In patients with head injury, endotracheal suctioning (ETS) is a potentially dangerous procedure, because it can increase intracranial pressure (ICP). The purpose of this prospective nonrandomized study was to evaluate the impact of ETS on intracranial dynamics in the acute phase of head injury. Seventeen patients with severe head injury (Glasgow Coma Score ≤ 8, range 4–8), sedated and mechanically ventilated, were studied during the first week after trauma. Single-pass ETS maneuver (with a 16-French catheter, negative pressure of 100 mm Hg, and duration of less than 30 seconds) was performed 60 seconds after the FiO 2 was increased to 100%. After ETS, FiO 2 was maintained at 100% for another 30 seconds. Before and after ETS, arterial blood gases and jugular oxygen saturation (S j O 2 ), ICP, and mean arterial pressure (MAP) were measured and cerebral perfusion pressure (CPP) was calculated. A total of 131 ETS episodes, which consisted of repeated assessment of each patient, were analyzed. Six patients in 20 cases coughed and/or moved during ETS because of inadequate sedation. After ETS, ICP increased from 20 ± 12 to 22 ± 13 mm Hg in well-sedated patients and from 15 ± 9 to 28 ± 9 mm Hg in patients who coughed and/or moved (mean change, 2 ± 6 versus 13 ± 6 mm Hg, P <.0001). CPP and S j O 2 increased in well-sedated patients (from 78 ± 16 to 83 ± 19 mm Hg, and from 71 ± 10 to 73 ± 13%, respectively) and decreased in patients who reacted to ETS (from 79 ± 14 to 72 ± 14 mm Hg and from 69 ± 7 to 66 ± 9%, respectively), and the differences were significant (mean change, CPP: 5 ± 14 versus -7 ± 15 mm Hg, P =.003; (S j O 2 ) 2 ± 5 vs. −3 ± 5%, P <.0001). In well-sedated patients, endotracheal suctioning caused an increase in ICP, CPP, and S j O 2 without evidence of ischemia. In contrast, in patients who coughed or moved in response to suctioning, there was a slight and significant decrease in CPP and S j O 2 . In the case of patients with head injuries who coughed or moved during endotracheal suctioning, we strongly suggest deepening the level of sedation before completing the procedure to reduce the risk of adverse effects.

Object: Since the 1990s, Gamma Knife radiosurgery (GKRS) has become the first-line treatment option for small- to medium-size vestibular schwannomas (VSs), especially in patients without mass effect–related symptoms and with functional hearing. The aim of this study was to assess the safety and efficacy of GKRS, in terms of tumor control, hearing preservation, and complications, in a series of 379 consecutive patients treated for VS.Methods: Of 523 patients treated at the authors' institution for VS between 2001 and 2010, the authors included 379 who underwent GKRS as the primary treatment. These patients were not affected by Type 2 neurofibromatosis and had clinical follow-up of at least 36 months. Clinical follow-up (mean and median 75.7 and 69.5 months, respectively) was performed for all patients, whereas audiometric and quantitative radiological follow-up examinations were obtained for only 153 and 219 patients, respectively. The patients' ages ranged from 23 to 85 years (mean 59 years). The mean tumor volume was 1.94 ± 2.2 cm³ (median 1.2 cm³, range 0.013–14.3 cm³), and the median margin dose was 13 Gy (range 11–15 Gy). Parameters considered as determinants of the clinical outcome were long-term tumor control, hearing preservation, and complications. A statistical analysis was performed to correlate clinical outcomes with the radiological features of the tumor, dose-planning parameters, and patient characteristics.Results: Control of the tumor with GKRS was achieved in 97.1% of the patients. In 82.7% of the patients, the tumor volume had decreased at the last follow-up, with a mean relative reduction of 34.1%. The rate of complications was very low, with most consisting of a transient worsening of preexisting symptoms. Patients who had vertigo, balance disorders, or facial or trigeminal impairment usually experienced a complete or at least significant symptom relief after treatment. However, no significant improvement was observed in patients previously reporting tinnitus. The overall rate of preservation of functional hearing at the long-term follow-up was 49%; in patients with hearing classified as Gardner-Robertson (GR) Class I, this value was 71% and reached 93% among cases of GR Class I hearing in patients younger than 55 years.Conclusions: Gamma Knife radiosurgery is a safe and effective treatment for VS, achieving tumor control in 97.1% of cases and resulting in a very low morbidity rate. Younger GR Class I patients had a significantly higher probability of retaining functional hearing even at the 10-year follow-up; for this reason, the time between symptom onset, diagnosis, and treatment should be shortened to achieve better outcomes in functional hearing preservation.

Objective: Mechanical ventilation contributes to diaphragmatic atrophy and dysfunction, and few techniques exist to assess diaphragmatic function: the purpose of this study was to quantify diaphragm atrophy in a population of critically ill mechanically ventilated patients with ultrasound and to identify risk factors that can worsen diaphragmatic activity. Design: Prospective observational study. Setting: ICU of a 1,200-bed university hospital. Patients: Newly intubated adult critically ill patients. Interventions: Diaphragm thickness in the zone of apposition was measured daily with ultrasound, from the first day of mechanical ventilation till discharge to the main ward. Measurements and Main Results: Daily atrophy rate (ΔTdi/d) was calculated as the reduction in percentage from the previous measurement. To analyze the difference in atrophy rate (ΔTdi/d), ventilation was categorized into four classes: spontaneous breathing or continuous positive airway pressure; pressure support ventilation 5–12 cm H₂O (low pressure support ventilation); pressure support ventilation greater than 12 cm H₂O (high pressure support ventilation); and controlled mechanical ventilation. Multivariate analysis with ventilation support and other clinical variables was performed to identify risk factors for atrophy. Forty patients underwent a total of 153 ultrasonographic evaluations. Mean (sd) ΔTdi/d was –7.5% (12.3) during controlled mechanical ventilation, –5.3% (12.9) at high pressure support ventilation, –1.5% (10.9) at low pressure support ventilation, +2.3% (9.5) during spontaneous breathing or continuous positive airway pressure. At multivariate analysis, only the ventilation support was predictive of diaphragm atrophy rate. Pressure support predicted diaphragm thickness with coefficient –0.006 (95% CI, –0.010 to –0.002; p = 0.006). Conclusions: In critically ill mechanically ventilated patients, there is a linear relationship between ventilator support and diaphragmatic atrophy rate.

This prospective randomized clinical study was designed to compare the effects of equal volumes of 7.5% hypertonic saline solution (HS) or 20% mannitol (M) on brain bulk and lumbar cerebrospinal fluid pressure (CSFP) during elective neurosurgical procedures (aneurysm, arteriovenous malformation, or tumor). After informed consent, 50 American Society of Anesthesiologists physical Status I (ASA I) patients were randomly assigned to M (n = 25) or HS (n = 25) groups. Anesthesia protocol was identical for both, and variables monitored included mean arterial blood pressure (MAP), heart rate (HR), central venous pressure (CVP), CSF pressure (CSFP), arterial blood gases (PaCO2 30–35 mm Hg), serum sodium, potassium, and osmolality, and diuresis. The study period started before hypertonic solution administration (T 0) and ended at the opening of the dura mater or 60 min after T 0. Data were assessed with repeated measures analysis of variance and Student t test with Bonferroni correction (p ≤ 0.05). MAP and CVP were the same in the two groups. After treatment, osmolality increased, and the increase at T 15 was higher in HS-treated patients [316.6 ± 9.3 vs. 304.0 ± 12.0 (SD) mOsmol/kg; p < 0.001]. Sodium decreased after M and increased after HS. During the study, brain bulk was always considered satisfactory. CSFP was not different between M and HS groups and significantly decreased over time (p = 0.0056) with no difference between treatments. The results of the present study demonstrate that hypertonic saline is as effective as manmtol in reducing the brain bulk and the CSFP during elective neurosurgical procedures under general anesthesia.