Elective Upper Abdominal Surgery Research Articles

Non-Invasive Positive airway Pressure thErapy to Reduce Postoperative Lung complications following Upper abdominal Surgery (NIPPER PLUS): a pilot randomised control trial

ObjectivesPostoperative pulmonary complications (PPCs) are a common serious complication following upper abdominal surgery. Postoperatively, physiotherapy-led non-invasive ventilation (NIV) may be a promising method to reduce PPC incidence. The objectives of this pilot trial were to examine preliminary effectiveness, feasibility and safety of additional intermittent physiotherapy-led NIV compared to continuous high-flow nasal cannula oxygen therapy (HFNC) alone. DesignSingle-centre, assessor-blinded, parallel-group, pilot randomised control trial. SettingPrimary-referral hospital in Australia. Participants130 high-risk patients undergoing upper abdominal surgery. InterventionsContinuous HFNC for 48-hours following surgical extubation, or HFNC plus five 30-minute physiotherapy-led NIV sessions. OutcomesPPC incidence, trial feasibility and safety. ResultsPPC incidence was similar between groups (HFNC alone 12/65 (18%) vs HFNC plus NIV 10/64 (16%) adjusted HR 0.95; 95% CI 0.40–2.29). Delivery of HFNC as per-protocol was achieved in 81% (n = 105) of all participants. Physiotherapy-led NIV initiated within four-hours of surgical extubation was achieved in 81% (n = 52) of intervention group participants, with a mean 4.2 (SD 1.3) total number of NIV sessions delivered in the first two postoperative days. NIV was delivered as per-protocol in 52% of this cohort. Two episodes of severe hypotension during NIV requiring medical intervention were reported. ConclusionDelivery of continuous HFNC was feasible. Delivery of NIV within four-hours of extubation was achieved and delivered safely with< 1% adverse events. The planned NIV intervention of five sessions within two postoperative days was not feasible. The results of this pilot study have informed the decision not to proceed to a fully powered trial. Clinical Trial RegistrationAustralian New Zealand Clinical Trials Registry, www.anzctr.org.au ACTRN12617000269336. Contribution of the Paper•A protocol of continuous postoperative HFNC is feasible, well-tolerated and acceptable to high-risk adults following elective upper abdominal surgery.•Prophylactic physiotherapy-led NIV within the early postoperative period is feasible in some cases. Physiotherapy-led NIV can be delivered safely to high-risk adults following elective upper abdominal surgery in the post-anaesthetic care unit, ICU and surgical ward setting.•Delivery of a physiotherapy-led NIV protocol of five sessions over two postoperative days is not feasible to warrant progression to a future definitive trial.

Effects of esmolol infusion on cardiovascular parameters and quality of general anaesthesia in younger and older patients

Background: Esmolol is a cardioselective b-adrenergic antagonist that is used during general anaesthesia to blunt the sympathetic reflex tachycardia and hypertension. The aim of the study was to investigate whether the potential beneficial and adverse effects of esmolol differ depending on the patient age. Methods: A total of 50 ASA I/II patients scheduled for elective upper abdominal surgery were divided in two groups: younger (patients aged up to 35 years) and older (patients older than 65). After premedication with Diazepam, they were infused with esmolol during the first 5 min at a rate of 0.3 mg/kg/min and 0.1 mg/kg/min thereafter. Anaesthesia was induced with thiopental sodium 3-5 mg/kg intravenously (iv) and fentanyl 1.5 µg/kg IV. Tracheal intubation was facilitated with suxamethonium 1-2 mg/kg IV. Long-term neuromuscular blockade was induced with pancuronium bromide 0.07 mg/kg IV bolus and maintained with incremental IV boluses of 0.01 mg/ kg. Inhalational anaesthesia was maintained with a mixture of oxygen and nitrous oxide (O2 /N2 O) 2 : 1. Results: The systolic blood pressure remained constant during the intubation phase in the group of older patients, at the same time being around 89 % of the pre-induction values, while in younger patients it rose up to 100 %. During the same phase of anaesthesia, the diastolic blood pressure in older patients remained at about 91 %, while in younger patients it rose up to 107 % of the pre-induction values. The consumption of drugs and the speed and quality of the recovery from anaesthesia did not differ between the two groups of patients. Conclusion: Infusion of esmolol contributes to the concept of general balanced anaesthesia in elective patients scheduled for upper abdominal surgery equally in younger and older patients.

A comparative study on adding Dexmedetomidine versus Clonidine to epidural 0.125% Bupivacaine for postoperative analgesia in patients undergoing upper abdominal surgeries

Background: The pain experienced after upper abdominal surgery leads to a reduction in 70-75% of vital capacity which leads to postoperative pulmonary complications. The ideal adjuvant for epidural analgesia in patients undergoing upper abdominal surgery seems to be every effective for better outcome and early immobilization in the immediate postoperative period. With this background we planned to conduct a study on epidural analgesia by comparing two alpha 2 agonists. Methods: 50 patients who have planned for elective upper abdominal surgery under general anaesthesia were enrolled in our study. Before induction of general anaesthesia, epidural catheterization was done. The surgical procedure was carried out under routine general anaesthesia with endotracheal controlled ventilation. The patients were given either Dexmedetomidine or Clonidine in the dosage of 2mcg/Kg with 0.125% Bupivacaine via epidural catheter after extubation. Patients were shifted to Post Anaesthesia Care Unit for observation. Sedation and pain were assessed with monitoring of vital parameters. The side effects were also noted. Results: Statistical analysis showed that the duration of analgesia was prolonged in the patients who received Dexmedetomidine as an adjuvant with local anaesthetic agent (417.32±67.36 minutes, p value < 0.05). The time to first rescue analgesia was comparatively delayed in Dexmedetomidine group while comparing with Clonidine group (425.6±64.27 minutes, p value < 0.05). The incidence of hypotension and bradycardia was greater in Clonidine group. There was no significant statistical difference with respect to side effects in both groups. Conclusion: From our study we concluded that Dexmedetomidine provides both analgesia and sedation with better hemodynamic status while compared to Clonidine used as adjuvants in epidural analgesia. But needs further study to optimize the dosage of these two adjuvants while giving via epidural route along with local an

Comparison of Lung Expansion Techniques on Thoracoabdominal Mechanics and Incidence of Pulmonary Complications After Upper Abdominal Surgery: A Randomized and Controlled Trial

Lung expansion techniques (LETs) are widely used to prevent postoperative pulmonary complications (PPCs). However, the effects of each of these techniques on thoracoabdominal mechanics and PPC incidence after abdominal surgery remain unclear. The objective of this study was to compare the effects of LET on pulmonary volumes, respiratory muscle activation, and PPC incidence after major, elective upper abdominal surgery. This randomized controlled trial enrolled 137 patients who were randomly assigned into four groups: control (n = 35), flow incentive spirometry (n = 33), deep breathing (n = 35), and volume incentive spirometry (n = 34). Each intervention was performed tid during 5 consecutive days. Subsequently, PPCs (pneumonia, atelectasis, or severe hypoxemia) were analyzed by a blinded assessor until hospital discharge. Lung volumes (optoelectronic plethysmography) and inspiratory muscular activation (surface electromyography) were assessed before and 3 days after surgery. Intention-to-treat analysis was performed. Before surgery, all groups were homogenous for age, sex, BMI, lung function, and thoracoabdominal mechanics. After surgery, no difference was observed in the lung volumes and inspiratory muscular activation during the lung expansion technique (P > .05). The PPC incidence was higher in the deep breathing group (P < .05). Higher American Society of Anesthesiologists scores and surgery duration were the only predictors of PPC (n = 14, 11.2%). LETs do not modify the changes on thoracoabdominal mechanics or prevent PPCs after abdominal surgery. The indiscriminate use of LETs should not be routinely prescribed to prevent PPCs; however, more studies are required to confirm our results and to change the standard practice. ClinicalTrials.gov; No.: NCT01993602; URL: www.clinicaltrials.gov.

Effect of dexmedetomidineon minimum alveolar concentration of isoflurane required to inhibit the body movementduring skin incision

：Objective To investigatethe effect of dexmedetomidine on minimum alveolar concentration (MAC) of isofluranerequired to inhibit the body movement during skin incision. Methods Forty-eight ASA Ⅰ or Ⅱ patients aged 40-60 yr withbody mass index of 22-27 kg/m2 undergoing elective upper abdominal surgery under generalanesthesia were randomly divided into 3 groups: control group (group C, n = 15);low dosedexmedetomidine group (group D1, n = 17) and high dose dexmedetomidine group (group D2, n= 16). The patients were unpremedicated. Dexmedetomidine 0.4 and 0.8 μg/kgin normal saline (NS) 15 ml was infused over 15 min before induction of anesthesia in D1and D2 groups respectively. Anesthesia was induced with fentanyl-propofol-succinylcholine.The patients were mechanically ventilated after tracheal intubation. Anesthesia wasmaintained with isoflurane. MAC of isoflurane was determined by up-and-down technique. Theinitial end-tidal isofiurane concentration was set at 1.0%, 0.8% and 0.6% in C, D1 and D2groups respectively. Each time the end-tidal isoflurane concentration wasincreased/decreased by 0.2%. Skin incision was made after 15 min of equilibration, whenthe twitch height returned to more than 90% of its control value. Movement of body andlimbs including swallowing and coughing were carefully looked for when skin incision wasmade. MAC of isoflurane was the mean of end-tidal concentration of isoflurane of eachcrossover pair, and 95 % CI was calculated. Results MAC of isoflurane was significantlydecreased in D1 and D2 groups as compared with group C and in group D2 as compared withgroup D1( P ＜ 0.05or 0.01 ). Conclusion Dexmedetomidine can significantly decrease MAC of isofluranerequired to inhibit the body movement during skin incision in a dose-dependent manner. Key words: Dexmedetomidine; Dose-response relationship, drug; Isoflurane

Effect of pre-emptive epidural analgesia on stress response to upper abdominal surgery

Objective To compare the effects of pre-emptive epidural analgesia and postoperative epiclural analgesia on stress response to upper abdominal surgery. Methods Thirty ASA Ⅰ or Ⅱ patients undergoing elective upper abdominal surgery performed under general anesthesia were randomly divided into 2 groups (n = 15 each): Ⅰ pre-emptive epidural analgesia group (group P) and Ⅱ postoperative epidural analgesia group (group C). A mixture of 0.5 μg/ml sufentanil and 0.15% ropivacaine 250 ml was used for epidural analgesia in both groups. The epidural catheter was placed at T10-11 interspace. The epidural regimen included a loading dose of 15 ml followed after 30 min by continuous epidurai infusion at 5 ml/h for 50 h. In group P the epidural analgesia was started at 20 min before skin incision, while in group C after operation when the patients emerged from general anesthesia and were extubated. The depth of general anesthesia was monitored using CSI and maintained at 45-55. Vcnoas blood samples were taken before epidnral catheter was placed (T0, baseline), at 2 h (T1) and at 18 h (T2) after operation for determination the concentrations of ACTH and cortisol (Cor) and C reaction protein (CLIP). Results Blood Cor, ACTH and CRP concentrations were significantly increased after operation as compared with the baseline values at T0 and were significantly lower at T1 and T1 in group P than in group C. Conclusion Pre-emptive epidural analgesia can more effectively inhibit stress response than postoperative epidural analgesia to upper abdominal surgery. Key words: Analgesia, epidural; Stress

Insulin resistance after abdominal surgery.

A study was carried out to determine the time course and degree of postoperative insulin resistance in patients undergoing elective abdominal surgery. Mean(s.e.m.) insulin sensitivity was determined before and on the first (n = 10), fifth, ninth and 20th (n = 5) days after elective open cholecystectomy using the normoglycaemic (4.7(0.1) mmol/l), hyperinsulinaemic (402(12)pmol/l) glucose clamp technique. Preoperative insulin sensitivity expressed as the M value varied from 2.3 to 8.2 mg per kg per min. The relative reduction in insulin sensitivity was most pronounced on the first day after surgery, at a mean(s.e.m.) of 54(2) per cent. Thereafter, a large variation between individuals was found during the course of recovery, and insulin sensitivity returned to normal 20 days after operation. On the first day after surgery, plasma concentrations of glucose, C peptide, noradrenaline and glucagon were slightly but significantly higher than before operation (P < 0.05), whereas insulin, growth hormone, cortisol and adrenaline levels were unaltered. Marked insulin resistance thus develops after elective upper abdominal surgery and persists for at least 5 days after operation. Factors other than simultaneous changes in levels of the hormones studied seem to regulate the maintenance of postoperative insulin resistance.

Validade de um índice prognóstico para ocorrência de complicações pulmonares no pós-operatório de cirurgia abdominal alta

To validate a previous prognostic index (Pereira et al.) to postoperative pulmonary complication in elective upper abdominal surgery, and observe the risk factor for mortality in this population. 283 patients were followed from pre to postoperative period. They were followed in a protocol including a clinical questionnaire, physical examination, thoracic radiogram and spirometry at pre operative period. The main variables measured were: clinical and functional subjects characteristics at pre operative, type of surgery, duration of surgery, time spent in intensive care unit and hospitalization and the occurrence of pulmonary complication. 69 patients had pulmonary complications (24.4%), in 87 events registered. These occurred because some patients had more than one complication. Pneumonia was the most freqüent event 34% (30/87) followed by atelectasis 24% (21/87), bronchoconstriction 17% (15/87), acute respiratory failure 13% (11/87), prolonged mechanical ventilation 9% (8/87) and bronchial infection 2% (2/87). The multiple logistic regression (MLR) showed the association between age above 56 years old (p = 0.0039); DS > 210 (p = 0.0044) and previous chronic pneumopathy (p = 0.0257) and postoperative pulmonary complication. The frequency of postoperative pulmonary complication observed in each categorical classis based on previous index (Pereira equation) did not differ statistically from the prognostic rate calculated, showing the validity of the prognostic index. When FEV1/FVC was included in MLR, the patients with VEF1/FVC<70% and DS> 210 minutes showed a statistically lower number of pulmonary postoperative compared with estimated by the previous Pereira index. The mortality analyses showed significant association with comorbidity, number of days in care unit and postoperative pulmonary complication, however in the MLR only postoperative pulmonary complication had a significant association with death (p = 0.003). The index based on Pereira equation is valid to estimate the prognosis of postoperative pulmonary complication after elective upper abdominal surgery. Age higher 56 years old, duration of surgery more than 210 minutes and pneumopathy are important markers of postoperative pulmonary complication. The only significant marker for mortality was the post operative pulmonary complication.

Sonographic measurement of diaphragmatic motion after upper abdominal surgery: A comparison of three breathing manoeuvres

The effects of three coached breathing manoeuvres on diaphragm excursion after upper abdominal surgery (UAS) were investigated using sonography: verbal instruction to deep breathe; coached diaphragmatic (abdominal) breathing; and thoracic expansion exercise (lateral costal breathing). Eighteen patients aged 34–89 years, undergoing elective UAS at the Royal Adelaide Hospital, were tested. Diaphragm displacement was measured using sonography the day before and the day after surgery. Measurements were taken during deep breaths from functional residual capacity (FRC) to maximal inspiration. There was no difference in diaphragm displacement between the three types of deep breathing manoeuvres pre-operatively. On the first post-operative day, mean diaphragm displacement from FRC to maximal inspiration fell by 58%. Post-operatively, there were differences between the manoeuvres. A simple verbal instruction to deep breathe resulted in less diaphragm movement than coached diaphragmatic breathing and thoracic expansion breathing. There was no difference between coached diaphragmatic breathing and thoracic expansion breathing. We conclude that the techniques of coached diaphragmatic breathing and thoracic expansion used in this group of patients recovering from UAS elicited a greater excursion from the diaphragm than a simple instruction to deep breathe when measured in a 60° long sitting position.

The effect of nebulized salbutamol therapy on the incidence of postoperative chest infection in high risk patients

Patients who smoke heavily and those with pre-existing airflow obstruction are at particular risk of postoperative respiratory infection following upper abdominal surgery. This invariably prolongs hospital stay and increases morbidity. In order to determine whether high dose bronchodilator therapy in the perioperative period reduced the risk of infection, all patients undergoing elective upper abdominal surgery were assessed for risk of developing postoperative infection. Fifty-three patients were identified as high risk according to previously published criteria and were randomly allocated to receive nebulized salbutamol (5 mg) or saline placebo 6 hourly for 48 h beginning 1 h preoperatively. There was no difference in rates of postoperative chest infection in the two groups and this study, therefore, provides no support for the routine preoperative use of bronchodilators in these patients.

Oxyhaemoglobin saturation following elective abdominal surgery in patients receiving continuous intravenous infusion or intramuscular morphine analgesia.

Oxygen saturation was continuously measured using computerised pulse oximetry for 8 h overnight pre-operatively and for the first 24 h postoperatively in 40 patients receiving intermittent intramuscular morphine or continuous infusion of morphine following elective upper abdominal surgery. The proportion of time with an oxygen saturation less than 94% was used as an index of desaturation. Patients receiving continuous infusion analgesia received a larger morphine dose and achieved better analgesia than the intramuscular group. Postoperatively, the duration of desaturation increased 10-fold over pre-operative values, 'intramuscular' patients spending 39.0% (SD, 37.0%) and 'continuous infusion' patients 40.0% (SD, 37.5%) of the time below 94% saturation. Although newer therapies (e.g. epidural analgesia and patient-controlled analgesia) are currently receiving greater attention, the sequelae of these more traditional analgesic techniques warrant further study.

The Relationship between Post-Operative Pain and FEV1following Upper Abdominal Surgery—a Pilot Study

The relationship between subjective pain and the change in forced expiratory volume in one second (FEV1) following elective upper abdominal surgery was studied in 20 patients.Measurements of subjective pain using Rollman's pain scale, and FEV1 using a Vitalograph spirometer, were made pre-operatively and 24–28 h post-operatively. Subjective pain increased from a pre-operative reading of 1 to a post-operative reading of 4.3 (mean). A mean decrease in FEV1 of 54.9% was recorded post-operatively. No significant correlation was found between the subjective pain score and the decrease in FEV1 seen post-operatively.

Endotoxin Levels in Portal and Systemic Blood

In order to resolve the argument as to whether endotoxin is taken up into portal blood in healthy people, simultaneous portal and systemic venous blood samples were taken from 17 patients undergoing elective upper abdominal surgery and assayed for endotoxin using a chromogenic substrate assay. Systemic blood samples from 119 control subjects were also tested. 116 of the controls (97.4%) had plasma endotoxin values below 0.15 optical density (OD) units (trace amounts). Endotoxin was undetectable in systemic samples from surgical patients and in 14 of 17 portal samples. 3 samples had endotoxin values below 0.05 OD units. We have found no evidence of significant uptake of endotoxin into portal blood in the absence of intestinal disease.

Pre- and postoperative lung function in sitting and supine position related to postoperative chest X-ray abnormalities and arterial hypoxaemia.

Spirometry in both sitting and supine position was performed before and 3-5 days after elective upper abdominal surgery in 53 men, aged 41-72 years. The results were related to postoperative respiratory complications as defined by chest radiography and to measurements of the arterial oxygen tension. Preoperative total lung capacity (TLC), functional residual capacity (FRC) and wash-out volume (WOV) were lower in both positions among patients who were to develop major chest X-ray abnormalities than among patients with normal chest radiographs postoperatively. All patients who developed major chest X-ray abnormalities had a negative value for FRC - closing capacity (CC) in the supine position preoperatively, indicating 'airway closure' during tidal breathing. Preoperative WOV and lung clearance index (LCI) were higher in both sitting and supine positions in patients who developed postoperative hypoxaemia than in patients who did not. The postoperative decrease in TLC, FRC and WOV in the sitting position was greater among patients with major X-ray abnormalities and/or arterial hypoxemia postoperatively than among patients without these complications. According to our results, conventional spirometry in the supine position is not superior to conventional spirometry in the sitting position as part of pre- or post-operative assessment of patients. On the other hand, both preoperative 'airway closure' and arterial oxygen tension, measured in the supine position, showed a correlation with postoperative chest X-ray abnormalities.

Changes in the proportions of plasma insulin, proinsulin and a higher-molecular-weight insulin during pre- and post-operative glucose-infusion tests.

1. Glucose-infusion tests were performed on patients admitted for elective upper abdominal surgery 1 day before and 1 day after operation. In addition to insulin and proinsulin, a third immunoreactive insulin species of mol. wt. 20 000--30 000 was detected in plasma from two patients. The heterogeneity of plasma immunoreactive insulin (IRI) and the need to consider the effects of all forms, including proinsulin and the high-molecular-weight species, is emphasized. 2. During preoperative glucose infusions there was an increase in the percentage of the total plasma IRI present as high-molecular-weight forms (i.e. proinsulin plus the species of mol. wt. 20 000--30 000) from 3.9% to 10.8%. On the first postoperative morning all patients showed an increase in the amounts of the heavier IRI types, which accounted for 13.9% of the total plasma IRI. 3. The changes in insulin and proinsulin are consistent with the release from the pancreas of an insulin/proinsulin mixture of constant proportions, and the longer circulating half-life of proinsulin. 4. Increases in the amounts of high-molecular-weight IRI species after surgery may have a partial role in the development of insulin resistance but are probably not a major determinant of the insulin-resistant state.

Ventilatory patterns and pulmonary complications after upper abdominal surgery determined by preoperative and postoperative computerized spirometry and blood gas analysis

Preoperative and postoperative measurements of the FVC, FEV 1, pCO 2, O 2 saturation, and pH were taken in forty-six patients having elective upper abdominal surgery. Postoperatively, the FVC and FEV 1 were reduced by 65 per cent and all patients demonstrated hypoxemia. A significant difference existed in the FVC and FEV 1 of the “normal” subjects versus those subjects in whom macroatelectasis developed. Impairment seen on preoperative pulmonary function studies, obesity, smoking, and prolonged anesthesia time increased postoperative pulmonary complications.