all individuals at the following times: 1) basal, before HBO; 2) after 10 min at 2 atm abs; 3) after 10 min at 2.8 atm abs; 4) 30 min after the end of HBO. In all collected samples thiobarbituric reacting substances were evaluated, using the spectrophotometric technique, IL1 TNF and IL6 serum levels by ELISA and endothelin 1 plasma levels by radioimmunoassay. RESULTS: In both groups, TBARS levels showed a twofold increase (p<0.05) in relation to the baseline, during and after hyperbaric oxygenation. Serum IL6 and IL1b values did not significantly change over the study in any of the volunteers. TNFa amounts significantly increased (p<0.05) during HBO, at 2 atm abs and 2.8 atm abs in both groups, with almost twofold increments. ET1 plasma values increased (p<0.05) in all volunteers during and after HBO: at 2 atm abs (range 7 to 24 pg/ml), 2.8 atm abs (range 7 to 19 pg/ml) and 30 min after (range 8 to 17 pg/ml) in relation to baseline (range 4 to 12 pg/ml). All the studied compounds had a similar trend in the two groups. CONCLUSIONS: Hyperbaric oxygenation in healthy volunteers can induce not only lipid peroxidation, but also liberation of compounds such as TNFa and endothelins, no matter whether pure oxygen is breathed or not. These results suggest that the phenomenon behind this release might be leukocyte activation as induced by HBO. The possible role of ET1 in determining vasoconstriction occurring during HBO is also suggested.

Non invasive ventilation in the treatment of FUdr-induced lesional pulmonary oedema.

2-deoxy-5-fluorouridine, also known as floxuridine (FUdr) is a fluoropyridine antimetabolite, used in the treatment of metastatic renal cell carcinoma. We report the first case of lesional pulmonary oedema developed after receiving Fudr, recently treated in our unit. The patient refused endotracheal intubation, and was successfully treated associating noninvasive ventilation (NIV) with full-face mask to steroid treatment. The authors conclude that mechanical ventilation via face-mask can be an effective, comfortable, dignified method of support for patients with end-stage disease and acute respiratory failure.

[Assessment of lipid peroxidation in hyperbaric oxygen therapy: protective role of N-acetylcysteine]. / Valutazione della perossidazione lipidica in corso di ossigenoterapia iperbarica: ruolo protettivo della N-acetilcisteina.

OBJECTIVE: To verify and quantify lipidic peroxidation by means of tiobarbituric-acid reactive substance (TBARS) dosage in patients treated daily with HBO. To verify if a potentiated glutathione enzymatic system, with N-acetylcisteine (NAC) treatment, may determine higher HBO tolerance and reduced lipidic peroxidation. DESIGN: Randomised study on patients treated with 20 HBO 2.2 ATA (90' oxygen) sessions. SETTING: Hyperbaric Medical Centre. PATIENTS: Seventeen patients divided, at random, into two groups; group A: 10 patients treated with only HBO; group B: 7 patients treated with NAC antioxidant therapy (Fluimucil, Zambon Group, Italy) 1800 mg/day in addition to HBO. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: TBARS on blood sample at T0 (basal) T1 (at the end of the 1st HBO session) T2 (at the beginning of the 20th HBO session) T3 (at the end of the 20th). The group A TBARS analysis at the different study time has shown significant data (p < 0.01) as the difference between TBARS values of the two groups at T2 (p < 0.01). CONCLUSIONS: HBO induces a lipidic peroxidation even if the therapeutical protocol cannot determine lung or cerebral oxygen toxicity symptoms. The NAC administration, during HBO treatment, determines a protection against the HBO radicalic stress.