Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CLAMPS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 343 records · Page 19Linked to original sources
PubMed2002

Shell clamping behaviour in the limpet Cellana tramoserica.

The behaviour of clamping the shell against the substratum may play an important role in the limpet adhesion mechanism because friction generated by this behaviour resists dislodgement by shear forces. This paper describes the development of an apparatus to analyse limpet clamping activity in relation to known forces, including simulated wave activity and predator attack. The results show that Cellana tramoserica clamps its shell in a closely regulated manner consistent with an active role in the limpet adhesion mechanism. Limpets clamped sharply for several seconds in response to single disturbances such as tapping the shell. In response to more continuous disturbance simulating a concerted predator attack, limpets clamped tightly for several minutes. In response to lifting forces applied to the shell, limpets clamped at a set proportion of the lifting force, even if the lift force was a highly dynamic wave profile. This behaviour has implications for numerical models that attempt to describe limpet adhesion because it shows that limpets cannot be represented by a simple mechanical analogue and that the clamping behaviour must be accounted for if useful predictions are to be drawn.

Adaptation, Physiological↗
PubMed2003

Yielding of the clamped-wire system in the Ilizarov external fixator.

This study demonstrates that the clamped-wire system used to suspend bones within an Ilizarov external fixator yields when the perpendicular load exceeds 50 N per wire. Cyclic loading was applied to tensioned wires clamped within an Ilizarov ring component, with steadily increasing load amplitude. Wires were tested at four initial tension settings. The amount of energy lost within the clamped-wire system per load cycle was calculated for every test. The results showed that there was a consistent trend to increasing non-recoverable energy loss per load cycle when peak loads exceed 50 N for all initial tension settings. A finite element (FE) model replicating the experimental conditions was performed to investigate the levels of stress within the loaded wires. The FE model analyses showed that high stresses were generated in the wires close to the clamping sites, and that the stress levels could reasonably be expected to exceed the material yield stress when loaded to about 55 N, for all initial tension settings. The results show that material yield, accompanied by some wire slippage through the clamps, is responsible for system yield, in agreement with previous studies. Although the initial wire tension has an appreciable effect on the wire stiffness, it did not affect the elastic load range of the clamped-wire system. To prevent yield of the clamped-wire system in practice, the fixator should be assembled with sufficient wires to ensure that the load transmitted to each wire by the patient does not exceed 50 N.

Bone Wires↗
PubMed2004

Methodological validity and feasibility of the nitric oxide clamp technique for nitric oxide research in human resistant vessels.

N(G)-methyl-L-arginine (L-NMMA) has been widely used for nitric oxide (NO) research, particularly for the assessment of NO-dependent vasodilatation evoked by agonists. However, such experiments may not be straightforward because L-NMMA causes vasoconstriction, which itself must non-specifically affect responses to any vasoactive agents. Therefore, in order to more accurately estimate the roles of NO in human vessels in vivo, we developed an NO clamp technique that uses co-infusion of an NO donor with L-NMMA. To assess the validity and feasibility of this technique, we compared the effects of intra-arterial infusion of L-NMMA on the forearm blood flow responses to vasodilators with and without the NO clamp technique in healthy males. All drugs were intra-arterially infused and changes in forearm blood flow (FBF) were measured by strain-gauge plethysmography. Vasodilatation evoked by atrial natriuretic peptide was significantly attenuated by L-NMMA alone (p = 0.001) but not by the NO clamp technique. L-NMMA significantly attenuated the responses to acetylcholine either with or without the NO clamp technique. However, the ratio of the area under the curve (AUC) of acetylcholine with L-NMMA to that without L-NMMA was significantly higher when the NO clamp technique was not used (AUC ratio: 0.62 +/- 0.13 vs. 0.48 +/- 0.14, respectively; p = 0.031). The contribution of NO to the FBF responses to vasodilators may be more properly assessed by the co-infusion of L-NMMA with the NO clamp technique than by L-NMMA alone. Our NO clamp technique thus appears to be valid and feasible for human NO research.

Acetylcholine↗
PubMed2004

Comparison of equivalence and determination of diagnostic utility of min-mod and clamp methods for insulin resistance in diabetes free subjects: a meta-analysis.

The gold standard for quantifying insulin sensitivity (IS) is the hyperinsulinemic-euglycemic clamp (Clamp) with a cut-off point of 5x10-2 (dL/min)/(microU/mL) or less to indicate insulin resistance. Bergman's minimal model (Min-Mod) is also being used to estimate IS, but there are doubts as to its equivalence with Clamp. The objective of the present study is to determine if Clamp and the tolbutamide and insulin techniques of Min-Mod are equivalent. Meta-analysis based on a bibliographic search from 1970 until the present was made for the MeSH terms: insulin resistance, hyperglycemic-clamp, euglycemic-clamp, Min-Mod, minimal model approach. Concordance was determined with both simple and intraclass correlation and Bland and Altman's concordance limits using R. Three of the 109 articles found were included. The concordance limits indicate that Clamp and Min-Mod are not equivalent, which could result in diagnostic errors if the accepted cut-off point is used for both methods. Given this lack of equivalence, a ROC analysis was performed and new diagnostic cut-off points of 2.4 and 4.6x0-2 (dL/min)/(microU/mL) for insulin and tolbutamide techniques of Min-Mod, respectively, are proposed, with adequate sensitivity, specificity, and predictive value. These values should be prospectively validated.

Blood Glucose↗
PubMed2006

Timing of cord clamping revisited.

Although cord cutting has been performed since the beginning of mankind, the timing and advantages of early versus delayed cord clamping are still controversial. Early cord clamping (within the first 30 s after birth) is usually justified for potential prevention of postpartum hemorrhage and for immediate treatment of the newborn, but at the same time, may increase Rh-sensitization. Delayed cord clamping is performed after a period of 30 s during which 'placental transfusion' of approximately 80 mL of blood occurs. This amount seems to protect the baby from childhood anemia without increasing hypervolemia-related risks. In preterm infants, delayed clamping appears to reduce the risk of intraventricular hemorrhage and the need for neonatal transfusion. Obtaining cord blood for future autologous transplantation of stem cells needs early clamping and seems to conflict with the infant's best interest. Although a tailored approach is required in the case of cord clamping, the balance of available data suggests that delayed cord clamping should be the method of choice.

Anemia, Iron-Deficiency↗
PubMed1986

The insulin sensitivity index in nondiabetic man. Correlation between clamp-derived and IVGTT-derived values.

Although the minimal-model-based insulin sensitivity index (S1) can be estimated from the results of a simple 180-min intravenous glucose tolerance test (IVGTT), its relationship to widely accepted but technically more difficult clamp-based techniques has not been resolved in humans. Therefore we measured S1 by standard IVGTT, modified IVGTT, and clamp methods in 10 nondiabetic men with %IBW of 109 +/- 12 (mean +/- SD). In the euglycemic clamp studies, insulin was infused to bring insulin levels (IRI) from basal, 8 +/- 4 microU/ml, to plateaus of 21 +/- 5 and 35 +/- 6 microU/ml. S1[clamp], measured as the increase in glucose (G) clearance per increase in IRI [delta INF/(delta IRI X G)], averaged 0.29 +/- 0.09 ml/kg X min per microU/ml. In the IVGTT studies, 300 mg/kg G was given as an i.v. bolus, and G and IRI were measured for 180 min; in the modified (mod) IVGTT, tolbutamide (300-500 mg) was given i.v. 20 min after the G to observe the effect of an IRI peak on G removal after G level was free of initial "mixing" effects. The S1 estimated by computer did not differ significantly between standard [(6.9 +/- 3.4) X 10(-4) min-1 per microU/ml] and modified [(6.7 +/- 3.5) X 10(-4) min-1 per microU/ml] tests, indicating no bias due to the differing insulin patterns and levels. There was a strong positive correlation between S1 (mod IVGTT) and S1(clamp): r = 0.84; N = 10; P less than 0.002. The correlation between S1(standard IVGTT) and S1(clamp) was 0.54, suggesting the modified test is less "noisy." Nonetheless, in eight euglycemic women with a wider range of adiposity, S1(standard IVGTT) has been significantly correlated with %IBW (r = -0.72) and basal IRI (r = -0.84). The correlation between S1 measures by clamp and IVGTT methods provides one step toward validation of the minimal model for studies of insulin action in man.

Adult↗
PubMed1982

Myocardial protection during aortocoronary bypass operations. Comparison of two different operative procedures: cold chemical cardioplegia versus intermittent cross-clamping of the aorta.

Myocardial injury was studied in 40 randomized coronary patients operated on electively with coronary bypass grafting using two different techniques, (A) cardioplegic arrest and continuous cross-clamping of aorta, and (B) ischaemic arrest and intermittent cross-clamping of aorta. The released quantity of the MB isoenzyme of creatine kinase was used as an indicator of myocardial injury. Of the whole group, 3 patients (8%) suffered a myocardial infarction as judged by ECG. The CK-MB release was not significantly different in the two groups. The total period of aortic cross-clamping was markedly longer in the cardioplegic group than in the intermittent clamping group. A significant correlation between the duration of aortic clamping and the amount of CK-MB release was found in the cardioplegic group. Our results indicate that the beneficial effects of cardioplegic arrest are outweighed by an unavoidable longer period of total aortic clamping as compared with the intermittent clamping technique.

Aorta↗
PubMed1983

Temporary incomplete ischemia of the legs induced by aortic clamping in man. Metabolic and hemodynamic effects of temporary extracorporeal by-pass.

The effects on central hemodynamics and skeletal muscle metabolism during surgery for abdominal aortic aneurysm were compared in 6 patients given a preoperative adrenergic block (group B) and in 6 patients who additionally had a temporary brachio-femoro-femoral by-pass during the aortic clamping (group B + S). The cardiac output, heart rate, arterial and pulmonary artery pressures and the cardiac filling pressure were studied. Biopsy specimens from the lateral vastus muscle and blood samples from the radial artery and the iliac vein were taken before aortic clamping and also before and 30 minutes, 4 and 16 hours after the aortic declamping. Intramuscular temperature and pH were measured. The glycogen, glucose, lactate, pyruvate, ATP, ADP, AMP, phosphocreatine (PCr) and creatine (Cr) contents of the muscle and the lactate and pyruvate concentration in iliac venous and radial arterial blood were determined, using enzymatic fluorometric techniques. In group B, aortic clamping induced severe temporary incomplete ischemia with a 300% increase in lactate/pyruvate (L/P) ratio and a fall in intramuscular pH (pHm). The adenylate energy charge (EC) decreased, but the creatine (PCr + CR) and the adenylate (ATP + ADP + AMP) pool remained unchanged. After aortic declamping, the L/P ratio, EC and pHm regained their preclamping values, but the pools of energy phosphate compounds were reduced, indicating dysfunction or damage of the muscle cells. In group B + S there were no major muscle metabolic changes during clamping or after declamping of the aorta. In group B the systemic vascular resistance (SVR), mean arterial blood pressure (MAP) and left ventricular stroke work (LVSW) increased during the occlusion. On release of the clamp, cardiac output rose, possibly due to the sudden reduction of SVR. A temporary marked fall of MAP occurred. In group B + S, no increase of SVR, MAP or LVSW was observed during aortic clamping. After the declamping, only a minor MAP drop was observed. In both groups, a brief rise in pulmonary vascular resistance after the aortic declamping suggested transient pulmonary microembolism. If a high-risk patient is to undergo reconstructive surgery of the abdominal aorta and/or technical difficulties can be expected to necessitate prolonged cross-clamping during the operation, a temporary extracorporeal by-pass may be a favorable adjuvant, improving cardiac performance and preventing derangement of muscle metabolism.

Adrenergic beta-Antagonists↗
PubMed1975

Postoperative hemodynamics following aortic cross-clamping during aortocoronary bypass surgery.

Forty-one patients undergoing aortocoronary bypass surgery were divided into two groups: an "unclamped" group (17 patients) in whom the aorta was not cross-clamped during operation and a "clamped" group (24 patients) in whom the ascending aorta was cross-clamped during performance of distal anastomoses. Myocardial protection was provided during aortic clamping by cooling the anoxic heart with cold saline immersion. Immediate postoperative hemodynamic function was assayed in both groups, as was cardiopulmonary bypass time and cardiopulmonary bypass time/graft. Cardiopulmonary bypass time was 107 minutes in the unclamped group and 87 minutes in the clamped group (P less than 0.05). Cardiopulmonary bypass time/graft was 48 minutes in the unclamped group and 40 minutes in the clamped group (P less than 0.01). Results of hemodynamic studies with values for the unclamped group listed first were as follows: cardiac index (L/min/m2) 2.3 and 2.5 (NS), stroke index (ml/beat/m2) 23 and 25 (NS), left ventricular minute work index (kg-m/min/m2) 3.03 and 2.81 (NS), and stroke work index (g-m/min/m2) 31 and 30 (NS). These data indicate that aortic cross-clamping during performance of distal anastomoses expedites the performance of aortocoronary bypass surgery and does not adversely affect postoperative hemodynamics.

Adult↗
PubMed2002

Nephron sparing surgery for renal cell carcinoma using selective renal parenchymal clamping.

PURPOSE: We describe a technical artifice facilitating nephron sparing surgery for renal cell carcinoma without clamping the renal pedicle. MATERIALS AND METHODS: Selective renal parenchymal clamping was performed using a large curved DeBakey aortic clamp placed around and sufficiently far from the tumor. The lesion was resected with a surrounding margin of normal renal parenchyma. The intrarenal vessels were suture ligated and the collecting system was closed as necessary. Time was not limited since the artery was not clamped. RESULTS: Ten patients with renal cell carcinoma in whom nephron sparing surgery was indicated underwent selective renal parenchymal clamping. The indication was elective in 8 patients and urgent in 2. The tumor was at the renal pole in 3 cases and peripheral in 7. Mean tumor size was 32 mm. (range 19 to 52). Blood loss was insignificant. Operative time was 81 minutes (range 61 to 125) and there were no perioperative or postoperative complications. CONCLUSIONS: Selective renal parenchymal clamping is a simple and efficient technical maneuver for facilitating nephron sparing surgery without pedicle dissection and clamping for renal peripheral or pole tumors. Neoplasm location and size are the limiting factors of this technique.

Aged↗
PubMed2002

[Vascular clamping in hepatic surgery].

Outcome of hepatectomy procedures depends greatly on proper control of intraoperative bleeding. We detail here the different techniques for vascular clamping, discussing their different indications. Four parameters can be used to define clamping: the zone of application: separate control of arterial or glisson pedicles and portal veins (pedicles, selective hilar, suprahilar and intrahilar clamps), suprahepatic veins or vena cava; selectivity: partial or total clamp of hepatic blood supply; duration, continuous or intermittent; association measures to favor tolerance to ischemia (cooling, preservation fluid) or to limit downstream consequences (extracorporal circulation, derivation). The optimal clamp depends on the localization of the lesion and its relations with the great vessels, presence of liver disease, and the patient's general and cardiovascular status as well as the experience of the operator and the anesthesist. The goal is to use clamp as sparingly as possible, favoring selective clamps to avoid ischemia.

Constriction↗
PubMedDate not supplied

Oxygen metabolism of the liver during an HA clamp: HV saturation and free radicals.

BACKGROUND/AIMS: To clarify changes in the hepatic oxygen metabolism and tissue damage resulting from oxygen-derived free radical generation from polymorphonuclear cells during a hepatic arterial clamp. METHODOLOGY: Subjects were 32 male Wistar rats. Hepatic tissue blood flow, and hepatic venous chemiluminescence, indicating oxygen-derived free radicals from polymorphonuclear cells, and liver lipid peroxide were measured, and hepatic and portal venous blood gas analysis were performed before and after 130 minutes of hepatic arterial clamping. RESULTS: Hepatic tissue blood flow decreased by hepatic arterial clamp. The values of hepatic arterial oxygen pressure (HTBF), hepatic venous oxygen saturation (ShvO2), and O2 contents after hepatic arterial clamp were lower than those before hepatic arterial clamp (P = 0.035, 0.024, and 0.028, respectively). Hepatic venous chemiluminescence decreased and the lipid peroxide level of the liver increased by hepatic arterial clamp (P = 0.001). CONCLUSIONS: ShvO2 is useful for the evaluation of hepatic oxygen metabolism and hepatic tissue blood flow during acute hepatic arterial clamp. This condition should prepare the following tissue damage due to oxygen-derived free radicals from polymorphonuclear cells.

Animals↗
PubMed2004

Relationship between circle of Willis morphology on 3D time-of-flight MR angiograms and transient ischemia during vascular clamping of the internal carotid artery during carotid endarterectomy.

BACKGROUND AND PURPOSE: A potential source of complication at carotid endarterectomy (CEA) is cerebral ischemia caused by hypoperfusion during clamping of the carotid artery. Configuration of primary collateral pathways may be a major risk factor for development of transient cerebral ischemia during clamping. We investigated whether circle of Willis morphology on 3D time-of-flight (TOF) MR angiograms can reliably predict transient ischemia during vascular clamping of the internal carotid artery (ICA) in patients undergoing CEA. METHODS: Three-dimensional TOF MR angiography and CEA were performed in 117 patients. Patients had unilateral stenosis (n = 86), unilateral stenosis with contralateral occlusion (n = 21), or bilateral severe stenosis (n = 10) of the ICA. Circle of Willis morphology on preoperative 3D TOF MR angiograms was analyzed and correlated with intraoperative history of ischemia during vascular clamping of the ICA. RESULTS: Patients with unilateral stenosis or bilateral severe stenosis experienced transient ischemia during clamping of ICA at a low rate (11 [11%] of 96). In these groups, we found no specific circle of Willis patterns associated with development of intraoperative ischemia. However, patients with contralateral ICA occlusion experienced ischemia frequently during clamping of the ICA (12 [57%] of 21). In this group, incompleteness of the circle of Willis was significantly related to the risk of intraoperative ischemia (P =.005). CONCLUSION: In patients without contralateral ICA occlusion, circle of Willis morphology on 3D TOF MR angiograms cannot predict the development of intraoperative ischemia. However, in patients with contralateral ICA occlusion, incompleteness of the posterior part of the circle of Willis is a significant risk factor for development of ischemia during vascular clamping of the ICA.

Aged↗
PubMed1991

[Effects on hemodynamics and myocardial metabolism of prostaglandin E1 and trimethaphan after a descending aorta cross-clamp in experimentally coronary constricted dogs].

We investigated the hemodynamic effects of prostaglandin E1 (PGE1) and trimethaphan (TMP) during cross-clamp of the descending aorta in experimentally coronary constricted dogs. Using 21 mongrel dogs, the blood flow of the left anterior descending coronary artery was reduced to 50% by constricting the artery. After stabilization of hemodynamics, we cross-clamped descending aorta and administered PGE1 (1.0 microgram.kg-1.min-1) or TMP (5.0 micrograms.kg-1.min-1). The drugs were discontinued just before the clamp on the aorta was released. In the PGE1 group, cardiac output (CO) and left ventricular dp/dt (LVdp/dt) increased significantly 5 minutes after clamping, with CO remaining at its high level even after the clamp was released. In the TMP group, CO increased significantly 15 minutes after administration and returned to the preclamping value soon after declamping. LVdp/dt was unchanged during clamping and decreased significantly after declamping. In addition, marked increase of the myocardial blood flow (MBF) in the ischemic areas was seen in the PGE1 group, whereas no changes were seen with the TMP. In the ischemic heart, PGE1 can not only decrease afterload which is elevated by the cross-clamping of the aorta, but also increase the coronary blood flow and MBF in the ischemic areas.

Alprostadil↗
PubMed1990

[A study of spinal cord ischemia during aortic cross-clamp--evoked spinal cord potential and histological analysis of the spinal cord].

The relationship between the evoked spinal cord potential (ESP) and the histological findings of the spinal cord after thoracic aortic cross-clamp was studied. Thoracic aorta was cross-clamped in 23 dogs and ESP was monitored before, during, and after cross-clamping. Incidence of paraplegia and histological findings were studied after the dogs recovered from the procedure. Aortic cross-clamp was maintained for 60 minutes in 20 dogs (Group A). And cross-clamp was released 10 minutes after the amplitude of ESP became lower than 20% of control in 3 dogs. (Group B). In group A, three types of ESP changes were detected; ESP became lower or lost during cross-clamping in type 1 response, ESP remained unchanged in type 2 response, and ESP returned after transient loss during cross-clamping in type 3 response. Four of five dogs with type 1, none of nine with type 2, two of five with type 3 response showed paraplegia. One of the dogs with type 2 response showed paraparesis. ESP could not detected in one dog, in which traumatic spinal cord injury during laminectomy caused paraplegia. In Group B, all dogs showed type 1 response and paraplegia. Characteristic histological finding of the spinal cords of the dogs with paraplegia was the ischemic necrosis mainly in the gray matter. Necrotic foci were limited in the posterior horn in mild, in the anterior and posterior horn in moderate changes. And neurons were lost in entire gray matter in severe histological changes. In the spinal cords of the dogs with spastic paraplegia, severe histological changes were limited in the lower lumbar region.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[The effect of porto-intrahepatic portal bypass on the ischemic liver during clamping the hepatic inflow].

The object of this study was to determine the critical bypass flow rate of the porto-intrahepatic portal bypass during clamping the hepatic inflow, and to clarify the pathophysiology caused by this bypass procedure with special emphasis on the hepatic injury. Porto-intrahepatic portal bypass was instituted, using anti-thrombogenic catheter (Anthron), during clamping the hepatic inflow in anesthetized dogs. Bypass flow rate (BFR) was controlled at 10%, 30% and 60% of the portal flow in the individual experimental groups. As the control study, double bypass (portosystemic and femoral arterio-intrahepatic portal bypass) or portal-systemic bypass was instituted during clamping the hepatic inflow, and porto-systemic bypass at 10% and 60% during clamping the portal vein. Total adenine nucleotide (TAN) and adenylate energy charge (EC) of the liver did not change during 2 hour clamp of the portal vein. Clamping the hepatic inflow, unless congested splanchnic circulation, demonstrated the same level as 30% porto-portal bypass. Taking changes in hemodynamics, portal into consideration and arterial pH and PO2 levels, serum transaminase levels, ICG retention rate and animal survival rate, we conclude that insufficient flow rate of porto-portal bypass (10%, 30%) even cause more severe hepatic damage, and critical flow rate must be between 30% and 60% during 1 hour clamp.

Adenine Nucleotides↗
PubMed1988

The effect of dopamine on renal function during aortic cross clamping.

Eighteen male patients undergoing elective surgical reconstruction of the abdominal aorta were divided into two groups. Patients in Group I (nine) were given dopamine intravenously, in a dose of 2 micrograms/kg/min, during the first half of the period of cross-clamping, whilst those in Group II received dopamine during the second half. Each patient acted as his own control and for each, three periods were examined, namely: pre-clamp, clamping with dopamine and clamping without dopamine. Dopamine infusion during aortic clamping caused a significant rise in sodium output (P less than 0.01), potassium output (P less than 0.05), creatinine clearance (P less than 0.05) and urine output (P less than 0.05). We conclude that dopamine infusion during aortic clamping helps to protect the kidney from any deleterious effect of clamping.

Aged↗
PubMed1983

Cardiac and renal responses to cross-clamping of the descending thoracic aorta.

The present study was performed to document the relative efficacy of commonly applied techniques used adjunctively during 1 hour of descending thoracic aortic cross-clamping. Renal and cardiac responses were determined by standard laboratory methods. There were four experimental groups: (1) heparin-bonded shunt; (2) partial femoral-femoral bypass; (3) sodium nitroprusside; (4) control. Each of the experimental groups showed abnormal hemodynamic responses during cross-clamping. Elevations in left ventricular end-diastolic pressure (LVEDP) and systolic blood pressure were common events during clamping, and cardiac output often decreased. Nevertheless, left ventricular performance curves after cross-clamping showed similar increases in left ventricular stroke work (LVSW) with increasing preload. In addition, left ventricular biopsy specimens showed preservation of myocardial high-energy phosphate stores and essentially normal ultrastructural integrity. Radioactive microspheres generally showed increased myocardial blood flow during and after cross-clamping, but no evidence of preferential subendocardial ischemia. Examination of renal function showed a marked decrease in urine output, glomerular filtration rate, and renal plasma flow during cross-clamping. Following the release of the cross-clamp, renal function returned to 50% to 85% of baseline status. Since we could find no major advantage of any of the techniques employed under the present experimental conditions, we suggest that all of the techniques should be part of the surgical armamentarium and the particular preoperative and/or intraoperative findings in a specific case should determine which technique is most appropriate for a given patient.

Adenosine Triphosphate↗