ABSTRACT
Objective To evaluate the diagnostic value of cerebrospinal lactate for the diagnosis of bacterial meningitis in patients post-neurosurgical operation (PNBM) with blood-contaminated cerebrospinal fluid (CSF). Methods A prospective observational study was conducted. 101 patients underwent neurosurgical operation and clinically suspected PNBM admitted to neurosurgical intensive care unit (NSICU) of the First Affiliated Hospital of Sun Yat-sen University from October 2015 to December 2016 were enrolled. Based on red blood cell quantitative test in CSF, the patients were divided into blood-contaminated and non blood-contaminated CSF groups. According to the PNBM diagnostic criteria of 2008 Centers for Disease Control and Prevention/National Healthcare Safety Network (CDC/NHSN), all patients were divided into PNBM group and non-PNBM group. The biochemical indexes levels in CSF were compared among the groups. Receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic power of CSF lactate for PNBM in blood-contaminated patients.Results A total of 101 suspected PNBM patients were enrolled. In 77 blood-contaminated CSF patients, 39 patients were diagnosed as PNBM (account for 50.6%); in 24 non-blood-contaminated patients, 12 patients were diagnosed as PNBM (account for 50.0%). ① In non-PNBM patients, the lactate level in blood-contaminated CSF was significantly higher than that of non-blood-contaminated CSF (mmol/L: 3.5±1.3 vs. 2.3±1.1,P 0.05). ② In both blood-contaminated and non blood-contaminated CSF, white blood cell (WBC), protein and lactate levels in PNBM group were significantly higher than those in non-PNBM group [WBC (×106/L): 660.0 (67.5, 1105.0) vs. 41.0 (15.0, 142.5) in blood-contaminated CSF,168.0 (86.5, 269.5) vs. 34.5 (7.0, 83.5) in non-blood-contaminated CSF; protein (mg/L): 4757.8 (2995.2, 10219.8) vs. 1292.8 (924.2, 1936.2) in blood-contaminated CSF, 39247.3 (14900.6, 62552.2) vs. 1441.6 (977.3, 2963.9) in non blood-contaminated CSF; lactate (mmol/L): 6.8±2.1 vs. 3.5±1.3 in blood-contaminated CSF, 6.9±2.5 vs. 2.3±1.1 in non blood-contaminated CSF, allP < 0.05], and glucose and CSF glucose/blood glucose ratio in PNBM group were significantly lower than those in non-PNBM group [glucose (mmol/L): 2.5±1.2 vs. 4.4±1.6 in blood-contaminated CSF, 1.9±1.4 vs. 3.4±0.9 in non blood-contaminated CSF; CSF glucose/blood glucose ratio: 0.28±0.15 vs. 0.46±0.16 in blood-contaminated CSF, 0.24±0.16 vs. 0.45±0.11 in non blood-contaminated CSF, allP < 0.01]. ③ It was shown by ROC curve analysis that CSF lactate level was a good diagnostic parameter for PNBM both in blood-contaminated and non blood-contaminated CSF, and the area under ROC curve (AUC) was 0.91 and 0.97, respectively. When the cutoff value of lactate in non blood-contaminated CSF was 3.35 mmol/L, the sensitivity was 100%, and the specificity was 91.7%. When the cutoff value of lactate in blood-contaminated CSF was 4.15 mmol/L, the sensitivity was 92.3%, and the specificity was 71.1%, and the combination of CSF lactate and glucose achieved better diagnostic specificity (AUC = 0.96, sensitivity was 97.4%, specificity was 84.2%).Conclusions Blood in CSF led to the elevation of CSF lactate as compared with that in non-blood-contaminated CSF of patients with PNBM. CSF lactate was still a good diagnostic parameter for PNBM both in blood-contaminated patients, and the combination of CSF lactate and glucose achieved better diagnostic specificity.
ABSTRACT
Objective To study the significance of the cerebrospinal fluid(CSF)lactate level in diagnosing neonatal bacterial meningitis(BM). Methods The CSF samples were collected from neonates admitted to Neonatal Ward of Children's Hospital of Fudan University between January 2014 and March 2015. CSF lactate and glucose con-centrations were measured with blood - gas analyzer. CSF and serum glucose levels were measured with glucometer. The enrolled neonates were divided into 2 groups based on CSF culture,CSF white blood cells(WBCs)and clinical presenta-tion:observation group(neonates with BM)and control group(neonates without BM). Statistical analysis of data was performed with Stata 12. 0. Results A total of 93 infants(16 assigned to observation group and 77 assigned to control group)met the inclusion criteria. Neonates in observation group had higher median CSF lactate level(4. 2 mmol/ L)and CSF lactate/ glucose ratio(L/ Gcsf)(2. 32 mmol/ L),than those in control group(1. 3 mmol/ L,0. 52),and there were significant differences(Z = - 6. 19,- 5. 92,all P ﹤ 0. 05). CSF glucose levels were lower in observation group(me-dian,1. 25 mmol/ L)than those in control group(median,2. 5 mmol/ L),and the difference was significant(Z = 4. 97, P ﹤ 0. 05);CSF/ serum glucose ratio(CSF/ Sglu)were lower in observation group(median,0. 44 vs 0. 81 in control group),and the difference was significant(Z = 4. 43,P ﹤ 0. 05). The optimal CSF lactate cutoff point of 2. 2 mmol/ L had a positive predictive value(PPV)of 72. 7% and negative predictive value(NPV)of 100. 0% for bacterial meningi-tis. The optimal L/ Gcsf cutoff point of 1. 24 had a PPV of 94. 1% and NPV of 100. 0% . The optimal CSF glucose cutoff point of 2. 0 mmol/ L had a PPV of 65. 0% and NPV of 95. 9% . The optimal CSF/ Sglu cutoff point of 0. 6 had a PPV of 60. 0% and a NPV of 96. 9% . Conclusion CSF lactate may be an excellent biomarker for early diagnosis of neo-natal BM.
ABSTRACT
Cerebrospinal fluid lactate and intracranial pressure were measured in 24 severely head-injured patients with Glasgow coma scale below 8. Cerebral perfusion pressure, vital sign and CVP were also measured simultaneously. Severely head-injured patients revealed increased CSF lactate and intracranial pressure which have been significantly correlated with outcome. But changes of vital sign, cerebral perfusion pressure and CVP were not correlated with outcome. The elevation of intracranial pressure checked on arrival was statistically significant in correlation to outcome. And the elevation of CSF lactate were correlated with statistically significance in correlation with outcome and lactate level checked on time interval(arrival, 12hr, 24hr, 48hr after trauma). And so CSF lactate levels are statistically more significant than intracranial pressure in predicting prognosis. We will expect good prognosis in severely head-injured patient by reducing intracranial pressure and CSF lactate, oxygenation and increasing cerebral perfusion.