Emergency and Critical Care, An Issue of Veterinary Clinics of North America: Equine Practice (eBook)

Diana M. Hassel (Autor)

eBook Download: PDF | EPUB

2014 | 1. Auflage
225 Seiten
Elsevier Health Sciences (Verlag)
978-0-323-32047-4 (ISBN)

Infos

Drs. Diana Hassel and Vanessa Cook have put together an expert team of authors focused on emergency and critical care topics. Articles include: Field Triage of the Neonatal Foal, CPR in the neonatal foal: has RECOVER changed our approach?, Update on the management of neonatal sepsis, SIRS or endotoxemia?, Ultrasound of the equine acute abdomen, Evaluation of the colic: Decision for referral, The utility of lactate in critically ill adults and neonates, Crystalloid and colloid therapy, Acute hemorrhage and blood transfusions, Coagulopathies, and more!

Inhalt

Front Cover 1
Emergency andCritical Care 2
Copyright 3
Contributors 4
Contents 8
Veterinary Clinics Of North America: Equine Practice 12
Preface 14
Field Triage of the Neonatal Foal 16
Key points 16
Introduction 16
Physical examination of the newborn foal 16
Dysphagia/Loss of Suckle/Milk Regurgitation 18
Triage of the weak neonatal foal 19
Sepsis 19
PAS 19
Prematurity/Dysmaturity 20
Specific Treatment of Sepsis 20
Specific Treatment of PAS 20
Specific Treatment of Prematurity 21
General therapy for the weak recumbent foal 21
Nutrition Support 21
Partial parenteral nutrition 22
Enteral feeds 22
FPT 23
IV Fluid Support of the Foal 23
Maintenance fluid therapy 23
Supportive Care 24
Respiratory Support 24
Other common disorders of the neonate 25
Neonatal Isoerythrolysis 25
Disorders of the Lungs 25
Pneumonia 25
Treatment 25
Apneustic breathing 26
Treatment 26
Disorders of the Umbilicus and Urinary Tract 26
Patent urachus 26
Treatment 26
Omphalophlebitis 26
Treatment 26
Dysuria 26
Urinary tract rupture and uroabdomen 27
Clinical signs 27
Diagnosis 27
Treatment 27
Disorders of the Musculoskeletal System 28
Flexor tendon laxity 28
Treatment 28
Septic arthritis/septic osteomyelitis 28
Clinical signs 28
Diagnosis septic arthritis/osteomyelitis 28
Treatment septic arthritis 28
Treatment septic osteomyelitis 29
Rib fractures 29
Treatment 29
Disorders of the gastrointestinal tract 29
Colic 29
Diagnostic aids for colic 30
Meconium impaction 30
Treatment 30
Oral laxatives 30
IV fluids 30
Analgesics/prokinetics 30
Atresia coli 31
Ileocecocolic aganglionosis (overo lethal white syndrome) 31
Enterocolitis/diarrhea 31
Nutritional causes of colic and diarrhea 32
Overfeeding 32
Lactose intolerance 32
Seizures 32
Causes of Seizures 32
Clinical Signs 32
Treatment Options 32
Additional Support for Seizures 33
References 33
CPR in the Neonatal Foal 34
Key points 34
What is RECOVER? 34
Causes for CPA in equine neonates 35
CPR training and team dynamics 35
Preparation 36
CPR—basic and advanced life support 36
Basic life support 36
What to Do 37
Patient Positioning 37
Ventilation 37
RECOVER Recommendations for Ventilation 38
Thoracic Compressions 38
RECOVER Recommendations 38
Recommendation 39
Advanced life support 39
Vasopressor and Vagolytic Therapy 39
Epinephrine dose 39
Vasopressin Versus Epinephrine 40
Atropine 40
Defibrillation 40
Defibrillation Technique 40
Antiarrhythmic Drug Therapy 40
Electrolyte Therapy 41
Other Therapies 41
Intratracheal Drug Administration 41
Open Chest CPR 41
Monitoring 42
Monitoring Patients During CPA 42
When to Stop 43
Post–cardiac arrest care 43
Resuscitation at the time of foaling 44
Summary 44
References 45
Update on the Management of Neonatal Sepsis in Horses 50
Key points 50
Introduction 50
The septic neonatal foal 51
Management strategies in neonatal sepsis 54
Infection Control 55
Antimicrobials 55
Plasma therapy 55
Hemodynamic Support 57
Fluid therapy 57
Vasoactive agents 58
Respiratory support 59
Antimediator Therapy 60
Supportive therapy 62
Tight Glucose Control 63
Corticosteroid Replacement Therapy 63
Summary 65
References 66
Is it the Systemic Inflammatory Response Syndrome or Endotoxemia in Horses with Colic? 70
Key points 70
Introduction 70
SIRS 71
The innate immune system 72
Pattern-recognition receptors and their role in equine SIRS 72
TLR4 and its interactions with LPS 73
Signaling pathways initiated by TLR4 activation 73
Other equine TLRs and their PAMPs 74
Mediators released via TLR activation and their physiologic effects 76
Differences in responses of equine cells to TLR activation 77
Responses of Equine TLR4 to LPS 77
Agonist/Antagonist LPS Responses 77
Equine-Specific Cellular Responses to Flagellin 78
The focus on endotoxemia 78
Detection of LPS 80
SIRS or endotoxemia? 80
Treatment 80
Current Treatment Approach 80
Caution Regarding Extrapolating Future Treatments to Horses 81
References 81
Ultrasound of the Equine Acute Abdomen 86
Key points 86
Introduction and clinical indications 86
Technique and Equipment 87
Patient preparation 88
Transducers and ultrasound machines 88
Scanning technique 88
Limited examination 88
FLASH technique 88
Full examination 89
Machine settings 89
Examiner experience and diagnostic complexity 89
Normal Ultrasonographic Anatomy of the Equine Abdomen 89
Left abdomen 90
Right abdomen 90
Ventrum 91
Gastric Abnormalities 92
Small Intestinal Abnormalities 93
Small intestinal strangulating obstructions 93
Intussusception 93
Proximal enteritis 94
Other small intestinal lesions 95
Duodenal abnormalities 95
Large Intestinal Abnormalities 96
Left dorsal displacement 96
Right dorsal displacement 97
Colon torsion 98
Colitis 99
Intussusception 99
Sand/Enteroliths 100
Peritoneal Fluid 100
Masses, Neoplasia, and Abscessation 103
Abdominal neoplasia 103
Abdominal abscessation 104
Other 106
Urolithiasis 106
Cholelithiasis 107
Thoracic and cardiac causes of colic 109
Pleuritis 109
Pericarditis 109
Aortic root disease 109
Diaphragmatic hernia 110
References 111
Evaluation of the Colic in Horses 116
Key points 116
Introduction: nature of the problem 116
Patient history and signalment 117
Physical examination 118
Pain Assessment and General Appearance 120
Heart Rate 120
Temperature 121
Gastrointestinal Motility 121
Rectal Palpation 121
Presence of Gastric Reflux 122
Imaging and additional testing 123
Transabdominal Ultrasound 123
Abdominocentesis 124
Lactate 126
Glucose 127
Summary 128
References 128
Blood Lactate Measurement and Interpretation in Critically Ill Equine Adults and Neonates 132
Key points 132
Introduction 132
Measuring lactate concentrations 133
Lactate metabolism in the healthy animal 134
Lactate metabolism in disease 135
Increased Na+/K+–Adenosine Triphosphatase Activity in Response to Inflammatory Mediators 135
Inhibition of PDH 136
Lactate Production by Leukocytes 136
Decreased Hepatic Clearance 136
Other Potential Causes of Hyperlactatemia 137
Source of Lactate During Disease 137
Interpretation of blood lactate concentrations in critically ill horses 137
Lactate Measurement and Interpretation in Adult Horses 138
Lactate Measurement and Interpretation in Equine Neonates 139
Limitations in the Clinical Use of Blood Lactate Concentrations 141
Summary 142
References 142
Crystalloid and Colloid Therapy 148
Key points 148
Hyperchloremia 149
Colloid research revisited 150
The No-Absorption Rule 150
Retraction of Studies Supporting Colloid Use 151
Remaining Evidence Addressing Colloid Use 151
Fluid overload 152
Treatment of Fluid Overload 153
The basic components of a fluid therapy plan 154
Are Intravenous Fluids Indicated? 154
Type of Fluid 155
Initial Resuscitation Fluid 155
Rate of Fluid Administration 155
End Points to Fluid Administration 155
References 156
Acute Hemorrhage and Blood Transfusions in Horses 160
Key points 160
Introduction 160
Acute hemorrhage 160
Recognizing Acute Hemorrhage in the Horse 160
Physiologic Hemostasis and Medical Management 161
Surgical and Topical Hemostasis 162
Blood transfusion 163
Criteria for Transfusion 163
Blood Products 163
Blood Donors and Pretransfusion Testing 164
Blood Collection and Storage 164
Transfusion Volume and Technique 166
Adverse Effects 166
Alternative Sources of Blood 167
Summary 167
References 167
Coagulopathies in Horses 170
Key points 170
Introduction 170
Nature of the Problem 170
Definitions 170
Normal hemostasis 170
Coagulopathy 172
Clinical findings 173
Physical Examination 173
Excessive bleeding 173
Excessive thrombosis 173
DIC 173
Underlying Disease 174
Diagnostics 174
Clinical Pathology 174
Other Tests 174
Decision Algorithms 177
Treatment options 178
For Excessive Bleeding 178
For Excessive Thrombosis 178
References 182
Trauma and Wound Management 186
Key points 186
Introduction 186
Classification of wounding potential 187
Impact energy 187
Bullet design 189
Tissues involved 190
Bullet wound classification system 191
Energy 191
Vital structures involved 192
Wound 192
Fractures 192
Contamination 192
Treatment of bullet wounds 193
Head, neck, and spine injuries 194
Thoracic wounds 195
Abdominal wounds 196
Soft tissue injuries and musculoskeletal trauma 196
Legal considerations 197
Acknowledgments 198
References 198
Infection Control in Equine Critical Care Settings 200
Key points 200
Importance of infection control in the critical care setting 200
General infection control concepts 201
Challenges of infection control in the critical care setting 202
Risks Associated with Caretaker-Patient Contacts 202
Risks Associated with Intravenous Catheterization 203
Special Considerations When Managing Critically Ill Foals 203
Risks associated with managing critical care patients 203
What Are the Risks? 203
Specific Agents of Concern 204
Eliminating Environmental Persistence of Potential Pathogens 204
Summary 205
References 205
Index 208

Textauszug

CPR in the Neonatal Foal

Has RECOVER Changed Our Approach?

Jonna Maaria Jokisalo, DVMa and Kevin Thomas Trent Corley, BVM&S, PhD, MRCVSb∗[e-mail],     aAnimagi Hevossairaala Hyvinkää, Hyyppäräntie 41, Hyvinkää 05800, Finland; bVeterinary Advances Ltd, 9 Ballysax Hills, The Curragh, Co Kildare, Ireland

∗Corresponding author.

RECOVER was created to optimize survival of small animal patients from cardiopulmonary arrest. Several findings from this study are applicable to cardiopulmonary resuscitation in the neonatal foal. In particular, chest compressions should be a priority with no pauses and a “push hard, push fast” approach. The importance of ventilation is minimized with short, infrequent breaths at a rate of 10 to 20 per minute recommended.

Keywords

Resuscitation

Cardiopulmonary arrest

Foal

Life support

Monitoring

Key points

• Respiratory arrest usually precedes cardiac arrest in the newborn foal.

• Team training and preparation is critical before resuscitation.

• Ventilation should be performed with short, infrequent breaths at a rate of 10 to 20 breaths per minute.

• In accordance with recommendations from RECOVER, a “push hard, push fast” approach should be used for chest compressions.

• If it proves necessary to use drugs during foal resuscitation, epinephrine is the principal drug used. A dose of 0.01 mg/Kg IV or 0.1 mg/Kg intratracheally should be used.

What is RECOVER?

RECOVER, The Reassessment Campaign on Veterinary Resuscitation, was created to optimize survival of small animal patients from cardiopulmonary arrest (CPA), and its aim was to improve preparedness and prevention measures, basic life support (BLS), advanced life support (ALS), and post-cardiac arrest (PCA) care. Before RECOVER, consensus-based guidelines for such strategies did not exist in veterinary medicine. The goal of RECOVER was therefore to systematically evaluate the evidence on clinical practice of veterinary cardiopulmonary resuscitation (CPR). The campaign was set up to devise clinical guidelines on how to best treat CPA in dogs and cats and also to identify important knowledge gaps in veterinary CPR that need to be filled to improve the quality of recommendations, and thus the quality of patient care in the future.1

Reported survival rates to hospital discharge after CPA occurring in the hospital differ greatly between small animal and humans. Less than 6% of dogs and cats have reported to survive to hospital discharge,2–5 whereas the survival rate is approximately 20% in humans in a similar setting.6,7 Studies looking at the survival rate to hospital discharge in horses experiencing CPA in hospital setting are lacking. Frauenfelder8 reported 75% success rate on external cardiovascular resuscitation in adult anesthetized ponies. Eight anesthetized ponies sustained unexpected cardiac arrest while being used in an endotoxin shock study. In 6 of these ponies, return of spontaneous circulation was achieved with the combination of external cardiac massage and ventilatory support. No longer-term data were published. Palmer9 presented a case series of 83 hospitalized large animal neonates (80% foals) requiring ALS (assisted ventilation and cardiac support [cardiac compressions and/or drugs]). Depending on the underlying cause, the rate of return of spontaneous circulation (ROSC) was 40% to 90%.

Causes for CPA in equine neonates

Although there are many reasons for CPA in foals, respiratory arrest almost always precedes cardiac arrest in the newborn foal. Premature placental separation, early severance or twisting of the umbilical cord, prolonged dystocia, or airway obstruction by fetal membranes are the most common reasons causing asphyxia in a neonatal foal, which can result in respiratory arrest. However, some foals do not start spontaneously breathing without any apparent birthing problem. Other causes for CPA in neonatal foals, not associated with birth, include primary lung disease leading to hypoventilation and hypoxia, septic shock, hypovolemia, metabolic acidosis, hyperkalemia, vasovagal reflex, hypoglycemia, and hypothermia. CPA resulting from tension pneumothorax and trauma has also been reported in foals.10 Unlike in adult humans, cardiac arrest in neonatal foals is usually secondary to other systemic conditions, such as septic shock or respiratory failure, and not caused by primary cardiac failure; this explains why ventricular fibrillation (VF) is not a common presenting arrhythmia. In the rare occasions where CPA is cardiac in origin, it is usually secondary to hypoxic-ischemic or cytokine-mediated myocardial damage, congenital cardiac defects, myocarditis, endocarditis with coronary artery embolism, or cardiac tamponade.

CPR training and team dynamics

It is important to recognize early which foals require resuscitation. If resuscitation is begun before a nonperfusing cardiac rhythm develops, the likelihood of revival is good (survival rate as high as 50%). If resuscitation efforts are delayed until after development of asystole, however, a less than 10% survival rate is to be expected.10 Clinical human studies have shown that training people to recognize the signs of cardiac arrest improves the ability of first responders to recognize the need for CPA.11 Cardiopulmonary resuscitation (CPR) given to patients not in CPA has been reported not to result in major harm.12 Therefore, veterinary hospitals should teach all employees CPR and repeat training before every breeding season.

It is especially important to recognize the foals needing resuscitation at birth, because the foal may have arrested during the birthing process and therefore have had a prolonged period of arrest. For this reason, it is important to be familiar with the normal events at birth. The average length of Stage II of labor is 16.7 minutes.13,14 The normal foal takes a few gasps initially but should be breathing regularly within 30 seconds of birth. The heart rate averages 70 bpm immediately after birth. Normal foals may have cardiac arrhythmias during the first hour of life.15 Foals should have pain and sensory awareness at birth, develop a righting reflex with 5 minutes and a suck reflex within 2 to 20 minutes.

Severe respiratory distress, large abdominal effort, and open mouth breathing can occur immediately after birth from several congenital upper respiratory conditions, including bilateral choanal atresia, stenotic nares, and dorsal displacement of the soft palate, necessitating immediate placement of an endotracheal tube per os or emergency tracheostomy. An important differential for dyspnea immediately after birth is perinatal equine herpesvirus 1 infection. Persistently abnormal heart rates and arrhythmias require further investigation with an electrocardiogram (ECG).

Newborn foals require resuscitation if

• Gasping for longer than 30 seconds

• Respiratory movements or heart beat are absent

• The heart rate is less than 50 bpm and falling

• There is obvious dyspnea

Hospitalized foals require resuscitation if

• The heart rate is less than 50 bpm and falling

• There is apnea

Decreases in venous oxygen saturation, end-tidal carbon dioxide (EtCO2) concentration, and muscle tone may be early signs of arrest.

Preparation

The most important step in resuscitation is thorough preparation. At the critical moment, there is no time to start looking for equipment or to try to remember CPR algorithms let alone drug doses. Everything that is needed for resuscitation should be easily accessible and able to be moved quickly to the stall side. The best way to achieve this is to organize a crash cart to be always kept in the same place in the hospital or car so it is easily found when needed. This crash cart should be checked before each breeding season and after every use so that it is ready when needed.

CPR—basic and advanced life support

CPR can be divided in three phases: BLS, ALS, and monitoring. Veterinary BLS consists of intubation, ventilation, and chest compressions. These include the recognition of CPA—or in foals, recognition of respiratory arrest—airway management, provision of ventilation, and chest compressions. BLS is the immediate response to CPA, and in humans and in some aspects also small animals, lay rescuers and medical professionals alike may accomplish most aspects. Numerous human and animal experimental studies have shown that the quality of BLS performed is associated with...

Produkt-Details

• Erscheint lt. Verlag: 9.10.2014
• Sprache: englisch
• Themenwelt: Medizin / Pharmazie
• Themenwelt: Veterinärmedizin ► Pferd
• ISBN-10: 0-323-32047-3 / 0323320473
• ISBN-13: 978-0-323-32047-4 / 9780323320474