Risk Factors For Regurgitation Research Articles

Postoperative regurgitation in dogs after upper airway surgery to treat brachycephalic obstructive airway syndrome: 258 cases (2013-2017).

To determine the incidence of and risk factors for regurgitation in dogs within 24 hours of surgical management of brachycephalic obstructive airway syndrome (BOAS). Retrospective single center study of dogs undergoing BOAS surgery over four years (2013-2017). Two hundred fifty-eight client-owned dogs referred for surgical intervention for BOAS. Electronic medical records were searched for dogs that had undergone surgery for BOAS at a UK specialist referral hospital. Data were assessed by using univariable binomial logistic regression; confounding factors were then identified in a multivariable model. There was an increase in the proportion of dogs that regurgitated while hospitalized preoperatively vs during the first 24 hours postoperatively, from 28 (10.9%) to 89 (34.5%), respectively (P < .0001). History of regurgitation (P = .017, odds ratio [OR] 2.539, 95% confidence interval [CI] 1.178-5.469) and age (P = .008, OR 0.712, 95% CI 0.553-0.916) were detected as risk factors for postoperative regurgitation. For every 1-year increase in age, the odds of experiencing postoperative regurgitation were reduced by 28.8%. Corrective surgery for BOAS was associated with a marked incidence of postoperative regurgitation. Younger dogs and those with a history of regurgitation were predisposed to postoperative regurgitation. The increased frequency of regurgitation after surgical treatment of BOAS, especially in younger dogs, provides justification for counseling owners regarding this postoperative complication.

The risk of passive regurgitation during general anaesthesia in a population of referred dogs in the UK

ObjectiveTo evaluate the risk of passive regurgitation during anaesthesia, and to identify major factors associated with this in dogs attending the Queen Mother Hospital for Animals (QMHA), the Royal Veterinary College. Study designA case-control study nested within the cohort of dogs undergoing anaesthesia with inhalation agents. Animal populationAll dogs undergoing general anaesthesia at the referral hospital between October 2006 and September 2008 (4271 cases). MethodsAll dogs anaesthetized at the QMHA during the study period were included. Regurgitating cases were defined as dogs for which reflux material was observed at the external nares or in the mouth, either during anaesthesia or before return to normal consciousness immediately after general anaesthesia. The risk of regurgitation was estimated and risk factors for regurgitation were evaluated with multivariable logistic regression (p < 0.05). ResultsThe overall risk of regurgitation was 0.96% (41 cases out of 4271 anaesthetics, 95% confidence interval [95% CI] 0.67–1.25%). Exclusion of animals where pre-existing disease was considered a contributing factor to regurgitation (n = 14) resulted in a risk of passive regurgitation of 0.63% (27 cases of 4257 anaesthetics, 95% CI 0.40–0.87%). In the multivariable logistic regression model, procedure and patient weight were significantly associated with regurgitation. Dogs undergoing orthopaedic surgery were 26.7 times more likely to regurgitate compared to dogs undergoing only diagnostic procedures. Dogs weighing more than 40 kg were approximately five times more likely to regurgitate than those weighing <20 kg. Conclusions and clinical relevanceThis study highlights the rare but important occurrence of perioperative regurgitation and identifies that dogs undergoing orthopaedic procedures, and those weighing more than 40 kg, are particularly at risk. Further work is required to evaluate the reasons for these observations.

A case series of the use of the ProSeal laryngeal mask airway in emergency lower abdominal surgery

The ProSeal laryngeal mask airway (PLMA) has been used routinely for anaesthesia and for difficult airway management including airway rescue in non-fasted patients. Compared with the classic laryngeal mask airway the PLMA increases protection against gastric inflation and pulmonary aspiration, by separating the respiratory and gastro-intestinal tracts. The PLMA has potential advantages over use of the tracheal tube including smoother recovery, reduced pharyngolaryngeal morbidity and even reduced postoperative pain. We report a series of patients scheduled for emergency appendicectomy, without other risk factors for regurgitation, managed with the PLMA. Anaesthesia was induced and maintained with remifentanil, target controlled propofol and rocuronium. A series of 102 cases were managed without complications and high rates of first time placement of the PLMA (inserted over a suction tube placed in the oesophagus). With careful patient selection the PLMA may offer an alternative airway for use by experienced anaesthetists in patients undergoing minor lower abdominal surgery.

Gastroscopy in awake and anaesthetized patients using a modified laryngeal mask

Gastroscopy in awake and anaesthetized patients using a modified laryngeal mask

Effects of sevoflurane and enflurane on lower esophageal sphincter pressure and gastroesophageal pressure gradient in children.

The effects of sevoflurane and enflurane on the intraluminal pressure of the lower esophagus (LE), lower esophageal sphincter (LES), and stomach were investigated in paralyzed and mechanically ventilated children under general anesthesia. A total of 14 children, ASA physical status class I without risk factors for regurgitation, scheduled for orthopedic surgery were studied. After induction of anesthesia, we inserted a gastrointestinal pressure sensor nasally and monitored the intraluminal pressure of the LE, LES, and stomach under various concentrations of sevoflurane or enflurane with 66% nitrous oxide in oxygen prior to surgical incision. The barrier pressure (BrP), which is the difference between LES pressure and intragastric pressure, was calculated. Sevoflurane at 2.0 and 2.5 minimum alveolar concentration (MAC) decreased LES pressure, and enflurane at 2.0 and 2.5 MAC decreased both LES pressure and BrP in anesthetized children. The intraluminal pressure of the LE and stomach were not altered in either group. Sevoflurane and enflurane have an inhibitory effect on LES smooth muscle in anesthetized children. However, since the reduction was relatively low, even at high concentrations, these inhalation anesthetics are unlikely to influence gastroesophageal reflux during anesthesia.

REGURGITATION OF GASTRIC CONTENTS DURING GENERAL ANAESTHESIA USING THE LARYNGEAL MASK AIRWAY

We have investigated the incidence of regurgitation of gastric contents during general anaesthesia administered via a laryngeal mask airway (LMA) or face mask and Guedel airway in 56 patients with no risk factors for regurgitation. Patients swallowed a gelatin capsule containing methylene blue 10 min before induction of anaesthesia. Fibreoptic laryngoscopy in the LMA group or conventional laryngoscopy in the face mask group was performed at the end of surgery. Dye was observed within the laryngeal mask in seven of 28 patients (25%). No patients in the face mask-Guedel airway group regurgitated dye (P = 0.005). There was no evidence of aspiration of dye.