1430
CASE REPORT GAUR ET AL TREATMENT OF A POSTESOPHAGECTOMY COMPLICATION
2. Wilson RW, Moran CA. Primary melanoma of the lung: a clinicopathologic and immunohistochemical study of eight cases. Am J Surg Pathol 1997;21:1196–202. 3. Leung AM, Hari DM, Morton DL. Surgery for distant melanoma metastasis. Cancer J 2012;18:176–84. 4. Jennings TA, Axiotis CA, Kress Y, Carter D. Primary malignant melanoma of the lower respiratory tract: Report of a case and literature review. Am J Clin Pathol 1990;94:649–55.
Endoluminal Suturing of an Anastomotic Leak Puja Gaur, MD, Calvin Lyons, MD, Tayyaba M. Malik, Min P. Kim, MD, and Shanda H. Blackmon, MD, MPH
FEATURE ARTICLES
Division of Thoracic Surgery, Weill Cornell Medical College of Cornell University, New York, New York, and Division of Thoracic Surgery, Houston Methodist Hospital, Houston, Texas
An anastomotic leak can be one of the most morbid and complex complications after esophagectomy. Typically, management can entail repair, stenting, or diversion. The leak complicates a patient’s postoperative course and delays initiation of any adjuvant therapy. Novel minimally invasive tools created to expedite healing of the anastomotic leak may potentially limit additional procedures traditionally used to treat the leak. We present the case of a 49-year-old man who sustained an anastomotic leak 5 days after undergoing esophagectomy for cancer. He was initially managed with drainage, and when this failed, he was transferred to our hospital. An endoscopic suturing device was used to close the leak and pexy a partially covered self-expanding metal stent that was left in place for 2 weeks. At the end of 2 weeks, the leak healed and there was no stent migration. (Ann Thorac Surg 2015;99:1430–2) Ó 2015 by The Society of Thoracic Surgeons
T
horacic surgeons typically have committed their patients with anastomotic leak after an esophagectomy to esophageal diversion or thoracotomy, followed by muscle flap or even esophageal stenting, all of which result in delayed use of the esophageal conduit. This case report introduces a novel minimally invasive way of dealing with such leaks in which an endoscopic approach is used to sew the leak site closed, thus resulting in earlier use of the esophageal conduit. The patient is a 49-year-old man who was transferred for management of an esophageal leak approximately 1 month after undergoing an esophagectomy. He had initially presented with dysphagia to solids, for which an esophagogastroduodenoscopy was performed that revealed a midesophageal 5-cm mass starting at 30 cm from the incisors in the setting of a short-segment Barrett’s
Ann Thorac Surg 2015;99:1430–2
metaplasia (cuT3 N1 M0; stage IIB). His pathology was consistent with moderately differentiated adenocarcinoma. He received neoadjuvant chemoradiation therapy (carboplatin/paclitaxel with 3,780 Gy), followed by restaging and surgical resection. He underwent an open esophagectomy through a transhiatal approach with a handsewn anastomosis in the neck. A 10-mm Jackson-Pratt drain was left in place. A pyloroplasty was performed, and a jejunostomy feeding tube was also placed. His final pathology was consistent with a complete pathologic response, with a final stage of ypTx N0. A fever developed on postoperative day 5, with purulent drainage from the neck incision and the JacksonPratt drain. A new left-sided pleural effusion was also noted, raising suspicion for an uncontained anastomotic leak. He was taken to the operating room, where an esophagogastroduodenoscopy demonstrated the anastomotic leak and that the conduit was viable. His neck wound was explored, and the Jackson-Pratt drain was exchanged for a Penrose drain. A left tube thoracostomy drained 600 mL of seropurulent fluid. The patient was then started on 2 weeks of intravenous levofloxacin and metronidazole while receiving jejunal enteral feeding. Despite these measures, he continued to have fevers, and repeat imaging questioned conduit viability, at which point, the patient was transferred to our hospital for further evaluation and treatment. On arrival, an esophagram was performed, which was limited secondary to aspiration of the contrast due to vocal cord paralysis from the primary procedure. Endoscopy showed the Penrose catheter was inside the lumen of the esophagus entering through the leak. The gastric conduit was viable, however. A novel endoscopic suturing device (OverStitch; Apollo Endosurgery, Austin, TX) was used to reapproximate the tissue to close the leak, followed by placement of a partially covered self-expanding metal esophageal stent that was pexied to the esophageal wall. An esophageal over-tube was placed through the oral cavity into the esophagus to facilitate entry of the suturing system. The suturing system was mounted on a GIF2TH180 dual-channel endoscope (Olympus, Center Valley, PA) and passed through the over-tube into the esophagus to the area of interest. Two interrupted sutures were placed to close the leak. For both sutures, the first bite was taken from the distal end of the anastomotic hole of the gastric conduit using the anchor/needle of the suturing system, and the second bite was placed through the normal proximal esophagus. The proximal end of the suture was locked with a small metal anchor, and a second device (Cinch device) was used to pexy the distal end, close the hole, and cut the suture at the end of placement (Fig 1). To buttress the closure and allow the patient to eat while the leak healed, a partially covered self-expanding metal esophageal WallFlex stent (28–23 mm 120–155 mm;
Accepted for publication Jan 14, 2014. Address correspondence to Dr Blackmon’s current affiliation, Thoracic Surgery Division, Department of Surgery, Mayo Clinic, MA 12-54W, 200 First St, SW, Rochester, MN 55905; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
Dr Kim discloses financial relationships with Ethicon and Covidien.
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.01.089
Ann Thorac Surg 2015;99:1430–2
CASE REPORT GAUR ET AL TREATMENT OF A POSTESOPHAGECTOMY COMPLICATION
1431
Fig 1. OverStitch (Apollo Endosurgery, Austin, TX) closure of the anastomotic leak. The endoscopic suturing device was used endoscopically to reapproximate the two edges of the leak site (arrows point toward the metal anchor). (A) Endoscopic suturing device within the esophagus. (B) The cinch device can be seen at the arrow in the picture depicting the closed leak with the lumen in the center.
Comment Anastomotic leaks after an esophagectomy continue to be one of the most dreaded complications for a thoracic surgeon, with leak rates as high as 10% [1, 2]. Leaks after esophagectomy are associated with significant
morbidity and death. Patients become septic, experience multisystem organ failure, requiring weeks of antibiotic therapy and enteral feeds as well as prolonged intensive care unit and hospital stays. Despite the use of novel anastomotic techniques, such as end-to-end anastomotic staplers and combined handsewn and stapled technique, the leak rate has not substantially changed [2, 3]. As surgeons, we continue to refine our operative technique to avoid this complication as well as continue to design novel ways to manage it. The OverStitch endoscopic suturing system is currently approved by the United States Food and Drug Administration for placement of sutures into the gastrointestinal tract without an incision, thus transforming operations, especially for bariatric patients and patients with achalasia [4–6]. We have previously reported other means for managing leaks and preventing stent migration [7, 8]. However, to our knowledge, this is the first report of endoluminal suture closure of an anastomotic leak and of stent pexy with an endoluminal suturing device. Therefore, this device, although successful and promising in our patient, is considered an “on-label use” for management of an anastomotic leak and “off-label use” for stent pexy. The technique certainly provides a potentially minimally invasive method to treat Fig 2. (A) Endoscopic image shows the overstitch pexy of a partially covered selfexpanding metal stent that was placed over the anastomosis. (B) The pexy clips are visible on the chest roentgenogram (arrow).
FEATURE ARTICLES
Boston Scientific, Boston, MA) was placed 3 cm proximal to the anastomosis, covering the leak. To prevent stent migration, the proximal esophagus was pexied to the stent by placing 2 more endoluminal sutures (Fig 2). The patient’s intraoperative cultures from the cervical wound grew Enterobacter, and his antibiotics were appropriately tapered to doxycycline. Throughout his recovery, the patient was fed enterally. Once the patient defervesced and his leukocytosis resolved, he received vocal cord medialization by an otolaryngologist, and after undergoing a swallow evaluation, he progressed on an oral diet with the stent in place. He returned 2 weeks later to have the stent removed. A postoperative esophagram confirmed that the anastomotic leak had healed. After removal of the stent, the patient’s leak healed, requiring two dilations over the next month for an anastomotic stricture. He has resumed an oral diet since.
1432
CASE REPORT UDEH ET AL NITROPRUSSIDE-INDUCED CYANIDE TOXICITY
leaks without committing a patient to esophageal diversion or reoperation and offers the patient a potentially enhanced recovery. Future studies are warranted to determine the efficacy and safety of this device and its role in the management of anastomotic leaks.
FEATURE ARTICLES
References 1. Kassis ES, Kosinski AS, Ross P Jr, et al. Predictors of anastomotic leak after esophagectomy: an analysis of The Society of Thoracic Surgeons General Thoracic Database. Ann Thorac Surg 2013;96:1919–26. 2. Urschel JD, Blewett CJ, Bennett WF, et al. Handsewn or stapled esophagogastric anastomoses after esophagectomy for cancer: meta-analysis of randomized controlled trials. Dis Esophagus 2001;14:212–7. 3. Orringer MB, Marshall B, Chang AC, et al. Two thousand transhiatal esophagectomies: changing trends, lessons learned. Ann Surg 2007;246:363–72; discussion 372–4; 4. Jirapinyo P, Slattery J, Ryan MB, et al. Evaluation of an endoscopic suturing device for transoral outlet reduction in patients with weight regain following Roux-en-Y gastric bypass. Endoscopy 2013;45:532–6. 5. Kurian AA, Bhayani NH, Reavis K, et al. Endoscopic suture repair of full-thickness esophagotomy during per-oral esophageal myotomy for achalasia. Surg Endosc 2013;27:3910. 6. Thompson CC, Chand B, Chen YK, et al. Endoscopic suturing for transoral outlet reduction increases weight loss after Roux-en-Y gastric bypass surgery. Gastroenterology 2013;145:129–37; e123. 7. Blackmon SH, Santora R, Schwarz P, et al. Utility of removable esophageal covered self-expanding metal stents for leak and fistula management. Ann Thorac Surg 2010;89:931–6; discussion 936–7; 8. Lyons CD, Kim MP, Blackmon SH. A novel fixation procedure to eliminate covered self-expanding metal stent migration. Ann Thorac Surg 2012;94:1748–50.
Delayed Presentation of Nitroprusside-Induced Cyanide Toxicity Chiedozie I. Udeh, MBBS, MHEcon, Michael Ting, MD, Matthew Arango, PharmD, and Stephanie Mick, MD Anesthesiology Institute, Department of Pharmacy, and Department of Cardiovascular Surgery, Cleveland Clinic, Cleveland, Ohio
Cyanide toxicity is a rare complication of sodium nitroprusside that can be difficult to diagnose in critically ill patients. We describe a case of cyanide toxicity after cardiac surgery that presented as lactic acidosis after discontinuation of nitroprusside. (Ann Thorac Surg 2015;99:1432–4) Ó 2015 by The Society of Thoracic Surgeons
S
odium nitroprusside is widely used for titratable control of blood pressure. Due to concerns over cyanide toxicity, it is recommended that dosing not exceed Accepted for publication May 28, 2014. Address correspondence to Dr Udeh, 9500 Euclid Ave (J4-331), Cleveland, OH 44195; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
Ann Thorac Surg 2015;99:1432–4
2 mcg $ kg 1 $ min 1. The incidence of nitroprussideinduced cyanide toxicity is unknown but is likely less than 2.5% [1, 2]. Nonetheless, the risk is serious because diagnosis can be challenging. We present a case of nitroprusside-induced cyanide toxicity after cardiac surgery, with delayed manifestation hours after discontinuation of nitroprusside infusion. It underscores the importance of a high index of suspicion when unexplained lactic acidosis occurs in the context of nitroprusside exposure and the utility of antidotes for empiric confirmation and treatment. The patient was a 67-year-old obese female, with sleep apnea, chronic kidney disease, hypertension, hyperlipidemia, and diabetes mellitus. She presented with congestive heart failure and underwent uneventful 3-vessel coronary artery bypass and mitral annuloplasty. Within 20 hours she was extubated and off all infusions except nitroprusside. Over the next 2 days she developed some typical postcardiac surgery complications including first degree heart block, junctional rhythm, and atrial fibrillation. Treatment with amiodarone caused complete heart block requiring epicardial pacing. Progressive oliguria also occurred due to acute-on-chronic kidney injury, despite fluids to attain euvolemia and later, attempted forced diuresis. We treated mild delirium with quetiapine. Meanwhile, she remained on nitroprusside for hypertension. By postoperative day 4 she was anuric, but delirium had resolved, cardiac rhythm was stable, and hypertension was controlled with oral medications. An incidental arterial blood gas (ABG) revealed lactate at 5.5 mmol/L. Her vital signs were normal and, aside from mild nausea, she was comfortable and had no complaints. Lactate was higher (7.2 mmol/L) on repeat ABG with worsening base deficit. Supplemental bicarbonate was given and evaluation initiated to ensure adequate oxygen delivery and detect increased metabolic demand. Echocardiogram showed normal biventricular function. Thermodilution cardiac index exceeded 2.4 L/m2. Mixed venous oxygen saturation (SVO2) was 78%. Filling pressures indicated euvolemia. Hemoglobin was 9 g/dL and had been stable postoperatively; abdomen was nontender with vigorous bowel sounds. She remained asymptomatic over the next 18 hours, although lactate steadily increased to 18 mmol/L by midnight of postoperative day 4. She then deteriorated, exhibiting restlessness, tachypnea, tachycardia, and hypotension. Inotropes, vasopressors, and bicarbonate infusions were started. She was reintubated for increasing work of breathing and uncompensated acidosis. Continuous hemodialysis was started yet lactate levels kept rising, peaking at 22 mmol/L by 0900 the next day. With clinical exam now unreliable, computerized tomography scans were obtained but found no ischemia, inflammation, or infection. Lipase, amylase, and liver function tests were normal. Further review clarified that she had received 319 mg of nitroprusside (0.12 to 2.125 mcg/kg/min) for 70 hours, ending about 12 hours prior to the rise in lactate. This 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.05.097
CASE REPORT GAUR ET AL TREATMENT OF A POSTESOPHAGECTOMY COMPLICATION
2. Wilson RW, Moran CA. Primary melanoma of the lung: a clinicopathologic and immunohistochemical study of eight cases. Am J Surg Pathol 1997;21:1196–202. 3. Leung AM, Hari DM, Morton DL. Surgery for distant melanoma metastasis. Cancer J 2012;18:176–84. 4. Jennings TA, Axiotis CA, Kress Y, Carter D. Primary malignant melanoma of the lower respiratory tract: Report of a case and literature review. Am J Clin Pathol 1990;94:649–55.
Endoluminal Suturing of an Anastomotic Leak Puja Gaur, MD, Calvin Lyons, MD, Tayyaba M. Malik, Min P. Kim, MD, and Shanda H. Blackmon, MD, MPH
FEATURE ARTICLES
Division of Thoracic Surgery, Weill Cornell Medical College of Cornell University, New York, New York, and Division of Thoracic Surgery, Houston Methodist Hospital, Houston, Texas
An anastomotic leak can be one of the most morbid and complex complications after esophagectomy. Typically, management can entail repair, stenting, or diversion. The leak complicates a patient’s postoperative course and delays initiation of any adjuvant therapy. Novel minimally invasive tools created to expedite healing of the anastomotic leak may potentially limit additional procedures traditionally used to treat the leak. We present the case of a 49-year-old man who sustained an anastomotic leak 5 days after undergoing esophagectomy for cancer. He was initially managed with drainage, and when this failed, he was transferred to our hospital. An endoscopic suturing device was used to close the leak and pexy a partially covered self-expanding metal stent that was left in place for 2 weeks. At the end of 2 weeks, the leak healed and there was no stent migration. (Ann Thorac Surg 2015;99:1430–2) Ó 2015 by The Society of Thoracic Surgeons
T
horacic surgeons typically have committed their patients with anastomotic leak after an esophagectomy to esophageal diversion or thoracotomy, followed by muscle flap or even esophageal stenting, all of which result in delayed use of the esophageal conduit. This case report introduces a novel minimally invasive way of dealing with such leaks in which an endoscopic approach is used to sew the leak site closed, thus resulting in earlier use of the esophageal conduit. The patient is a 49-year-old man who was transferred for management of an esophageal leak approximately 1 month after undergoing an esophagectomy. He had initially presented with dysphagia to solids, for which an esophagogastroduodenoscopy was performed that revealed a midesophageal 5-cm mass starting at 30 cm from the incisors in the setting of a short-segment Barrett’s
Ann Thorac Surg 2015;99:1430–2
metaplasia (cuT3 N1 M0; stage IIB). His pathology was consistent with moderately differentiated adenocarcinoma. He received neoadjuvant chemoradiation therapy (carboplatin/paclitaxel with 3,780 Gy), followed by restaging and surgical resection. He underwent an open esophagectomy through a transhiatal approach with a handsewn anastomosis in the neck. A 10-mm Jackson-Pratt drain was left in place. A pyloroplasty was performed, and a jejunostomy feeding tube was also placed. His final pathology was consistent with a complete pathologic response, with a final stage of ypTx N0. A fever developed on postoperative day 5, with purulent drainage from the neck incision and the JacksonPratt drain. A new left-sided pleural effusion was also noted, raising suspicion for an uncontained anastomotic leak. He was taken to the operating room, where an esophagogastroduodenoscopy demonstrated the anastomotic leak and that the conduit was viable. His neck wound was explored, and the Jackson-Pratt drain was exchanged for a Penrose drain. A left tube thoracostomy drained 600 mL of seropurulent fluid. The patient was then started on 2 weeks of intravenous levofloxacin and metronidazole while receiving jejunal enteral feeding. Despite these measures, he continued to have fevers, and repeat imaging questioned conduit viability, at which point, the patient was transferred to our hospital for further evaluation and treatment. On arrival, an esophagram was performed, which was limited secondary to aspiration of the contrast due to vocal cord paralysis from the primary procedure. Endoscopy showed the Penrose catheter was inside the lumen of the esophagus entering through the leak. The gastric conduit was viable, however. A novel endoscopic suturing device (OverStitch; Apollo Endosurgery, Austin, TX) was used to reapproximate the tissue to close the leak, followed by placement of a partially covered self-expanding metal esophageal stent that was pexied to the esophageal wall. An esophageal over-tube was placed through the oral cavity into the esophagus to facilitate entry of the suturing system. The suturing system was mounted on a GIF2TH180 dual-channel endoscope (Olympus, Center Valley, PA) and passed through the over-tube into the esophagus to the area of interest. Two interrupted sutures were placed to close the leak. For both sutures, the first bite was taken from the distal end of the anastomotic hole of the gastric conduit using the anchor/needle of the suturing system, and the second bite was placed through the normal proximal esophagus. The proximal end of the suture was locked with a small metal anchor, and a second device (Cinch device) was used to pexy the distal end, close the hole, and cut the suture at the end of placement (Fig 1). To buttress the closure and allow the patient to eat while the leak healed, a partially covered self-expanding metal esophageal WallFlex stent (28–23 mm 120–155 mm;
Accepted for publication Jan 14, 2014. Address correspondence to Dr Blackmon’s current affiliation, Thoracic Surgery Division, Department of Surgery, Mayo Clinic, MA 12-54W, 200 First St, SW, Rochester, MN 55905; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
Dr Kim discloses financial relationships with Ethicon and Covidien.
0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.01.089
Ann Thorac Surg 2015;99:1430–2
CASE REPORT GAUR ET AL TREATMENT OF A POSTESOPHAGECTOMY COMPLICATION
1431
Fig 1. OverStitch (Apollo Endosurgery, Austin, TX) closure of the anastomotic leak. The endoscopic suturing device was used endoscopically to reapproximate the two edges of the leak site (arrows point toward the metal anchor). (A) Endoscopic suturing device within the esophagus. (B) The cinch device can be seen at the arrow in the picture depicting the closed leak with the lumen in the center.
Comment Anastomotic leaks after an esophagectomy continue to be one of the most dreaded complications for a thoracic surgeon, with leak rates as high as 10% [1, 2]. Leaks after esophagectomy are associated with significant
morbidity and death. Patients become septic, experience multisystem organ failure, requiring weeks of antibiotic therapy and enteral feeds as well as prolonged intensive care unit and hospital stays. Despite the use of novel anastomotic techniques, such as end-to-end anastomotic staplers and combined handsewn and stapled technique, the leak rate has not substantially changed [2, 3]. As surgeons, we continue to refine our operative technique to avoid this complication as well as continue to design novel ways to manage it. The OverStitch endoscopic suturing system is currently approved by the United States Food and Drug Administration for placement of sutures into the gastrointestinal tract without an incision, thus transforming operations, especially for bariatric patients and patients with achalasia [4–6]. We have previously reported other means for managing leaks and preventing stent migration [7, 8]. However, to our knowledge, this is the first report of endoluminal suture closure of an anastomotic leak and of stent pexy with an endoluminal suturing device. Therefore, this device, although successful and promising in our patient, is considered an “on-label use” for management of an anastomotic leak and “off-label use” for stent pexy. The technique certainly provides a potentially minimally invasive method to treat Fig 2. (A) Endoscopic image shows the overstitch pexy of a partially covered selfexpanding metal stent that was placed over the anastomosis. (B) The pexy clips are visible on the chest roentgenogram (arrow).
FEATURE ARTICLES
Boston Scientific, Boston, MA) was placed 3 cm proximal to the anastomosis, covering the leak. To prevent stent migration, the proximal esophagus was pexied to the stent by placing 2 more endoluminal sutures (Fig 2). The patient’s intraoperative cultures from the cervical wound grew Enterobacter, and his antibiotics were appropriately tapered to doxycycline. Throughout his recovery, the patient was fed enterally. Once the patient defervesced and his leukocytosis resolved, he received vocal cord medialization by an otolaryngologist, and after undergoing a swallow evaluation, he progressed on an oral diet with the stent in place. He returned 2 weeks later to have the stent removed. A postoperative esophagram confirmed that the anastomotic leak had healed. After removal of the stent, the patient’s leak healed, requiring two dilations over the next month for an anastomotic stricture. He has resumed an oral diet since.
1432
CASE REPORT UDEH ET AL NITROPRUSSIDE-INDUCED CYANIDE TOXICITY
leaks without committing a patient to esophageal diversion or reoperation and offers the patient a potentially enhanced recovery. Future studies are warranted to determine the efficacy and safety of this device and its role in the management of anastomotic leaks.
FEATURE ARTICLES
References 1. Kassis ES, Kosinski AS, Ross P Jr, et al. Predictors of anastomotic leak after esophagectomy: an analysis of The Society of Thoracic Surgeons General Thoracic Database. Ann Thorac Surg 2013;96:1919–26. 2. Urschel JD, Blewett CJ, Bennett WF, et al. Handsewn or stapled esophagogastric anastomoses after esophagectomy for cancer: meta-analysis of randomized controlled trials. Dis Esophagus 2001;14:212–7. 3. Orringer MB, Marshall B, Chang AC, et al. Two thousand transhiatal esophagectomies: changing trends, lessons learned. Ann Surg 2007;246:363–72; discussion 372–4; 4. Jirapinyo P, Slattery J, Ryan MB, et al. Evaluation of an endoscopic suturing device for transoral outlet reduction in patients with weight regain following Roux-en-Y gastric bypass. Endoscopy 2013;45:532–6. 5. Kurian AA, Bhayani NH, Reavis K, et al. Endoscopic suture repair of full-thickness esophagotomy during per-oral esophageal myotomy for achalasia. Surg Endosc 2013;27:3910. 6. Thompson CC, Chand B, Chen YK, et al. Endoscopic suturing for transoral outlet reduction increases weight loss after Roux-en-Y gastric bypass surgery. Gastroenterology 2013;145:129–37; e123. 7. Blackmon SH, Santora R, Schwarz P, et al. Utility of removable esophageal covered self-expanding metal stents for leak and fistula management. Ann Thorac Surg 2010;89:931–6; discussion 936–7; 8. Lyons CD, Kim MP, Blackmon SH. A novel fixation procedure to eliminate covered self-expanding metal stent migration. Ann Thorac Surg 2012;94:1748–50.
Delayed Presentation of Nitroprusside-Induced Cyanide Toxicity Chiedozie I. Udeh, MBBS, MHEcon, Michael Ting, MD, Matthew Arango, PharmD, and Stephanie Mick, MD Anesthesiology Institute, Department of Pharmacy, and Department of Cardiovascular Surgery, Cleveland Clinic, Cleveland, Ohio
Cyanide toxicity is a rare complication of sodium nitroprusside that can be difficult to diagnose in critically ill patients. We describe a case of cyanide toxicity after cardiac surgery that presented as lactic acidosis after discontinuation of nitroprusside. (Ann Thorac Surg 2015;99:1432–4) Ó 2015 by The Society of Thoracic Surgeons
S
odium nitroprusside is widely used for titratable control of blood pressure. Due to concerns over cyanide toxicity, it is recommended that dosing not exceed Accepted for publication May 28, 2014. Address correspondence to Dr Udeh, 9500 Euclid Ave (J4-331), Cleveland, OH 44195; e-mail: [email protected].
Ó 2015 by The Society of Thoracic Surgeons Published by Elsevier
Ann Thorac Surg 2015;99:1432–4
2 mcg $ kg 1 $ min 1. The incidence of nitroprussideinduced cyanide toxicity is unknown but is likely less than 2.5% [1, 2]. Nonetheless, the risk is serious because diagnosis can be challenging. We present a case of nitroprusside-induced cyanide toxicity after cardiac surgery, with delayed manifestation hours after discontinuation of nitroprusside infusion. It underscores the importance of a high index of suspicion when unexplained lactic acidosis occurs in the context of nitroprusside exposure and the utility of antidotes for empiric confirmation and treatment. The patient was a 67-year-old obese female, with sleep apnea, chronic kidney disease, hypertension, hyperlipidemia, and diabetes mellitus. She presented with congestive heart failure and underwent uneventful 3-vessel coronary artery bypass and mitral annuloplasty. Within 20 hours she was extubated and off all infusions except nitroprusside. Over the next 2 days she developed some typical postcardiac surgery complications including first degree heart block, junctional rhythm, and atrial fibrillation. Treatment with amiodarone caused complete heart block requiring epicardial pacing. Progressive oliguria also occurred due to acute-on-chronic kidney injury, despite fluids to attain euvolemia and later, attempted forced diuresis. We treated mild delirium with quetiapine. Meanwhile, she remained on nitroprusside for hypertension. By postoperative day 4 she was anuric, but delirium had resolved, cardiac rhythm was stable, and hypertension was controlled with oral medications. An incidental arterial blood gas (ABG) revealed lactate at 5.5 mmol/L. Her vital signs were normal and, aside from mild nausea, she was comfortable and had no complaints. Lactate was higher (7.2 mmol/L) on repeat ABG with worsening base deficit. Supplemental bicarbonate was given and evaluation initiated to ensure adequate oxygen delivery and detect increased metabolic demand. Echocardiogram showed normal biventricular function. Thermodilution cardiac index exceeded 2.4 L/m2. Mixed venous oxygen saturation (SVO2) was 78%. Filling pressures indicated euvolemia. Hemoglobin was 9 g/dL and had been stable postoperatively; abdomen was nontender with vigorous bowel sounds. She remained asymptomatic over the next 18 hours, although lactate steadily increased to 18 mmol/L by midnight of postoperative day 4. She then deteriorated, exhibiting restlessness, tachypnea, tachycardia, and hypotension. Inotropes, vasopressors, and bicarbonate infusions were started. She was reintubated for increasing work of breathing and uncompensated acidosis. Continuous hemodialysis was started yet lactate levels kept rising, peaking at 22 mmol/L by 0900 the next day. With clinical exam now unreliable, computerized tomography scans were obtained but found no ischemia, inflammation, or infection. Lipase, amylase, and liver function tests were normal. Further review clarified that she had received 319 mg of nitroprusside (0.12 to 2.125 mcg/kg/min) for 70 hours, ending about 12 hours prior to the rise in lactate. This 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.05.097
