Cristina Modesti

The effects of the reverse Trendelenburg position on respiratory mechanics and blood gases in morbidly obese patients during bariatric surgery

Anesthesia adversely affects respiratory function, particularly in morbidly obese patients. Although many studies have been performed to determine the optimal ventilatory settings in these patients, this question has not been answered. The aim of this study was to evaluate the effect of reverse Trendelenburg position (RTP) on gas exchange and respiratory mechanics in 15 obese patients undergoing biliopancreatic diversion. A standardized anesthetic regimen was used and patients were examined at standard times: 1) after tracheal intubation, 2) after laparotomy, 3) after positioning of subcostal retractors, 4) with retractors in RTP. The measurements of respiratory mechanics were repeated for a wide range of tidal volumes by using the technique of rapid occlusion during constant flow inflation. We noted a wide alveolar-arterial oxygen difference [P(A−a)o2] in all patients, particularly during Phase 3. When the patients were placed in RTP, P(A−a)o2 showed a significant improvement and a return toward baseline values. As for mechanics, total respiratory system compliance was significantly higher in RTP than in the other phases. In conclusion, our data suggest that RTP is an appropriate intraoperative posture for obese subjects because it causes minimal arterial blood pressure changes and improves oxygenation. Implications The aim of the study was to assess whether the reverse Trendelenburg position could improve pulmonary gas exchange in obese patients undergoing abdominal surgical procedures. Our work may have a clinical value because few studies deal with this issue.

Volatile Anesthesia in Bariatric Surgery

Background: Obesity causes anesthesiologists a broad variety of perioperative theoretical and practical problems. The aim of this study was to compare two protocols of anesthesia employing Isoflurane and Sevoflurane and evaluate the cardiorespiratory parameters, postoperative recovery and analgesia. Methods: 90 patients underwent biliopancreatic diversion. 60 patients (group A) received Isoflurane and 30 patients (group B) were anesthetized with Sevoflurane. Intraoperative monitoring consisted of EKG, invasive arterial pressure, Sp02, EtCO2, Etanest, Spirometry, urinary output and TOF. Cardiorespiratory parameters and end tidal expiratory concentrations of volatile agents were collected during specific phases of surgery: 1) before induction of anesthesia, 2) after intubation, 3) after skin incision, 4) after positioning of costal retractors, 5) in the reverse Trendelenburg position, 6) end of surgery. During the postoperative period the Aldrete test was carried out to evaluate the recovery from anesthesia. VAS was administered for 6 hours after the end of surgery to set the quality of analgesia. Results: No statistically significant differences in cardiorespiratory parameters were found between the two groups. Extubation time was significantly less in the Sevoflurane Group than in the Isoflurane (15 ± 7 min vs 24 ± 5 min, p< 0.05). The Sevoflurane Group showed an Aldrete score significantly higher than the Isoflurane (8.8 ± 0.3 vs 8.1 ± 0.4, p < 0.05). VAS values did not show statistical differences. Conclusion: The introduction of Sevoflurane, a volatile agent with rapid pharmacokinetic properties, seems to offer an interesting application in these 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.

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. Pearsons 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.

Approach to thyroid carcinoma in pregnancy

Thyroid carcinoma is the first cancer found in general population and the second diagnosed during pregnancy following the breast one. Diagnostic and therapeutic approaches to thyroid malignancy in pregnant women pose several and serious issues to the physicians. Even if there is no consensus about the surgical treatment of thyroid carcinomas during pregnancy, a large number of women undergo surgery over the world. The best surgical and anesthesiological treatment should be chosen after reaching a consensus between surgeons, anesthesiologists, obstetrics, and the patients. From 2000 to 2016, 18 pregnant patients underwent thyroidectomy under local anesthesia (cervical plexus block) combined with conscious sedation using benzodiazepines and opiates with ultrashort duration of action. Our 15-year experience on the thyroidectomies performed using the cervical plexus block combined with conscious sedation confirms that this combined technique offers a safe chance to defeat cancer also during pregnancy. Application of hypnosis could be an interesting alternative approach to pharmacological sedation in patients who would avoid intravenous drugs.