Analysis of cardiovascular, acid-base status, electrolyte, and coagulation changes during small bowel transplantation

Maintaining oxygen delivery is crucial to prevent intestinal ischemia in critical ill patients

Background

Intestinal ischemia is a common complication with obscure pathophysiology in critically ill patients. Since insufficient delivery of oxygen is discussed, we investigated the influence of oxygen delivery, hemoglobin, arterial oxygen saturation, cardiac index and the systemic vascular resistance index on the development of intestinal ischemia. Furthermore, we evaluated the predictive power of elevated lactate levels for the diagnosis of intestinal ischemia.

Methods

In a retrospective case-control study data (mean oxygen delivery, minimum oxygen delivery, systemic vascular resistance index) of critical ill patients from 02/2009–07/2017 were analyzed using a proportional hazard model. General model fit and linearity were tested by likelihood ratio tests. The components of oxygen delivery (hemoglobin, arterial oxygen saturation and cardiac index) were individually tested in models.

Results

59 out of 874 patients developed intestinal ischemia. A mean oxygen delivery less than 250ml/min/m² (LRT vs. null model: p = 0.018; LRT for non-linearity: p = 0.012) as well as a minimum oxygen delivery less than 400ml/min/m² (LRT vs null model: p = 0.016; LRT for linearity: p = 0.019) were associated with increased risk of the development of intestinal ischemia. We found no significant influence of hemoglobin, arterial oxygen saturation, cardiac index or systemic vascular resistance index. Receiver operating characteristics analysis for elevated lactate levels, pH, CO₂ and central venous saturation was poor with an area under the receiver operating characteristic of 0.5324, 0.52, 0.6017 and 0.6786.

Conclusion

There was a significant correlation for mean and minimum oxygen delivery with the incidence of intestinal ischemia for values below 250ml/min/m² respectively 400ml/min/m². Neither hemoglobin, arterial oxygen saturation, cardiac index, systemic vascular resistance index nor elevated lactate levels could be identified as individual risk factors.

Anesthetic management for intestinal transplantation: A decade of experience

BACKGROUND

Intestinal transplantation (ITx) is the definitive therapy for patients suffering from intestinal failure. Previously published reports suggest that these cases should be managed perioperatively with the same intensive monitors and techniques as in liver transplantation.

METHODS

We retrospectively reviewed the anesthetic management of 67 isolated intestinal, intestinal-pancreas, and intestinal-kidney transplants over the previous decade (2005-2015) in our tertiary care institution.

RESULTS

Patients were typically managed with a single arterial line, a single central venous catheter, and rarely intensive modalities such as a pulmonary artery catheter, a transesophageal echocardiography, a second arterial catheter or central venous catheter, a rapid infusion system, a cell salvage device, or viscoelastic testing. Significant hemodynamic derangements were rare, and the rate of postreperfusion syndrome was 8.96%. Our fluid administration type and volume and transfusion type and volume were similar to previous reports in which more intensive anesthetic management was employed.

CONCLUSION

We demonstrate that ITx can safely occur without utilizing the intensive resources requisite for a liver transplant.

Anesthesia for Intestinal Transplantation

The diagnosis of irreversible intestinal failure confers significant morbidity, mortality, and decreased quality of life. Patients with irreversible intestinal failure may be treated with intestinal transplantation. Intestinal transplantation may include intestine only, liver-intestine, or other visceral elements. Intestinal transplantation candidates present with systemic manifestations of intestinal failure requiring multidisciplinary evaluation at an intestinal transplantation center. Central access may be difficult in intestinal transplantation candidates. Intestinal transplantation is a complex operation with potential for hemodynamic and metabolic instability. Patient and graft survival are improving, but graft failure remains the most common postoperative complication.

Intestinal transplantation: The anesthesia perspective

Intestinal transplantation is a complex and challenging surgery. It is very effective for treating intestinal failure, especially for those patients who cannot tolerate parenteral nutrition nor have extensive abdominal disease. Chronic parental nutrition can induce intestinal failure associated liver disease (IFALD). According to United Network for Organ Sharing (UNOS) data, children with intestinal failure affected by liver disease secondary to parenteral nutrition have the highest mortality on a waiting list when compared with all candidates for solid organ transplantation. Intestinal transplant grafts can be isolated or combined with the liver/duodenum/pancreas. Organ Procurement and Transplantation Network (OPTN) has defined intestinal donor criteria. Living donor intestinal transplant (LDIT) has the advantages of optimal timing, short ischemia time and good human leukocyte antigen matching contributing to lower postoperative complications in the recipient. Thoracic epidurals provide excellent analgesia for the donors, as well as recipients. Recipient management can be challenging. Thrombosis and obstruction of venous access maybe common due to prolonged parenteral nutrition and/or hypercoaguability. Thromboelastography (TEG) is helpful for managing intraoperative product therapy or thrombosis. Large fluid shifts and electrolyte disturbances may occur due to massive blood loss, dehydration, third spacing etc. Intestinal grafts are susceptible to warm and cold ischemia and ischemia-reperfusion injury (IRI). Post-reperfusion syndrome is common. Cardiac or pulmonary clots can be monitored with transesophageal echocardiography (TEE) and treated with recombinant tissue plasminogen activator. Vasopressors maybe used to ensure stable hemodynamics. Post-intestinal transplant patients may need anesthesia for procedures such as biopsies for surveillance of rejection, bronchoscopy, endoscopy, postoperative hemorrhage, anastomotic leaks, thrombosis of grafts etc. Asepsis, drug interactions between anesthetic and immunosuppressive agents and venous access are some of the anesthetic considerations for this group.

Outcome of pigs with short gut syndrome submitted to orthotopic intestinal transplantation

PURPOSE

To evaluate the current model of small bowel resection and intestinal transplantation in pigs.

METHODS

Forty two Large White pigs were distributed in five groups: G1(n=6), G2(n=6) and G3(n=6) were submitted to 80%,100% and 100% plus right colon resection respectively and G4(n=7) and G5(n=5) to 100% SBR plus IT without and with immunosuppression based on Tacrolimus and Mycophenolic acid. Evaluation included weight control, clinical status, biochemical analysis and endoscopies for graft biopsies. Follow-up in G1 and 2 was 84 days, while in G3, four and five was ± three weeks.

RESULTS

G1 increased weight suggesting adaptation while G2 and 3 loused weight and inadequate adaptation. G4 and 5 died of acute cellular rejection (ACR) and sepses respectively. Overall survival in G1, 2, 3, 4 and 5 at 30 days was 100, 100, 0 and 20 %, respectively. Medium survival in G4 and 5 was 14 and 16 days.

CONCLUSIONS

The resection of 80% of small intestine in pigs is not suitable for short bowel syndrome induction. Intestinal transplantation with the proposed immunosuppression protocol was effective in prevent the occurrence of severe acute rejection, but inappropriate to increase recipients survival.

Prolonged post-reperfusion syndrome during multivisceral organ transplantation in a pediatric patient: a case report

Multivisceral organ transplantation involves the transplantation of three or more abdominal organs, including small bowel, duodenum, stomach, liver, pancreas, colon, and so on. The large amounts of cold and acidic loading into systemic circulation from the graft during multivisceral organ transplantation may result in severe post-reperfusion syndrome (PRS). We describe here a 6-year-old pediatric patient with chronic intestinal pseudo-obstruction who experienced prolonged PRS and severe metabolic acidosis during seven abdominal organ transplantation including the liver, spleen, stomach, duodenum, small bowel, colon and pancreas. The hypotensive period lasted approximately 10 minutes after graft reperfusion and was accompanied by severe metabolic acidosis and hypothermia. Since PRS can be easily associated with adverse outcomes, such as poor early graft function and primary non-function, not only meticulous surveillance for aggravating factors for PRS but also their immediate correction were necessary in managing a pediatric patient undergoing multivisceral organ transplantation.

Post-reperfusion syndrome during isolated intestinal transplantation: outcome and predictors

BACKGROUND

Post-reperfusion syndrome (PRS) during isolated intestinal transplantation (ITx) is characterized by decreased systemic blood pressure, systemic vascular resistance, and cardiac output and by a moderate increased pulmonary arterial pressure. We hypothesize that the more severe PRS causes a poorer long-term outcome. The primary aim of this study was to determine the independent clinical predictors of intra-operative PRS, as well as to investigate the link between the severity of PRS and the intra-operative profiles and to examine the post-operative complications and their relationship with transplant outcome.

METHODS

This observational study was conducted on 27 patients undergoing isolated ITx in a single adult liver and multivisceral transplantation center. PRS was considered when the mean arterial blood pressure was 30% lower than the pre-unclamping value and lasted for at least one min within 10 min after unclamping.

RESULTS AND CONCLUSIONS

The main results of this study can be summarized in two findings: in patients undergoing ITx, the duration of cold ischemia and the pre-operative glomerular filtration rate were independent predictors of PRS and the occurrence of intra-operative PRS was associated with significantly more frequent post-operative renal failure and early post-operative death.

Evaluation of hemodynamic, metabolic, and electrolytic changes after graft reperfusion in a porcine model of intestinal transplantation

BACKGROUND

We sought to establish an anesthetic protocol to evaluate the hemodynamic, metabolic, and electrolytic changes after graft reperfusion in pigs undergoing orthotopic intestinal transplant (ITx).

METHODS

Fifteen pigs were distributed into two groups: GI (n = 6), without immunosuppression, and GII (n = 9), immunosuppressed before surgery with tacrolimus (0.3 mg/kg). The animals were premedicated at 1 hour before surgery with IM acepromazine (0.1 mg/kg), morphine (0.4 mg/kg), ketamine (10 mg/kg), and atropine (0.044 mg/kg IM). Anesthesia induction used equal proportions of diazepam and ketamine (0.1-0.15 mL/kg/IV) and for maintenance in IV infusion of xylazine (1 mg/mL), ketamine (2 mg/mL), and guaiacol glyceryl ether 5% (50 mg/mL), diluted in 250 mL of 5% glucose solution. In addition, recipient pigs were treated with isofluorane inhalation. Heart rate (HR), systolic (SAP), mean (MAP), and diastolic (DAP) arterial pressure, pulse oximetry, respiratory frequency (f), capnography, body temperature (T), blood gas analysis (pH, Paco(2), Pao(2), base excess, BE; Hco(3)(-), Sato(2)), serum potassium (K), calcium (Ca), sodium, hematocrit (Hct), and glucose (Glu) were measured at four times; M0: after incision (basal value); M1: 10 minutes before reperfusion; and M2 and M3: 10 and 20 minutes after graft reperfusion.

RESULTS

All groups behaved in a similar pattern. There was significant hypotension after graft reperfusion in GI and GII (M2 = 56.2 +/- 6.4 and M3 = 57.2 +/- 8.3 mm Hg and M2 = 65.7 +/- 10.2 and M3 = 67.8 +/- 16.8 mm Hg, respectively), accompanied by elevated HR. The ETco(2) was elevated at M2 (42 mm Hg) and M3 (40 mm Hg). Metabolic acidosis was observed after reperfusion, with significant increase in K levels.

CONCLUSION

The anesthetic protocol for donors and recipients was safe to perform the procedure, allowing control of hemodynamic and metabolic changes after reperfusion without differences regarding immunosuppression.

Metabolic, Coagulative, and Hemodynamic Changes During Intestinal Transplant: Good Predictors of Postoperative Damage?

BACKGROUND

Analysis of intraoperative changes of metabolic, hemodynamic, and coagulative parameters is useful to detect early ischemia-reperfusion damage after intestinal transplant.

METHODS

The objective of our study is to correlate the histological damage at the end of transplant in relation to the intraoperative changes after reperfusion. The histological aspect was graded according to Park's classification at the end of the surgical procedure with biopsies of the graft. Patients were divided into two groups according to the presence or absence of histological damage of the small bowel wall: group A (normal mucosa/minimal damage: Park's grades 0-1) and group B (mucosal damage: Park's grades 2-8).

RESULTS

Significant hemodynamic, metabolic, and coagulative disorders were observed in group B. Consequently, these disorders are thought to be early indicators of graft damage.

CONCLUSIONS

Actual monitoring procedures used for postoperative graft surveillance remain paramount in detecting postoperative intestinal dysfunction, but the indicators described in this paper could represent a further help in intraoperative and postoperative management.