Advances in pain

Effects of hydromorphone-based intravenous patient-controlled analgesia with and without a low basal infusion on postoperative hypoxaemia: study protocol for a randomised controlled clinical trial

INTRODUCTION

When patients receive patient-controlled intravenous analgesia (PCIA), no basal infusion is always recommended, as the addition of a basal infusion increases the occurrence of postoperative opioid-induced respiratory depression. However, few studies have investigated whether low basal infusions increase the incidence of postoperative hypoxaemia relative to no basal infusion. We intend to conduct a clinical trial to test the hypothesis that PCIA with a low basal infusion does not increase the occurrence of postoperative hypoxaemia relative to PCIA with no basal infusion.

METHODS AND ANALYSIS

This single-centre parallel randomised controlled clinical trial will be conducted with 160 patients undergoing gastrointestinal tumour surgery. The assigned nurse will set analgesic pumps (low or no basal infusion PCIA) according to block-based randomisation sequence. Other investigators and all participants will be blinded to intervention allocation. All patients will be monitored continuously with the ep pod, a wireless wearable device, recording of oxygen saturation (SpO₂) and daily ambulation duration for 48 hours postoperatively. Three follow-up evaluations will be conducted to assess the analgesic effect (Numeric Rating Scale (NRS) pain score) and opioid-related side effects (Overall Benefit of Analgesic Score (OBAS)). The primary outcome will be the area under the curve for hypoxaemia (defined as SpO₂<95%) per hour. The secondary outcomes will be the areas under the curve for hypoxaemia defined as SpO₂<90% and <85% per hour, hydromorphone consumption, OBASs at 24 and 48 hours postoperatively, NRS scores at 4, 24 and 48 hours postoperatively, and the ambulation time per hour over 48 hours.

ETHICS AND DISSEMINATION

The study has been approved by the Xijing Hospital Ethics Committee (KY20212163-F-1). Written informed consent will be obtained from all patients or their authorised surrogates. All data will be managed with confidentiality. Findings will be disseminated at international conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ChiCTR2100054317.

Vital sign monitoring with continuous pulse oximetry and wireless clinical notification after surgery (the VIGILANCE pilot study)-a randomized controlled pilot trial

Background

Respiratory depression is a serious perioperative complication associated with morbidity and mortality. Recently, technology has become available to wirelessly monitor patients on regular surgical wards with continuous pulse oximetry and wireless clinician notification with alarms. When a patient’s SpO₂ falls below a set threshold, the clinician is notified via a pager and may intervene earlier to prevent further clinical deterioration. To date, the technology has not been evaluated with a randomized controlled trial (RCT).

Methods

We designed a parallel-group unblinded pilot RCT of a wireless monitoring system on two surgical wards in an academic teaching hospital. Postsurgical patients with an anticipated length of stay of at least 1 day were included and randomized to standard care or standard care plus wireless respiratory monitoring for up to a 72-h period. The primary outcomes were feasibility outcomes: average patients recruited per week and tolerability of the system by patients. Secondary outcomes included (1) respiratory events (naloxone administration for respiratory depression, ICU transfers, and cardiac arrest team activation) and (2) system alarm types and details. The analysis of the outcomes was based on descriptive statistics and estimates reported using point (95% confidence intervals). Criteria for success of feasibility were recruitment of an average of 15 patients/week and 90% of the patients tolerating the system.

Results

The pilot trial enrolled 250 of the 335 patients screened for eligibility, with 126 and 124 patients entering the standard monitoring and wireless groups, respectively. Baseline demographics were similar between groups, except for slightly more women in the wireless group. Average patient recruitment per week was 14 95% CI [12, 16] patients. The wireless monitoring was quite tolerable with 86.6% (95% CI 78.2–92.7%) of patients completing the full course, and there were no other adverse events directly attributable to the monitoring. With regard to secondary outcomes, the respiratory event rate was low with only 1 event in the wireless group and none in the control group. The average number of alarms per week was 4.0 (95% CI, 1.6–6.4).

Conclusions

This pilot study demonstrated adequate patient recruitment and high tolerability of the wireless monitoring system. A full RCT that is powered to detect patient important outcomes such as respiratory depression is now underway.

Trial registration

ClinicalTrials.gov, Registration number NCT02907255, registered 7 September 2016—retrospectively registered.

Anaesthesia: the patient's point of view

Patients scheduled for surgical procedures continue to express concerns about their safety, outcome, and comfort. All medical interventions carry risks, but the patient often considers anaesthesia as the intervention with the greatest risk. Many still worry that they will not wake up after their surgery, or that they will be awake during the operation. Such events have received attention from the media, but are very rare. Challenges to improve the comfort of patients continue, especially with regard to the almost universal problems of nausea, vomiting, and pain after surgery. A newer concern is that patients will develop some degree of mental impairment that may delay return to a full work and social lifestyle for days and weeks. Developments in technology, education, and training have had a major effect on anaesthetic practice, so that anaesthesia is increasingly regarded as safe for the patient. This article explores patients' concerns, and considers whether science and technology help to provide solutions to these complex difficulties.