Hypercapnia Caused by a Therapeutic Dosage of Pregabalin in a Tetraplegic Patient With Cervical Spinal Cord Injury

Cervical spinal stenosis and risk of pulmonary dysfunction

Background:

Cervical spinal stenosis (CSS) is defined as an abnormal narrowing of the cervical spinal canal. The essential clinical challenges with CSS are altered cervical spinal cord function and cervical radiculopathy. Phrenic nerve palsy leading to hemidiaphragmatic paresis may be a temporary or persistent phenomenon after cervical cord injury and CSS.

Objective:

The objective of the study is to elucidate the potential effect of CSS on the pulmonary functions.

Methods:

This is a case–control study which included 40 patients divided into two groups 30 females and 10 males patients with CSS (C5 and above) and 60 healthy volunteers with body mass index (BMI) <30 Kg/m². Pulmonary function tests have been done for all the patients.

Results:

The present study showed that VC in expiration (VC EX%), forced expiratory volume (FEV%), forced vital capacity % (FVC%), PEF%, and mean voluntary ventilation % (MVV%), were low in patients CSS compared with the control groups; P < 0.001, P < 0.001, P < 0.001, P = 0.042, and P = 0.037, respectively. As well, VC EX%, FEV1%, and FVC% were low in male patients in comparison to the controls P < 0.05. Besides, there were no significant differences regarding age, BMI, VC in inspiration (VC IN%), PEF%, FEV1/FVC%, and MVV%. Moreover, VC EX%, FEV1%, and FVC% were low in female patients compared to the controls, P < 0.001. Whereas, there were no significant differences that had been identified between female patients and female controls regarding age, BMI, VC IN%, PEF%, FEV1/FVC%, and MVV%. On the other hand, weight, height, and MVV% were low in female patients compared to male patients, P < 0.001.

Conclusion:

Chronic CSS leads to subclinical pulmonary dysfunction due to the involvement of the phrenic nerve. FEV% is the most sensitive parameter in the detection these disorders.