Laparoscopic surgery offers several advantages over laparotomy including decreased postoperative pain, morbidity, and mortality.1 However, surgery-specific patient positioning can increase the technical challenges faced by surgeons and anesthesiologists. Furthermore, excess visceral adiposity leads to technical challenges in laparoscopic surgery, and the obesity-related comorbidities such as obstructive sleep apnea, hypertension, and cardiomyopathy are associated with increased perioperative complications. In the past few decades, obesity, defined by a body mass index of ≥30 kg/m2, has increased at an alarming rate. According to the World Health Organization, >1.9 billion adults worldwide were overweight in 2014, and >600 million of these individuals were considered obese.2 When events such as refractory hypotension occur in the operating room, establishing the correct diagnosis may be difficult. This is particularly true in the obese patient because ischemic heart disease, congestive heart failure, and thromboembolic events can all present in a similar manner. When intraoperative events occur, transesophageal echocardiography (TEE) can be an effective tool to identify the etiology and to direct management.
CONSENT FOR PUBLICATION
The patient described in this case report is now deceased. Multiple unsuccessful attempts were made to reach the family. This review and report were written after receiving institutional review board approval.
A 63-year-old woman with a body mass index of 42.6 kg/m2 and metastatic ovarian cancer presented for a laparoscopic abdominal debulking procedure. She had recently completed 3 cycles of chemotherapy with paclitaxel and carboplatin. Her medical history was remarkable for paroxysmal atrial fibrillation, hypertension, chronic obstructive pulmonary disease, and gastroesophageal reflux. Given the paucity of peripheral IV sites, her in situ port-A-cath was accessed. After the application of standard monitors, rapid-sequence induction of general anesthesia followed uneventfully. Subsequently, a 3-lumen central venous catheter was easily placed in the left internal jugular vein under ultrasound guidance. The patient was placed in the lithotomy position with the arms tucked in by each side. On initial surgical entry to the abdomen, no ascites was noted. After abdominal insufflation, steep Trendelenburg position was requested to optimize surgical exposure. Fifteen minutes after pneumoperitoneum, her arterial blood pressure was noted to decrease from 131/92 to 73/43 mm Hg, and her heart rate increased from 74 to 118 beats per minute. No ST changes were noted on her electrocardiogram. The hypotension persisted despite a 1-L bolus of lactated Ringer’s solution, 15 mg ephedrine, and a total of 400 μg phenylephrine. Phenylephrine and vasopressin infusions were initiated. During this time, the end-tidal carbon dioxide level decreased from 40 to 21 mm Hg. The surgical team was informed, and the pneumoperitoneum was released. A tension pneumothorax (from central line placement) was initially suspected. However, breath sounds were equal bilaterally, and the peak airway pressure after abdominal desufflation was unchanged from the value preceding insufflation (30 cm H2O). Visual inspection of the operative field through the laparoscope revealed no evidence of bleeding. A pulmonary embolus (PE) or acute coronary event was considered given the patient’s severe obesity, history of malignancy, and cardiovascular risk factors. Rescue intraoperative TEE was performed.
The initial echo loops (Fig. 1; Supplemental Digital Content, Video 1, http://links.lww.com/AACR/A75) were significant for a very small left ventricular end-diastolic diameter consistent with hypovolemia. Biventricular function was normal without left ventricular wall motion abnormalities. Examination of the pulmonary artery and the 4 cardiac chambers revealed no visible echo densities consistent with thrombus; there was no suggestion of right heart strain. Furthermore, there was no pericardial effusion, no pleural effusions, and no suggestion of aortic dissection. The transgastric views revealed fluid around the liver (Fig. 1; Supplemental Digital Content, Video 1, http://links.lww.com/AACR/A75). An intraoperative hemoglobin sent 1 hour after the start of surgery returned as <5 g/dL. Given these findings the most likely diagnosis was hypovolemic shock secondary to unrecognized hemorrhage. An emergent laparotomy was performed, which revealed an iatrogenic injury to a branch of the superior mesenteric artery secondary to surgical instrumentation in the left upper quadrant.
Resuscitation of the patient continued with surgical control of bleeding, transfusion of blood products, and titration of vasopressors. The surgical procedure such as diagnostic laparoscopy, laparoscopic lysis of adhesions, and exploratory laparotomy was completed in approximately 3.5 hours. The patient received a total of 3 L of crystalloid, 8 units of packed red blood cells, 5 units of fresh, frozen plasma, and 1 L of 5% albumin. Her intraoperative urine output totaled 100 mL. Given concerns for abdominal compartment syndrome, a wound vacuum-assisted closure device was used in lieu of closure of the abdominal incision. The patient remained mechanically ventilated and was transported to the intensive care unit, where she failed to improve postoperatively. In view of the patient’s underlying metastatic ovarian cancer, deteriorating condition, and overall poor prognosis, a discussion regarding goals of care took place with the family. Subsequently, the treatment goals were changed to comfort measures only. The patient died the next day.
This case illustrates the value of early rescue echocardiography in making a diagnosis. Markin et al.3 retrospectively reviewed 364 perioperative rescue echocardiograms and found that a change in management occurred in 59% of the cases. Similarly, Brandt et al.4 examined 66 emergency intraoperative TEEs; new findings were apparent in 80% of patients, and alterations in management took place in 23% of these cases. The comorbidities associated with obesity place the affected individuals at a higher risk for intraoperative myocardial infarction (MI), PE, and congestive heart failure.5 Under general anesthesia, these conditions can present with a similar hemodynamic profile yet the therapy is quite different. In addition, abdominal insufflation is associated with TEE changes such as decreased left ventricular ejection fraction and decreased left ventricular stroke volume; these need to be incorporated into the TEE interpretation of the patient undergoing a laparoscopic procedure.6,7
From the information disclosed during the preprocedure huddle, we were not anticipating excess blood loss. We felt that potential intra-abdominal bleeding would be recognized during the procedure by visual inspection; thus, we chose not to transduce the central line. Had we done so initially, we likely would have made the diagnosis earlier. However, the amount of time required to get the rescue TEE or set up the transducer was judged to be the same, and because our leading hypothesis was PE, a high central venous pressure would not have differentiated between PE and right-sided failure.
In our patient, the intraoperative hypotension was because of bleeding from a site distant to the operative field. The steep Trendelenburg position allowed the blood to accumulate in the upper abdomen, away from the view of the pelvic region where the surgical procedure was taking place. Although changing the bed position from steep Trendelenburg to level might have allowed the surgical team to visualize the intra-abdominal accumulation of blood, it would have worsened the hypotension by diminishing venous return. Given the premise that there was no ongoing blood loss, we proceeded to consider other causes of shock such as PE and MI. Rescue TEE was crucial in our situation to diagnose the actual cause of hypotension (bleeding) and redirect the team’s management.
The key to differentiating ascites from pleural or pericardial fluid lies in a sound understanding of anatomy during an echocardiographic examination. The diaphragm separates pleural effusions from ascites, and the descending aorta serves as a landmark separating pericardial fluid from pleural fluid. The transgastric view (Fig. 1) shows the liver edge, an important anatomical landmark located below the pleural space and outside the pericardial region, as well as the hepatorenal recess, a potential space normally devoid of hypoechoic material (i.e., fluid) on ultrasound examination. The steep Trendelenburg position allowed blood/fluid to pool in the most dependent area below the liver. Because our patient did not have ascites, the hypoechoic material on TEE was presumed to be blood. Figure 2 and Video 2 (Supplemental Digital Content, http://links.lww.com/AACR/A76) were obtained after resuscitation and show the same TEE view as Figure 1 and Video 1 (http://links.lww.com/AACR/A75) but with adequate ventricular filling.
Several lessons emerged as a result of this laparoscopic intra-abdominal case. First, excellent intraoperative communication between the anesthesia and surgery teams is paramount to sorting out potential causes of the patient’s instability. The collaborative approach between the anesthesia and surgery teams extended into the root cause analysis of the event, leading to changes in surgical practice. For example, patients will be taken out of Trendelenburg position to more adequately assess for bleeding, and the surgeons will now have a lower threshold to convert from laparoscopic to open procedures if there is persistent hemodynamic instability.
Second is the value of early rescue TEE to aid in the differential diagnosis. In our case, TEE not only detected intraperitoneal fluid, but also allowed us to exclude PE and acute MI. Along with modalities such as point-of-care testing, TEE should be an integral component of a multimodal diagnostic approach during an intraoperative emergency. Although not without limitations, TEE is a relatively safe tool with a low morbidity rate. In a review of 1500 cases, Vignon et al.8 documented a 1.9% incidence of minor complications such as intolerance of the probe in the awake patient, pharyngeal bleeding, nausea, and/or vomiting. In a study of their TEE experience involving 901 patients, Chee et al.9 noted a major complication rate of 0.6%. In a retrospective review of 7200 adult cardiac patients, Kallmeyer et al. found a 0.2% incidence of TEE-associated morbidity and 0% mortality. The most common complication was odynophagia (0.1%).10
Contraindications to TEE include patient refusal, gastroenterologic pathologies that would make perforation more likely, cervical spine instability, severe coagulopathy, and respiratory distress in a nonintubated patient.11 Complications range from dysphagia and dental injury to esophageal perforation, esophageal injury, hematoma, laryngeal palsy, and death.12 Given that the interpretation and quality of the study is only as reliable as the person performing it, a major limitation of this technique is the availability of experts trained in TEE. The procedure can also have an added cost, and there can be limited availability of staff and equipment. However, if resources are available, then transthoracic echocardiography and TEE are easy ways to provide life-saving information in an emergency situation. When access to the chest is feasible, point-of-care ultrasound is also an option to detect acute pneumothorax and fluid accumulation. As the importance of rescue echocardiography in the perioperative setting is increasingly recognized, we suggest that hospitals take the initiative to form rescue echocardiography teams that can arrive expeditiously during perioperative conditions to aid in diagnosis.
1. Afors K, Centini G, Murtada R, Castellano J, Meza C, Wattiez A. Obesity in laparoscopic surgery. Best Pract Res Clin Obstet Gynaecol 2015;29:55464.
3. Markin NW, Gmelch BS, Griffee MJ, Holmberg TJ, Morgan DE, Zimmerman JM. A review of 364 perioperative rescue echocardiograms: findings of an anesthesiologist-staffed perioperative echocardiography service. J Cardiothorac Vasc Anesth 2015;29:828.
4. Brandt RR, Oh JK, Abel MD, Click RL, Orszulak TA, Seward JB. Role of emergency intraoperative transesophageal echocardiography. J Am Soc Echocardiogr 1998;11:9727.
5. Graham D, Faggionato E, Timberlake A. Preventing perioperative complications in the patient with a high body mass index. AORN J 2011;94:33444.
6. Myre K, Buanes T, Smith G, Stokland O. Simultaneous hemodynamic and echocardiographic changes during abdominal gas insufflation. Surg Laparosc Endosc 1997;7:4159.
7. Alfonsi P, Vieillard-Baron A, Coggia M, Guignard B, Goeau-Brissonniere O, Jardin F, Chauvin M. Cardiac function during intraperitoneal CO2 insufflation for aortic surgery: a transesophageal echocardiographic study. Anesth Analg 2006;102:130410.
8. Vignon P, Guéret P, Chabernaud JM, Lacroix P, Maudière A, Cassat C, Doumeix JJ, Abrieu O, Sénéchal C, Bensaid J. [Failure and complications of transesophageal echocardiography. Apropos of 1500 consecutive cases] [in French]. Arch Mal Coeur Vaiss 1993;86:84955.
9. Chee TS, Quek SS, Ding ZP, Chua SM. Clinical utility, safety, acceptability and complications of transoesophageal echocardiography (TEE) in 901 patients. Singapore Med J 1995;36:47983.
10. Kallmeyer IJ, Collard CD, Fox JA, Body SC, Shernan SK. The safety of intraoperative transesophageal echocardiography: a case series of 7200 cardiac surgical patients. Anesth Analg 2001;92:112630.
11. Cardiovascular Section of the Canadian Anesthesiologists’ Society1; Canadian Society of EchocardiographyBéïque F, Ali M, Hynes M, Mackenzie S, Denault A, Martineau A, MacAdams C, Sawchuk C, Hirsch K, Lampa M, Murphy P, Honos G, Munt B, Sanfilippo A, Duke P. Cardiovascular Section of the Canadian Anesthesiologists’ Society1; Canadian Society of Echocardiography, Canadian guidelines for training in adult perioperative transesophageal echocardiography. Recommendations of the Cardiovascular Section of the Canadian Anesthesiologists’ Society and the Canadian Society of Echocardiography. Can J Cardiol 2006;22:101527.
12. American Society of Anesthesiologists and Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography. Practice guidelines for perioperative transesophageal echocardiography. An updated report by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography. Anesthesiology 2010;112:108496.