Purpose

Shunt pumping test has often been used clinically to detect functional status of ventriculoperitoneal (VP) shunt. Its ability to correctly predict the status is not reliably known. Ethical dilemmas make it difficult to perform any studies in patients with blocked shunts, and hence, a requirement of devising an experimental model was felt.

Method

An experimental model was devised using a Chhabra Slit N Spring shunt. The pressures were maintained in the proximal and distal chamber by real-time monitoring and maintained similar to intra-ventricular and intra-abdominal pressures. Three such models with scenarios of proximal block (PB), distal block (DB), and a functional shunt (BO) were created. Twenty-five participants were tested using these models to assess the efficacy of shunt pumping test.

Results

The experimental model could be used successfully to perform the test. The sensitivity of the test to detect a shunt with block on any side (AB) was found to be 0.79 (95% confidence interval 0.72–0.85) and specificity to be 0.69 (95% confidence interval 0.59–0.80). Its ability to detect the side of block was also evaluated. Absolute correctness value, odds ratio, and interpersonal heterogeneity were also evaluated. Pressure changes in proximal and distal catheter on compressing the chamber in various scenarios were recorded.

Conclusion

The shunt pumping test has moderate ability to predict a blocked shunt and can aid clinical assessment of shunt block. It has only limited ability to detect the side of block. Pressure changes in the proximal and distal catheters on chamber compression are commensurate with the rationale of “shunt pumping test.”

中文翻译：

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“分流测试”：通过实验模型检测其功效

目的

临床上经常使用分流泵测试来检测心室腹膜（VP）分流器的功能状态。无法正确知道其正确预测状态的能力。道德困境使分流受阻的患者难以进行任何研究，因此，人们感到有必要设计一个实验模型。

方法

使用Chhabra Slit N Spring分流器设计了一个实验模型。通过实时监测将压力维持在近端和远端腔室中，并保持类似于心室内和腹腔内的压力。创建了三种具有近端阻滞（PB），远端阻滞（DB）和功能性分流（BO）的模型。使用这些模型对25位参与者进行了测试，以评估分流泵测试的有效性。

结果

实验模型可以成功地用于执行测试。发现检测任一侧阻塞的测试的敏感性（AB）为0.79（95％置信区间0.72-0.85），特异性为0.69（95％置信区间0.59-0.80）。还评估了其检测块侧的能力。还评估了绝对正确性值，优势比和人际异质性。记录在各种情况下压缩腔室时近端和远端导管中的压力变化。

结论

分流器抽气测试具有中等的预测阻塞分流器的能力，可以帮助临床评估分流器阻滞。它仅具有有限的检测块侧面的能力。腔室受压时，近端和远端导管中的压力变化与“分流泵测试”的原理相称。