Right hemicolectomy in a patient with severe pulmonary hypertension anesthesia approach.

A 59-year-old obese female patient was diagnosed to be having severe pulmonary hypertension secondary to mixed connective tissue disease and pulmonary fibrosis. She presented for right hemi-colectomy for a large right-sided colonic polypoid mass and multiple polyps diagnosed by colonoscopy. Her surgery was postponed by 2 months by the anesthesiologist due to dyspnea at rest and high pulmonary artery pressure (70-80 mmHg) for further optimization of medical treatment. After 2 months, she was adequately fit enough to undergo surgery. High lumbar epidural anesthesia was adopted and weaned off. She was discharged after 5 days of surgery from the hospital without any sequel. This report presents the merits and recommendations for such patients.

INTRODUCTION

Pulmonary hypertension (PH) results in significant morbidity and mortality in patients undergoing surgery, irrespective of the type of anesthetic technique used.[12] Therefore, medical optimization seems critical. The number of reports in literature concerning the effect of PH on the outcome of patients undergoing non-cardiac surgery is quite insufficient.[13] It has been indicated that PH is one of the important causes of morbidity [respiratory failure (60%) and right ventricular failure (50%)] and early postoperative mortality. This case report explains our recent experience of a case of PH indicating the approach of management.

CASE REPORT

A 59-year-old, obese [body mass index (BMI) 32.9], Saudi woman presented for right hemi-colectomy. She was diagnosed as a case of PH, systemic hypertension, restrictive lung disease, cor-pulmonale and mixed connective tissue disorder with colonic polyposis.

Three months prior to the surgery, she presented with a resistant hypoxemia with pneumonia and was treated with antibiotics and other supportive therapy. In addition, further investigations were done to grade the underlying pathologies.

The ECG showed right bundle branch block, right axis deviation and right ventricular hypertrophy. Chest X-ray showed cardiomegaly and prominent pulmonary arteries [Figure 1].

Figure 1

Cardiomegaly with dilated pulmonary arteries. Peripheral pruning of the lung fields also seen

Trans-thoracic echocardiography (TTE) was performed and it revealed a mild right ventricular systolic dysfunction with tricuspid regurgitation (grade III/IV) [Figure 2]. The estimated systolic pulmonary artery pressure was 70–80 mmHg. TTE further revealed a normal left ventricular systolic function (ejection fraction 60%) with a mild left ventricular hypertrophy and trabeculations and mild diastolic dysfunction. The possible association of pulmonary embolism was ruled out by pulmonary angiography as it revealed no filling defects in the major pulmonary vasculature.

Figure 2

Tricuspid regurgitation of severe PH

A final diagnosis of mixed connective tissue disease with interstitial pulmonary fibrosis and secondary PH was made. In addition, the colonoscopy revealed a large right-sided colonic polypoid mass and multiple polyps.

The patient was referred to anesthesia services for right hemicolectomy. The surgery was postponed by the anesthesiologist as the patient was required to have more medical optimization.

Concerning the drug history, she was on prednisolone and hydroxychloroquine for mixed connective tissue disease. Also, she was on high dose calcium channel blocker; nifedipine, carvedilol, escitalopram, a serotenogenic antidepressant, warfarin, and atrovastatin. Then, she was discharged by the pulmonologists with additional vasodilatory drugs, iloprost and salbutamol inhalers and endothelin receptor antagonist, bosentan, and home oxygen.

Following 2 months of treatment, she was readmitted. On this occasion, she was found to be in In the best period of time, to undergo although her 6-minute walking test (6MWT) was about 198 m (547 m), which is 36% of the predicted value with a drop of saturation from 99% to 73%. In addition, she was dyspneic on mild exertion, hence categorized as class III according to the classification of New York Heart Association.

In the preoperative period, we had a multispeciality discussion including surgeons, pulmonologists and the patient. The advantages of lumbar epidural anesthesia and rescue general anesthesia (GA) and the possible continued ventilatory supports in the intensive care unit were discussed and informed consent was obtained.

Preoperative care

All the medications were continued in the perioperative period and heparin was given instead of warfarin, appropriately. An additional dose of ilioprost and salbutmaol inhalers was administered in the operating theater. Trans-esophageal echocardiography, nitric oxide inhalation and intravenous epoprostenol were kept as the standby.

A 14-gauge cannula was inserted and 1000 ml of 0.9% saline administration was commenced. Left radial artery and central venous pressure (CVP) cannulations were done and monitoring was started. The sheath of pulmonary artery catheter (8 French) was inserted into right internal jugular vein; however, insertion of the pulmonary artery catheter was skipped due to the presence of frequent atrial extrasystoles.

The epidural catheter was sited at the L1–L2 level. A gradual loading of 0.5% bupivacaine was done with 5 ml increments, over 20 minutes period of time. A total of dose of 15 ml of 0.5% bupivacaine and fentanyl 50 μg were given. Blood pressure dropped to 75/56 from 139/79 mmHg with a simultaneous drop of CVP to 4 from 19 cm H2O. A volume infusion of 1000 ml of crystalloids improved the hemodynamic parameters back to normal (113/65 mmHg, heart rate 70/minute and CVP 8 mmHg). No vasopressors were used. The level of the sensory block was at a level of T5.

Skin incision (sub-xyphoid midline incision) was done and surgery progressed with no complaints. About 40 minutes later, the patient developed nausea and retching that coincided with manipulation of the intestine. This was treated with intravenous 0.4 mg of glycopyrolate and 4 mg of ondansetrone.

Oxygen saturation was maintained around 99% all over the procedure with 5 L of oxygen via a non re-breathing mask without any respiratory discomfort. The surgery was completed in 150 minutes, uneventfully. At the end, the patient was bright, rational and reasonably comfortable and hemodynamically stable with no pain.

Immediately before transferring the patient to ICU, a bolus of 10 ml bupivacaine 0.1% with fentanyl 20 μg was given through the epidural catheter. Her ICU stay was for about 24 hours and uneventful and she was discharged from the hospital 5 days after the surgery with her drugs, without any added complications.

DISCUSSION

From a review of the case reports concerning anesthesia for patients with PH (especially in Eisenminger's syndrome), a higher tendency to use GA was noticed than neuroaxial block (68 cases versus 19 cases out of 103 cases, combined anesthesia used for the remaining 16 cases), although mortality rate was 18% among GA patients in comparison to 5% among neuroaxial block patients.[2]

GA is still preferred in some case studies due to the fact that it offers better control of patient's oxygen saturation and end tidal carbon dioxide, thereby increase of pulmonary vascular resistance can be averted. In addition, use of nitric oxide is facilitated in an intubated patient.

In this case study, a successful trial of lone epidural anesthesia for a major abdominal surgery was done. The selection of site of insertion of the epidural catheter is important. It should be at a level corresponding to the center of the surgical field to avoid being at the periphery of the block. This enables creation of a dense block at the surgical site, surrounded by a wide extended block reaching higher thoracic segments. Blocking of sympathetic outflow would avoid the compensatory increase in sympathetic activity secondary to lumbar and lower thoracic sympathetic block. This procedure could prevent the homeometric deterioration in right ventricular function (secondary to deterioration in right ventricular–pulmonary arterial coupling), especially in patients with documented severe PH and cor-pulmonale.[4]

Use of lumbar epidural anesthesia affects the motor power of intercostal muscles minimally thereby protecting the patient from hypoxia, hypercarbia and subsequent exacerbation of PH. Prophylactic use of anti-cholinergics and centrally acting anti-emetics is advised in these patients, especially with procedures that include extensive intestinal manipulation.

Thoracic epidural analgesia (TEA) is another well-established pain control strategy in patients recovering from major abdominal surgery,[5] and has been demonstrated to decrease postoperative pulmonary complications.[6] TEA was shown to be associated with reduced postoperative morbidity and mortality compared to that of GA.[4]

A disadvantage of lumbar epidural anesthesia seemed to be the increase in thoracic sympathetic discharge which occurs as a compensatory mechanism in unblocked thoracic segments. This increase of sympathetic tone is quite significant and results in hemodynamic deterioration, especially during pulmonary embolism.[7] Finally, epidural blocking effect on the right side of the heart and pulmonary circulation is not well understood and has contradicting effects.

Insertion of catheters into the heart may precipitate dysrhythmia which may not be tolerated as these patients are reliant on atrial contraction for adequate cardiac output.[7] Only the CVP catheter was inserted with caution as a guide of hemodynamic monitoring. The flow-directed thermodilution catheter was avoided since the patient already had atrial premature beats. Sometimes, in the presence of severe PH, it is difficult to insert catheters into pulmonary arteries and the risk of rupture of pulmonary artery during balloon inflation is high.[8]

CONCLUSION

High lumber epidural anesthesia offers a good alternative in the management of patients with severe PH, undergoing abdominal surgery.

When there is a severe PH, clinical optimization prior to surgery would be hardly perfect. Moreover, the presence of a suspicious tumor may not allow protracted waiting for optimum conditions. Hence, minimal intervention and preparedness for risk management give a good outcome.

More case series or comparative studies are needed to compare the outcome of patients undergoing general and epidural anesthesia. A well-constructed evaluation scale should be adopted to evaluate the preoperative morbidity as well.