Inflammatory biomarker concentrations in dogs with gastric dilatation volvulus with and without 24-h intravenous lidocaine

Background

Canine gastric dilatation volvulus (GDV) is characterized by tissue ischemia, reperfusion, and systemic inflammation. Evidence exists that lidocaine exerts anti-inflammatory properties and potentially improves outcome.

Design and setting

Prospective, randomized observational cohort study in client-owned dogs with GDV.

Objective

The primary objective of the study was the determination of pro- and anti-inflammatory biomarker concentrations in dogs with GDV with and without intravenous (IV) lidocaine therapy. The second objective was the evaluation of side effects of lidocaine.

Methods

Of 35 dogs included in the study, 20 dogs were assigned to receive lidocaine (LIDO) (2 mg/kg initially, followed by a continuous infusion at a rate of 50 μg/kg/min over 24 h) and 15 dogs not to receive lidocaine (NO-LIDO). Plasma concentrations of cytokines interleukin (IL)-6, IL-7, IL-8, IL-10, IL-15, IL-18, interferon gamma, keratinocyte chemotactic-like, monocyte chemotactic protein, and C-reactive protein (CRP) were measured at admission (prior any therapeutic intervention, T0), immediately after surgery (T1), at 24 h (T24), and at 48 h (T48) post-surgery.

Results

No significant differences in concentrations of any cytokines were found between the LIDO- and the NO-LIDO group. Significant lower CRP concentrations (median [range]) were found in dogs with lidocaine compared to dogs without at T24 (97.5 pg/mL [46.3-161.7] vs. 127.9 pg/mL [26.9-182.0]; p = 0.046) and T48 (73.7 pg/mL [18.4-169.4] vs. 116.3 pg/mL [71.4-176.8]; p = 0.002). Dogs receiving lidocaine exhibited significantly impaired mentation, a prolonged period of anorexia, and longer hospitalization compared to dogs without lidocaine.

Conclusion

Lidocaine administration had no impact on the plasma levels of cytokines during the 48-h study period, but significantly lower CRP concentrations were found at T24 and T48. Lidocaine's potential side effects require careful decision making regarding its use.

Concentrations and kinetics of renal biomarkers in dogs with gastric dilatation-volvulus with and without 24-h intravenous lidocaine

Background

Gastric dilatation volvulus (GDV) can lead to organ failure including acute kidney injury (AKI). Due to its cytoprotective, antioxidant and anti-inflammatory effects, lidocaine has a potential to prevent AKI in dogs with GDV.

Design and setting

Prospective, observational cohort study in client-owned dogs with GDV.

Objective

To determine concentrations of renal biomarkers for AKI in dogs with GDV with and without intravenous (IV) lidocaine therapy.

Methods

Thirty-two dogs were randomized to receive either IV lidocaine (2 mg/kg, followed by a lidocaine constant rate infusion at a dose of 50 μg/kg/min over 24 h; n = 17) or no lidocaine (n = 15). Blood and urine samples were taken at admission (T 0) (only blood), during or immediately after surgery (T 1), and 24 (T 24) and 48 (T 48) h after surgery. Plasma creatinine (pCr), plasma neutrophil gelatinase-associated lipocalin (pNGAL), urinary NGAL (uNGAL), uNGAL to creatinine ratio (UNCR), and urinary gamma-glutamyl transferase to creatinine ratio (uGGT/uCr) were evaluated. Biomarker concentrations were compared between dogs with and without IV lidocaine and the course of each marker was determined in comparison to its admission value.

Results

In the entire population, a significantly higher pCr at T 0 (median, 95 μmol/L, interquartile range, 82-105) compared with T 1 (69 μmol/L, 60-78), T 24 (63 μmol/L, 52-78), and T 48 (78 μmol/L, 65-87) (P < 0.001) was found. Plasma NGAL increased significantly between T 0 (5.66 ng/mL, 3.58-7.43) and T 24 (7.50 ng/mL, 4.01-11.89) (P = 0.006) and T 48 (9.86 ng/mL, 5.52-13.92) (P < 0.001), respectively. Urinary NGAL increased significantly between T 1 (0.61 ng/mL, 0.30-2.59) and T 24 (2.62 ng/mL, 1.86-10.92) (P = 0.001) and T 48 (4.79 ng/mL, 1.96-34.97 (P < 0.001), respectively. UNCR increased significantly between T 1 (0.15 μg/mmol, 0.09-0.54) and T 24 (1.14 μg/mmol, 0.41-3.58) (P = 0.0015) and T 48 (1.34 μg/mmol, 0.30-7.42) (P < 0.001), respectively. Concentrations of uGGT/uCr increased significantly from T 0 highest at T 24 (6.20 U/mmol, 3.90-9.90) and significantly decreased at T 48 (3.76 U/mmol, 2.84-6.22) (P < 0.001). No significant differences in any renal biomarker concentration were found between dogs with and without IV lidocaine therapy.

Conclusion and clinical relevance

Plasma NGAL, uNGAL and UNCR remained increased up to 48 h post-surgery. No evidence of lidocaine-associated renoprotection was found.

Pharmacological Conditioning of the Heart: An Update on Experimental Developments and Clinical Implications

The aim of pharmacological conditioning is to protect the heart against myocardial ischemia-reperfusion (I/R) injury and its consequences. There is extensive literature that reports a multitude of different cardioprotective signaling molecules and mechanisms in diverse experimental protocols. Several pharmacological agents have been evaluated in terms of myocardial I/R injury. While results from experimental studies are immensely encouraging, translation into the clinical setting remains unsatisfactory. This narrative review wants to focus on two aspects: (1) give a comprehensive update on new developments of pharmacological conditioning in the experimental setting concentrating on recent literature of the last two years and (2) briefly summarize clinical evidence of these cardioprotective substances in the perioperative setting highlighting their clinical implications. By directly opposing each pharmacological agent regarding its recent experimental knowledge and most important available clinical data, a clear overview is given demonstrating the remaining gap between basic research and clinical practice. Finally, future perspectives are given on how we might overcome the limited translatability in the field of pharmacological conditioning.

Suspicion of Postanesthetic Femoral Paralysis of the Non-Dependent Limb in a Horse

A 15-year-old Selle Francais gelding was presented to the equine referral hospital for treatment of a left guttural pouch mycosis previously diagnosed. After induction, the horse was shortly hoisted by all four feet, moved on a padded surgical table, and positioned in right lateral recumbency. In order to reduce the risk of bleeding during surgical manipulation of the carotid and maxillary arteries, a mean arterial pressure between 60 and 70 mmHg was targeted. After surgery, the horse was moved in a padded recovery box keeping the same lateral recumbency. Four unsuccessful attempts were performed, with the horse always returning to sternal recumbency keeping the left hind limb up. At the fifth attempt, performed 120 min after the end of the general anesthesia, the horse stood up correctly but moderate ataxia and absence of weight bearing on the left hind limb were shown. Both the stifle and the fetlock joint were held in a flexed position and could not be extended properly in order to set the foot on the ground, resulting in a very short step. The horse was calm, not sweating, and willing to move; the muscles of the affected limb were relaxed, and the limb was neither warm nor painful at palpation. Occasionally, the horse flexed the affected hind limb in an exaggerated motion with marked abduction. No additional laboratory analyses were performed. Due to a strong suspicion of neuropathy, a sling support was initiated and a supportive bandage associated with flunixine administration was performed until resolution of the symptoms. The horse fully recovered after 3 days. This case report does not clarify the pathogenesis of the possible postanesthetic neuropathy accounted on the non-dependent limb, highlighting the need for future research in this field. Non-dependent limb neuropathy should be an expected problem even after having ruled out the most commonly known causes predisposing to postanesthetic lameness.

Bacterial translocation in critical illness

Bacterial translocation involves the passage of intestinal bacteria to extraintestinal sites and has been shown to increase morbidity and mortality in critical illness. This review outlines the pathophysiology of bacterial translocation, host defence mechanisms, and reviews the evidence for the clinical management of critically ill patients in order to minimise the negative outcomes associated with bacterial translocation.

An ex vivo comparison of adenosine and lidocaine solution and University of Wisconsin solution for hypothermic machine perfusion of porcine kidneys: potential for development

BACKGROUND

The optimal hypothermic machine perfusion (HMP) solution has not yet been developed. An adenosine and lidocaine (AL) solution has been shown to be protective in cardiac preservation. The aim of the present study was to examine a modified AL solution with low Ca²⁺, 16 mM Mg²⁺, and 4% albumin on kidney preservation compared with University Wisconsin solution (UW).

METHODS

Twenty donation of organs after cardiac death porcine kidneys underwent HMP for 10 h (AL, n = 10; UW, n = 10) and then 2 h of normothermic reperfusion. Perfusion dynamics, functional parameters, histology, and real-time microdialysis were used to assess kidney responses and viability.

RESULTS

During HMP, modified AL-perfused kidneys maintained higher flow rates (21.5 versus 17.9 mL/min/100 g, P = 0.01), with perfusion flow index during the first 3 h 25% greater than with UW (AL = 0.50 ± 0.2, UW = 0.40 ± 0.17 mL/min/100 g/mmHg; P = 0.03), followed by an increase in UW kidneys which was not significantly different to AL over the remaining 7 h (0.54 versus 0.55 mL/min/100 g/mmHg, respectively). During warm reperfusion, there were no significant differences between the two HMP groups in creatinine clearance, oxygen, and glucose consumption between groups. Modified AL kidneys had significantly lower perfusate lactates (3.1 versus 4.1 mmol/L, P = 0.04) during reperfusion and lower cortical lactate levels (AL = 0.66 ± 0.31, UW = 0.89 ± 0.53 mM, P = 0.33). Histology showed similar degrees of reperfusion injury.

CONCLUSIONS

We conclude that HMP with modified AL solution showed improved perfusion compared with UW and lower perfusate lactate levels during warm reperfusion. Further modification of the AL composition is warranted and may lead to more rapid kidney stabilization and improved graft viability assessment, potentially expanding donor pools.

Surgical Removal of a Canine Aortic Thromboembolism Secondary to Pancreatitis

A 7-year-old castrated male Pomeranian was evaluated on emergency for diagnostic work-up and treatment for acute nonpainful paraparesis. The neurologic examination suggested a L4-S3 myelopathy, but physical examination revealed lack of femoral pulses and rectal hypothermia, as well as a grade II/VI systolic heart murmur, so ischemic neuromyopathy was suspected. Clinicopathologic analysis revealed increased muscle enzymes and proteinuria. Abdominal ultrasonography confirmed aortic thromboembolism (ATE), and surgical histopathology diagnosed necrotizing pancreatitis. Surgical aortic thrombectomy was performed, and antithrombotic therapy was instituted. Pancreatitis was treated supportively. The dog was discharged to the owners after 10 days of hospitalization. Recheck examination 6 weeks after initial presentation revealed a normal neurologic examination and normal femoral pulses. The patient has had no further bouts of pancreatitis and remains neurologically normal 5 years after initial presentation. Canine ATE is relatively rare compared to the feline counterpart. Directed therapy for feline ATE is often not recommended, as underlying conditions are oftentimes ultimately fatal. Underlying etiologies for canine ATE include cardiovascular disease and endocrinopathies, but canine ATE secondary to pancreatitis has not yet been reported. Surgical removal of aortic thromboembolus should be considered as curative for pelvic limb dysfunction in the canine patient without a terminal underlying disease.

Postoperative management of dogs with gastric dilatation and volvulus

The objective of the study was to review the veterinary literature for evidence-based and common clinical practice supporting the postoperative management of dogs with gastric dilatation and volvulus (GDV). GDV involves rapid accumulation of gas in the stomach, gastric volvulus, increased intragastric pressure, and decreased venous return. GDV is characterized by relative hypovolemic-distributive and cardiogenic shock, during which the whole body may be subjected to inadequate tissue perfusion and ischemia. Intensive postoperative management of the patients with GDV is essential for survival. Therapy in the postoperative period is focused on maintaining tissue perfusion along with intensive monitoring for prevention and early identification of ischemia-reperfusion injury (IRI) and consequent potential complications such as hypotension, cardiac arrhythmias, acute kidney injury (AKI), gastric ulceration, electrolyte imbalances, and pain. In addition, early identification of patients in need for re-exploration owing to gastric necrosis, abdominal sepsis, or splenic thrombosis is crucial. Therapy with intravenous lidocaine may play a central role in combating IRI and cardiac arrhythmias. The most serious complications of GDV are associated with IRI and consequent systemic inflammatory response syndrome and multiple organ dysfunction syndrome. Other reported complications include hypotension, AKI, disseminated intravascular coagulation, gastric ulceration, and cardiac arrhythmias. Despite appropriate medical and surgical treatment, the reported mortality rate in dogs with GDV is high (10%-28%). Dogs with GDV that are affected with gastric necrosis or develop AKI have higher mortality rates.

Evaluation of potential topical and systemic neuroprotective agents for ocular hypertension-induced retinal ischemia-reperfusion injury

OBJECTIVE

To evaluate for drugs with superior neuroprotective efficacy and investigate their underlying mechanisms related to antioxidation.

PROCEDURES

Brinzolamide (1%), timolol (0.5%), minocycline (22 mg/kg), lidocaine (1.5 mg/kg), and methylprednisolone (30 mg/kg) were administered to Sprague-Dawley (SD) rats. The retina was evaluated by electroretinography and histological analysis. The antioxidative capacity of drugs was evaluated to clarify the underlying mechanism. The oxidant/antioxidant profiles of plasma, red blood cells, and retina were analyzed by lipid peroxidation (malondialdehyde) and by measuring the activities of antioxidants. Proteomic analysis was used to investigate the possible protective mechanisms of the drug against ischemia-reperfusion injury.

RESULTS

The results suggested that timolol, methylprednisolone, and minocycline protected retinal function. Methylprednisolone and minocycline possessed good antioxidative activity. Brinzolamide and lidocaine preserved the structural integrity of the retina, but not retinal function.

CONCLUSION

Methylprednisolone, minocycline, and timolol have potential acute or delayed benefit in retinal ischemia-reperfusion injury. Their neuroprotective actions depend at least partially on the ability to alleviate oxidative stress.

Intravenous anaesthesia in goats: A review

Intravenous anaesthesia is gradually becoming popular in veterinary practice. Traditionally, general anaesthesia is induced with intravenous drugs and then maintained with inhalation agents. Inhalation anaesthetic agents cause more significant dose-dependent cardiorespiratory depression than intravenous anaesthetic drugs, creating a need to use less of the inhalation anaesthetic agents for maintenance of general anaesthesia by supplementing with intravenous anaesthesia drugs. Better still, if anaesthesia is maintained completely with intravenous anaesthetic drugs, autonomic functions remain more stable intra-operatively. Patient recovery from anaesthesia is smoother and there is less pollution of the working environment than happens with inhalation anaesthetic agents. Recently, a number of drugs with profiles (pharmacokinetic and pharmacodynamic) suitable for prolonged intravenous anaesthesia have been studied, mostly in humans and, to a certain extent, in dogs and horses. There is currently very little scientific information on total intravenous anaesthesia in goats, although, in the past few years, some scholarly scientific articles on drugs suitable for partial intravenous anaesthesia in goats have been published. This review article explored the information available on drugs that have been assessed for partial intravenous anaesthesia in goats, with the aim of promoting incorporation of these drugs into total intravenous anaesthesia protocols in clinical practice. That way, balanced anaesthesia, a technique in which drugs are included in anaesthetic protocols for specific desired effects (hypnosis, analgesia, muscle relaxation, autonomic stabilisation) may be utilised in improving the welfare of goats undergoing general anaesthesia.

Evaluation of lidocaine treatment on frequency of cardiac arrhythmias, acute kidney injury, and hospitalization time in dogs with gastric dilatation volvulus

OBJECTIVE

To assess the efficacy of IV lidocaine in decreasing complication rate and improving the outcome in dogs with gastric dilatation volvulus (GDV).

DESIGN

Prospective non-controlled study of 83 lidocaine-treated dogs with GDV compared to 47 untreated historical controls with GDV.

SETTING

University veterinary teaching hospital.

ANIMALS

One hundred and thirty client-owned dogs with naturally occurring GDV.

INTERVENTIONS

Study group dogs were treated at presentation with lidocaine (2 mg/kg, IV bolus) followed by constant rate infusion (CRI) of 0.05 mg/kg/min for 24 h. Historical control dogs did not receive any lidocaine.

MEASUREMENTS AND MAIN RESULTS

There were no group differences in age, body weight, time lag from onset of clinical signs to presentation, rectal temperature and pulse rate at presentation, and proportion of gastric wall necrosis. The proportions of cardiac arrhythmias and acute kidney injury (AKI) were significantly (P< 0.001 and P = 0.045, respectively) lower in the lidocaine group (10/83 [12%] versus 18/47 [38.3%] and 3/83 [3.6] versus 0/47). Median hospitalization time period was shorter (P = 0.05) in the lidocaine group compared to the controls (median 48 h; range 24-360 h versus median 72 h; range 24-144 h, respectively).

CONCLUSION AND CLINICAL RELEVANCE

Early treatment with IV lidocaine bolus, followed by CRI of lidocaine for 24 h post presentation decreased the occurrence of cardiac arrhythmias, AKI and hospitalization time period significantly in lidocaine-treated dogs with GDV compared to untreated historical controls. Due to the nonblinded, placebo-uncontrolled, nonrandomized nature of the current study, further evaluation of the efficacy of lidocaine in dogs with GDV is warranted.

The neuroprotective effects of lidocaine and methylprednisolone in a rat model of retinal ischemia-reperfusion injury

Retinal ischemia is a common cause of visual impairment for humans and animals. The neuroprotective effects of lidocaine (LDC) and methylprednisolone (MP) upon retinal ischemic injury were investigated in a rat model. Sprague-Dawley rats were divided into 3 groups, the IR control, LDC and MP. A very high intraocular pressure (HIOP) and retinal ischemia were induced. In LDC group, LDC bolus (1.5 mg/kg) was i.v. injected 30 min before ischemia and then a constant rate infusion (CRI) with 2 mg/kg/hr was given until 60 min after reperfusion. In MP group, MP bolus (30 mg/kg) was i.v. administered twice at 2 min before and immediately after ischemia, respectively. The HIOP damage to retina was evaluated by electroretinogram (ERG) and morphometrical histology. The functional analysis of the retina by ERG revealed a 35.2% reduction of a-wave in the IR group, 49.7% reduction in the LDC group but no significant change in the MP group compared to normal controls. An 81.0% reduction of b-wave was observed in the IR group, 80.7% reduction in the LDC group and 17.6% reduction in the MP group. In the morphometrical histology, the retinal inner plexiform layer/outer nuclear layer (IPL/ONL) ratio was reduced to 48.8% in the IR group, 80.1% in the LDC group and 96.2% in MP group. In conclusion, the MP showed significantly good neuroprotective effects on retinal IR injury, and the LDC showed moderate neuroprotective effects demonstrated in retinal structure but not in retinal function.

The impact of lidocaine on flap survival following reperfusion injury

BACKGROUND

Inflammatory events triggered by the mediators released from free oxygen radicals and infiltrated leukocytes play a direct role in formation of the ischemia-reperfusion (IR) injury. The aim of this study was to investigate the impact of lidocaine on IR injury due to its anti-inflammatory properties.

MATERIALS AND METHODS

Following delivery of lidocaine to the ischemic flaps in two different doses prior to the reperfusion, flap survival, malondialdehyde (MDA) level, myeloperoxidase (MPO) level, neutrophil count, and measurement of vascular diameters were studied. Twelve hours after reperfusion, tissue specimens were collected for measurement of MDA level, MPO level, neutrophil count, and vascular diameters. Flap survival was evaluated on the fifth day.

RESULTS

Flap survival rate was 15.54% ± 8.23% in the control group, whereas the groups treated wtih lidocaine showed remarkable elevations in survival rates as follows: 70.83% ± 33.53% and 67.42% ± 30.81%, respectively. MDA levels in sham and lidocaine treatment groups were significantly lower than those observed in control group.

CONCLUSION

Lidocaine inhibited the increase in MDA level associated with IR injury while showing no influence over increases in number of neutrophils and tissue MPO level, and it elevated the flap survival rate.

Development of post-pump syndrome in a sheep after mitral valve stenting

Summary

A one-year-old healthy sheep received an implant stenting the mural (‘posterior’) leaflet of the mitral valve. The experiment was authorized by the Cantonal Ethical Committee. The surgery was performed on the open, beating heart during cardiopulmonary bypass (CPB). Management of anaesthesia was based on isoflurane with mechanical intermittent positive pressure ventilation (IPPV) of the lungs, combined with intercostal nerve blocks and intravenous fentanyl and lidocaine. Marked cardiovascular depression occurred towards the end of CPB time and required high doses of dopamine, dobutamine, lidocaine and ephedrine to allow for weaning off the CPB pump. Moreover, severe pulmonary dysfunction developed when IPPV was re-initiated after CPB. Hypoxaemia persisted throughout the recovery from general anaesthesia. Multiple organ failure developed gradually during the three postoperative days, leading to euthanasia of the animal. As described in this case, marked lung injury associated with some degree of failure of other vital organs may occur in sheep after CPB. Intraoperative cardiorespiratory complications when weaning-off may indicate the development of ‘post-pump syndrome’.

Evaluation of lidocaine treatment and risk factors for death associated with gastric dilatation and volvulus in dogs: 112 cases (1997–2005)

OBJECTIVE

To determine clinical features, outcome, risk factors for death, and efficacy of IV administration of lidocaine as a prophylactic treatment for ischemic reperfusion injury in gastric dilatation and volvulus (GDV) in dogs.

DESIGN

Retrospective case series.

ANIMALS

112 dogs with GDV.

PROCEDURES

Data pertaining to breed; time lag to admission; clinical, clinicopathologic, and surgical findings; lidocaine treatment; and postoperative complications were assessed for association with outcome.

RESULTS

German Shepherd Dogs (28.6%) and Great Danes (17%) were significantly over-represented. Risk factors for death included time lag (> or = 5 hours vs < 5 hours) from onset of clinical signs to admission (46.0% vs 11.3%), rectal temperature (< or = 38 degrees C vs > 38 degrees C [< 100.4 degrees F vs > 100.4 degrees F]) at admission (40.0% vs 14.9%), presence or absence of ARF (67.0% vs 23.3%), presence or absence of suspected gastric wall necrosis (59.3% vs 16.0%), and untreated gastric wall necrosis, compared with treated gastric wall necrosis (100% vs 47.6%). Overall mortality rate was 26.8%; no significant differences were detected in mortality rate or postoperative complications between dogs that received lidocaine IV prior to surgical intervention (52.0%) and dogs that did not (48.0%). Mean +/- SD hospitalization time was longer in the lidocaine treatment group (3.5 +/- 1.9 days vs 2.5 +/- 1.4 days).

CONCLUSIONS AND CLINICAL RELEVANCE

Presence of the identified risk factors should warrant aggressive treatment. Lidocaine treatment was not associated with mortality rate or postoperative complications, but was associated with prolonged hospitalization time.

Drug treatment and thrombolytics during cardiopulmonary resuscitation

PURPOSE OF REVIEW

During cardiopulmonary resuscitation, no specific drug therapy has been shown to improve survival to hospital discharge after cardiac arrest, and only few drugs have a proven benefit for short-term survival. This article reviews recent experimental and clinical data about vasopressor, antiarrhythmic and thrombolytic agents.

RECENT FINDINGS

General use of high-dose epinephrine (>1 mg) can not be recommended, whereas it should be considered during prolonged cardiopulmonary resuscitation. No catecholamine superior to epinephrine has been identified. Arginine vasopressin has been shown to be as effective as epinephrine in patients with ventricular fibrillation and pulseless electrical activity, and may be more effective in patients presenting with asystole or as the second vasopressor (after epinephrine) in refractory cardiac arrest. Sodium bicarbonate should not be 'blindly' administered during cardiopulmonary resuscitation unless an arterial blood gas analysis can be obtained, or after prolonged unsuccessful cardiopulmonary resuscitation. Amiodarone should be preferred over lidocaine, since it may improve short-term survival. Thrombolytic therapy during cardiopulmonary resuscitation may be beneficial if a pulmonary embolism or acute myocardial infarction is suggested to be the cause of the cardiac arrest.

SUMMARY

Epinephrine still represents the first-line vasopressor during cardiopulmonary resuscitation. Arginine vasopressin may be considered in patients presenting with asystole or who are unresponsive to initial treatment with epinephrine. Amiodarone should be preferred to other antiarrythmic agents in patients with cardiac arrest. Thrombolytic therapy during cardiopulmonary resuscitation is a promising new therapeutic option, but its general use in cardiac arrest cannot be recommended until the results of a large multicentre trial become available.