Postoperative urinary retention (POUR): A narrative review.

Postoperative urinary retention (POUR) is defined as the inability to void in the presence of a full bladder after surgery. Complications include delirium, pain, prolonged hospitalization, and long-term altered bladder contractility. Comorbidities, type of surgery and anesthesia influence the development of POUR. The incidence varies between 5% and 70%. History and clinical examination, the need for bladder catheterization and ultrasonographic evaluation are three methods used to diagnose POUR. The prevention of POUR currently involves identifying patients with pre-operative risk factors and then modifying them where possible. Bladder catheterization is the standard treatment of POUR, however, further studies are necessary to establish patients who need a bladder catheter, bladder volume thresholds and duration of catheterization.

Obesity Surgery Mortality Risk Score as a Predictor for Intensive Care Unit Admission in Patients Undergoing Laparoscopic Bariatric Surgery.

Background: Laparoscopic bariatric surgery provides many benefits including lower postoperative pain scores, reduced opioid consumption, shorter hospital stays, and improved quality of recovery. However, the anaesthetic management of obese patients requires caution in determining postoperative risk and in planning adequate postoperative pathways. Currently, there are no specific indications for intensive care unit (ICU) admission in this surgical population and most decisions are made on a case-by-case basis. The aim of this study is to investigate whether Obesity Surgery Mortality Risk Score (OS-MRS) is able to predict ICU admission in patients undergoing laparoscopic bariatric surgery (LBS). Methods: We retrospectively reviewed data of patients who underwent LBS during a 2-year period (2017-2019). The collected data included demographics, comorbidities and surgery-related variables. Postoperative ICU admission was decided via bariatric anaesthesiologists' evaluations, based on the high risk of postoperative cardiac or respiratory complications. Anaesthesia protocol was standardized. Logistic regression was used for statistical analysis. Results: ICU admission was required in 2% (n = 15) of the 763 patients. The intermediate risk group of the OS-MRS was detected in 84% of patients, while the American Society of Anaesthesiologists class III was reported in 80% of patients. A greater OS-MRS (p = 0.01), advanced age (p = 0.04), male gender (p = 0.001), longer duration of surgery (p = 0.0001), increased number of patient comorbidities (p = 0.002), and previous abdominal surgeries (p = 0.003) were predictive factors for ICU admission. Conclusions: ICU admission in obese patients undergoing LBS is predicted by OS-MRS together with age, male gender, number of comorbidities, previous abdominal surgeries, and duration of surgery.

Efficacy and Safety of Prothrombin Complex Concentrates in Liver Transplantation: Evidence from Observational Studies.

The risk/benefit ratio of using prothrombin complex concentrates (PCCs) to correct coagulation defects in patients with end-stage liver disease is still unclear. The primary aim of this review was to assess the clinical effectiveness of PCCs in reducing transfusion requirements in patients undergoing liver transplantation (LT). This systematic review of non-randomized clinical trials was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol was previously registered (PROSPERO:CRD42022357627). The primary outcome was the mean number of transfused units for each blood product, including red blood cells (RBCs), fresh frozen plasma, platelets, and cryoprecipitate. Secondary outcomes included the incidence of arterial thrombosis, acute kidney injury, and haemodialysis, and hospital and intensive care unit length of stay. There were 638 patients from 4 studies considered for meta-analysis. PCC use did not affect blood product transfusions. Sensitivity analysis, including only four-factor PCC, showed a significant reduction of RBC effect size (MD: 2.06; 95%CI: 1.27-2.84) with no true heterogeneity. No significant differences in secondary outcomes were detected. Preliminary evidence indicated a lack of PCC efficacy in reducing blood product transfusions during LT, but further investigation is needed. In particular, future studies should be tailored to establish if LT patients will likely benefit from four-factor PCC therapy.

Effects of deep neuromuscular block on surgical workspace conditions in laparoscopic bariatric surgery: a systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: It has been hypothesized that routine use of deep neuromuscular block (dNMB) is advisable in laparoscopic bariatric surgery to optimize workspace conditions. dNMB seems to have advantages in laparoscopic procedures on non-obese patients as it improves surgical space conditions and reduces postoperative pain scores. This systematic review and meta-analysis aimed at comparing the impact of deep vs. moderate NMB (mNMB) on surgical conditions and outcomes, including duration of surgery and postoperative pain in patients undergoing laparoscopic bariatric surgery. EVIDENCE ACQUISITION: Studies were identified from Medline, Embase and Cochrane library (update: Sep 1, 2019). Randomized controlled trials (RCTs) comparing dNMB with mNMB were identified if they reported surgeon satisfaction for workspace conditions (primary outcome). The effects of dNMB on surgery duration and postoperative pain (secondary outcomes) were also investigated. EVIDENCE SYNTHESIS: Of the 45 retrieved records, four were finally included. dNMB improved the surgeon's satisfaction score about workspace (on a scale ranging from 1 to 5), with a mean difference (MD) of 0.52 (95% CI: 0.36-0.68). Surgical duration was not affected by block level (MD: -3.29 minutes; 95% CI: from -14.35 to 7.76). Only one study showed that dNMB also decreased postoperative pain. CONCLUSIONS: It was found that dNMB helps improve surgical space conditions in patients undergoing laparoscopic bariatric surgery whereas it fails to shorten procedure duration. More high-quality large-sampled RCTs are needed to confirm these results. The relationship between dNMB use and other clinical outcomes, such as complications occurrence, needs to be further investigated.

Further Hemodynamic Insight Into Patients Undergoing Liver Transplantation: A Preliminary Report on Cardiac Power Index.

INTRODUCTION: The aim of this retrospective study was to evaluate any relationship between cardiac power index (CPI) and preload indexes during liver transplantation (LT). METHODS: Thirty-three patients with normal preoperative cardiac evaluation undergoing LT were included. Anesthesia management was standardized. Monitoring included continuous cardiac output determination by pulmonary artery catheter. CPI was calculated throughout LT by using the following standard formula: Mean Arterial Pressure [mm Hg] × Cardiac Index [L/min/m2] × k, where k = 0.0022. A logistic regression to determine which preload indexes predicted an adequate CPI (≥ 0.4 watt/m2) was performed. Postregression analysis was carried out to calculate a cutoff of right ventricle end diastolic volume index (RVEDVI) able to guarantee an adequate CPI after establishing a sensitivity >0.9. The area under receiver operating characteristic curve (AUC) was also run separately for patients with a Model for End-Stage Liver Disease (MELD) score < or ≥ 25 to establish an accurate level of prediction in these subgroups (post-hoc analysis). RESULTS: Logistic regression showed that RVEDVI was the only predictor of CPI (AUC = 0.81). A cutoff value for RVEDVI of 105 mL/m2 was found (sensitivity = 90.5%; specificity = 50%). RVEDVI predicted CPI with moderate accuracy (AUC = 0.80) in patients with MELD < 25 (n = 25), whereas the prediction was highly accurate (AUC = 0.96) in patients with MELD ≥ 25 (n = 8). CONCLUSION: An RVEDVI = 105 mL/m2 can be considered a valid cutoff to perform a fluid challenge to optimize preload during LT. Sicker recipients (with MELD ≥ 25) could exhibit less tolerance to preload reduction, proven by a decrease of CPI below the minimum value considered safe (0.40 watt/m2).

Patient-Related Factors Predicting Workspace Conditions during Laparoscopic Bariatric Surgery.

BACKGROUND: Previous studies have focused on the role of deep neuromuscular blockade (NMB) in improving surgical conditions during laparoscopic bariatric surgery. However, a wide inter-individual variability has been noted. The aim of this study was to identify patient-related factors affecting surgeon satisfaction with the surgical space and surgery duration in laparoscopic bariatric surgery under deep NMB. METHODS: One hundred eighty-five patients scheduled for laparoscopic gastric bypass were enrolled. Anesthesia was standardized. A deep NMB was maintained together with fixed patient positioning (30 reverse Trendelenburg) and constant pneumoperitoneum pressure (14 mmHg) during the whole surgical procedure. Immediately after surgery, the surgeon was invited to state his satisfaction with the surgical space through a verbal numeric scale (VNS) ranging from 0 (extremely poor) to 10 (optimal). RESULTS: VNS score was negatively correlated with male gender (r = - 0.35; p = 0.0001), BMI (r = - 0.16; p = 0.03), and age (r = - 0.20; p = 0.008). Surgery duration was positively correlated with male gender (r = 0.27; p = 0.0003) and BMI (r = 0.22; p = 0.006). Multivariate linear regressions showed that lower VNS scores were predicted by male gender (p = 0.000001) and increased age (p = 0.009), and that a longer surgery duration was predicted by male gender (p = 0.0002). CONCLUSIONS: Findings showed that male gender and higher patient age were independent predictors of lower surgeon satisfaction with the workspace during laparoscopic bariatric surgery. Male gender also had a significant role in predicting longer surgery duration. The role of android obesity, which is more frequently associated with male gender, in affecting surgeon-perceived workspace conditions needs further investigation.

Usefulness of postreperfusion lactate clearance for predicting early graft recovery in liver transplant patients: a single center study.

BACKGROUND: The role of postreperfusion lactate clearance in assessing graft function has not yet been investigated. The aim of this study was to examine whether lactate clearance, assessed in the postreperfusion phase, can predict poor graft function in liver transplant patients. METHODS: Seventy patients undergoing liver transplantation (LT) were enrolled. Standardized anesthesia and intraoperative monitoring were applied. The lactate levels measured immediately after venous reperfusion and six hours later were used to calculate lactate clearance by the following formula: [(reperfusion lactate - 6 h post-reperfusion lactate)/reperfusion lactate] ×100. Student's t-test was performed to evaluate differences in lactate clearance between patients with good and poor graft function. Logistic regression was used to assess predictors of poor graft function. RESULTS: Postreperfusion lactate clearance was lower in patients with poor graft function compared to those with good graft function (P=0.0007). Logistic regression showed that postreperfusion lactate clearance may represent an early predictor of poor graft function (area under receiver operating characteristic curve =0.83). A lactate clearance cut-off of 59.7% was found (90% sensitivity, 38.3% specificity). CONCLUSIONS: Postreperfusion lactate clearance may be useful for the early identification of poor graft function after LT. In patients with lactate clearance <59.7%, it could be useful to search for the underlying cause of poor graft function.

Factors affecting acute pain perception and analgesics consumption in patients undergoing bariatric surgery.

BACKGROUND: Previous studies performed in non-obese patients undergoing elective surgery have revealed that psychological factors may affect postoperative analgesic requirements. The aim of this observational prospective study was to investigate the extent to which psychopathological dimensions, including anxiety, depression and alexithymia, may influence postoperative pain intensity and analgesics consumption using patient-controlled analgesia (PCA) in patients undergoing bariatric surgery. METHODS: 120 patients, aged 18-60years, with an ASA physical status I-II, undergoing gastric bypass were enrolled. Anxiety and depression Hamilton scales, and Toronto Alexithymia scale, were administered to patients on the day before surgery. General anesthesia was standardized. After awakening, a PCA pump with intravenous tramadol was immediately made available for a 36-hour postoperative analgesia. Visual analog scale at rest (VASr) and after coughing (VASi), and effective PCA requests number were postoperatively recorded. Pearson's correlations, Anova analyses and multiple linear regression were used for statistical purpose. RESULTS: Positive correlations were found between anxiety, depression, alexithymia and all pain indicators (p<0.01). Analyses of variance showed that anxious (p<0.001), depressed (p<0.001) and alexithymic (p<0.05) patients had high pain indicators. VASr and VASi were predicted by anxiety and depression (p<0.05), but not by alexithymia; effective PCA requests number was predicted by anxiety, depression and alexithymia (p<0.001). CONCLUSIONS: Obese patients with high depression, anxiety and alexithymia levels rated their pain as more intense and required a larger amount of tramadol. Pain perception intensity was predicted by anxiety and depression but not by alexithymia, whereas analgesics consumption was predicted by all the investigated psychopathological dimensions.

Suction catheter guided insertion of ProSeal laryngeal mask airway: Experience by untrained physicians.

BACKGROUND: The use of suction catheter (SC) has been shown to improve success rate during ProSeal laryngeal mask airway (PLMA) insertion in expert users. AIMS: The aim of this study was to compare insertion of PLMA performed by untrained physicians using a SC or the digital technique (DT) in anaesthetised non-paralysed patients. METHODS: In this prospective randomised double-blind study, conducted in the operating setting, 254 patients (American Society of Anaesthesiologists I-II, aged 18-65 years), undergoing minor surgery were enrolled. Exclusion criteria were body mass index >35 kg/m(2), laryngeal or oesophageal varices, risk of aspiration or difficult face mask ventilation either referred or suspected (Langeron's criteria ≥2) and modified Mallampati classification score >2. Participants were randomly allocated to one of the two groups in which PLMA was inserted using DT (DT-group) or SC (SC-group). STATISTICAL ANALYSIS: Chi-square test with Yates' correction, Mann-Whitney U-test or Student's t-test were carried-out as appropriate. RESULTS: The final insertion success rate was greater in SC-groupcompared with DT-group 90.1% (n = 109) versus 74.4% (n = 99) respectively (P = 0.002). Mean airway leak pressure was higher in SC-group compared to DT-group (23.7 ± 3.9 vs. 21.4 ± 3.2 respectively; (P = 0.001). There were no differences in insertion time, post-operative airway morbidity and complications. CONCLUSION: The findings of this study suggest that SC-technique improves the success rate of PLMA insertion by untrained physicians.

Prediction of poor graft function by means of gastric tonometry in patients undergoing liver transplantation.

UNLABELLED: INTRODUCTION. Splanchnic hypoperfusion appears to play a key role in the failure of functional recovery of the graft after orthotopic liver transplantation (LT). The aim of this study was to determine if alterations of tonometric parameters, which are related to splanchnic perfusion, could predict poor graft function in patients undergoing LT. MATERIALS AND METHODS: After Ethics Committee approval, 68 patients undergoing LT were enrolled. In all the patients, regional-arterial CO2 gradient (Pr-aCO2) was recorded; in addition, the difference between Pr-aCO2 recorded at anhepatic phase (T1) and at the end of surgery (T2) (T2- T1 = ΔPr-aCO2) was calculated. Poor graft function was determined on the basis of Toronto's classification 72 hours after LT. Student t-test and logistic regression analysis were used for statistical purpose. Results. ΔPr-aCO2 was significantly greater in patients with poor graft function (3.5 ± 13.2) compared to patients with good graft function (-5.8 ± 12.3) (p = 0.014). The logistic regression analysis showed that the ΔPr-aCO2 was able to predict the onset of poor graft function (p = 0.037). A value of ΔPr-aCO2 ≥ -4 was associated with poor graft function with a sensibility of 93.3% and a specificity of 42.3%. CONCLUSION. Our study suggests that the change of Pr-aCO2 may be a valuable index of graft dysfunction. Gastric tonometry might give early prognostic information on the graft outcome, and it may aid clinicians in planning a more strict follow-up and proper interventions in order to improve graft survival.

Carbon dioxide elimination pattern in morbidly obese patients undergoing laparoscopic surgery.

BACKGROUND: Hypercapnia can result from carbon dioxide pneumoperitoneum and adversely affect the postoperative period, particularly in morbidly obese patients. The purpose of the present study was to examine carbon dioxide homeostasis using a metabolic monitor in morbidly obese and normal weight patients during laparoscopic surgical procedures. The setting was a university hospital in Italy. METHODS: The data from 25 patients with a body mass index of 47.7 ± 5.5 kg/m2 undergoing laparoscopic gastric mini-bypass were compared with the data from 25 normal weight patients undergoing laparoscopic cholecystectomy. The minute ventilation was adjusted to maintain a normal arterial partial pressure of carbon dioxide and normal end-tidal partial pressure of carbon dioxide throughout surgical procedures. The arterial partial pressure of carbon dioxide, end-tidal partial pressure of carbon dioxide, total exhaled carbon dioxide per minute, and arterial blood gas analysis were obtained at 10-minute intervals, along with other cardiorespiratory parameters. RESULTS: The total exhaled carbon dioxide per minute increased by the same percentage in both groups (around 20%). In the laparoscopic cholecystectomy patients, a definite plateau in the total exhaled carbon dioxide per minute was observed within 20 minutes from the start of pneumoperitoneum but not in the morbidly obese patients. After desufflation, the total exhaled carbon dioxide per minute returned more rapidly to the baseline values in the laparoscopic cholecystectomy group than in the morbidly obese group (17.4 ± 6.2 and 24.1 ± 8.3 min, respectively). CONCLUSION: The results of our study have shown that the load of carbon dioxide insufflated is well tolerated in morbidly obese patients, as well as in normal patients, with proper intraoperative ventilation adjustments. However, after pneumoperitoneum, the return to a normal total exhaled carbon dioxide per minute required a longer period in the morbidly obese group. Prolonged mechanical ventilation is therefore advisable in morbidly obese patients.

Preinductive use of clonidine and ketamine improves recovery and reduces postoperative pain after bariatric surgery.

BACKGROUND: In obese patients, concomitant use of clonidine and ketamine might be suitable to reduce the doses and minimize the undesired side effects of anesthetic and analgesic drugs. In this study, we evaluated the perioperative effects of administration of clonidine and ketamine in morbidly obese patients undergoing weight loss surgery at a university hospital in Rome, Italy. METHODS: A total of 50 morbidly obese patients undergoing open biliopancreatic diversion for weight loss surgery were enrolled. The patients were randomly allocated into a study group (n = 23) receiving a slow infusion of ketamine-clonidine before anesthesia induction and a control group (n = 27) who received standard anesthesia. The hemodynamic profile, intraoperative end-tidal sevoflurane and opioid consumption, tracheal extubation time, Aldrete score, postoperative pain assessment by visual analog scale, and analgesic requirements were recorded. RESULTS: The patients in the study group required less end-tidal sevoflurane, lower total doses of fentanyl (3.8 +/- 0.3 gamma/kg actual body weight versus 5.0 +/- 0.2 gamma/kg actual body weight, respectively; P <.05) and had a shorter time to extubation (15.1 +/- 5 min versus 28.2 +/- 6 min, P <.05). The Aldrete score was significantly better in the postanesthesia care unit in the study group. The study group consumed less tramadol than did the control group (138 +/- 57 mg versus 252 +/- 78 mg, P <.05) and had a lower visual analog scale score postoperatively during the first 6 hours. CONCLUSION: The preoperative administration of low doses of ketamine and clonidine at induction appears to provide early extubation and diminished postoperative analgesic requirements in morbidly obese patients undergoing open bariatric surgery.