Impact of Oleoresin Capsicum Spray on Respiratory Function in Human Subjects in the Sitting and Prone Maximal Restraint Positions in San Diego County, 1998 (ICPSR 2961)

Time Period(s) View help for Time Period(s)

Date of Collection View help for Date of Collection

Data Collection Notes View help for Data Collection Notes

Study Purpose View help for Study Purpose

Oleoresin capsicum (OC), or pepper spray, has gained wide acceptance as standard police equipment in law enforcement as a swift and effective method to subdue violent, dangerous suspects in the field. Derived from the extract of the capsicum pepper plant, OC spray causes inflammation and edema over areas of contact (primarily the face, eyes, nose, and mouth), resulting in pain and discomfort such that many suspects lose their capacity to resist. With widespread use, however, OC spray as a use-of-force method has been alleged in the media to have been associated with a number of in-custody deaths. Because symptoms of coughing, gagging, and shortness of breath are common with OC exposure, concern has focused on the respiratory effects of OC spray as playing a potential role in these deaths. Moreover, individuals subdued with OC spray in the field often require physical restraint, including the prone maximal restraint or hobble position. Some have argued that OC in combination with restraint can lead to significant respiratory compromise and risk for asphyxiation and death. While capsaicin, the active ingredient of OC, has been studied extensively in the medical literature for its ability to induce coughing, few studies on the physiologic effects of OC on humans have been conducted, particularly relating to respiratory function. In addition, no prior studies have been done on the effects of OC in combination with positional restraint. The goal of this study was to assess the safety of a commercially available OC spray in use by law enforcement agencies nationwide. Specifically, the researchers examined both OC spray and positional restraint in human subjects to determine if OC exposure by itself or in combination with positional restraint resulted in clinically significant respiratory compromise as measured by pulmonary function testing and assessment of oxygenation and ventilation. Additionally, they sought to determine if OC spray by itself or in combination with positional restraint resulted in any hemodynamic compromise as measured by pulse rate and blood pressure, whether body size and weight influenced the effects of OC spray in regard to respiratory and pulmonary function, and whether pulmonary disease (such as asthma), the use of respiratory inhaler medications, or history of smoking tobacco influenced the effects of OC spray in regard to respiratory and pulmonary function, with both of the latter two measured by pulmonary function testing and assessment of oxygenation and ventilation.

Study Design View help for Study Design

The study was conducted as a randomized, cross-over, controlled trial on volunteer human subjects recruited from the local law enforcement training academy in San Diego County, California. Subjects participated in four different experimental trials in random order over two separate days in a pulmonary function testing laboratory: (a) placebo spray exposure followed by sitting position, (b) placebo spray exposure followed by sitting position, (c) OC spray exposure followed by sitting position, and (d) OC spray exposure followed by restraint position. Prior to participation, subjects completed a short questionnaire regarding their health status, history of lung disease and asthma, smoking history, medication use, and respiratory inhaler medication use. Prior to exposure, subjects also underwent a brief screening spirometry in the sitting position by means of a portable spirometry device to determine baseline pulmonary function. Subjects then placed their heads in a 5' x 3' x 3' exposure box that allowed their faces to be exposed to the spray. A one-second spray was delivered into the box from the end opposite the subject (approximately five feet away). Subjects remained in the box for five seconds after the spray was delivered. During this time, subjects underwent impedance monitoring to assess whether inhalation of the OC or placebo spray had occurred. After this exposure period, subjects were placed in either the sitting or prone maximal restraint position. Subjects remained in these positions for ten minutes. Repeat spirometric measurements were performed at 1.5 and 10 minutes. Oxygen saturation, end-tidal carbon dioxide levels, and pulse rate were recorded at 1, 5, and 9 minutes. Blood pressure was recorded at 3, 6, and 9 minutes. An arterial blood sample was drawn at 8 minutes. After the 10-minute period, the subject had a one-hour rest and wash-out period to allow for resolution of any residual effects from either exposure or position. After this rest period, the subject performed a second experiment trial. The subject performed only two trials on each experiment day. Though the sequence of trials was randomized, no subject received two exposures to OC in a single day. A total of 34 subjects completed the study, comprising 128 separate analyzable study trials. Eight trials were excluded because the subjects did not inhale adequately when exposed to OC spray.

Sample View help for Sample

Volunteers were recruited from the training staff and cadets of the San Diego Regional Public Safety Training Institute.

Universe View help for Universe

Healthy, young adult human subjects.

Unit(s) of Observation View help for Unit(s) of Observation

Data Source View help for Data Source

Data Type(s) View help for Data Type(s)

Description of Variables View help for Description of Variables

Variables provided in all three parts of this collection include subject's age, gender, ethnicity, height, weight, body mass index, past medical history, tobacco use history, and history of medication use, as well as OC spray or placebo exposure and sitting or restraint position during the trial. Part 1 also includes tidal volume, respiratory rate, and heart rate at baseline and at 1, 5, 7, and 9 minutes, and systolic and diastolic blood pressure at baseline and at 3, 6, and 9 minutes. Additional variables in Part 2 include predicted forced vital capacity and predicted forced expiratory volume in 1 second, and the same measures at baseline, 1.5 minutes, and 10 minutes. Derived variables include percent predicted and mean percent predicted values involving the above variables. Part 3 also provides end-tidal carbon dioxide and oxygenation levels, oxygen saturation, oxygen consumption at baseline and at 1, 5, 7, and 9 minutes, blood pH, partial pressure of oxygen, and partial pressure of carbon dioxide at 8 minutes.

Response Rates View help for Response Rates

Not applicable.

Presence of Common Scales View help for Presence of Common Scales

None.

Original Release Date View help for Original Release Date

2001-06-29

Version History View help for Version History