Following the concise general anesthesia induction steps of 0, 1, and 3 mins, an optimized general anesthesia induction regimen of rocuronium bromide that was administered rapidly, and a single final intravenous bolus of sufentanil, sufentanil-induced coughing reaction was completely eliminated. The hemodynamic indices were also stable during the induction period of general anesthesia, and the patients did not experience any particular discomfort.
The primary objective of this study was to investigate the preventive effect of opioid-induced coughing. Therefore, in the order of administration, we fully considered the time of onset and effects of lidocaine, propofol, and rocuronium bromide on cough suppression. In terms of study design, midazolam and lidocaine were administered intravenously in sequence at 0 min; propofol, rocuronium, and sufentanil were injected sequentially at 1 min and within 50–60 seconds; 1 min after this administration, the drugs for anesthesia induction reached their peak effect, while ensuring that the patients did not choke and had relatively stable hemodynamics during general anesthesia induction of tracheal intubation. At the same time, among the induction drugs, lidocaine has the best effect on preventing opioid cough and suppressing emergency response to endotracheal intubation [10–12]. Injection of propofol before rocuronium can avoid pain caused by rocuronium injection when the patient is awake; moreover, the injection pain caused by rocuronium bromide is more severe than that of propofol [13, 14]. Therefore, the preferential intravenous injection of propofol can cause the patient to sleep while taking advantage of the analgesic effect of lidocaine [4, 15], and when combined with diluted rocuronium bromide, this can ultimately reduce or avoid the pain of rocuronium bromide injection.
Opioids such as sufentanil can attenuate or eliminate the stress response caused by endotracheal intubation, allowing patients to tolerate the procedure without coughing. However, in a single intravenous injection of fentanyl or sufentanil, up to 65% of patients will have brief coughs [2]. Many clinical studies have been conducted on the prevention of choking reactions to fentanyl or sufentanil. The methods to prevent opioid choking include central administration [16], active deep breathing during the induction period, divided administration [9], lowering the injection speed [9], changing the injection sequence, and pre-injecting dexamethasone, lidocaine [10, 11, 17], dexmedetomidine [18, 19], propofol [20, 21], dezocine [22], rocuronium bromide, and other drugs [23]. In this study, pre-injection of sufentanil at 0.1 µg/kg before propofol resulted in a 9% incidence of choking reactions. Although slowing down the injection speed, dividing the bolus injection, or using other drugs for prevention can reduce the incidence and degree of choking, it cannot be completely avoided nor independently controlled. However, no choking reaction occurred during the last single intravenous bolus injection of sufentanil, mainly because previous intravenous bolus injections of lidocaine, propofol, and rocuronium bromide effectively played a role in suppressing the opioid choking reaction effect.
Both propofol and rocuronium, especially rocuronium, can cause injection pain [23–25]. Our observations showed that there was no severe injection pain during intravenous propofol and rocuronium administration in either group and no facial expressions of pain during rocuronium injection. The main reason for this is the effect of lidocaine and propofol before rocuronium injection, and the effective dilution of rocuronium bromide. The program considers the characteristics of avoiding drug choking and coughing, minimizing or avoiding drug injection pain, and faster onset of drug effects; it can improve the comfort and satisfaction of patients in medical treatment.
Reflux aspiration during induction in satiated patients did not occur in this study because of the elective surgery. A general anesthesia induction program should be reasonably formulated for patients with a full stomach, which can effectively prevent coughing during the induction period and complete tracheal intubation quickly, as well as effectively prevent reflux and aspiration in patients with a full stomach [26].
This study had some limitations. First, this study was a single-center study, and no multi-center larger sample observation was conducted. Second, this study only reported on observations during the induction period and not the entire perioperative period. Third, this study only used sufentanil and other opioid induction regimens requiring further in-depth research. Fourth, this study failed to achieve investigator blinding due to the method of administration.