Variability in targeted arterial oxygenation levels in patients with severe sepsis or septic shock.

BACKGROUND: Supplemental oxygen therapy is used for intensive care (ICU) patients with severe sepsis, but with no general guidelines and few safety data. The aim of this observational study was to describe the variability in oxygen administration as well as the association between partial pressure of arterial oxygen (PaO2 ) and mortality. METHODS: We extracted data from two Scandinavian clinical trials of ICU patients with severe sepsis or septic shock. We calculated average PaO2 and fraction of inspired oxygen (FiO2 ) from trial inclusion and the following 5 days, and assessed the association between PaO2 and 90-day mortality. RESULTS: The median PaO2 was 9.8 kPa [5-95% range 6.4-19.9] and FiO2 was 0.51 [5-95% range 0.27-1.00], respectively. Eight hundred and five of 1,770 patients (45%) died. The relative risk of mortality was 1.43 [95% CI: 1.19-1.65] in patients with average PaO2 < 8 kPa and 1.29 [95% CI: 0.84-1.68] in patients with average PaO2 ≥ 16 kPa, as compared to patients with average PaO2 10-12 kPa. The relative risk of mortality was 1.38 [95% CI: 1.17-1.58] in patients with an average FiO2 0.60-0.80 and 2.10 [95% CI: 1.88-2.23] in patients with an average FiO2  ≥ 0.80 as compared to patients with an average FiO2  ≤ 0.40. CONCLUSION: Administration of oxygen in patients with severe sepsis resulted in a wide range of PaO2 . Significantly higher mortality was observed in patients with an average PaO2 < 8 kPa and FiO2 ≥ 0.60. The results do not imply causation and the associations between average PaO2 and adverse outcomes have to be assessed further.

Remifentanil-induced spike activity as a diagnostic tool in epilepsy surgery.

OBJECTIVES: To assess the value of remifentanil in intraoperative evaluation of spike activity in patients undergoing surgery for mesial temporal lobe epilepsy (MTLE). MATERIALS AND METHODS: Twenty-five patients undergoing temporal lobectomy for medically intractable MTLE were enrolled in the study. Electrocorticography (ECoG) recordings were performed on the intraventricular hippocampus and from the anterior inferior temporal and lateral neocortex before and after a 300 microg intravenous bolus of remifentanil. Spike activity was quantified as spike-count per minute. RESULTS: A significant increase (P < 0.005) in spike activity was observed after administration of remifentanil in 23 of 25 patients (92%). Furthermore, two patients who did not have any spike activity on the baseline ECoG developed spikes after administration of remifentanil. CONCLUSIONS: The results suggest that remifentanil can enhance spike activity in the epileptogenic zone and reveal otherwise concealed epileptogenic tissue in patients with MTLE. Thus, remifentanil may prove to be an important diagnostic tool during surgical treatment for intractable focal epilepsy.

The feasibility of tricuspid annular plane systolic excursion performed by transesophageal echocardiography throughout heart surgery and its interchangeability with transthoracic echocardiography.

Tricuspid annular plane systolic excursion (TAPSE) is a robust measure of RV function, but the performance of transesophageal echocardiography (TEE) measured TAPSE during surgery is not well established. We aim to evaluate feasibility of various TEE views before, during and after surgery. Furthermore, we compare performance of individual TEE measurements depending on view and method (AMM- and M-mode as well as 2D) as well as TAPSE measured using TEE with transthoracic echocardiography (TTE) TAPSE. The study was conducted from January 2015 through September 2016. In 47 patients with normal left ventricular ejection fraction, TEE was prospectively performed during coronary artery bypass grafting surgery. TAPSE and tricuspid annulus tissue Doppler imaging (TDI) were recorded in five different views at pre-specified time points during surgery. Data were analyzed for availability (obtainable/readable images) and reliability (intra-/inter-observer bias and precision). Finally, TEE TAPSE was compared to TTE TAPSE immediately before and after surgery. TAPSE and TDI with TEE was achievable in > 90% of patients in the transgastric view during surgery. The AM- and M-mode had the best reliability and the best correlation with TAPSE measured with TTE. The deep transgastric view was achievable in less than 50% after sternotomy, and TAPSE measured from 2D had a poorer performance compared to the AM- and M-mode. TDI demonstrated a high reliability throughout surgery. RV function can be evaluated by TAPSE and TDI using TEE during surgery. TEE values from the transgastric view demonstrated high performance throughout surgery and a good agreement with TTE TAPSE measurements.