In the case of toxins, sufficient quantities must penetrate the body to produce intoxicatio n. The time between exposure and clinical features is known as the latent period. BIOLOGICAL INCIDENTS1 633 Biological threats Class A agents (most dangerous due to easy dissemination, high mortality ) Bacteria Viruses Toxins Smallpox Ebola* Botulinum Anthrax Marburg* Some mycotoxins Plague Arena viruses Botulism Lassa fever Tularaemia Junin and related viruses* Dengue Class B agents (moderate ease of dissemination, moderate mortality and morbidity) Bacteria Viruses Toxins Q fever Venezuelan EE** Ricin Brucellosis Eastern EE** Epsilon toxin Glanders, melioidosis Western EE** Staph. Enterotoxin B Salmonella (WC) Other alphaviruses Shigella dysenteria (WC) E.coli O157:H7 (WC) Cryptosporidium parvum (WC) Class C agents (low to moderate threat) Multidrug resistant TB Nipah virus Hantaviruses Tickborne haemorrhagic fever encephalitis viruses Yellow fever Haemorrhagic fever viruses Equine encephalitis From C. perfringens WC=potential water contamination agents CHAPTER 11 CBRN 634 Transmissibility Transmissibility is the potential for a BA to be transmitted from one pers on to another directly or through a vector. Those agents transmitted easily from one person to another constitute a major concern. Lethality The lethality or fatality rate is an expr ession of the number of deaths in relation to the number of casualties. Stability The stabi lity of a BA depends on many factors including temperature, humidity, and exposure to sunli ght. Infectious dose This is the dose of an organism needed to infect a person. Due to indi vidual variation, this is expressed as the median dose given \200\224the dose needed to inf ect 50% of those exposed. Lethal dose This is the dose of a BA needed to cause death. Classification An understanding of the characteristics of a BA is essential for identificat ion, prophylaxis, and treatment. BAs used as weapons can be grouped into: - Bacteria - Viru ses - Toxins. (See box on p.633.) Dissemination Dissemination describes the process of dispersal of BAs or toxins. They are m ost commonly dispersed covertly and by aerosol. Routes of entry are similar to naturally oc curring diseases, including percutaneous, inhalation, and ingestion (contamination of food and water). Recognition It is quite likely that a biological warfare attack will be covert and late at night or in the early morning to avoid inactivation of an aerosol driven BA by ultraviolet light. Activation within a closed space may have a more profound and obvious effect. It may be difficult to differentiate illness produced by a BA from an endemic disease. Diseases o ccurring outside their normal geographical location may be more easily identified as suspi- cious. Alerting features include: - Large numbers of casualties occurring over a short per iod of time - Signs of illness or death in the animal population. Casualty management Patients may be a victim of the BA or a traumatic injury. Attempts shou ld be made to minimize cross-contamination without compromising effec- tive clinical care. ABC management of life-threatening injuries should take priority over decontamination if po ssible. Clinical care should be delivered by practi- tioners wearing appropriate PPE. BIOLOGICAL INCIDENTS1 635 Treatment should include general supportive measures: maintenance of adequate respiration, intravenous access, and analgesia, as well as the management of any co-existing injuries an d pre-morbid conditions. Antibiotic therapy, antiviral therapy, and antitoxin therapy shoul d be given as ap- propriate. Attempts should be made to separate contaminated victims from non-affected patients. Medical personnel should be familiar with the local response plan for handling biological emergencies. All suspected biological agent cases should be evacuated to a specialist center wherever po ssible. Anthrax Causative organism Bacillus anthracis Incubation period 1 to 6 days; may be longer Symptoms - Fever, non-productive cough, malaise, fatigue, chest discomfort, sore throat May be followed by a brief period of improvement - Followed by sudden deterioration with se vere respiratory distress, sweating, stridor, cyanosis, and shock Death 24 to 36 hours after onset of severe symptoms. Signs - Pleural effusion, chest wall oedema, meningitis (inhalational anthrax) - Papule les ion, becoming vesicular with a black scab (eschar); local and systemic infection (cutaneous anthrax) Tonsillar ulceration (oropharyngeal anthrax). Immediate management - Wear appropriate standard PPE (if there is a risk of anthrax spore contamination, breathing apparatus will be required) - Decontaminate patient with copious s oap and water - Triple bag and seal patient \200\231s clothing - Transfer urgently to hospi tal \200\224warn them in advance; DO NOT enter the hospital until advised to do so Ensure appropriate decontamination (hypochlorite is appropriate) - If confident about diagn osis or clinically concerned, give intravenous benzyl penicillin Seek advice. Note Inhalational anthrax is not infectious; skin lesions and spore-contaminat ed clothing are. CHAPTER 11 CBRN 636 Nuclear and radiological incidents Nuclear incidents (i.e. detonations or releases of radio active material) are, fortunately, much rarer than radiation incidents (release of ionizing radiation). Radioactive materials occur widely \200\224for example, in industry, medicine, and waste from the nuclear power industry. Associated with these activities is the frequen t movement of radioactive materials on road and rail systems. The Health Protection Agency provides advice and support in the event of a radiation incide nt through the National Radiological Protection Board (NRPB) who in turn advise both the go vernment and the local emergency centers involved with the incident. This involves specifyi ng and providing guidance on emergency reference levels (ERLs) including ERLs requiring urg ent evacuation, shelter, and administration of stable iodine as well as advice on the contr ol of food and drinking water. In addition, the NRPB provides information on recovery metho ds post incident. Where the potential for an incident exists, there are statutory obligations to ensure suita ble contingency plans to protect workers and the public. In the event of an unforeseen inci dent, the NAIR arrangements can be implemented. NAIR may provide assistance to local emerge ncy plans and are activated by the police when they feel that there is a need for radio- lo gical assistance. Other emergency services, (for example, the fire service, British Transpo rtation Police, and the airport and docks police) may also initiate NAIR assistance. The NRPB co-ordinates the NAIR arrangements. Monitoring NAIR provides prompt assistance to the police and emergency services where no ra diation expert is available. Assistance is provided in two stages. - Stage 1: a radiation e xpert, with the aid of simple monitoring equipment, can determine whether a hazard exists and can advise the police accordingly. If required, the police can obtain stage 2 assistance. Stage 2: comprises more sophisticated resources and a team, usually provided by a major nuclear establishment and consisting of up to four persons who can resp ond urgently with monitoring, decontamination equipment, and special clothing. In addition, the NRPB will collate and interpret data from other agencies involved. Action to be taken in the event of an apparent radioactivity emergency: - Police will deter mine whether a pre-existing plan exists. In the event of there being no plan, NAIR assistance will be obtained. Stage 1 respondent will determine whether a stage 2 response is required immediately. A major spillage will require a stage 2 response immediately. NUCLEAR AND RADIOLOGICAL INCIDENTS1 637 NAIR will contact the nearest NAIR respondent who in turn will contact the person dealing with the incident directly. NAIR respondent will provide technical advice and assistance to manage the incident. NAIR respondent will liaise with the relevant environmental agency to assist. Press The NRPB will provide effective communication for the media to ensure consistent advi ce and information. All of these activities are co-ordinated at its Chilton Emergency Cente r. Types of radiation For the purpose of this chapter, radiation means ionizing radiation \200\223 the form of electromagnetic radiation that produces charged particles (ions) in ma terial with which it interacts. In human cells this may cause short- and long-term damage. Substances which give off radiation are said to be radioactive. This definition excludes mi crowaves, ultraviolet, infrared radiation, and radio waves. Most day-to-day incidents invol ve low-dose exposure which constitutes a very small risk to attending medical personnel. The types of radiation relevant to pre-hospital care are: Alpha radiation Small positively charged particles which: - Travel a short distance in air - Are easily stopped by paper, clothing, or a dressing - Can penetrate superficial layers o f the skin without causing any harm - Can be detrimental on inhalation or ingestion. Exampl es of alpha emitters are uranium, radon, and plutonium. Beta radiation Small negatively charged particles which: - Travel a few centimeters in air - Are stopped by heavier clothing and aluminum - Can damage the skin, producing radiation b urns - Produce most damage when in direct contact with the skin. Examples of beta emitters include iodine and tritium. Gamma radiation, X-rays, and neutrons - All travel great distances - Produce damage some di stance from the source - Pass through the body causing damage or energy disposition. Exampl es of these emitters include caesium and cobalt. CHAPTER 11 CBRN 638 Risk of exposure Exposure to ionized radiation may effect a part of the body, (for example, producing radiation burns to the skin) or the whole body (producing systemic effects \200 \224radiation syndrome). Most commonly, the exposure is going to be of a low dose and the p atient is likely to be asymptomatic. If symptoms are present, the implication is of a more significant exposure. Emergency services personnel are at risk due to the spread of low-dos e particles as a result of contamination in dust, aerosols, or liquid. The greater risk, th erefore, is from gamma rays, X-rays, and neutrons which travel greater distances. Simple measures will reduce the risk to emergency personnel. Rescue personnel should consider three scenarios which pose a risk: - Exposure to gamma rays or X- rays from a source near to the patient - Transfer of contamination from the patient \200 \231s skin, hair, and clothes - The inhalation or ingestion of contamination during patient contact. Type of accident - Over-exposure to penetrating radiation \200\224this may follow over-exposure to X-rays or gamma rays (for example, incidents involving industrial radiogra phic sources). These patients are not radioactive and pose no threat to the rescuer. External contamination \200\223 this may follow release of radioactive material. The patient and their clothes may be contaminated and may present a risk to the c arer. Internal contamination \200\223 exposure due to ingestion, inhalation, or absorption (for example, a casualty exposed to a fire involving radioactive substances). Contaminated wounds \200\223 an open wound may become contaminated by radiation if there h as been a radiation leak at the time of the injury. Irradiated patients pose no threat to the rescuer Dealing with a nuclear incident To reduce the risk external penetrating radiation and of co ntamination it is important to: - Assess the risk from all hazards - Park the ambulance upw ind from the accident site - Undertake an ABC assessment and immediate treatment assuming contamination and taking appropriate precautions Keep the on-scene time to a minimum - Move the patient 10 meters from the source, if there is a risk of continued radiation exposure. Consider establishing a \200\230shield \200\231 in cases of entrapment. Protection Simple precautions, similar to those used in the case of a chemical incident, will reduce the risk of contamination: - Assume contamination is present if handling a patient at an incident involving radioactivity. NUCLEAR AND RADIOLOGICAL INCIDENTS1 639 Wear a simple face mask with eye protection, gloves, an appropriate disposable impregnable gown, and overshoes or washable boots to avoid contamination of the face and hands. Keep activities within the area of the incident to a minimum to reduce airborne contamination. Cover open wounds to prevent contamination and reduce the risk from contaminated blood. Remove the patient \200\231s external clothing and place in an appropriate sealable plastic bag. It is estimated that up to 90% of contamination will be removed with the patient \200 \231s clothes. Wrap the patient in a blanket or contamination control envelope. - Do not drink, eat, or sm oke until checked for contamination. Clinical assessment and management It is likely, at an incident, that there will be no over t signs and symptoms resulting from over-exposure to penetrating radiation. In the event of explosions, other traumatic injuries are likely to be apparent. Early symptoms of significant exposure include: Nausea and vomiting - Erythema on exposed skin. Features of life-threatening exposure may n ot be apparent for days or weeks. From the patient \200\231s perspective, providing the car er is wearing appropriate PPE, attention should be given to life-threatening emergencies, f ollowing the ABCD priorities, prior to patient decontamination. The doctor should be familiar with the ambulance service policy for handling a radiological /radioactive emergency and should comply with agreed policy and protocols. This page intentionally left blank Chapter 12 641 Emergency obstetrics and gynecology Anatomy and physiology of pregnancy 642 The pregnant patient 644 Antepartum hemorrhage 652 Hypertensive disorders: eclampsia and pre-eclampsia 656 Other problems during pregnancy 658 Preterm labor 660 Trauma in pregnancy 662 Normal labor 664 Retained placenta 670 Abnormal labor 672 Multiple birth 676 Neonatal resuscitation 678 CHAPTER 12 Emergency obstetrics and gynecology 642 Anatomy and physiology of pregnancy An understanding of the anatomical and physiological ch anges are essential to the correct management of the pregnant patient and of labor. Airway Anatomical and physiological changes affecting the airway and its man- agement inclu de: - Facial and neck swelling (increased fat deposition) leading to difficulty fitting a cervical collar Airway swelling due to oedema leading to difficulty with intubation - Breast engorgement (m ay make intubation more difficult) - Increased risk of gastro-oesophageal reflux - Altered gastro-oesophageal junction - Relaxation of upper oesophageal sphincter - Increased gastric acid secretion - Delayed gastric emptying. leading to a potential for airway compromise In addition, pregnant patients can be expected to have a full dentition. Breathing Management of breathing during pregnancy is complicated by the following factors: - Alteration in chest shape (lower ribs flare outwards and diaphragm rises) Splintage of the diaphragm and chest by the expanding uterus - Change from predominantly di aphragmatic to a thoracic movement respiratory pattern Ventilation/perfusion mismatch - Increased tidal volume (+20% at 12 weeks; +40% by 40 weeks ) - Increased minute volume (+50% at term) mainly due to increased tidal volume - Relative hyperventilation. It should be remembered that many women are mildly breathless in the later stages of prtegnancy. Note: FEV1 and PEFR are unchanged during pregnancy; vital capacity remains effectively unal tered. Circulation The circulatory changes during pregnancy include: - Increased cardiac output (+ 40% by the end of the second trimester) \200\224both stroke volume and heart rate increase Heart enlarges due to muscular hypertrophy, moves upwards and anteriorly, and rotates, resu lting in large Q waves and T wave inversion in lead III. A left ventricular strain pattern with inverted T waves in V2and V3 occurs. 3rd heart sound and ejection systolic murmur may be heard - Plasma volume increases by 50% (hormonally induced peripheral vasodilatation, increased vascular bed-fetus and placenta) - Relative anemia (red cell mass only increases by 20 \200\22330%) ANATOMY AND PHYSIOLOGY OF PREGNANCY1 643 Slight reduction in systolic blood pressure; more marked reduction in diastolic pressure Vena caval compression by the gravid uterus reduces venous return by up to 40% signs of hemorrhage may only occur when 35% of blood volume has already been lost. Management of vena caval compression Vena caval compression in the supine position by the g ravid uterus reduces venous return by up to 40%. Persisting caval compression may lead to h ypotension, reduced cerebral perfusion, and inadequate perfusion of the uterus and placenta . In order to avoid this, the mother should be treated in a position which relieves caval c ompression. This can be achieved by: - Holding the uterus to the left, by hand - Placing a sandbag or pillow (or similar) under the right buttock - Nursing the patient on a long spin e board tilted approximately 30o to the left log rolling the patient to the left and then gently rolling them back to rest on the rescuers \200\231 knees (the human wedge, see Fig. 12.1). The safest me thod, if there is any possibility of a spinal injury in a traumatized patient, is to use a long spine board. Fig. 12.1 The human wedge. Reprinted with permission from Greaves I et al. (2005). Emergenc y care: a textbook for paramedics, 2nd edn. W.B. Saunders Co. Ltd. CHAPTER 12 Emergency obstetrics and gynecology 644 The pregnant patient The approach to the management of the severely ill or injured pregnant patient is essentially the same as that to a non-injured patient, bearing in mind: - That there are two patients to worry about \200\224mother and fetus - That maternal anatomy and physiology is different in pregnancy - That most pre-hospital care practitioners have very little experience in this field. It is all the more important, therefore, that a structured logical approach is used. Taking a history When the patient \200\231s condition and time constraints permit, in addit ion to the patient \200\231s history of presenting complaint and past medical history, the following additional features should be established by careful questioning: - Last menstrua l period (LMP) - Normal period length and regularity - Gestation in weeks - Contraceptive u sage (use of the IUCD is associated with an increased risk of ectopic pregnancy) Previous obstetric history including: miscarriage, premature onset of labor, pregnancy related complications, ectopic pregnancy, previous abdominal/pelv ic surgery, assisted conception - Previous pregnancy and birth history including number and type of deliveries Other gynecological pathology such as fibroids, ovarian cysts, sexually transmitted infections. The patient \200\231s maternity record card, if available, will provide additional importan t information such as blood pressure recordings and ultrasound scan results. Examination The obstetric examination should be limited to that which is necessary in order to carry out immediate treatment and plan further management. Features to note include: - Assessment of fundal height \200\224is the height \200\230right for dates \200\231? - Insp ection of the perineum for blood loss. There are three possible indications for pre-hospital vaginal examination: For removal of a retained tampon in toxic shock syndrome - For removal of products of conce ption from the cervical canal in uterine hemorrhage Inspection of open or closed os in miscarriage. In many cases, it will be more appropriate to wait unit arrival in hospital before an assessment of the os is carried out. Effective auscultation of the fetal heart is usually difficult in the pre- hospital environ ment and rarely provides information of immediate benefit. It is usually best delayed until after arrival in hospital. A full cardiorespiratory assessment is mandatory, but should not delay urgent transfer to h ospital when this is indicated by the history or initial examination findings. THE PREGNANT PATIENT1 645 Shock in pregnancy Clinically apparent shock in a pregnant patient is a life-threatening em ergency. The pregnant patient may compensate for shock for some time due to an increased bl ood cell volume and red cell mass as well as restriction of blood flow to the placenta, wit h obvious consequences for the fetus. Once decompensation occurs, it is likely to be rapid and difficult or impossible to reverse. General approach The general approach to the pregnant patient is based on effective resusci tation using ABC principles (bearing in mind the anatomical and physiological changes in pr egnancy) combined with rapid evacuation to hospital where appropriate. Airway - Ensure that the airway is patent and protected \200\224remember the increased risk of aspiration. Breathing - Administer high-flow oxygen (15l/min by non-rebreathing bag) at the earliest opportunity. Circulation - Displace the fundus off the inferior vena cava (see above) - Do not delay tra nsfer to hospital whilst trying to obtain intravenous access. CHAPTER 12 Emergency obstetrics and gynecology 646 Ectopic pregnancy Ectopic pregnancy is defined as any pregnancy occurring outside the uteru s. The vast majority are tubal although ovarian, abdominal, and cervical ectopic pregnancie s may also occur. The incidence has been variously estimated to be between 1 in 100 and 1 i n 400 pregnancies. Risk factors - None in 50% of cases - Previous ectopic pregnancy - Previous abdominal or pe lvic surgery - Pelvic inflammatory disease; endometriosis - Assisted conception. Presenting features - May be absent - Amenorrhoea usually between 5 and 10 weeks, but not a lways present - Lower abdominal pain - Vaginal bleeding - Peritonism and shoulder tip pain (minority of cases only) - Shock and collapse. Immediate management The key to the successful management of ectopic pregnancy is to suspect the diagnosis. Ensure a patent airway (effective suction must be available in case of vomiting) Administer high-flow oxygen (15l/min via a non-rebreathing mask) - Transfer urgently to hos pital; warn A&E department - Gain intravenous access and commence resuscitation (if required) \200\224DO NOT delay transfer Maintain a systolic BP of 90mmHg (presence of a radial pulse) - Monitor pulse, BP, respirat ory rate, ECG, and pulse oximetry - Administer analgesia. THE PREGNANT PATIENT1 647 50 45 90th centile 50th centile 10th centile 40 ) m c ( 35 t h g e h i 30 s u d n u f \200\223 s i s y h p m y S 25 20 15 10 16 20 24 28 32 36 40 44 Weeks Weeks Xiphisternum 36 32 and 40 28 24 20 18 16 14 12 Growth approximately one finger \200\231s breadth every two weeks Umbilicus Growth approximately two finger \200\231s breadth every two weeks Symphysis Pubis Fig. 12.2 Fundal height and gestation. Reprinted with permission from Greaves I et al. (200 5). Emergency care: a textbook for paramedics, 2nd edn. W.B. Saunders Co. Ltd. CHAPTER 12 Emergency obstetrics and gynecology 648 Miscarriage Miscarriage is loss of a pregnancy before 24 weeks \200\231 gestation. The term \200\230abortion \200\231 should no longer be used. Risk factors - Smoking - Alcohol - Diabetes mellitus, systemic and connective tissue disord ers - Fibroids - Cervical incompetence. Presenting features - Vaginal bleeding - Lower abdominal pain - \200\230Tissue \200\231 pa ssed per vaginam. Immediate management In threatened miscarriage, the cervical os is closed, whereas in inevi table miscarriage it is open. - If the os remains closed (threatened miscarriage), the trad itional management is bed rest at home, avoidance of intercourse, and appropriate GP follow -up. There is little if any evidence that bed rest or avoiding sex effects the outcome of t he pregnancy. - In incomplete miscarriage, there is no possibility of successful continuation of the placenta. Persistence of products of conception within the cervical can al may be associated with continuing hemorrhage. - Assess ABC, administer high-flow oxygen, gain iv access - Administer fluids to maintain a systolic BP of 90mmHg (presence of a radial pulse) Document vital signs - Transfer immediately to hospital; warn obstetric team of arrival - I f there is continuing bleeding, remove retained products from the cervical canal followed b y administration of syntocinon Maintain patient nil by mouth In complete miscarriage, no immediate action is necessary, although appropriate support and counseling will be required. If there is significant hemorrhage, immediate transfer to hospital is appropriate. Transfer should not be delayed whilst a line is inserted. This can be done in transit if necessary. Give syntocinon 10 units. Septic abortion This condition is fortunately much rarer than when \200\230back street \200\231 abortions were more common. The patient is usually systemically unwell with fever, rigors, sweating, nausea, and headache. There is an offensive vaginal discharge and abdomi nal tenderness. Shock may occur. The patient must be transferred immediately to hospital. I ntravenous access can be obtained in transit or whilst waiting for an ambulance. Intravenou s fluids can be administered to maintain a palpable radial pulse or systolic BP of 90mmHg. Scrupulous attention to ABC and administration of high-flow oxygen is essential. THE PREGNANT PATIENT1 649 The following patients may require anti-D prophylaxis, depending on their rhesus status: - Spontaneous miscarriage - Threatened miscarriage - Abdominal trauma. CHAPTER 12 Emergency obstetrics and gynecology 650 Toxic shock syndrome An aggressive staphylococcal infection caused by organisms introduced into the vagina on a tampon. It most commonly occurs on the 2nd to 4th day of menstruation. The condition is fortunately rare. Presenting features - Fever - Circulatory collapse - Diarrhea - Macular rash - Purulent vag inal discharge. Immediate management - Immediate transfer to hospital - Oxygen 15l/min via non-rebreathing mask - Commence resuscitation as appropriate \200\224DO NOT delay transfer. Remove tampon i f possible This page intentionally left blank CHAPTER 12 Emergency obstetrics and gynecology 652 Antepartum hemorrhage Whatever the cause of antepartum hemorrhage (placenta praevia and pla cental abruption are the possibility of massive blood loss cannot be excluded. In all cases , therefore, the patient should be transferred to hospital for assessment. In cases of obvi ous severe bleeding, transfer urgently to A&E; in apparently minor bleeding, transfer to th e local obstetric unit is usually appropriate. By definition, antepartum hemorrhage occurs after 24 weeks \200\231 gestation. the most common), Placenta praevia Placenta praevia occurs when the placenta implants wholly or partly across the cervical os (see Fig. 12.3). With the advent of routine ultrasound scanning, most case s are identified before symptoms occur. Incidence increases with maternal age and a history of previous caesarian sections. Presenting features - Painless bright red vaginal bleeding after 24 weeks \200\231 gestatio n \200\224may vary from spotting to life-threatening hemorrhage Uterus usually relaxed and non-tender - Usually painless unless labor has begun. Immediate management - Urgent transfer to hospital - Maintain a patent protected airway - A dminister high-flow oxygen 15l/min via non-rebreathing mask - Commence resuscitation but do not delay transfer; administer fluids to maintain a systolic BP of 90mmHg (presence of a palpable radial pulse) Transportation the patient in the left lateral position - Do not perform a vaginal examinat ion as it may precipitate torrential bleeding - Maintain nil by mouth. Vaginal examination is ABSOLUTELY CONTRAINDICATED ANTEPARTUM hemorrhage1 653 Fig. 12.3 Placenta praevia. Reprinted with permission from Greaves I et al. (2005). Emergen cy care: a textbook for paramedics, 2nd edn. W.B. Saunders Co. Ltd. CHAPTER 12 Emergency obstetrics and gynecology 654 Placental abruption Placental abruption occurs when a normally sited placenta separates fro m the wall of the uterus. Bleeding occurs between the uterine wall and the separated placen tal surface. The cause is not usually apparent except in those patients in whom abruption o ccurs secondary to trauma. Traumatic abruption may not present for up to 48 hours after tra uma. Presenting features - Lower abdominal pain - Vaginal hemorrhage \200\224may be concealed or revealed (see Fig. 12.4) - Uterine tender and hard - Maternal shock (may be disproportiona te to observed blood loss) - Premature labor - Reduced or absent fetal movements (ask the m other) or heart sounds Increased fundal height (compared to dates). Immediate management - Vaginal examination is contraindicated although inspection may aid the diagnosis by demonstrating bleeding The fundal height should be marked on the abdominal wall - Transfer urgently to hospital - Administer high-flow oxygen 15l/min via a non-rebreathing mask - Gain intravenous access an d resuscitate as necessary but DO NOT delay transfer Maintain nil by mouth. ANTEPARTUM hemorrhage1 655 (a) (b) Fig. 12.4 Placental abruption: (a) concealed (b) revealed. Reprinted with permission from G reaves I et al. (2005). Emergency care: a textbook for paramedics, 2nd edn. W.B. Saunders C o. Ltd. CHAPTER 12 Emergency obstetrics and gynecology 656 Hypertensive disorders: eclampsia and pre-eclampsia Risk factors - Primagravida - Age <20 o r >35 - Previous history of eclampsia, migraine, Reynaud \200\231s disease, hypertension, or renal disease Positive family history - Multiple pregnancy. Presenting features: pre-eclampsia - Over 20 weeks \200\231 gestation - Diastolic BP 100 or rapidly rising, BP >140/90 or +30/+15 from booking - Proteinuria - Excessive/sudden weight gain - Upper abdominal pain - Headache - Vi sual disturbance - Hyperreflexia, clonus. Eclampsia is the development of fits following a prodromal period of the above symptoms. HYPERTENSIVE DISORDERS: ECLAMPSIA AND PRE-ECLAMPSIA1 657 Immediate management Pre-eclampsia Always recheck an elevated blood pressure If BP moderately elevated but otherwise asymptomatic, arrange for further check by GP (or consider hospital referral if no other means of monitoring) If symptoms are present, refer to hospital irrespective of degree of hypertension If diastolic BP >100mmHg or has risen by >20mmHg, or systolic by >30mmHg since booking, transfer to hospital for assessment. Eclampsia - Manage in left lateral position - Establish and maintain a patent airway, admin ister high-flow oxygen 15l/min via a non-rebreathing mask To control the fitting: Give magnesium 4g intravenous over 10 \200\22315 minutes OR - Diazemuls 5 \200\22310mg intr avenous, with further smaller aliquots as required Transfer urgently to hospital with minimum stimulation - Support respiration if necessary. CHAPTER 12 Emergency obstetrics and gynecology 658 Other problems during pregnancy Appendicitis Occurs in 1 in 1000 pregnancies. Accurate diag nosis of appendicitis is more difficult in pregnancy since the location of the appendix may change. The perforation rate and mortality are both, therefore, signifi- cantly higher. In addition, nausea, vomiting, and anorexia may be dismissed as symptoms of pregnancy. Any su spicion of this diagnosis mandates urgent hospital assessment. Asthma Asthma often, but by no means invariably, improves during pregnancy. Conventional tr eatment protocols should be followed. Fibroids Fibroids increase in size in pregnancy and torsion or red degeneration may occur. These present (usually after 20 weeks) with abdominal pain and tenderness, vomiting (not al ways present), and fever. Treatment is with rest and analgesia and symptoms usually settle within seven days. In view of the potential for confusion with an acute abdomen, referral f or assessment is appropriate. DVT and pulmonary embolism Both these conditions are more common in pregnancy and a high in dex of suspicion should be maintained. Presenting features include shortness of breath, hae moptysis, pleuritic chest pain, cyanosis, tachycardia, and collapse. Resuscitation should b e commenced with urgent transfer to hospital which should not be delayed. Pyelonephritis Pyelonephritis is common in the second trimester and presents with fever, vo miting, and loin pain. In severe cases, admission may be necessary. This page intentionally left blank CHAPTER 12 Emergency obstetrics and gynecology 660 Preterm labor Preterm labor is defined as labor before 37 weeks \200\231 gestation. Possibl e features include: - Reduced or absent contraction pain - More rapid progression to delive ry - Increased risk of malpresentation - Early rupture of membranes - Risk of cord prolapse . Imminent labor should be managed in situ (with assistance from a midwife if possible, in ti me). Management is as for normal full term delivery. If delivery is not imminent, transfer to an obstetric unit is appropriate. Once the baby is born, the priority is to prevent heat loss by wrapping. Immediate transfer is appropriate. A baby which is significantly smaller than would be expected by dates shou ld raise the possibility of twins. This page intentionally left blank CHAPTER 12 Emergency obstetrics and gynecology 662 Trauma in pregnancy A knowledge of the anatomical and physiological changes in pregnancy is essential for the optimal management of these patients. The most common lifethreatening co nditions are traumatic placental abruption, uter- ine rupture, and pelvic fracture. These c onditions are, fortunately, rare. However, ALL PREGNANT women should be reviewed in hospita l after any significant trauma. Patient management Primary survey The principles of the primary survey are exactly the same in the pregnant as the non-pregnant patient. - A vaginal examination should NEVER be perfo rmed following trauma in pregnancy as it may precipitate torrential vaginal bleeding. In the second and third trimesters, the patient should be managed in the left lateral position. In the presence of significant trauma, fluids should be administered with less caution than in the non-pregnant patient. Secondary survey The secondary survey should be performed after arrival in hospital. An ass essment of fundal height may be performed. Traumatic placental abruption Presenting features - History of trauma - Lower abdominal pai n - Vaginal hemorrhage \200\224 may be concealed or revealed (see Fig. 12.4) - Uterine ten derness - Maternal shock (may be disproportionate to observed blood loss) - Premature labor - Reduced or absent fetal movements (ask the mother) - Increased fundal height (very diffi cult to assess pre-hospital). The presence of a tense hard uterus with contractions and continuous pain suggests the pres ence of a major abruption and a very poor fetal outcome. Placental abruption may follow minor as well as major trauma Immediate management - Follow ABCDE primary survey protocol as for any injured patient - Ma nage the patient in the left lateral position - Administer fluids to maintain a radial puls e but do not delay transfer - Treat other immediately life-threatening injuries - Transfer urgently to hospital - Mark the fundal height on the abdominal wall. TRAUMA IN PREGNANCY1 663 Traumatic uterine rupture Traumatic uterine rupture is, fortunately, very rare. Presenting features - More easily palpable fetus in a severely shocked mother - Vaginal ble eding (not always present) - Abdominal pain (not always present). Immediate management - Follow ABCDE primary survey protocol as for any injured patient - Ma nage the patient in the left lateral position - Administer fluids to maintain a radial puls e but do not delay transfer - Treat other immediately life-threatening injuries - Transfer urgently to hospital. Blunt trauma Engorgement of pelvic venous plexuses during pregnancy significantly increases the risk of catastrophic hemorrhage following blunt trauma. Urgent transfer to hospital of any patient who has suffered significant trauma is, therefore, essential. Conventional pro tocols should be followed with the patient in the left lateral position. Intravenous access should be started en route or at the scene, if this will not delay evacuation. Penetrating trauma The gravid uterus provides some degree of protection to the mother, at t he expense of the fetus, in penetrating injury to the abdomen. Conven- tional management pr otocols should be followed. CHAPTER 12 Emergency obstetrics and gynecology 664 Normal labor First stage What happens - The cervix effaces and then dilates. Once the cervi x is dilated to 10cm, the first stage is complete. After 3cm, dilatation usually occurs at approximately 1cm/hr in a primagravida and 2cm/hr in a multigravida. There is a \200\230show \200\231 of blood-stained mucus from the cervical canal. - The amn iotic sac bulges through the cervical os and ruptures. - Contractions begin and increase in frequency from every 20 minutes to every 2 to 3 minutes. The fetal head descends into the pelvis. Management - Reassure and support mother; tell her that she is in labor - Determine whether there is time to transfer to a delivery suite or call for expert assistance Gather and record information (see box) - Check the patient \200\231s obstetric records - I f a home delivery was planned, a delivery kit may be available - Ensure that the environmen t is warm. If there is no time to transfer the patient - Perform a vaginal examination - Record the pr ogress of labor (length and frequency of contractions is measured by abdominal palpation) Listen to the fetal heart before, during, and after a contraction (a toilet roll tube is effective as a stethoscope). Passage of meconium (dark green, sticky material) during labor may be a sign of fetal distr ess and an indication for transfer to an obstetric unit: - Administer oxygen to mother - Tu rn mother on side - Transfer. History - Expected date of delivery - Place of booking - Problems in this or previous pregn ancies - Time labor started. Examination - Maternal vital signs - Fundal height - Fetal vital signs - Progress of labor. NORMAL labor1 665 (a) Pelvic brim Bladder Cervix beginning to open Normal anus (b) Physiological retraction ring Upper segment (thick) Bladder Lower segment (thick) Vagina distending Anus stretched Cervix fully dilated Fig. 12.5 The birth canal: (a) in the early part of the first stage of labor; (b) at the be ginning of the second stage of labor. Reprinted with permission from Greaves I et al. (2005 ). Emergency care: a textbook for paramedics, 2nd edn. W.B. Saunders Co. Ltd. CHAPTER 12 Emergency obstetrics and gynecology 666 Second stage of labor The second stage of labor is from full dilatation until the delivery of the baby. It is usually marked by the development of an urge to push. Second stage usual ly lasts 1 \200\2233 hours in a primagravida and 1 hour or less in a multigravida. What happens - The perineum bulges, the anus dilates, and the baby \200\231s head appears at the vulva. The baby \200\231s head flexes, then rotates, so that the occiput is anterior and the face posterior (see Fig.12.6)