Chest wall rigidity during fentanyl– and midazolam–fentanyl induction: ventilatory and haemodynamic effects

Abstract

In a double-blind randomised study, we examined if pretreatment with small doses of midazolam, given before anaesthesia induction with fentanyl, influences the occurrence of fentanyl-induced thoracic rigidity (FITR). At the same time, the effect of rigidity on the cardiovascular and respiratory system was assessed. Sixteen patients undergoing coronary artery bypass surgery were divided into two groups. The midazolam group (M) received 0.075 mg/kg midazolam i.v. and the placebo group (P) NaCl 0.9% 3 min before the start of fentanyl induction. During the induction period, FITR was assessed clinically on a 3-point scale. Haemodynamic and respiratory variables were collected before anaesthesia induction, at the end of the fentanyl infusion and 3 min after intubation. The incidence of FITR was high in both groups: 63% in Group M and 75% in Group P (n.s.); however, its severity was less in Group M. The appearance of rigidity affected the cardiovascular and the respiratory system: central venous and pulmonary capillary wedge pressures showed a sharp increase in patients with FITR accompanied by CO2 retention, due to an inability to ventilate these patients adequately. We conclude that small doses of midazolam do not prevent, but may attenuate, FITR and that the appearance of rigidity causes alterations of haemodynamic and respiratory variables during induction.

Priming with rocuronium or vecuronium prevents remifentanil-mediated muscle rigidity and difficult ventilation

“…The incidence of rigidity noted with opioid anesthetic techniques varies greatly with differences in the dose and speed of All of the patients could breathe deeply while they remained conscious. Priming with vecuronium or rocuronium signifi cantly increased the incidence of diffi culty with eye opening (*P = 0.000076; **P = 3.4 × 10 −8 vs group B) opioid administration, the concomitant use of N 2 O or midazolam, and patient age [6,20]. Moreover, in obese patients, breathing work is increased [21].…”

The Role of Fentanyl in Cancer-Related Pain

“…[33][34][35] Intravenous fentanyl may cause chest wall rigidity. 36 This has been observed postoperatively in adult and pediatric patients, as well as in healthy volunteers; the effects are reversed with naloxone. 37,38 Fentanyl-induced rigidity is associated with peak plasma concentrations.…”

Opiate slowing of feline respiratory rhythm and effects on putative medullary phase-regulating neurons

“…Fentanyl also prolonged discharges of postinspiratory and late-inspiratory neurons in doses that slowed the rhythm of inspiratory and expiratory neurons without altering peak membrane depolarization and hyperpolarization, input resistance, or action potential properties. The temporal changes evoked in the tested neurons can explain the slowing of network respiratory rhythm, but the lack of significant, direct opioid-mediated membrane effects suggests that actions emanating from other types of upstream bulbar respiratory neurons account for rhythm slowing.fentanyl; medullary respiratory neurons; phrenic nerve activity; naloxonazine; naltrindole OPIATES ARE WELL KNOWN for their ability to depress ventilation by slowing breathing frequency and reducing tidal volume, gas exchange, upper airway patency, and chest wall compliance (3,4,36,39). They also blunt respiratory network responsiveness to hypoxia and CO 2 /acidosis (11,25,51,60).…”

“…fentanyl; medullary respiratory neurons; phrenic nerve activity; naloxonazine; naltrindole OPIATES ARE WELL KNOWN for their ability to depress ventilation by slowing breathing frequency and reducing tidal volume, gas exchange, upper airway patency, and chest wall compliance (3,4,36,39). They also blunt respiratory network responsiveness to hypoxia and CO 2 /acidosis (11,25,51,60).…”