Serum Neuron-Specific Enolase Levels from the Same Patients Differ Between Laboratories: Assessment of a Prospective Post-cardiac Arrest Cohort

Background

In comatose post-cardiac arrest patients, a serum neuron-specific enolase (NSE) level of >33 μg/L within 72 h was identified as a reliable marker for poor outcome in a large Dutch study (PROPAC), and this level was subsequently adopted in an American Academy of Neurology practice parameter. Later studies reported that NSE >33 μg/L is not a reliable predictor of poor prognosis. To test whether different clinical laboratories contribute to this variability, we compared NSE levels from the laboratory used in the PROPAC study (DLM-Nijmegen) with those of our hospital’s laboratory (ARUP) using paired blood samples.

Methods

We prospectively enrolled cardiac arrest patients who remained comatose after resuscitation. During the first 3 days, paired blood samples for serum NSE were drawn at a median of 10 min apart. After standard preparation for each lab, one sample was sent to ARUP laboratories and the other to DLM-Nijmegen.

Results

Fifty-four paired serum samples from 33 patients were included. Although the serum NSE measurements correlated well between laboratories (R = 0.91), the results from ARUP were approximately 30 % lower than those from DLM-Nijmegen. Therapeutic hypothermia did not affect this relationship. Two patients had favorable outcomes after hypothermia despite NSE levels measured by DLM-Nijmegen as >33 μg/L.

Conclusions

Absolute serum NSE levels of comatose cardiac arrest patients differ between laboratories. Any specific absolute cut-off levels proposed to prognosticate poor outcome should not be used without detailed data on how neurologic outcomes correspond to a particular laboratory’s method, and even then only in conjunction with other prognostic variables.     

Long-Term Outcome of Laparoscopic Surgery for Pancreatic Neuroendocrine Tumors

Background

As most pancreatic neuroendocrine tumors (PNET) are relatively small and solitary, they may be considered well suited for removal by a minimally invasive approach. There are few large series that describe laparoscopic surgery for PNET. The primary aim of this study was to describe the feasibility, outcome, and histopathology associated with laparoscopic pancreatic surgery (LS) of PNET in a large series.

Methods

All patients with PNET who underwent LS at a single hospital from March 1997 to April 2011 were included retrospectively in the study.

Results

A total of 72 patients with PNET underwent 75 laparoscopic procedures, out of which 65 were laparoscopic resections or enucleations. The median operative time of all patients who underwent resections or enucleations was 175 (60–520) min, the median blood loss was 300 (5–2,700) ml, and the median length of hospital stay was 7 (2–27) days. The overall morbidity rate was 42 %, with a surgical morbidity rate of 21 % and postoperative pancreatic fistula (POPF) formation in 21 %. Laparoscopic enucleations were associated with a higher rate of POPF than were laparoscopic resections. Five-year disease-specific survival rate was 90 %. The T stage, R stage, and a Ki-67 cutoff value of 5 % significantly predicted 5-year survival.

Conclusion

LS of PNET is feasible with acceptable morbidity and a good overall disease-specific long-term prognosis.