Intraoperative Hiccups

Hiccups are involuntary spasmodic contractions of the diaphragm followed by sudden closure of the vocal cords, which produces the characteristic “hic” sound. Although hiccups are generally benign and self-limiting in the general population, they can pose significant challenges during surgical procedures and under general anesthesia. Intraoperative hiccups can interfere with surgical precision, affect respiratory mechanics, and complicate overall patient management (1).

The pathophysiology of hiccups is complex and not fully understood, but it is thought to involve reflex arcs originating from peripheral stimuli that activate the phrenic and vagus nerves or from central nervous system stimuli. These stimuli can range from mechanical irritation of the diaphragm or stomach to more systemic causes such as electrolyte imbalances or pharmacological agents used in anesthesia. During surgical procedures, hiccups may be precipitated by the mechanical manipulation of abdominal organs, the stretching of the diaphragm, or the effects of certain anesthetic agents (2). Some anesthetic agents, like propofol and opioids, have been linked to the development of intraoperative hiccups due to their depressant effects on the central nervous system and their ability to alter the normal reflex pathways of the diaphragm.

The management and treatment of intraoperative hiccups requires a multimodal approach that is tailored to the severity of the hiccups and their underlying cause. For mild and transient cases, no specific treatment may be necessary as they might resolve spontaneously. However, persistent or severe hiccups can disrupt the surgical field, particularly in procedures involving the upper abdomen or thorax, necessitating active intervention.

Pharmacological treatments for hiccups include the administration of antiemetics such as metoclopramide, which acts as a dopamine antagonist with prokinetic properties that can mitigate the hiccup reflex (3). Similarly, baclofen, a gamma-aminobutyric acid (GABA) receptor agonist, has been used effectively to suppress refractory hiccups, although its use in the operative setting is limited due to its central nervous system depressant effects (3).

Various non-pharmacological strategies have also been employed to suppress hiccups. One strategy is rebreathing from a paper bag to increase carbon dioxide levels. However, this maneuver is not feasible under general anesthesia. Instead, modulation of the anesthetic technique can be beneficial (4). For instance, deepening the level of anesthesia and ensuring adequate relaxation may alleviate hiccups by reducing diaphragmatic irritability. For procedures that do not require general anesthesia, converting to a regional anesthetic technique may prevent recurrence by preserving diaphragmatic function while providing adequate pain control and sedation. Despite the availability of these treatments, the evidence base guiding the management of hiccups in the perioperative setting is limited, consisting mainly of case reports and small case series. Therefore, clinical judgment and individualized patient assessment remain paramount in determining the most appropriate intervention (2).

Although typically harmless, intraoperative hiccups can present unique challenges in the operative setting. It is important to understand any potential triggers and to have management strategies to minimize their impact on surgical procedures and patient recovery. Additional research is necessary to clarify the mechanisms behind intraoperative hiccups and establish evidence-based guidelines for their treatment.

References

1. Kranke P, Eberhart LH, Morin AM, Cracknell J, Greim CA, Roewer N. Treatment of hiccup during general anaesthesia or sedation: a qualitative systematic review. Eur J Anaesthesiol. 2003;20(3):239-244. doi:10.1017/s0265021503000401
2. Cole JA, Plewa MC. Singultus. [Updated 2023 Jul 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538225/
3. Baumann A, Weicker T, Alb I, Audibert G. Baclofen for the treatment of hiccup related to brainstem compression. Ann Fr Anesth Reanim. 2014;33(1):e27-e28. doi:10.1016/j.annfar.2013.10.023
4. Moretto EN, Wee B, Wiffen PJ, Murchison AG. Interventions for treating persistent and intractable hiccups in adults. Cochrane Database Syst Rev. 2013;(1):CD008768.