Respiratory changes during treatment of postoperative pain with high dose transdermal fentanyl

Abstract

This study made a longterm (72 hours) evaluation of the efficacy and possible side-effects of transdermal delivery of fentanyl (TTS-system) for post-operative pain relief. The study was double-blind, placebo-controlled with either a TTS-system delivering fentanyl 100 micrograms.h-1 and rescue analgesic on demand or a placebo system and analgesic on demand. Analgesic consumption, pain, general satisfaction, respiratory rate, and levels of SpO2 and tcCO2 (pulse oximetry and transcutaneous CO2 measuring) were evaluated. Recruitment was stopped after enrolment of 24 patients, on safety grounds. The Fentanyl group was more satisfied with postoperative pain relief (P = 0.008); they had a lower analgesic demand (P < 0.05) but also a lower respiratory rate (P < 0.05) and a higher level of tcCO2 23 hours after application (P < 0.05). There were three cases (25%) of increased PaCO2 (> 6.5 kPa) in the Placebo group but without low PaO2 levels, sedation or bradypnoea. Conversely, there were three cases (33%) in the Fentanyl group with bradypnoea (< 10 breaths/minute), two without influence on PaO2 or PaCO2, but one (no. 24) with bradypnoea, heavy sedation, a marked decrease in PaO2 (5.8 kPa) and increased PaCO2 (7.5 kPa). These findings terminated the study. The 100 micrograms transdermal fentanyl system is agreeable to the patients, but apparently too potent for routine postoperative pain relief due to a risk of respiratory depression. Respiratory frequency can not be relied upon as sole indicator of insufficient respiration.

Transdermal fentanyl patch for postoperative analgesia in total knee arthroplasty: a randomized double-blind controlled trial

“…Sedation scores do not increase, albeit reductions in the respiratory rate rise, with doses up to 75 μg/hour 15,16,23. We concur with Bulow et al that a TFP administering 100 μg/hour would be too potent, because of the potential for life-threatening respiratory depression 24. For patient safety, we chose the lower dosage, ie, 50 μg/hour, for our study.…”

Oral morphine and respiratory function amongst hospice inpatients with advanced cancer

“…None had received analeptic drugs, psychostimulants or oxygen at any time since admission. The median time since diagnosis of malignancy was 11 months (range 3-174 months) and since admission to hospice 66 days Of the 20 patients, 12 had a history of chronic bronchitis (including 6 of the 7 with lung cancer), and 1 of the lung cancer patients also had a history of silicosis (R23) and 1 (not a lung cancer patient) had pulmonary tuberculosis (R11); 14 were regular smokers although 5 had stopped since becoming ill; 6 had a history of dyspnea (R11, 13,18,20,22,23); and 17 were receiving a phenothiazine regularly in addition to morphine and 9 a benzodiazepine (all got two or more drugs in addition to these). All peak flow values were low (except in R20) despite good cooperation during examination.…”

“…Transient impairment of ventilatory function might occur during a dosing period perhaps most likely at the peak of the morphine plasma level but this could not be assessed in this study. Acute opioid-induced respiratory depression has been demonstrated in healthy volunteers and postsurgical patients [16,17,18,19] who were opioid-naive. Protection against this respiratory depressant effect by prior opioid exposure, i.e.…”

Efficacy and Safety of Transdermal Fentanyl in the Control of Postoperative Pain After Photorefractive Keratectomy

“…10 However, in most of these cases the specific causes are difficult to evaluate because of the concomitant use of other opioids such as morphine, [29][30][31][32][33][34][35] which may enhance respiratory depression. 10 Also, in these cases surgeries were performed under general anesthesia and TDF was delivered at much higher rates (ranging 50-100 mg/h) than in the present study (12 mg/h).…”