When fasted is not empty: a retrospective cohort study of gastric content in fasted surgical patients†

Background

Perioperative aspiration leads to significant morbidity and mortality. Point-of-care gastric ultrasound is an emerging tool to assess gastric content at the bedside.

Methods

We performed a retrospective cohort study of baseline gastric content on fasted elective surgical patients. The primary outcome was the incidence of full stomach (solid content or >1.5 ml kg−1 of clear fluid). Secondary outcomes included: gastric volume distribution (entire cohort, each antral grade); the association between gastric fullness, fasting intervals, and co-morbidities; anaesthetic management changes and incidence of aspiration.

Results

We identified 538 patients. Thirty-two patients (6.2%) presented with a full stomach. Nine of these (1.7%) had solid content and 23 (4.5%) had clear fluid >1.5 ml kg−1. An empty stomach was documented in 480 (89.8%) patients. The examination was inconclusive in the remaining 20 patients (5.0%). As expected, increasing antral grade was correlated with larger antral cross-sectional area and higher gastric volume (P<0.001). Of the 32 patients with a full stomach, only six had a documented risk factor for prolonged gastric emptying. The anaesthetic management was changed in all nine patients with solid content. No aspiration was reported.

Conclusions

This retrospective cohort study suggests that a small proportion of elective surgical patients may present with a full stomach despite the recommended duration of fasting. Further research is needed to establish the clinical implications of these findings in the elective setting. At present, the clinical role of gastric ultrasound continues to be for the evaluation of gastric contents to guide management when the risk of aspiration is uncertain or unknown.

Preoperative fasting in the department of plastic surgery

Preoperative fasting is necessary to reduce the risk of regurgitation of gastric contents and pulmonary aspiration in patients undergoing general anaesthetic and procedural sedation. Excessive fasting is associated with metabolic, cardiovascular and gastrointestinal complications and patient discomfort. We aimed to reduce the fasting time for patients on the plastic surgery trauma list. Adult inpatients awaiting surgery were asked to complete a preoperative assessment sheet. Questions included the length of preoperative fasting, clarity of instructions and wellness scores. Three cycles of data collection were performed over a 12-month period, patients who declined to participate or were unable to consent were excluded. The first cycle revealed the need for significant improvement. Interventions included staff education, patient information sheets, preoperative drinks, greater availability of ward snacks and improved communication between the ward staff and surgical team through our electronic trauma database. The initial audit of 15 patients revealed a mean fasting time of 16.3 hours for fluid (range 10–22) and a mean of 19.3 hours for solid food (range 10–24). The mean wellness score was 6/10 (10 being very well), 67% of patients felt they were given clear information. The final cycle demonstrated clear improvement in all domains. The mean fasting time declined to 5.1 hours for fluid (range 3–10 hours) and 13 hours for solid food (range 7.5–17 hours). The mean wellness score (10=very well) increased from 6 to 8, the mean thirst score declined from 6.1 to 5.1 and 100% patients felt they had been given clear information. Removal of the traditional ‘NBM from midnight’, patient education, a clear fasting routine with preoperative drinks and improved communication between the full multidisciplinary team has led to a reduction in the fasting times on our trauma list.

The Use of Ultrasonography in Obstetric Anesthesia

This article provides an overview of the use of ultrasonography in obstetric anesthesia. It discusses the indications, benefits, and techniques of using ultrasonography to optimize the delivery of anesthesia and provide safe and efficacious clinical care. More specifically, it discusses the use of ultrasonography to facilitate neuraxial anesthesia, abdominal field blocks, central and peripheral vascular access, as well as the assessment of the lung fields and gastric contents, and identification of the cricothyroid membrane.

Safety and benefits of self-expandable metallic stents with chemotherapy for malignant gastric outlet obstruction

BACKGROUND AND AIM

The influence of chemotherapy on placement of self-expandable metallic stents (SEMS) for malignant gastric outlet obstruction (MGOO) has not been evaluated extensively. We investigated the influence of chemotherapy on the clinical outcomes of SEMS placement for MGOO.

METHODS

A total of 152 cancer patients with MGOO from a university hospital and affiliate hospitals were included. The patients were classified according to chemotherapy status and evaluated for palliative efficacy and safety of SEMS placement.

RESULTS

Technical success rate, time to oral intake, and parameters indicating improvement of physical condition did not differ between the with- and without-chemotherapy groups after stent placement. Re-intervention and stent migration were significantly more frequent in the with-chemotherapy group than in the without-chemotherapy group after stent placement (re-intervention, 32.4% vs 7.8%, P = 0.0005; stent migration, 13.5% vs 1.7%, P = 0.0097). The frequency of adverse events did not differ between the with- and without-chemotherapy groups. Although chemotherapy after stent placement was an independent predictive factor for shortening the stent patency period (hazard ratio [HR], 3.10; P = 0.0264), the use of additional stents facilitated uneventful recovery and further prolonged survival time (HR, 0.60; P = 0.0132).

CONCLUSIONS

Various cancer patients with MGOO can undergo SEMS placement safely regardless of chemotherapy, and concurrent chemotherapy after stent placement can prolong survival time, although re-intervention and stent migration may be increased.

The role of perioperative chewing gum on gastric fluid volume and gastric pH: a meta-analysis

STUDY OBJECTIVE

To determine if preoperative gum chewing affects gastric pH and gastric fluid volume.

DESIGN

Systematic review and meta-analysis.

METHODS

Data sources included Cochrane, PubMed, and EMBASE databases from inception to June 2012 and reference lists of known relevant articles without language restriction. Randomized controlled trials in which a treatment group that chewed gum was compared to a control group that fasted were included. Relevant data, including main outcomes of gastric fluid volume and gastric pH, were extracted.

RESULTS

Four studies involving 287 patients were included. The presence of chewing gum was associated with small but statically significant increases in gastric fluid volume (mean difference = 0.21 mL/kg; 95% confidence interval, 0.02-0.39; P = .03) but not in gastric pH (mean difference = 0.11 mL/kg; 95% confidence interval, -0.14 to 0.36; P = .38). Gastric fluid volume and gastric pH remained unchanged in subgroup analysis by either sugar or sugarless gum type.

CONCLUSIONS

Chewing gum in the perioperative period causes small but statically significant increases in gastric fluid volume and no change in gastric pH. The increase in gastric fluid most likely is of no clinical significance in terms of aspiration risk for the patient. Elective surgery should not necessarily be canceled or delayed in healthy patients who accidentally chew gum preoperatively.

Incidence, risk factors, and mortality associated with aspiration in cervical spine surgery

STUDY DESIGN

Retrospective national database analysis.

OBJECTIVE

A population-based database was analyzed to characterize the incidence, mortality, and associated risk factors for aspiration pneumonia in cervical spine surgery.

SUMMARY OF BACKGROUND DATA

Aspiration pneumonia represents a potentially fatal complication of any surgical procedure. The incidence of this complication is not well characterized after cervical spine surgery.

METHODS

Data from the Nationwide Inpatient Sample was obtained from 2002-2009. Patients undergoing anterior cervical fusion, posterior cervical fusion, or posterior cervical decompression for radiculopathy and/or myelopathy were identified. Patient demographics, incidence of aspiration, costs, and mortalities were assessed. Statistical analysis was performed using Student t test for discrete variables and χ test for categorical data. Logistic regression was used to identify independent predictors for aspiration.

RESULTS

A total of 202,694 patients were identified in the Nationwide Inpatient Sample from 2002 to 2009. Of these, 166,633 were anterior cervical fusions (82.2%), 13,298 were posterior cervical fusions (6.6%), and 22,764 were posterior cervical decompressions (11.2%). The overall incidence of aspiration was 5.3 events per 1000 cases. The greatest incidence was demonstrated in posterior cervical fusion-treated patients with 13.7 per 1000 cases, followed by posterior cervical decompressions with 6.4 per 1000 and anterior cervical fusions with 4.5 per 1000. Patients affected by aspiration were significantly older, more frequently male, and had greater comorbidities than unaffected patients (P < 0.001). Patients diagnosed with aspiration demonstrated significantly greater length of stay, costs, and mortality (P < 0.001). Logistic regression analysis demonstrated independent predictors of aspiration to include advanced age (≥65 yr), male sex, congestive heart failure, coagulopathy, neuropsychiatric disorders, and weight loss (P < 0.001).

CONCLUSION

We demonstrated an overall incidence of 5.3 cases of aspiration per 1000 cervical procedures. Patients most commonly affected by aspiration were older males with greater comorbidity. Hospital courses complicated by aspiration had greater length of stay, costs, and mortality. Identification of patients with risk factors for aspiration may assist in early diagnosis and treatment to prevent further morbidity and mortality.

Gum chewing during pre-anesthetic fasting

Many ad hoc fasting guidelines for pre-anesthetic patients prohibit gum chewing. We find no evidence that gum chewing during pre-anesthetic fasting increases the volume or acidity of gastric juice in a manner that increases risk, nor that the occasional associated unreported swallowing of gum risks subsequent aspiration. On the contrary, there is evidence that gum chewing promotes gastrointestinal motility and physiologic gastric emptying. Recommendations against pre-anesthetic gum chewing do not withstand scrutiny and miss an opportunity to enhance comfort and sense of wellbeing for patients awaiting anesthesia. Gum chewing during the pre-anesthetic nil per os (NPO) period would also permit the development of gum-delivered premedications and should be permitted in children old enough to chew gum safely. Gum chewing should cease when sedatives are given and all patients should be instructed to remove any chewing gum from the mouth immediately prior to anesthetic induction.