Prospective study: Long-term outcome at 12-15 years after aneurysmal subarachnoid hemorrhage.

BACKGROUND: Patients with aneurysmal subarachnoid hemorrhage (aSAH) have poor outcome. Studies on outcome beyond 1 year post-aSAH are few, and late recovery is poorly investigated, initiating this prospective outcome study on patients 12-15 years after an aSAH. We hypothesized to find; functional improvement > 1 year post-ictus; increased long-term mortality in aSAH patients vs matched controls, and finally to present; predictors of long-term favorable outcome (GOS 4-5). METHODS: We prospectively investigated patients, admitted 2000-2003 to the Sahlgrenska University Hospital, 1 year post-ictus using Glasgow Outcome Scale (GOS). The patients were revalidated 12-15 years post-aSAH by structured-telephone interviews (GOS), followed by statistical analysis. RESULTS: A total of 158 patients were included, (women n = 114, men n = 44), with a mean age of 55 years at aSAH. Patients treated with surgical clipping had lower mortality. At the follow-up 12-15 years post-aSAH, all 103 survivors (65.2%) were categorized as having; good recovery (39.9%), moderate disability (15.2%), or severe disability (10.1%). Within the patient cohort, 23.6% improved GOS over time. Fifty-five patients died, median at 4 years post-ictus. aSAH patients had 3.5 times increased mortality 12-15 years post-ictus vs matched controls (P < .0001). Patients with favorable outcome at 1 year (67.3%, n = 101) had similar survival probability as control patients. Prognostic indicators of long-term favorable outcome were low age and high GOS at 1-year follow-up, (AUCROC, 0.79). CONCLUSIONS: Individual functional improvement was found >1 year post-ictus. Patients with favorable outcome at 1 year had similar long-term life expectancy as the general population. Indicators of long-term favorable prognosis were low age at ictus and high GOS at 1-year follow-up.

Prolonged moderate pressure recruitment manoeuvre results in lower optimal positive end-expiratory pressure and plateau pressure.

BACKGROUND: In acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), recruitment manoeuvres (RMs) are used frequently. In pigs with induced ALI, superior effects have been found using a slow moderate-pressure recruitment manoeuvre (SLRM) compared with a vital capacity recruitment manoeuvre (VICM). We hypothesized that the positive recruitment effects of SLRM could also be achieved in ALI/ARDS patients. Our primary research question was whether the same compliance could be obtained using lower RM pressure and subsequent positive end-expiratory pressure (PEEP). Secondly, optimal PEEP levels following the RMs were compared, and the use of volume-dependent compliance (VDC) to identify successful lung recruitment and optimal PEEP was evaluated. PATIENTS AND METHODS: We performed a prospective randomised cross-over study where 16 ventilated patients with early ALI/ARDS each were subjected to the two RMs, followed by decremental PEEP titration. Volume-dependent initial, middle and final compliance (C(ini) , C(mid) and C(fin) ) were determined. Electric impedance tomography and end-expiratory lung volume measurements were used to follow lung volume changes. RESULTS: The maximum response in compliance, PaO2/FIO2, venous admixture and C(ini) /C(fin) after recruitment, during decremental PEEP, was at significantly lower PEEP and plateau pressure after SLRM than VICM. Fewer patients responded in gas exchange after the SLRM, which was not the case for lung mechanics. The response in C(ini) was more pronounced than in conventional compliance. CONCLUSIONS: The same compliance increase is achieved with SLRM as with VICM, and lower PEEP can be used, with correspondingly lower plateau pressures. VDC seems promising to identify successful recruitment and optimal PEEP.

A new non-radiological method to assess potential lung recruitability: a pilot study in ALI patients.

INTRODUCTION: Potentially recruitable lung has been assessed previously in patients with acute lung injury (ALI) by computed tomography. A large variability in lung recruitability was observed between patients. In this study, we assess whether a new non-radiological bedside technique could determine potentially recruitable lung volume (PRLV) in ALI patients. METHODS: Sixteen mechanically ventilated patients with early ALI/ARDS were subjected to a recruitment manoeuvre and decremental PEEP titration. Electric impedance tomography, together with measurements of end-expiratory lung volume (EELV) and tracheal pressure, were used to determine PRLV. The method defines fully recruited open lung volume (OLV) as the volume reached at the end of two consecutive vital capacity manoeuvres to 40 cmH2O. It also uses extrapolation of the baseline alveolar pressure/volume curve up to 40 cmH2O, the volume reached being the non-recruited lung volume. The difference between the fully recruited and the non-recruited volume was defined as PRLV. RESULTS: We observed a considerable heterogeneity among the patients in lung recruitability, PRLV range 11-47%. In a post hoc analysis, dividing the patients into two groups, a high and a low PRLV group, we found at baseline before the recruitment manoeuvre that the high PRLV group had lower compliance and a lower fraction of EELV/OLV. CONCLUSIONS: Using non-invasive radiation-free bedside methods, it may be possible to measure PRLV in ALI/ARDS patients. It is possible that this technique could be used to determine the need for recruitment manoeuvres and to select PEEP level on the basis of lung recruitability.

Regional intratidal gas distribution in acute lung injury and acute respiratory distress syndrome assessed by electric impedance tomography.

BACKGROUND: Regional tidal volume distribution and end-expiratory lung volume (EELV) distribution in patients with acute lung injury and acute respiratory distress syndrome (ALI, ARDS) have previously been investigated using computed tomograpy and electric impedance tomography (EIT). In the present study, we utilized the high temporal resolution of EIT to assess intratidal gas distribution. METHODS: Sixteen ventilator patients with ALI/ARDS were studied. EIT was used for analysis of intertidal, intratidal and EELV regional distribution. Intratidal regional gas distribution (ITV) was analyzed by dividing the regional tidal impedance signal into eight iso-volume parts. Alveolar pressure/volume curves during ongoing ventilation and volume-dependent compliance during the initial inspiration (Cini) were calculated. A low-pressure (~32 cm H2O) recruitment maneuver and a decremental PEEPtrial were implemented. RESULTS: The increase in EELV was preferentially distributed to non-dependent lung regions. The intratidal gas distribution pattern was similar to the tidal volume distribution following increased PEEP; non-dependent distribution decreased and dependent distribution increased during inspiration. Cini increased, indicating successful recruitment. The distribution varied widely among individual patients. In one patient with a low EELV, the ITV pattern showed that non-dependent distribution increased and dependent distribution decreased. This coincided with minimal improvement in volume-dependent compliance. This patient probably needed higher recruitment pressure. In one patient with a high baseline EELV, there was very little change in regional ITV, and non-dependent Cini decreased. This was probably a patient with low potential recruitability, who required only moderate PEEP. CONCLUSION: On-line intratidal gas distribution monitoring offers additional information on recruitability and optimal PEEP.