The Impact of Nasogastric Tube Gastric Decompression on Postoperative Nausea and Vomiting in Orthognathic Surgery

Postoperative Nausea Clinical Trial

Official title: The Impact of Nasogastric Tube Gastric Decompression on Postoperative Nausea and Vomiting in Orthognathic Surgery

Status Not yet recruiting

Clinical Trial Summary

Postoperative nausea and vomiting (PONV) is a major concern for patients undergoing orthognathic surgery (corrective jaw surgery). These symptoms affect up to 60% of jaw surgery patients and can be quite distressing. The mechanisms underlying PONV are complex, but it is thought that surgical site bleeding and blood pooling in the stomach is the primary stimulus in this type of surgery. Nasogastric (NG) tubes have been used to suction out pooled blood in the stomach (gastric decompression), in hopes of minimizing symptoms. However, new research shows that NG tube gastric decompression may not demonstrate any benefit, and may even worsen PONV. Our study aims to directly compare PONV in participants undergoing gastric decompression or not. Participants will be randomized into two groups, either no NG tube gastric decompression or NG tube gastric decompression throughout the surgery and removed approximately one hour postoperatively. It is hypothesized that there will be less PONV in the group that does not undergo gastric decompression. We hope that the results from this study will better patient outcomes for this common postoperative problem and guide future practices for NG tube gastric decompression in orthognathic surgery.

Clinical Trial Description

Orthognathic surgery is a common surgical procedure performed to correct dentofacial deformities. Patients are held in maxillomandibular fixation with elastics for several weeks following surgery, limiting mouth opening during the postoperative period. Although fixation can be released, if necessary, PONV is distressing in this patient population and many patients voice concern around the idea of emesis. Patients who suffer from nausea and vomiting often have poor oral intake of fluids and analgesic medications, demonstrated by dehydration and suboptimal pain control. From a surgical perspective, vomiting puts tension on fragile oral wounds that can provoke wound dehiscence and surgical site bleeding, in turn worsening symptoms. Occasionally, PONV can necessitate increased length of stay in hospital thereby increasing costs to the healthcare system.

The pathophysiology underlying nausea and vomiting is complex and multifactorial involving both centrally mediated and peripherally mediated pathways. Mechanisms that trigger emesis include, but are not limited to, activation of chemoreceptors and mechanoreceptors in the oropharynx and stomach by ingested blood and intraoperative manipulation, direct stimulation of the chemoreceptor trigger zone in the area postrema and stimulation of the glossopharyngeal and vagus nerves. In the gastrointestinal system, vagal afferents are activated by numerous emetogenic substances, of which blood is thought to be the strongest peripheral emetic stimulus. Activation of this pathway induces nausea and/or vomiting and is thought to be of particular importance in oral surgeries, specifically orthognathic surgery. Despite best hemostatic efforts with airway protection, thorough suctioning and primary wound closure, orthognathic surgery generates intraoral bleeding and ingestion of blood that is often seen in evacuated gastric contents. Gastric pooling of blood is thought to be one of the primary mechanisms by which orthognathic surgery stimulates PONV. Patient specific factors, anesthetic medications, and postoperative opioids are also thought to play key roles. In orthognathic surgery literature, prevalence of PONV is relatively high, documented at 40-60%. This is more than with general postoperative incidence of 50% for nausea and 30% for vomiting for all surgeries. Postoperative nausea and vomiting typically occur within the first 24 hours after surgery, although this is most prevalent in the first 2 hours following orthognathic surgery. This is generally considered to be early PONV, whereas delayed PONV occurs from 2 to 24 hours postoperatively.

It has traditionally been believed that gastric evacuation of ingested blood using a NG tube should minimize PONV and increase patient comfort. Nasogastric tube insertion involves passing the NG tube through one nostril and maneuvering it down the oropharynx into the esophagus until adequately positioned in the stomach. It can then be hooked up to suction to remove gastric contents, a process commonly known as gastric decompression. Nasogastric tube insertion is a routine procedure that is minimally invasive, although major and minor complications have been documented in the literature. Nasogastric tube insertion has been associated with pain, tearing of the nasal mucosa, submucosal insertion, pulmonary insertion, and aspiration. Additionally, its presence can be anxiety-provoking for many patients.

Several studies have previously evaluated the impact of NG tube gastric decompression on PONV for various surgical specialties. In anesthesia literature, one study looked at more than 1000 patients undergoing various surgeries and found strong evidence that the use of NG tubes does not decrease PONV. Based on this study, the routine use of NG tubes is no longer supported by the Consensus Guidelines for Management of PONV. In orthognathic surgery literature, there have been several studies with conflicting results. One retrospective study evaluated PONV in 772 orthognathic surgery patients with and without gastric suction and found that PONV was significantly worse in the group that did not have NG tube gastric decompression. Conversely, a randomized control trial evaluated PONV in 24 orthognathic surgery patients with and without gastric suction and could not associate gastric decompression with any meaningful decrease in PONV. Furthermore, another prospective study compared the incidence of PONV in 29 orthognathic surgery patients with and without NG tube gastric decompression and concluded that the presence of the NG tube instead increased the prevalence and severity of PONV. It is postulated that this may be related to stimulation of the glossopharyngeal nerve activating the gag reflex.

At our institution, surgeons follow a variety of protocols for NG tube gastric decompression in orthognathic surgery. Historically, a NG tube was used in all cases, although practices have changed over the past several years. Whether a NG tube is used or not is dependent on the surgeon's expert judgement and experience. Common protocols include no NG tube and NG tube insertion at the start of surgery with intermittent suction and removal within the first hour postoperatively after transfer to the post anesthesia care unit (PACU). Our routine practices are in keeping with Canadian standards of practice. We recently conducted a survey of the Canadian Association of Oral and Maxillofacial Surgeons to better understand common practices and protocols relating to this topic. It was found 73% of respondents routinely use NG tube for gastric decompression and either remove the NG tube prior to extubation or in the PACU. The remaining 27% of respondents did not believe there is any benefit to gastric decompression and routinely do not use NG tubes for orthognathic surgery.

To our knowledge, there has yet to be a randomized control trial directly comparing PONV in orthognathic surgery patients subject to these common NG tube regimens. An evidence-based protocol addressing the impact of NG tube gastric decompression in orthognathic surgery has yet to be determined. Oral and Maxillofacial Surgeons (OMFS) are using a variety of practices, including omitting NG tube gastric decompression altogether. Available literature is conflicting and some suggests that NG tube gastric decompression may worsen PONV. Further studies in this field have been recommended but not carried out to date. The aim of this study is to determine how NG tube gastric decompression impacts PONV. The results of this study will guide procedures and protocols that optimize care of this patient population at our institution, and possibly across other institutions in the future. As PONV can increase length of stay in hospital, this study may be helpful to decrease the occurrence of prolonged admission and its associated costs to the healthcare system. This research will benefit patients directly by determining a perioperative protocol to minimize PONV and may negate the need for NG tube insertion, possibly improving patient safety and outcomes.

Research Question The aim of this study is to determine if nasogastric tube gastric decompression has any impact on PONV within the first 24 hours following orthognathic surgery. More specifically, this will be achieved by comparing the incidence of PONV in orthognathic surgery patients randomized into one of two study groups: A. No NG tube gastric decompression; B. NG tube insertion before surgery with intermittent suction and removal within the first hour post-operatively.

Research Plan Study Arms This is a prospective study for all patients undergoing orthognathic surgery who meet inclusion criteria. Patients will be asked whether they would like to enroll in this study at their routine preadmission appointment, which typically occurs 1-2 weeks before their scheduled surgery date. Orthognathic surgery patients always require this appointment to take final measurements, models and photos that help the surgical team determine a precise final surgical plan. Another important part of this visit is reviewing the patient's past medical and surgical history, medications, allergies, smoking status, and other social history pertinent to surgery. This appointment allows ample time to thoroughly discuss our proposed study with all eligible patients and answer any questions they may have prior to consenting for enrollment. They will also be provided with a document explaining the nature of the study and will be informed they can withdraw from the study at any given time. If patients choose not to enroll, the decision around NG tube gastric decompression will be at the discretion of the surgical and anesthesia teams the day of surgery. If they do choose to enroll, their Apfel score will be calculated to determine pre-existing risk of PONV based on sex, smoking status, history of PONV or motion sickness, and use of postoperative opioid analgesics. They will be randomized into one of two study groups using a random treatment sequence determined on www.randomization.com. This randomization sequence is stratified with a 1:1(No NG: NG in at beginning of surgery and removed in PACU) allocation using random block sizes of 6 to ensure balance among groups of 14 blocks. Participants will be sequentially assigned to the next protocol group listed by the random generator at the time of enrollment. Participants will be blinded from their treatment group to minimize placebo effect, although they may later recall NG tube presence/removal if they belong in the group that gets the NG tube. Surgeons and anesthesiologists will not be blinded, as the nature of the study is not conducive to a double-blinded method.

Pre-Operative and Intra-Operative Management All participants will be seen by the surgical team and the anesthesiologist the day of their surgery before being brought into the operating room. All participants receive Ibuprofen 600mg and Acetaminophen 975mg one hour pre-operatively. As all participants require nasal endotracheal intubation for orthognathic surgery, 0.1% Xylometazoline nasal spray (a topical vasoconstrictor) is administered in each nostril to minimize the likelihood of epistaxis from insertion of the nasal endotracheal tube and the NG tube, if applicable. All participants will receive a standard dose of pre-operative steroids (125-1000mg Methylprednisolone) and intravenous antibiotics (2g Cefazolin), with three doses of post-operative Cefazolin 2g IV every 8 hours. The anesthetic regimen will be determined by the attending anesthesiologist and may include total intravenous anesthetic or combined volatile and intravenous anesthesia. All participants are given a single dose of Ondansetron 4mg IV 15-30 minutes prior to completion of surgery as a prophylactic antiemetic as per anesthesia practice standards. Any given medications are documented on the Anesthesia Record accessible for later review.

The surgery will be performed by one of 5 attending surgeons with a resident or fellow assist. The length of surgery often ranges from 1-3 hours depending on the procedure and its complexity. A mean arterial pressure of 60 is targeted throughout the procedure to minimize blood loss, particularly during the time of osteotomies. A throat pack is inserted and remains in place until surgery is complete to minimize the ingestion of blood from intraoral wounds. When surgery is complete, the throat pack is removed and thorough suctioning of the oropharynx using a Yankauer suction is carried out. Most patients will have an acrylic occlusal splint fixated to their maxillary orthodontic arch wire to guide their bite and are placed into maxillomandibular fixation (MMF) using a range from tight elastics to loose guiding elastics. The type of MMF depends on their pre-existing deformity, stability of the movement, surgeon preference and other patient specific factors.

Participants will be assigned to their respective study arm at the time of surgery. The attending surgeon and resident /fellow will be aware of which group the participant is in and will inform the anesthesiologist before the patient is brought into the operating room.

Group A: Participants in group A (No NG) will not have any intervention in the operating room.

Group B: Participants in Group B will have a NG tube placed. In this group, participants will be anesthetized, intubated, and a NG tube will be inserted in the naris opposite the nasotracheal tube. A #14 French NG tube will be used, as the size allows for adequate suction while minimizing trauma on nasal passage. This measures 48 inches in length (122 cm) and is 4.7mm in diameter. Once inserted, it will be hooked up to low suction to confirm placement. If in the correct position, gastric contents will be seen in suction tubing. If no gastric contents are seen, the NG tube will be adjusted until appropriately positioned. The NG tube will be connected to suction until all stomach contents are effectively removed, as demonstrated by no new secretions in the suction tubing. The NG tube will be secured with tape throughout surgery and will be temporarily hooked back up to suction at the end of surgery to confirm its position and suction any stomach contents present. The NG tube will then be secured to the participant's nose using NG tape and will be left in place during extubation and transfer to PACU. The PACU nursing team will be asked to connect the NG tube to low intermittent suction and to complete the Study Form. The OMFS resident will complete the Study Form to document NG placement details and any complications.

Post-Operative Management Orthognathic surgery patients are held in PACU for up to several hours following surgery, until they are suitable to be transferred to the inpatient unit. While in PACU, they are monitored by nursing for pain and PONV. Medications available in PACU are ordered by the attending anesthesiologist. Orders for multimodal analgesia often include acetaminophen, short-acting opioids, and long-acting opioids in keeping with routine anesthesia practice. Orders for antiemetics often include haloperidol, dimenhydrinate and ondansetron in keeping with routine anesthesia practice. While in PACU, nursing will be asked to fill out the Study Form to indicate whether the participant experienced nausea or emesis in the first 2 hours postoperatively. Episodes of nausea, vomiting, and antiemetics administered and associated time will be recorded on the Study Form. As per our routine practices, nursing will be instructed to remove the NG tube within the first hour post-operatively before transfer to the inpatient floor. Timing of removal is guided by signs and symptoms of PONV, participant comfort/ability to tolerate the tube, and quantity of gastric secretions.

Once participants are transferred to the inpatient unit, their assigned nurse will be responsible for continuing completion of the Study Form. Patients are routinely ordered analgesics including Acetaminophen 650mg PO (orally) q6h (every 6 hours), Ibuprofen 600mg PO q6h, and Hydromorphone 2-4mg PO q6H as needed. Antiemetics are also available including Dimenhydrinate 25-50mg PO/IV q6h as needed and Ondansetron 4mg IV q8h as needed. All episodes of nausea, emesis and any antiemetics given with associated times will be documented on the Study Form. During morning rounds on postoperative day one, the surgical resident team will also ask the participant if they experienced nausea or emesis in the delayed postoperative period (2-24 hours postoperatively) to ensure no symptoms were missed and will document this information on the Study Form. Although most participants will not have completed a full 24-hour postoperative course at this time, this information should be representative of the delayed postoperative period. It unlikely to impact study results, as participants must not be reliant on antiemetics to manage PONV and must be tolerating adequate oral intake of fluids to meet discharge criteria from hospital. If any participant experiences delayed discharge secondary to PONV, this will be recorded on the Study Form.

Patients are given post-operative instructions by an OMFS resident prior to discharge home, including instructions pertaining to management of PONV. Diet for the first several weeks is strictly liquid to allow for appropriate healing but is equally beneficial by preventing vomiting of solid foods in the postoperative period. Participants are sent home with suture scissors and are instructed that elastic MMF can be cut and released if there is ever airway concern. Under these circumstances, they are instructed to notify the OMFS resident on call and immediately proceed to the nearest emergency department. Participants are not routinely discharged with prescriptions for antiemetic medications since PONV should have largely resolved while in hospital for the patient to meet discharge criteria. If a participant has delayed discharge due to PONV, this will be considered an adverse event and will be recorded on the Study Form.

Chart Review The Anesthesia Record and Progress Notes from each participant's surgery and subsequent hospital admission will be reviewed by the research team. Data collected from this review will include the type of anesthetic administered, the medication administration record, and nursing notes describing the patient's course in hospital. This information is necessary to better understand the course of PONV (if any) and to help minimize confounding variables by further evaluating study groups based on general anesthesia protocol and number of prophylactic antiemetics given. This information can only be accessed through the Nova Scotia Health Authority (NSHA) web-based application OneContent, which is password protected through NSHA Intranet. This data will be reviewed within two weeks of discharge home, once available in the OneContent system.

Data Collection and Analysis Data will be obtained from pre-admission and inpatient records including the history and physical record, the anesthesia record, the intra-operative record, progress notes, study forms, and the medication administration record.

Data collected will include the patient's age (years), weight (kg), sex, smoking status (smoker or non-smoker), history of PONV or motion sickness, length of time taken to insert NG tube successfully (seconds), complications arising from NG tube insertion, length of surgery (from first incision to closure), type of orthognathic surgery (LeFort, BSSO, or both), type of general anesthesia (total intravenous anesthetic vs combined volatile/ intravenous anesthetic), length of stay in hospital (hours), episodes of nausea or vomiting (yes or no) during two different time intervals (0-2 hours postoperatively and 2-24 hours postoperatively), and amount and frequency of antiemetics taken for the first 24 hours in hospital or until discharge home.

This study will use descriptive statistics in the form of percentages and counts for categorical variables and means and standard deviations for continuous variables. Differences between groups will be analyzed with a chi square test. Final data analysis plan to be determined in conjunction with a biostatistician.

Informed Consent Participants will be recruited and enrolled in this study during their routine preadmission appointment several days prior to their scheduled surgery. The consent discussion will be conducted by the resident completing the preoperative assessment. The resident having this discussion will have previously completed training regarding the study protocol and all aspects of the consent form. A SOP will be provided to all staff members outlining the procedures for obtaining informed consent, and all questions can be addressed at the training session or later by contacting the principal or supervising investigators. Contact information for the research team will be provided and available to all research team members. Documentation of training will be completed.

Study enrollment and consent to participate will be completely voluntary and free of coercion or undue influence. Prior to consenting, all aspects of the study will be thoroughly discussed by the resident completing the assessment. The aim of this study, potential benefits and harms, group allocation and probability of assignment, expectations of participants, duration of participation, voluntariness of participation and ability to withdrawal any time will be addressed. Participants will be made aware that their surgical plan will be uninfluenced, and their care will be held to the same standard regardless of study enrollment. Potential participants will also be made aware that should they choose not to enroll in the study, the decision regarding nasogastric tube gastric decompression will be made by their surgical and anesthesia teams the day of surgery. Potential participants will be given a printed handout addressing all aspects of the study and a copy of the consent form to review. The study will be discussed in simple language, in keeping with the participant's health literacy. All questions will be answered as clearly as possible and potential participants will be given as much time as needed to decide whether to enroll. If a participant chooses to enroll, they will sign the consent form with a witness present.

Participants will be made aware that they are able to withdraw from the study at any time. Participants will be given a phone number where they are able to contact the principal or supervising investigators, who will then assist them with withdrawal from the study as per their wishes. The quality of care they receive will not be affected by withdrawal from the study.

Confidentiality Participants will be de-identified using a study number. No dates of birth will be recorded. Data described in the "Data Analysis" section will be obtained with only necessary information recorded. All electronic data will be stored on an encrypted, password protected NSHA computer located in a locked resident office in the Department of Oral and Maxillofacial Surgery at the Victoria General Hospital. Only research team members directly involved in patient care will have access to the office and computer. All hard copy data will be kept in a locked filing cabinet. Data will be kept for 15 years following completion of the study as per NSHA policy. When the data retention period is completed, the Director of Health Information Services will be contacted and all data will be destroyed in a way that is not recognizable, retrievable, or reconstructed. All electronic data will be wiped from the encrypted folder and computer, and all paper records will be shredded.

Patient Benefits This study aims to establish an evidence-based protocol for nasogastric tube gastric decompression that can help to minimize PONV in patients undergoing orthognathic surgery. If one study arm is found to be superior to the others, future patients will benefit from their surgical team following this protocol.

For study participants, potential benefits are dependent on study outcomes. The interventions proposed by this study are in keeping with routine practices at our institution. If one regimen is superior, participants in this group will benefit from decreased PONV, which is a major concern for many orthognathic surgery patients associated with suboptimal pain control, poor oral intake, increased length of stay in hospital, and poor overall experience. If the "No NG" group is found to be superior, patients in this group will benefit from not requiring insertion of the NG tube which is invasive, has potential complications, and is generally associated with patient anxiety.

Patient Harms There are no hams to this study that differ from pre-existing risks for all orthognathic surgery patients. Interventions in both study arms are in keeping with current standards of practice at our institution. The decision around NG tube gastric decompression is currently decided by surgeon and anesthetist preference, which will instead be randomized for this study. As per our knowledge, to date, there has been no significant harm to patients who have not undergone NG tube gastric decompression. In case of patients experiencing PONV, the same antiemetic medications are available to both study groups. Patients are also provided with scissors and undergo teaching on how to cut MMF elastics in case of airway concern during vomiting. Patients are on a fully liquid diet, so there is little risk of aspirating any solids.

For the study arm with NG tube insertion, there are potential complications associated with this procedure, including pain and epistaxis, and rarely, submucosal insertion or aspiration. Some patients may also voice anxiety around NG tube insertion. All NG tubes will be inserted when the patient is anesthetized, so they will not recall the insertion. Any complications that do arise will be recorded and managed appropriately by the surgical team. ;

Related Conditions & MeSH terms

• Nausea
• Postoperative Nausea
• Postoperative Nausea and Vomiting
• Postoperative Vomiting
• Vomiting

• NCT number: NCT06422793
• Study type: Interventional
• Source: Nova Scotia Health Authority
• Contact: Katherine A Curry, DDS
• Phone: 9024732070
• Email: katherinea.curry@nshealth.ca
• Status: Not yet recruiting
• Phase: N/A
• Start date: July 31, 2024
• Completion date: May 2025