Cyanide toxicity during cardiopulmonary bypass with small dose of nitroprusside: a case report.

Sodium nitroprusside (SNP) is an anti-hypertensive drug, commonly used to decrease the systemic vascular resistance and lower the blood pressure. When the amount of cyanide generated by the SNP exceeds the metabolic capacity for detoxification, cyanide toxicity occurs. Under general anesthesia and cardiopulmonary bypass (CPB), it may be difficult to detect the development of cyanide toxicity. In cardiac surgical patients, hemolysis, hypothermia and decreased organ perfusion, which emphasize the risk of cyanide toxicity, may develop as a consequence of CPB. In particular, hemolysis during CPB may cause an unexpected overproduction of cyanide due to free hemoglobin release. We experienced a patient who demonstrated SNP tachyphylaxis and cyanide toxicity during CPB, even though the total amount of SNP administered was much lower than the recommended dose. We therefore report this case with a review of the relevant literature.

Malposition of central venous catheter in the jugular venous arch via external jugular vein -a case report.

The central venous cannulation is commonly performed in the operating rooms and intensive care units for various purposes. Although the central venous catheter (CVC) is used in many ways, the malpositioning of the CVC is often associated with serious complications. We report a case of an unexpected malposition of a CVC in the jugular venous arch via external jugular vein.

Accuracy of cardiac output measurements during off-pump coronary artery bypass grafting: according to the vessel anastomosis sites.

BACKGROUND: During beating heart surgery, the accuracy of cardiac output (CO) measurement techniques may be influenced by several factors. This study was conducted to analyze the clinical agreement among stat CO mode (SCO), continuous CO mode (CCO), arterial pressure waveform-based CO estimation (APCO), and transesophageal Doppler ultrasound technique (UCCO) according to the vessel anastomosis sites. METHODS: This study was prospectively performed in 25 patients who would be undergoing elective OPCAB. Hemodynamic variables were recorded at the following time points: during left anterior descending (LAD) anastomosis at 1 min and 5 min; during obtuse marginal (OM) anastomosis at 1 min and 5 min: and during right coronary artery (RCA) anastomosis at 1 min and 5 min. The variables measured including the SCO, CCO, APCO, and UCCO. RESULTS: CO measurement techniques showed different correlations according to vessel anastomosis site. However, the percent error observed was higher than the value of 30% postulated by the criteria of Critchley and Critchley during all study periods for all CO measurement techniques. CONCLUSIONS: In the beating heart procedure, SCO, CCO and APCO showed different correlations according to the vessel anastomosis sites and did not agree with UCCO. CO values from the various measurement techniques should be interpreted with caution during OPCAB.

Comparative effects of norepinephrine and vasopressin on internal thoracic arterial graft flow after off-pump coronary artery bypass grafting.

OBJECTIVE: Vasoconstrictors such as norepinephrine and vasopressin are commonly used to raise the blood pressure during myocardial revascularization. The internal thoracic artery is commonly used for coronary artery grafting because of its long-term patency. However, the internal thoracic artery is a living conduit that responds to vasoactive substances. The objective of this study was to measure change in internal thoracic arterial flow after infusion of norepinephrine or vasopressin. METHODS: Forty-one patients undergoing elective off-pump coronary artery bypass grafting participated in this study. After the median sternotomy, the left internal thoracic artery was dissected with a pedicle and grafted to the left anterior descending artery. After all anastomoses were performed and hemodynamic parameters were stable, the grafted internal thoracic arterial blood flow was measured by transit time flowmeter on the distal portion of the graft as a baseline. Norepinephrine or vasopressin was then infused until mean arterial pressure was increased to 20% of baseline. Graft flow and hemodynamic variables were measured when mean arterial pressure reached the intended level. RESULTS: Baseline grafted internal thoracic arterial flows were similar (norepinephrine 57.1 ± 17.7 mL min(-1), vasopressin 66.0 ± 34.3 mL min(-1)). With norepinephrine, flow increased significantly relative to baseline (77.2 ± 31.0 mL min(-1)); with vasopressin, it remained unchanged (68.3 ± 37.0 mL min(-1)). CONCLUSIONS: For patients needing vasopressor support after coronary artery bypass grafting, norepinephrine appeared superior to vasopressin because of increased internal thoracic arterial flow.

Occlusion of the right subclavian artery after insertion of a transesophageal echocardiography probe in an adult with a vascular ring -A case report-.

Intraoperative transesophageal echocardiography (TEE) has become an important monitoring device for patients undergoing cardiac or noncardiac surgery. Complications associated with TEE are unusual, but the potential for TEE probe compression of the posterior vascular structures has been reported in pediatric patients. We present here a case of occlusion of the right subclavian artery in an adult patient with a vascular ring after insertion of a TEE probe.

Resolution of peripheral artery catheter-induced ischemic injury in infants -Two case reports-.

The occurrence of catheter-induced vasospasm of small caliber arteries is a well known complication of arterial catheterization in neonates. However, there is rare publication about these complications in infants. We report infants with peripheral ischemia caused by arterial catheterization of the femoral artery.

Effects of head-up tilt on intrapulmonary shunt fraction and oxygenation during 1-lung ventilation in the lateral decubitus position.

OBJECTIVE: Hypoxemia is a common problem of 1-lung ventilation. Arterial oxygenation progressively decreases after 1-lung ventilation. The surgical position influences the shunt and arterial oxygenation. Therefore we evaluated the effect of head-up tilt on intrapulmonary shunt and oxygenation during 1-lung ventilation in the lateral decubitus position. METHODS: Twenty patients requiring 1-lung ventilation were included in this study. During 1-lung ventilation, hemodynamic and respiratory variables were measured 15 minutes after horizontal positioning in the lateral decubitus position (baseline), 5 and 10 minutes after a 10-degree head-up tilt (T5 and T10, respectively), and 10 minutes after the patient was returned to a horizontal position (T20). Arterial and mixed venous blood analyses were performed at the same time points. RESULTS: Arterial oxygenation was increased, and shunt was decreased significantly during head-up tilt position in 1-lung ventilation. These changes were accompanied by decreases in the mean arterial pressure and cardiac filling pressures without significant changes in cardiac index. CONCLUSIONS: Head-up tilt during 1-lung ventilation in the lateral decubitus position caused a significant decrease in shunt and an increase in arterial oxygenation that persisted after the patient was returned to the horizontal lateral decubitus position.

Pressure-controlled versus volume-controlled ventilation during one-lung ventilation in the prone position for robot-assisted esophagectomy.

BACKGROUND: The prone position during robotic esophageal mobilization for minimally invasive esophagectomy (MIE) provides several advantages with regards to operative times, surgeon ergonomics, and surgical view; however, this technique requires one-lung ventilation (OLV). There are no guidelines about ventilatory modes during OLV in the prone position. We investigated the effects of volume-controlled (VCV) and pressure-controlled ventilation (PCV) on oxygenation and intrapulmonary shunt during OLV in the prone position in patients who underwent robot-assisted esophagectomy. METHODS: Eighteen patients, no major obstructive or restrictive pulmonary disease, were allocated randomly to one of two groups. In the first group (n = 9), OLV was started by VCV and the ventilator was switched to PCV after 30 minutes. In the second group (n = 9), the modes of ventilation were performed in the opposite order in the prone position. Hemodynamic and respiratory variables were obtained during OLV at the end of each ventilatory mode. RESULTS: There were no significant differences in arterial oxygen tension (PaO(2)), airway pressures, dynamic lung compliance, or physiologic dead space (Vd/Vt) during OLV between PCV and VCV in the prone position. Intrapulmonary shunt (Qs/Qt) was significantly lower with VCV than with PCV during OLV in the prone position (p = 0.044). CONCLUSION: PCV provides no advantages compared with VCV with regard to respiratory and hemodynamic variables during OLV in the prone position. Either ventilatory mode can be safely used for patients who undergo robot-assisted esophagectomy and who have normal body mass index and preserved pulmonary function.

The anesthetic management of a venous bullet embolism to the right ventricle: A case report.

Bullet embolism is a rare complication of non-penetrating gunshot trauma. There are two types of bullet embolisms: arterial and venous. Accurate preoperative localization of the bullet is important for selecting the proper surgical and anesthetic techniques. We report here on a rare case of venous bullet embolus to the right ventricle from the right iliac vein, as was demonstrated by transesophageal echocardiography.

Intravalvular regurgitation of the mitral bioprosthetic valve detected by intraoperative transesophageal echocardiography : A case report .

Intraoperative transesophageal echocardiography (IOTEE) is an invaluable diagnostic method for management of cardiac surgical patients, including patients undergoing valve replacement surgery. We report a patient who underwent reoperation for mitral valve replacement due to intravalvular regurgitation following mitral valve replacement with a bioprosthetic valve. The condition was detected by IOTEE and caused by suture entrapment.

Asystole induced by laryngosopy and tracheal intubation after induction of general anesthesia: A case report.

Vagal reflex during laryngosopy and tracheal intubation may result in cardiac arrhythmia such as bradyarrhythmia and asystole. A 66-year-old woman, scheduled for coronary artery bypass surgery, received intravenous bolus of midazolam 2 mg, sufentanil 50 microgram, and vecuronium 10 mg for induction of general anesthesia. After two minutes of manual ventilation, tracheal intubation was attempted and the patient became asystolic during laryngoscopic manipulation. The laryngoscope was immediately withdrawn, and the patient returned to normal sinus rhythm. Ten minutes later, more experienced practitioner performed the second laryngoscopic intubation, but it eventually induced asystole again. External cardiac massage was commenced and normal sinus rhythm retuned at a rate of 60 beats/min after 1-2 minute later.

Pregabalin and gabapentin inhibit substance P-induced NF-kappaB activation in neuroblastoma and glioma cells.

Pregabalin and gabapentin are lipophilic amino acid derivatives of gamma-amino butyric acid that show anticonvulsant and analgesic activity against neuropathic pain. In this study, we investigated their actions on substance P-induced NF-kappaB activation in human neuroblastoma and rat glioma cells. Pregabalin and gabapentin decreased substance P-induced NF-kappaB activation in these cells. These drugs also inhibited NF-kappaB activation in rat spinal dorsal root ganglia cells pre-treated in vitro with substance P. These results suggest a previously undefined role of pregabalin and gabapentin in the regulation of inflammation-related intracellular signaling in both neuronal and glial cells.

Effects of head-down tilt on intrapulmonary shunt fraction and oxygenation during one-lung ventilation in the lateral decubitus position.

OBJECTIVE: During one-lung ventilation, surgical positions significantly affect deterioration of oxygenation, and the lateral decubitus position is superior in preventing dangerous hypoxemia compared with the supine position. However, additional head-down tilt causes more compression of the dependent ventilated lung by the abdominal contents and may result in dangerous hypoxemia, as occurs in the supine position. Therefore, we evaluated the effect of head-down tilt on intrapulmonary shunt and oxygenation during one-lung ventilation in the lateral decubitus position. METHODS: Thirty-four patients requiring one-lung ventilation were randomly allocated to the control group (n = 17) or the head-down tilt group (n = 17). Hemodynamic and respiratory variables were measured 15 minutes after one-lung ventilation in the lateral decubitus position (baseline), 5 and 10 minutes after a 10-degree head-down tilt (T5 and T10, respectively), and 10 minutes after the patient was returned to a horizontal position (T20) in the head-down tilt group. Measurements were done at the same time points in the control group without head-down tilting. RESULTS: In the head-down tilt group, cardiac filling pressures were increased after head-down tilt without any changes in cardiac index. Percent change of shunt to baseline value was significantly increased at T10 and T20 in the head-down tilt group. Percent change of arterial oxygen tension to baseline value was significantly decreased at T5, T10, and T20 in the head-down tilt group, whereas it was decreased only at T20 in the control group. CONCLUSION: Head-down tilt during one-lung ventilation in the lateral decubitus position caused a significant increase in shunt and a decrease in percent change of arterial oxygen tension, without causing dangerous hypoxemia.

Effect of oral sildenafil citrate on intraoperative hemodynamics in patients with pulmonary hypertension undergoing valvular heart surgery.

OBJECTIVE: Pulmonary hypertension remains a major problem during the perioperative period for surgical correction of long-standing valvular heart disease. Sildenafil citrate (INN sildenafil) is a selective phosphodiesterase type 5 inhibitor that is being increasingly recognized as a treatment modality for pulmonary hypertension. There is lack of evidence, however, regarding its pulmonary vasodilatory effect in anesthetized cardiac surgical patients. We therefore evaluated the effects of sildenafil on hemodynamics in patients with concomitant pulmonary hypertension undergoing valvular heart surgery in a controlled, prospective, randomized, double-blind trial. METHODS: Fifty-three patients scheduled for valvular heart surgery with mean pulmonary arterial pressure greater than 30 mm Hg were randomly treated with either 50 mg oral sildenafil (n = 26) or placebo (n = 27) 10 minutes before induction of anesthesia. Hemodynamic variables were measured 5 minutes after induction of anesthesia (baseline) and at 30 and 60 minutes after medication. RESULTS: Patient characteristics and baseline hemodynamics were similar between groups. Systolic and mean pulmonary arterial pressures and pulmonary vascular resistance were significantly lower in the sildenafil group at 30 minutes after medication, without any changes in mean systemic arterial pressure and systemic vascular resistance. CONCLUSION: Sildenafil produced significant pulmonary vasodilatory effect relative to placebo in anesthetized cardiac surgical patients with pulmonary hypertension. With respect to the predominant selectivity of sildenafil to pulmonary vasculature shown in this study and other potentially beneficial effects such as myocardial protection, use of sildenafil in the intraoperative period in cardiac surgical patients with pulmonary hypertension should be considered.

The effect of milrinone on the right ventricular function in patients with reduced right ventricular function undergoing off-pump coronary artery bypass graft surgery.

This investigation evaluated the effect of continuous milrinone infusion on right ventricular (RV) function during off-pump coronary artery bypass graft (OPCAB) surgery in patients with reduced RV function. Fifty patients scheduled for OPCAB, with thermodilution RV ejection fraction (RVEF) <35% after anesthesia induction, were randomly allocated to either milrinone (0.5 microg/kg/min) or control (saline) group. Hemodynamic variables and RV volumetric data measured by thermodilution method were collected as follows: after anesthesia induction (T1); 10 min after heart displacement for obtuse marginal artery anastomosis (T2); after pericardial closure (T3). Cardiac index and heart rate increased and systemic vascular resistance significantly decreased in milrinone group at T2. Initially lower RVEF of milrinone group was eventually comparable to control group after milrinone infusion. RVEF did not significantly change at T2 and T3 in both groups. RV end-diastolic volume in milrinone group consistently decreased from the baseline at T2 and T3. Continuous infusion of milrinone without a bolus demonstrated potentially beneficial effect on cardiac output and RV afterload in patients with reduced RV function during OPCAB. However, aggressive augmentation of intravascular volume seems to be necessary to maximize the effect of the milrinone in these patients.

Effects of milrinone on blood flow of the Y-graft composed with the radial and the internal thoracic artery in patients with coronary artery disease.

OBJECTIVE: Milrinone has been known to dilate the internal thoracic artery (ITA) and the radial artery (RA). The effect of milrinone, however, on each graft is unclear when the left ITA (LITA) and the RA form a Y-graft. This study evaluated the changes in blood flow of a composite Y-graft in response to milrinone. METHODS: Thirty-two patients undergoing an isolated coronary artery bypass graft surgery were included in this study. A Y-graft was created with an in situ LITA and free RA graft attached to the proximal side of the LITA. Graft flow was measured by opening the graft end for 30s, and is expressed in 'ml/min'. Graft flow and hemodynamic data were recorded before and 10 min after intravenous milrinone (50 microg/kg) administration. RESULTS: Milrinone significantly increased the RA graft flow, measured while the LITA graft end was clamped, and total Y-graft flow. Respective graft flows were not increased by milrinone when both clamps were released simultaneously, in spite of a significant decrease in the resistance of both grafts. The ratio of flows through the RA and the LITA grafts was not changed by milrinone. CONCLUSION: Milrinone significantly reduced RA and LITA resistances and increased the total Y-graft flow. Milrinone might dilate each individual arterial graft to a different degree. Milrinone did not, however, change the flow ratio through the RA to LITA grafts when they were measured simultaneously. Therefore, it would not significantly divert graft flow to one side in a composite Y-graft.

Transcriptional regulation of artemin is related to neurite outgrowth and actin polymerization in mature DRG neurons.

Artemin is a member of the glial cell line-derived neurotrophic factor (GDNF) family of ligands that helps to ensure the survival of sensory neurons. We used an in vitro isolated dorsal root ganglia model to study the effects of artemin on the adult rat neuronal system and investigate differentially regulated genes. We found that 285 genes were differentially transcribed by artemin after 3 h of treatment, including genes related to cell adhesion and actin polymerization. A series of genes involved in the regulation of actin dynamics, including coronin, Myr 5, Wiskott-Aldrich syndrome protein interacting protein, cofilin, drebrin and dynamin were down-regulated by artemin, suggesting that it plays a previously undefined role in the regulation of actin polymerization and synaptic vesicle movement. Artemin also down-regulated the expression of genes related to cell adhesion and matrix assembly, including biglycan, plectin, nestin, neuronatin and the neuron-glia-CAM-related cell adhesion molecule, which is functionally relevant to neurite elongation in DRG neurons. Artemin resulted in increases in total neurite length and branching of the DRG neurons. Also artemin caused an increase of synaptic vesicle clustering. Our results showed that the inhibition of DNA methylation suppressed the artemin-dependent neurite growth, suggesting that the genetic regulation could be relevant to neurite elongation in mature DRG.

The effect of skin surface warming during anesthesia preparation on preventing redistribution hypothermia in the early operative period of off-pump coronary artery bypass surgery.

OBJECTIVE: Redistribution hypothermia adversely affects hemodynamics and postoperative recovery in patients undergoing cardiac surgery. In off-pump coronary bypass surgery (OPCAB), maintaining the temperature is important because warming by cardiopulmonary bypass is omitted. Pre-warming studies reported earlier showing pre-warming as an effective means of preventing redistribution hypothermia was time consuming since it required at least 1-2h to pre-warm the patients before the surgery. Because pre-warming for such a long time is impractical in clinical practice, this study evaluated the efficacy of active warming during the preanesthetic period for the prevention of redistribution hypothermia in the early operative period of OPCAB. METHODS: After gaining the approval of Institutional Review Board and informed consent from the patients, 40 patients undergoing OPCAB were divided into control and pre-warming groups. The patients in control group (n=20) were managed with warm mattresses and cotton blankets, whereas patients in pre-warming group (n=20) were actively warmed with a forced-air warming device before the induction of anesthesia. Hemodynamic variables and temperature were recorded before anesthesia (Tpre) and at 30 min intervals after anesthesia for 90 min (T30, T60, and T90). RESULTS: Active warming duration was 49.7+/-9.9 min. There were no statistically significant differences in skin temperature, core temperature and hemodynamic variables between the two groups at preinduction period except for mean arterial pressure and central venous pressure. The core temperature at T30, T60, and T90 was statistically higher in pre-warming group than that in control group. Core temperature of six (30%) and seven patients (35%) in control group was reduced below 35 degrees C at T60 and T90, respectively, whereas core temperature of only one patient (5%) in pre-warming group was reduced below 35 degrees C at T90 (P=0.02). CONCLUSIONS: Active warming using forced air blanket before the induction of anesthesia reduced the incidence and degree of redistribution hypothermia in patients undergoing OPCAB. It is a simple method with reasonable cost, which does not delay the induction of anesthesia nor the surgery.

Alteration of surgical management following intraoperative transesophageal echocardiography in a patient with mobile left atrial thrombi embolized during anesthesia.

This report describes alteration of surgical management in a patient with a large free-floating ball thrombus in the left atrium, which was embolized before sternotomy as demonstrated by intraoperative transesophageal echocardiography. Due to new findings observed by intraoperative transesophageal echocardiography, unnecessary sternotomy could be avoided.