|Year : 2018 | Volume
| Issue : 3 | Page : 1058-1063
Early versus delayed feeding after placement of percutaneous endoscopic gastrostomy tube with safe anesthetic techniques
Mohamed M Abdalgaleil1, Ahmed M Shaat2, Osama S Elbalky1, Mohamed S Elnagaar1, Amr M Kamoun1
1 Department of General Surgery, Damanhour Teaching Hospital, Damanhour, El Beheira, Egypt
2 Department of Anesthesia, Damanhour Teaching Hospital, Damanhour, El Beheira, Egypt
|Date of Submission||28-Apr-2018|
|Date of Acceptance||09-Jun-2018|
|Date of Web Publication||31-Dec-2018|
Mohamed M Abdalgaleil
KafrEldawar, El Beheira
Source of Support: None, Conflict of Interest: None
To compare the safety of early (≤4 h) versus 24 h tube feeding after percutaneous endoscopic gastrostomy (PEG) tube placement and to determine the effectiveness of i.v. sedation combined with ultrasound-guided, left side transversus abdominis plane (TAP) block versus combination with local anesthetic (LA) infiltration for PEG placement.
Tube feeding used to be delayed up to 24 h after PEG placement, but results from many randomized controlled trials revealed that there was no need for delaying the tube feeding. The procedure was earlier done with general anesthesia or i.v. sedation with LA infiltration, but the use of i.v. sedation with TAP block may be another option.
Patients and methods
This was a prospective randomized study including 60 patients, requiring long-term nutritional support, who underwent the PEG procedure at GIT Endoscopy Unit, Damanhour Teaching Hospital, El Beheira, Egypt; between August 2017 and March 2018. Patients were randomly allocated into two equal groups, in group A; early tube feeding (≤4 h) was done and performed with i.v. midazolam and propofol-based sedation combined with ultrasound-guided, left side TAP block, whereas in group B; delayed tube feeding (24 h postprocedure) was done and performed with i.v. midazolam and propofol-based sedation with LA infiltration.
There were no statistically significant differences between both groups with respect to procedure-related or anesthesia-related complications.
Early tube feeding (≤4 h) after PEG placement may be a safe option to delayed (24 h postprocedure) feeding. I.v. sedation combined with ultrasound-guided, left side TAP blockade can be used successfully as the primary anesthetic modality for PEG placement.
Keywords: anesthesia, early tube feeding, endoscopic, percutaneous gastrostomy, sedation, transversus abdominis plane block
|How to cite this article:|
Abdalgaleil MM, Shaat AM, Elbalky OS, Elnagaar MS, Kamoun AM. Early versus delayed feeding after placement of percutaneous endoscopic gastrostomy tube with safe anesthetic techniques. Menoufia Med J 2018;31:1058-63
|How to cite this URL:|
Abdalgaleil MM, Shaat AM, Elbalky OS, Elnagaar MS, Kamoun AM. Early versus delayed feeding after placement of percutaneous endoscopic gastrostomy tube with safe anesthetic techniques. Menoufia Med J [serial online] 2018 [cited 2020 Feb 28];31:1058-63. Available from: http://www.mmj.eg.net/text.asp?2018/31/3/1058/248726
| Introduction|| |
Percutaneous endoscopic gastrostomy (PEG) tubes were first used in 1980 for nutrition of many patients unable to ingest adequate oral nutrition and played an important role in nutrition for patients with strokes, dysphagia, and maxillofacial cancers undergoing treatment,,. There is no doubt that early tube feeding prevents the occurrence of complications resulting from inadequate oral intake. It is especially useful in providing daily caloric and nutritional requirements for the patients in high dependency units and those with severe malnutrition. PEG tube feeding has been delayed for many hours or days, due to prior surgical guidelines after surgically placed tubes, with very little evidence. Despite many researches indicating early PEG feeding and the well-known benefits of early application of PEG tube placement, there is still a delay in post-PEG feeding. Midazolam, propofol, and fentanyl are commonly used for monitored anesthesia care, with common side effects as respiratory depression and difference in patient response. When midazolam is combined with fentanyl or other opioids for monitored anesthesia care, the risk of hypoxia and apnea is increased. Combination of low doses of midazolam and propofol, does not prolong the recovery time, as combination decreases the dose of a single drug and increases the effectiveness. Transversus abdominis plane (TAP) block was used successfully for placement of peritoneal dialysis catheter, so we tried it with i.v. sedation for PEG tube placement. The aim of this study was to compare the safety of early (≤4 h) versus 24 h tube feeding after placement of PEG tube and to determine the effectiveness of i.v. sedation combined with ultrasound-guided, left side TAP block versus combination with local anesthetic (LA) infiltration for PEG placement.
| Patients and Methods|| |
After obtaining approval from the local ethics committee, written consent was obtained from each patient to participate in the study. This was a prospective randomized study including 60 patients requiring long-term nutritional support. Cases were admitted from the outpatient clinic of surgery department and underwent the PEG procedure at GI Endoscopy Unit, Damanhour Teaching Hospital, El Beheira, Egypt; between August 2017 and March 2018. Inclusion criteria were patients requiring long-term nutritional support, age more than or equal to 6 years. with American Society of Anesthesiologist physical status II–III. Exclusion criteria included previous PEG placement, patients younger than 6 years or with American Society of Anesthesiologist physical status more than III, patient refusal, and allergy to LA. Patients were randomly allocated into two equal groups. In group A; early tube feeding (≤4 h) was done whereas in group B; delayed tube feeding (24 h postprocedure) was done. Procedures were performed with i.v. midazolam and propofol-based sedation combined with ultrasound-guided left side TAP block in group A or with LA infiltration, in group B. The primary outcome variable of the study was short hospital stay duration, the secondary outcome variables were anesthesia and procedure-related complications during and after the procedure. A single prophylactic dose of 50 mg/kg of ceftriaxone was given i.v., 1 h before procedure; to guard against local or systemic infection. I.v. line was established with the patients entering the preparation room. The patients were continuously monitored by ECG, blood pressure (BP), heart rate (HR), and oxygen saturation (SpO2). Oxygen was supplied via a nasal cannula at 4 l/min. Moderate sedation was induced with i.v. midazolam 30 μg/kg to all patients, in group A patients received left TAP block and in group B patients received 5 ml lidocaine 1% infiltration at feeding tube site then i.v. propofol 1 mg/kg was given to all patients before beginning of the procedure. I.v. propofol 0.25–0.5 mg/kg was further administered according to the patient's sedation level; titrated to Modified Observer's Assessment of Alertness/Sedation scale 3 or 4. For ultrasound-guided TAP block; full resuscitation equipment and a predetermined volume of LA bupivacaine (0.2–0.3 ml/kg in pediatric patients; up to 20 ml in adults or older children) was prepared in 20 ml syringes to be injected on the left side as single shot under ultrasound guidance. The concentration of solution used will depend on the calculated maximum dose of bupivacaine allowed (2 mg/kg). The blocks were performed with the patient sedated and in supine position. In this study, we used ultrasound machine (SII; Fujifilm SonoSite, Washington, District of Columbia, USA) with a multifrequency linear array probe (HFL38, 13–6 MHz broad band; Fujifilm SonoSite) with probe cover and sterile gel. The operative side was cleaned using an antiseptic iodine solution and draped. Local infiltration of the skin with 2 ml lidocaine 1% at the point of needle insertion was done, the ultrasound probe was placed in a transverse plane between the lower costal margin and the iliac crest in the midaxillary line. A sterile block needle 22 G × 80 mm (Stimuplex; B. Braun, Melsungen, Germany) was advanced using an in-plane technique with an anteromedial-to-posterolateral direction between the aponeurosis of the internal oblique and transversus abdominis muscles. With intermittent aspiration, the LA was deposited and seen as a hypoechoic shadow pushing the two layers apart that ensures proper deposition. Endoscopy was performed after the patients reached (Modified Observer's Assessment of Alertness/Sedation) scale 3 or 4. If sedation was not adequate, it would be converted to general anesthesia. With spontaneous respiration, SpO2 was maintained at more than 90%. Oxygen desaturation was defined as SpO2 of less than or equal to 90% for more than 10 s. In this event, head extension and increased oxygen flow to the nasal cannula, from 4 to 6 l/min, would be done. If desaturation was not improved or the patient suffered from apnea, airway assistance maneuvers (noninvasive ventilation with 100% O2 using anesthesia face mask and anesthesia machine) were performed and recorded. After completion of the procedure, patients were monitored in Post Anesthesia Care Unit (PACU) and not transferred back to the ward until their vital signs were stable. All PEG procedures were done using a Pentax video esophago-gastro-duodenoscope (Pentax Corporation, Tokyo, Japan). Gastroscope was inserted through endoscopic bite block, mouth, throat, and esophagus to the stomach. The fistula site was located under the guidance of gastroscopy, an incision of about 1 cm was made in different layers of the abdominal wall and fistula was applied, then feeding tube, 24 Fr gauge, was inserted and fixed well. The ‘pull’ method is used for insertion. The procedure is illustrated in [Figure 1] and [Figure 2]. After completion of the procedure, patients were transferred back to the ward after discharge from PACU and observed for post-PEG complications. Demographic data (age, sex, weight, height) and vital signs were continuously monitored during surgery. Non Invasive Blood Pressure (NIBP), HR, and SpO2 were recorded after patients entered the endoscopy room (T0), 10 min after procedure beginning (T1), and at PACU (T2). Anesthesia-related complications were defined as follows: hypertension or hypotension (increase or decrease in BP by 20% from baseline); tachycardia (HR >100 beat/min) or bradycardia (HR <60 beat/min); any cardiac arrhythmias; hypoxemia (oxygen desaturation, SpO2 <90%), failure of TAP block, LA toxicity, intraperitoneal injection, and bowel injury were observed and recorded. Duration of procedure and hospital stay were also recorded. Numeric Pain Rating Scale (NPRS) was used to record pain 2 and 24 h after PEG procedure, where 0 = no pain and 10 = worst possible pain, analgesia was given when NPRS more than 5. Yes/no questionnaire was used to reflect patients' satisfaction of the service. Procedure-related complications during, early, and late postprocedure, such as vomiting, diarrhea, fever, bleeding, leakage, pneumoperitoneum, PEG-site infection, and death less than or equal to 3 days were recorded. Also, all patients were observed in the ward to rule out post-PEG complications at least 1 day after the procedure. We called each patient at the 13th day after the procedure and the overall complications rate in both groups were recorded. In this randomized clinical trial, after reviewing the literature we found that with a confidence level of 95% (i.e. α = 0.05, Zα/2 = 1.96) and with a power of 80% (i.e. β = 0.2, Zβ = 0.84) to detect a 6 h difference in the duration of hospital stay (primary outcome variable) between groups (i.e. δ = 6) with a SD of 8 (i.e. σ = 8), the sample size was calculated from the following formula: [n = [2(Zα/2 + Zβ)2·σ2]/δ2 and determined that at least 28 patients were required per group. We included 30 patients in each group to allow for dropouts and protocol violation. The sample was randomly allocated by Random allocation software program, version 1. Data was statistically analyzed using statistical package for the social science program (IBM SPSS Statistics for Windows 2011, Version 20.0.: IBM Corp., Armonk, NY, USA), version 20, for windows 2011. Data were tested with: Student's t test; for comparison between parametric means and expressed as mean ± SD, Mann–Whitney U test; for comparison between nonparametric values and expressed as median (range) and χ2 tests with Fisher's exact test; for comparison between the incidences and expressed as number of patients (percentage). A P value less than 0.05 was considered statistically significant and P value less than 0.01 highly significant.
|Figure 1: (a) Trocar is pushed into the gastric cavity under complete endoscopic visualization. (b) A thread is passed through the trocar into the stomach and grasped with a biopsy forceps. (c) A thread is retrieved by withdrawal of the endoscope. (d) The PEG tube is secured to the thread at the oral end and pulled antegrade into the stomach. PEG, percutaneous endoscopic gastrostomy.|
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|Figure 2: (a) The internal retaining device is holding the stomach close to the abdominal wall. (b) The tube is anchored to its final position in the anterior abdominal wall.|
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| Results|| |
All 60 patients recruited and randomized completed the study and were included in the analysis. There were no statistically significant differences between both studied groups with respect to age, sex, weight, height, operative duration, and patient satisfaction as shown in [Table 1]. Monitoring the HR (beat/min), SpO2 (%), systolic blood pressure (SBP) (mm Hg), and diastolic blood pressure (DBP) (mm Hg) after patients entered the endoscopy room (T0), 10 min after procedure beginning (T1), and at PACU (T2) showing the following results: baseline HR, after patients entered the endoscopy room (T0), was comparable among both groups. HR significantly decreased in both groups 10 min after surgery beginning (T1) compared with baseline. HR changes during the procedure showed no statistically significant difference between group A and group B, as shown in [Table 2]. Baseline SBP and DBP were comparable among both groups. SBP and DBP were significantly decreased in both groups, 10 min after surgery beginning (T1) compared with baseline. SBP and DBP changes during the procedure showed no statistically significant difference between group A and group B, as shown in [Table 3]. SpO2 changes showed no statistically significant difference between group A and group B as shown in [Table 2]. In anesthesia-related complications [Table 4]; hypertension (BP >20% from baseline) occurred in four (13.3%) patients in group A and six (20%) patients in group B with no statistically significant difference (P = 0.488). Hypotension (BP <20% from baseline) occurred in seven (23.3%) patients in group A and five (16.7%) patients in group B with no statistically significant difference(P = 0.519) and was treated with ephedrine. Tachycardia occurred in five (16.7%) patients in group A and four (13.3%) patients in group B with no statistically significant difference(P = 0.718). Bradycardia occurred in six (20%) patients in group A and seven (23.3%) patients in group B with no statistically significant difference(P = 0.754) and was treated with atropine. Incidence of arrhythmia was seen in 10 (33.3%) patients in group A compared to 11 (36.7%) patients in group B with no statistically significant difference (P = 0.787), and no patient required treatment. Incidence of hypoxemia was seen in two (6.7%) patients in group A compared with four (13.3%) patients in group B with no statistically significant difference (P = 0.389). There were no incidences of TAP block failure, LA toxicity, intraperitoneal injection, or bowel injury in both the study groups. Analysis of postprocedure pain assessment by NPRS, 2 h after the end of surgical procedure showed that pain scores were lower in group A than in group B and there was statistically highly significant difference between both groups, P value less than 0.001, as shown in [Table 1]. Duration of hospital stay was lower in group A than in group B and there was statistically highly significant difference between both groups, P value less than 0.001, as shown in [Table 1]. No patient of the group A complained of any pain up to 24 h after procedure. With respect to procedure-related complications [Table 4]; there was no significant difference in aspects of vomiting, diarrhea, fever, bleeding, leakage, pneumoperitoneum, and PEG-site infection and death less than or equal to 3 days between the two groups.
|Table 1: Demographic data, operative duration, patient satisfaction, Numeric Pain Rating Scale, and hospital stay duration|
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| Discussion|| |
PEG tubes are very beneficial for long-term nutrition for patients unable to tolerate adequate oral intake for various reasons, however, there is still debates regarding the timing of feedings after PEG placement. A survey of gastroenterologists in the United States in 1998 revealed that although 82% of specialists were aware of the recent literature showing safety of early feedings, only 39% started feedings before 8 h and 11% initiated feedings before 3 h, the remaining 61% of delayed feedings from 9 to more than24 h,. The traditional concept that feeding starts the day after PEG feeding is based on the possibility of peritonitis, peritoneal leak, bleeding, and intestinal motility after surgical gastrostomy, which was performed in the past. In prospective nonrandomized studies in adults, it has been reported that early (3–6 h) feeding did not associate with an increase in complications, in three studies, 136 patients were evaluated, and five complications were reported that included one case of aspiration pneumonia, one death caused by underlying disease, and three wound site infections,,. Local infections can occur after primary wound healing, mostly dependent on the quality of skin care and local antibiotics are used for management. Rarely, systemic antimicrobial therapy or surgical intervention in the case of an abscess is needed. Pertaining to bleeding, which is one of the major complications, our results concedes with that of Gumaste et al. that declared that post-PEG intraperitoneal hemorrhage is a very rare complication. During the procedure, bleeding may be caused by the puncture of gastric wall vessels, the most common cause of bleeding is gastric mucosa erosions beneath the internal bumper when fixed tightly to the mucosa. Bleeding from the skin incision is common but usually self-limited. With respect to peristomal internal leakage; clinically unapparent leakage occurs commonly after tube placement because separation from the abdominal wall can take place easily and persistent leakage of gastric contents intraperitoneally can lead to peritonitis,,,. Wirth et al., reported in their study that peristomal internal leakage was 1–2%, which was very low and in agreement with our results. Pneumopertonium due to air escape into the peritoneal cavity during needle puncture of the stomach and tube passage through the abdominal wall occurs in 5–50% of PEG insertions and resolves within 72 h. This is often a radiographic finding with no clinical hazards, but it may be a sign of iatrogenic bowel injury and should be put in mind when clinical signs, such as peritonitis or sepsis are present. Loser et al., reported in their study that pneumopertonium was of over 50%, which was very high and this disagrees with results of our study. There were no deaths in the first 3 days due to the procedure or feeding in both groups. Six randomized controlled trials consisting of a total of 467 patients found no statistically significant differences in complications between early feeding (≤4 h) and delayed or next-day feedings,,,,,. The combined result of the six studies evaluated 467 patients and found that there was no difference in terms of complications for early (<4 h) and late/next-day feeding,,,,,. In a prospective controlled study performed by Corkins et al., which divided patients into two groups with early and delayed feeding, significant complications were not detected in both groups, which concedes with our results that demonstrated early feeding after PEG (≤4 h) is safe with no serious complications, such as local infections, peritoneal leakage, and peritonitis. This also allows for a short hospital stay with lower cost and less hospital-acquired infection. Our study aimed also to compare the effect of i.v. sedation in combined with either TAP block or with LA infiltration as sedative and analgesic during PEG. I.v. midazolam with propofol provided effective and safe sedation. TAP block and LA infiltration were comparable as regards HR, SpO2, SBP, DBP, and anesthetic complications. In our study, it was observed that patients in the TAP block group had slower HR, lower NIBP, and lower NPRS. Our result suggested that TAP block in combination with sedation offer more analgesic benefits compared with LA infiltration during PEG. All group A patients' had decreased NPRS postprocedure and at all times up to 24 h, in agreement with the results of a study by McDonnell et al., where 32 patients undergoing large bowel resection through midline abdominal incision were randomized to receive patient controlled analgesia and TAP blocks, and he found that the TAP group has significantly decreased pain at emergence and up to 24 h postprocedure. Also, similar to the results of El-Dawlatly et al., who studied 42 patients undergoing laparoscopic cholecystectomy randomized to receive standard general anesthesia either with or without TAP block. He concluded that the group that TAP block group consumed less intraoperative and postoperative analgesia as compared to the other group. And coincide with Chatterjee et al., who studied the placement of peritoneal dialysis catheter under TAP block in 52 end-stage renal disease patients. He reported that no patient with successful block had significant pain 24 h postoperatively. As discussed above, most of the literature research reveals studies in which TAP blocks were given in conjugation with or without general anesthesia and the analgesic requirements were compared thereafter. However, our study is one of the few studies giving information regarding the TAP block quality with i.v. sedation in PEG tube placement.
| Conclusion|| |
Early feeding less than or equal to 4 h after PEG placement appears to be a safe, well-tolerated alternative to delayed feedings, without an increase in the rate of complications and result in decreased duration of hospital stay and health care costs for those patients undergoing PEG placement. I.v. sedation combined with ultrasound-guided, left side TAP blockade can be used successfully as the primary anesthetic modality for PEG placement. There were no systemic toxic effects or other complications recorded. This technique prolongs postprocedure analgesia and reduces the postprocedure analgesic requirements in a better quality without additional side effects to the patient.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Zopf Y, Rabe C, Bruckmoser T, Maiss J, Hahn E, Schwab D. Percutaneous endoscopic jejunostomy and jejunal extension tube through percutaneous endoscopic gastrostomy: a retrospective analysis of success, complications and outcome. Digestion 2009; 79
Chang WK, Hsieh TY. Safety of percutaneous endoscopic gastrostomy in high-risk patients. J Gastroenterol Hepatol 2013; 28
Keung EZ, Liu X, Nuzhad A, Rabinowits G, Patel V. In-hospital and long-term outcomes after percutaneous endoscopic gastrostomy in patients with malignancy. J Am Coll Surg 2012; 215
Michelle L, Wilson C, Hoole D, Munro F, Gillett P, Wilson D. Antibiotic prophylaxis significantly reduces infection rates at paediatric percutaneous endoscopic gastrostomy (PEG) tube insertion: results of an RCT. Gastroenterology 2008; 134
Richter M, Plank C, Lang T, Behrens R, Carbon RT, Dötsch J, Köhler H. Benefits and risks of tube feeding via gastrostoma in infants and children with peritoneal dialysis. Z Gastroenterol 2010; 48
ASA Task Force on Sedation and Analgesia by Non-Anesthesiologists. Practice guidelines for sedation and analgesia by non-anesthesiologists. Anesthesiology 2002; 96
Szary NM, Arif M, Matteson ML, Choudhary A, Puli SR, Bechtold ML. Enteral feeding within three hours after percutaneous endoscopic gastrostomy placement: a meta-analysis. J Clin Gastroenterol 2011; 45
Amornyotin S, Chalayonnavin W, Kongphlay S. Propofol-based sedation does not increase rate of complication during percutaneous endoscopic gastrostomy procedure. Gastroenterol Res Pract. 2011; 2011
Liu S, Liu Z, Zhang J, Li Z, Hu Z, Yang W, et al
. Anesthetic strategy for percutaneous endoscopic gastrostomy in amyotrophic lateral sclerosis patients. Int J Clin Exp Med 2017; 10
Chatterjee S, Bain J, Christopher S, Gopal TVS, Raju KP, Mathur P. Role of regional anesthesia for placement of peritoneal dialysis catheter under ultrasound guidance: our experience with 52 end-stage renal disease patients. Saudi J Anaesth 2015; 9
Kowalski R, Mahon P, Boylan G, McNamara B, Shorten G. Validity of the modified observer's assessment of alertness/sedation scale (MOAA/S) during low dose propofol sedation. Eur J Anaesth 2007; 24
Vervloessem D, van Leersum F, Boer D. Percutaneous endoscopic gastrostomy (PEG) in children is not a minor procedure: risk factors for major complications. Semin Pediatr Surg 2009; 18
Arora G, Rockey D, Gupta S. High in-hospital mortality after percutaneous endoscopic gastrostomy: results of a nationwide population-based study. Clin Gastroenterol Hepatol 2013; 11
Disario J. Endoscopic approaches to enteral nutritional support. Best Pract Res Clin Gastroenterol. 2006; 20
Stehr W, Farrell M, Lucky A, Johnson N, Racadio J, Azizkhan R. Nonendoscopic percutaneous gastrostomy placement in children with recessive dystrophic epidermolysis bullosa. Pediatr Surg Int 2008; 24
Gumaste VV, Bhamidimarri KR, Bansal R, Sidhu L, Baum J, Walfish A. Factors predicting early discharge and mortality in post-percutaneous endoscopic gastrostomy patients. Ann Gastroenterol 2014; 27
Ali T, Le V, Sharma T. Post-PEG feeding time: a web based national survey amongst gastroenterologists. Dig Liver Dis 2011; 43
Manjunath RS, Fisher NC. Percutaneous endoscopic gastrostomy tube placement in patients with compound hiatus hernia and intrathoracic stomach: a case series. Gut 2011; 60
Bechtold ML, Matteson ML, Choudhary AE. Early versus delayed feeding after placement of a percutaneous endoscopic gastrostomy: a meta-analysis. Am J Gastroenterol 2008; 103
Milanchi S, Allins A. Early pneumoperitoneum after percutaneous endoscopic gastrostomy in intensive care patients: sign of possible bowel injury. Am J Crit Care 2007; 16
Wirth R, Voss C, Smoliner C, Sieber CC, Bauer JM, Volkert D. Complications and mortality after percutaneous endoscopic gastrostomy in geriatrics: a prospective multicenter observational trial. J Am Med Dir Assoc 2012; 13
Loser C, Aschl G, He×buterne X. ESPEN guidelines on artificial enteral nutrition percutaneous endoscopic gastrostomy (PEG). Clin Nutr 2005; 24
Corkins MR, Fitzgerald JF, Gupta SK. Feeding after percutaneous endoscopic gastrostomy in children: early feeding trial. J Pediatr Gastroenterol Nutr 2010; 50
McDonnell JG, O'Donnell B, Curley G, Heffernan A, Power C, Laffey JG. The analgesic efficacy of transversus abdominis plane block after abdominal surgery: a prospective randomized controlled trial. Anesth Analg 2007; 104
El-Dawlatly AA, Turkistani A, Kettner SC, Machata AM, Delvi MB, Thallaj A, et al
. Ultrasound-guided transversus abdominis plane block: description of a new technique and comparison with conventional systemic analgesia during laparoscopic cholecystectomy. Br J Anaesth 2009; 102
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]