A Systematic Review of Viscoelastic Testing in Patients with Subarachnoid Hemorrhage

OBJECTIVE

Bleeding and thromboembolic complications frequently occur after subarachnoid hemorrhage (SAH) and substantially contribute to poor outcome. Viscoelastic testing could be used for detection of coagulopathies after SAH. This review summarizes literature on the usefulness of viscoelastic testing to detect coagulopathy in patients with SAH and explores whether viscoelastic parameters are associated with SAH-related complications and clinical outcome.

METHODS

PubMed, Embase, and Google Scholar were systematically searched on August 18, 2022. Two authors independently selected studies that reported viscoelastic testing in patients with SAH and assessed the quality of studies using the Newcastle-Ottawa Scale or a previously reported framework for quality assessment. Data were meta-analyzed if methodologically possible.

RESULTS

The search yielded 19 studies (1160 patients with SAH). Pooling of data including all relevant studies was not possible for any of the outcome measurements because of methodological differences. Thirteen of 19 studies evaluated the association of coagulation profiles and SAH, of which 11 studies showed a hypercoagulable profile. Rebleeding was associated with platelet dysfunction, deep venous thrombosis was associated with faster clot initiation, and both delayed cerebral ischemia and poor outcome were associated with increased clot strength.

CONCLUSIONS

This explorative review shows that patients with SAH frequently have a hypercoagulable profile. Thromboelastography (TEG) and rotational thromboelastometry (ROTEM) parameters are associated with rebleeding, delayed cerebral ischemia, deep venous thrombosis, and poor clinical outcome after SAH; however, more research on the subject is needed. Future studies should focus on determining the optimal time frame and cutoff values for TEG or ROTEM to predict these complications.

Clinical Usage of Different Doses of Cis-Atracurium in Intracranial Aneurysm Surgery and Its Effect on Motor-Evoked Potentials

The objective of this work was to investigate the effect of different doses of cis-atracurium on patients undergoing general anesthesia induction (GAI) during intracranial aneurysm surgery (ICAS). In this work, 90 patients who underwent ICAS under the elective motor-evoked potential (MEP) monitoring in the First Affiliated Hospital of Northwest University (Xi'an No. 1 Hospital) from January 2021 to May 2022 were enrolled as the research objects. Randomly, they were rolled into a S1 group (30 cases, 2 times 95% effective dose (ED95) cis-atracurium), a S2 group (30 cases, 3 times ED95 cis-atracurium), and a S3 group (30 cases, 4 times ED95 cis-atracurium). The endotracheal intubation conditions, the train-of-four (TOF) rate (TOFR), body movement, and spontaneous breathing were compared among the three groups of patients. The results showed that the MEP inhibition time of the patients in the S3 group was much longer than that of the S1 and S2 groups, but it showed no significant difference between the S1 group and S2 group (P > 0.05). The good rates of endotracheal intubation conditions in the S2 group (100%) and S3 group (100%) were obviously higher than the rate in the S1 group (43.33%). The TOFRs of patients in S2 and S3 groups at time t2 and t3 were lower obviously to that at time t0, while the TOFRs of patients in S3 group at time t2 and t3 were still lower in contrast to the S2 group (P < 0.05). The mean arterial pressure (MAP) and heart rate (HR) of patients in all groups were lower at t1, t2, and t3 than at t0 (P < 0.05), while the differences among different groups were not remarkable (P > 0.05). Finally, using 3 times ED95 cis-atracurium for GAI could reduce the risk of intraoperative body movement and spontaneous breathing, as well as the residual degree of muscle relaxation, in patients with ICAS, without affecting MEP monitoring, improving endotracheal intubation conditions, and increasing safety during open neurosurgery operations.

Characterizing Risk of In-Hospital Mortality Following Subarachnoid Hemorrhage Using Machine Learning: A Retrospective Study

Background

Subarachnoid hemorrhage has a high rate of disability and mortality, and the ability to use existing disease severity scores to estimate the risk of adverse outcomes is limited. Collect relevant information of patients during hospitalization to develop more accurate risk prediction models, using logistic regression (LR) and machine learning (ML) technologies, combined with biochemical information.

Methods

Patient-level data were extracted from MIMIC-IV data. The primary outcome was in-hospital mortality. The models were trained and tested on a data set (ratio 70:30) including age and key past medical history. The recursive feature elimination (RFE) algorithm was used to screen the characteristic variables; then, the ML algorithm was used to analyze and establish the prediction model, and the validation set was used to further verify the effectiveness of the model.

Result

Of the 1,787 patients included in the mimic database, a total of 379 died during hospitalization. Recursive feature abstraction (RFE) selected 20 variables. After simplification, we determined 10 features, including the Glasgow coma score (GCS), glucose, sodium, chloride, SPO₂, bicarbonate, temperature, white blood cell (WBC), heparin use, and sepsis-related organ failure assessment (SOFA) score. The validation set and Delong test showed that the simplified RF model has a high AUC of 0.949, which is not significantly different from the best model. Furthermore, in the DCA curve, the simplified GBM model has relatively higher net benefits. In the subgroup analysis of non-traumatic subarachnoid hemorrhage, the simplified GBM model has a high AUC of 0.955 and relatively higher net benefits.

Conclusions

ML approaches significantly enhance predictive discrimination for mortality following subarachnoid hemorrhage compared to existing illness severity scores and LR. The discriminative ability of these ML models requires validation in external cohorts to establish generalizability.

Safety of heparin loading during endovascular embolization in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

Of the complications that can occur during endovascular surgery in aneurysmal subarachnoid hemorrhage (aSAH) patients, thromboembolism remains a particular challenge for many surgeons. Heparin has been widely used for its prevention, but it has not been able to eliminate concerns about bleeding. Therefore, in this study, we tried to determine the risk of rebleeding associated with heparin use.

METHODS

We retrospectively analyzed the medical and surgical records of 109 patients that underwent endovascular embolization for a ruptured cerebral aneurysm at a single institution from 2010 to 2014. These patients were divided into two groups according to whether heparin was loaded or not, to determine the effect of heparin on rebleeding and to identify other risk factors of rebleeding.

RESULTS

This series included 40 men (36.7 %) and 69 women (63.3 %) of mean age 57.9 ± 14.8 years. In 80 patients (73.4 %), endovascular embolization was conducted using an intraoperative bolus of 5000 units of heparin, whereas in the other 29 (26.6 %) endovascular embolization was performed without an intraoperative heparin bolus. After procedures, 16 patients (14.7 %) experienced rebleeding and 2 (1.8 %) a thromboembolic event. Intraoperative heparin loading (OR 0.683 [95 % CI 0.199-2.338]) was not found to be related to postoperative rebleeding. Rather, logistic regression analysis showed preoperative modified Fisher grade (OR 2.037 [95 % CI 1.077-3.853]) and external ventricular drainage (OR 5.389 [95 % CI 1.171-24.801]) independently predicted rebleeding.

CONCLUSIONS

Heparin loading during endovascular treatment of ruptured cerebral aneurysms did not affect rebleeding. We conclude heparin loading to prevent thromboembolism during endovascular treatment may be considered a good option in aSAH patients.