Intra-Abdominal Hypertension

 

A 48 year old male was admitted to the ICU with rapidly evolving multi-organ dysfunction. He was in type I respiratory failure, hypotensive and had stage II acute kidney injury. He had been an inpatient recovering from a laparotomy for major urological surgery 5 days prior to his ICU admission. This was complicated by a major intraoperative haemorrhage.

The patient was commenced on treatment for presumed hospital acquired pneumonia. He was placed on mechanical ventilation and a noradrenaline infusion was commenced to maintain a mean arterial pressure of ≥65mmHg. Over the following 24 hours the patient displayed worsening lung compliance in the context of adequate oxygenation and an atracurium infusion was started. Simultaneously the patient appeared to develop an ileus and he became anuric. Repeated clinical examination revealed an increasingly distended abdomen. A CT of the abdomen and pelvis showed a large left sided retroperitoneal haematoma with evidence of pelvico-ureteric leak on the left and an associated fluid collection. The patient was taken to theatre for urgent re-laparotomy.

At the conclusion of the operation, the surgical team was unable to close the abdomen due to significant bowel oedema. They accepted a laparostomy and returned the patient to ICU with a negative pressure wound dressing in-situ. Post-operatively, there was significant improvement in lung compliance, vasopressor requirement and urine output. Enteral feeding was quickly re-established. The abdomen was closed during the same hospital admission and the patient survived-to-discharge home. At no point was this patient’s intra-abdominal pressure measured.

 

Describe the management of intra-abdominal hypertension.

Christopher Westall

Intra-abdominal hypertension (IAH)- abdominal compartment syndrome (ACS) is a well-recognised cause of morbidity and mortality in critically ill patients, rising to prominence in the 1990s with increased early survival of patients with intra-abdominal pathology requiring emergent laparotomy (principally abdominal aortic aneurysm repair and blunt trauma).1,2 IAH/ ACS may be precipitated by a range of insults local (primary IAH) and distant (secondary IAH) to the abdomen.3 The syndrome encompasses a spectrum of severity and there are a range of treatment options, though with little high quality evidence to support these.

The World Society of the Abdominal Compartment Syndrome (WSACS) consensus guidelines recommend that intra-abdominal pressure (IAP) is measured using the trans-bladder technique in any critically ill patient with an associated risk factor for IAH. The normal value for IAP is <12mmHg. IAH is then categorized by increasing pressure increments from grade I (IAP 12-15mmHg) to grade IV (>25mmHg). Abdominal compartment syndrome is defined as sustained IAP >20mmHg associated with new organ dysfunction.3

The WSACS Consensus proposes a management algorithm for IAH/ ACS that is loosely analogous to commonly encountered algorithms for managing raised intracranial pressure The abdomen is considered a fixed compartment with intra-luminal and extra-luminal volumes that can be manipulated through neutral-negative fluid balance, nasogastric and colonic decompression and percutaneous drainage of ascites/collections. In this instance, however, the compliance of the “box”, the abdominal wall, can also be manipulated by patient position, ventilatory strategy and neuromuscular blockade. Decompressive [laparotomy] therapy is reserved for algorithm failure.

The efficacy of protocolised management of IAH/ACS has never been demonstrated. A single prospective observational study suggested reduction in morbidity and mortality using algorithm based management of IAH; the authors quoted an increase in survival-to-discharge rate from 50 to 72% (p= 0.015) across 6 years with improved rates of same-admission closure. However the study was single centre, recruiting patients only after the laparostomy, with substantial selection and observer bias. Furthermore it was unclear which parts of the protocol were effective.4 While the basic principles underlying the WCASC 2013 algorithm are sensible, it must be acknowledged that proposed therapies such as resuscitation with hypertonic fluids, diuretic-driven diuresis and ultrafiltration through renal replacement therapies have no evidence to support them and have potentially serious implications for the patient.

Given that the efficacy of protocolised management of IAH/ACS is uncertain, is there then any evidence to support the measurement of IAP in every “at risk” patient, especially since the list of risk factors for IAH is so extensive that it is difficult to imagine a critically ill patient that is not at risk. This would not be without significant task-burden to critical care nursing staff, and as with any clinical index in ICU, risks morbidity from misinterpretation. There are only two small studies that have examined whether clinical examination can reliably predict intra-abdominal pressure; both small studies with significant methodological flaws and both conducted between 1996- 2000 when awareness of IAH was comparatively low. Importantly both studies compared examination to IAP measurement at pressures well below 20mmHg, where there is little evidence that specific intervention improves patient outcome, beyond highlighting that that patient is at risk of ACS.5,6

Decompressive laparotomy is recommended for the treatment of all patients with ACS refractory to medical therapy.3 In modern practice it is difficult to accurately assess the performance of this strategy in primary IAH/ACS, such is the absence of clinical equipoise. As many reviews acknowledge, the improvement in patient survival rates associated with primary laparostomy in abdominal trauma patients in the 1990s caused a fundamental paradigm shift from which it is now difficult to ethically justify alternative treatment strategies.1,2 That is to say that many patients with IAH/ ACS will now present to the ICU once decompressive laparostomy has either occurred or is imminently planned.

The benefits of decompressive laparotomy in secondary ACS are certainly less; data exists only for acute severe pancreatitis and sepsis associated with secondary peritonitis. While in both instances it must be acknowledged that laparostomy reduces IAP, like many interventions in a critically ill patient population, this does not translate into mortality benefit.7,8 As commentators note, laparostomy may often be performed because of a conceptual benefit of relook-laparotomy 48 hours later, rather than inability to close the abdomen or specific concerns regarding ACS.2 Indeed, regarding secondary peritonitis, there is good evidence that primary closure with on-demand re-laparotomy is non-inferior to laparostomy and planned re-laparotomy, and is associated with fewer surgeries and lower healthcare costs.9 This strategy is now [weakly] endorsed by the WCACS.3

One point that is widely agreed upon is the management of laparostomy. It appears universally agreed that negative pressure wound therapy (NPWT, i.e. “vac dressings”), with or without a form of dynamic retention system, is superior to previously popular methods such as bioprosthetic mesh and Bogota bag. The largest systematic review on the subject suggests that NPWT is associated with improved rates of primary delayed fascial closure (57.8%, 95% CI 50.8- 64.7) and mortality (22.3%, 95% CI 17.5- 27.5) with lower rates of entero-atmospheric fistulation (7.0%, 95% CI 5.0- 9.3) and abscess formation (4.2%, 95% CI 2.3- 6.9).10 This systematic review heavily influenced the most recent NICE review on the topic leading to endorsement of NPWT in clinical guideline IPG467, “Negative pressure wound therapy for the open abdomen” (2013).


Conclusion

The measurement of IAP in all at-risk critically ill patients is probably unnecessary and burdensome in resource terms. Critical care practitioners should have a low index of suspicion for ACS in their patients; if this develops then decompressive laparotomy is the treatment of choice (unless there is a large extra-luminal collection amenable to urgent drainage), particularly since modern laparostomy management appears to be associated with an increasingly low complication rate, if the abdomen cannot be closed.

The consensus guidelines for IAH/ACS remind us that attention to detail; such as ensuring that enteral nutrition is succeeding, that bowel care is optimal and that fluid balance is tightly controlled, may prevent numerous serious ICU-associated syndromes from ever developing.


References

1. Balogh ZJ, Lumsdaine W, Moore EE, Moore FA. Postinjury abdominal compartment syndrome: from recognition to prevention. Lancet,  2014; 384:1466-75

2. Leppaniemi AK. Laparostomy: why and when? Critical Care 2010; 14: 216. DOI: 10.1186/cc8857

3. Kirkpatrick AW, Roberts DJ, De Waele J, Jaeschke R, Malbrain MLNG, De Keulenaer B, Duchesne J, Bjorck M, Leppaniemi A, Ejike JC, Sugrue M, et al.  Intra-abdominal compartment syndrome: updated consensus definitions and clinical practice guidelines from the World Society of the Abdominal Compartment Syndrome. Intensive Care Med, 2013; 39:1190-1206

4. Cheatham ML, Safcsak KRN. Is the evolving management of intra-abdominal hypertension and abdominal compartment syndrome improving survival? Crit Care Med,  2010; 38:402-407

5. Kirkpatrick AW, Brenneman FD, McLean RF, Rapanos T, Boulanger BR. Is clinical examination an accurate indicator of raised intra-abdominal pressure in critically injured patients? Can J Surg, 2000:43:207-11

6. Sugrue M, Bauman A, Jones F, Bishop G, Flabouris A, Parr M, Stewart A, Hillman K, Deane SA. Clinical examination is an inaccurate predictor of intra-abdominal pressure. World J Surg, 2002; 26:1428-31

7. Mentula P, Hienonen P, Kemppainen E, Puolakkainen P, Leppaniemi A. Surgical decompression for abdominal compartment syndrome in severe acute pancreatitis. Arch Surg, 2010; 145:764-9

8. Robledo FA, Luque-de-Leon E, Suarez R, Sanchez P, de la Fuente M, Vargas A, Mier J. Open versus closed management of the abdomen in the surgical treatment of severe secondary peritonitis: a randomized clinical trial. Surg Infect (Larchmt), 2007; 8:63–72

9. van Ruler O, Mahler CW, Boer KR, Reuland EA, Gooszen HG, Opmeer BC, de Graaf PW, Lamme B, Gerhards MF, Steller EP, van Till JW, et al. Comparison of on-demand vs planned relaparotomy strategy in patients with severe peritonitis: a randomized trial. JAMA, 2007; 298:865-73

10. Quyn AJ, Johnston C, Hall D, Chambers A, Arapova N, Ogston S, Amin AI. The open abdomen and temporary abdominal closure systems- historical evolution and systematic review. Colorectal Dis, 2012; 14: e429–38

 

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Post-operative Opioid-Induced Hyperalgesia

 

An elderly female was admitted to the intensive care unit (ICU)following a planned hemi-hepatectomy to remove metastatic lesions from a previously resected primary colorectal cancer. The patient had declined neuraxial anaesthesia. The surgery proceeded uneventfully via a rooftop incision under general anaesthesia, which was maintained with remifentanil, sevofluorane and paralysis with atracurium.

30 minutes before the termination of the three hour operation, a bolus of 10mg of morphine was given intravenously and a patient-controlled analgesia (PCA) morphine pump was prepared. At emergence from anaesthesia, paralysis was reversed, and the patient was successfully extubated. In the ICU the patient was instructed in the use of the PCA. She was initially comfortable, but within 30 minutes she complained of worsening abdominal pain around the upper abdominal incision and became tachycardic.

To address this patient’s worsening post-operative abdominal pain 10mg of morphine was given intravenously. Simultaneously she was reassessed and the potential cause of the pain was sought. The abdomen remained soft and mildly tender. Drains were dry, and parameters including blood pressure, respiratory rate, haemoglobin, and arterial blood gases were satisfactory.

The morphine was ineffective. She was given 1g of intravenous paracetamol, a further bolus of 10mg of morphine and two sequential 500mL aliquots of crystalloid. Surgical review was requested. After another 20 minutes the pain had not diminished so she received a bolus of fentanyl and a trial dose of 100mg of intravenous tramadol. Unfortunately these measures did not reduce the pain at all. Although vital signs were unchanged, the patient was increasingly distressed.

There was no apparent clinical deterioration to account for the increased pain. Yet, control of her symptoms had clearly been lost and routine analgesia was ineffective. Urgent senior review was requested. Suspecting that she had become refractory to opioid analgesia, and concerned about the severity of the pain and its potential complications, the consultant stopped the patient’s PCA, increased the inspired oxygen fraction to 0.80 through a non-rebreathe mask, and gave 50mg of ketamine intravenously.

These interventions significantly improved symptoms over the next ten minutes. The patient remained conscious though slightly drowsy and her tachycardia settled. Simple analgesics and a low dose infusion of 2-5 mcg/kg/min (approximately 10-25 mg/h) of ketamine were prescribed. These effectively controlled her pain. After the patient had remained comfortable and clinically stable for several hours, the PCA was gradually re-introduced and the ketamine was discontinued. She was discharged to the ward the following day.

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Invasive Fungal Infections on ICU

A 42 year old woman was admitted to the intensive care unit with necrotising pancreatitis. She required sedation and mechanical, vasopressors to maintain adequate mean arterial pressure and extensive crystalloid resuscitation. Enteral nutrition was initially maintained via nasogastric feeding. She was treated with empirical broad-spectrum antibiotics (meropenem) and was prescribed antifungal prophylaxis (fluconazole) at the request of the hepatobiliary surgical team.

 

The patient experienced a prolonged systemic inflammatory response syndrome. She ultimately underwent a pancreatic necrosectomy and required recurrent radiologically-guided percutaneous drainage of intra-abdominal collections. For a large proportion of her ICU admission, enteral nutrition failed and the patient required total parenteral nutrition. Candida albicans was isolated from central venous catheter exits sites, drain exit sites, drain fluid, urine and sputum on several occasions, but there was never any evidence of invasive fungal disease.

The patient was eventually discharged from ICU and survived to discharge from hospital. She was left dependent on pancreatic enzyme replacement and subcutaneous insulin therapy.

Describe the incidence, clinical features and management of fungal infections in non-neutropaenic, non-transplant critical care patients.Read More »

Faecal Peritonitis: The Role of Laparostomy

A 68-year-old previously fit woman was admitted with left lower abdominal pain and signs of cardiovascular shock. She had had a 2 day history of crampy left lower abdominal pain and altered bowel habit. Clinically she had a diagnosis of bowel perforation with generalised peritonitis. She was exhibiting signs of shock with a pronounced tachycardia and a reduced systolic blood pressure.

She was started on fluid resuscitation and intravenous antibiotics. After her cardiovascular system stabilised she was taken to the operating theatre where she had a laparotomy. A sigmoid perforation was found with four quadrant faecal contamination. A Hartmann’s procedure was performed. A laparostomy was decided upon at the first instance, and was covered with a VAC dressing.

She was transferred to the intensive care unit (ICU) still intubated and ventilated.

Her condition rapidly worsened on the ICU. She required vasopressor support intra-operatively and her requirements rapidly escalated. She seemed to stabilse over the next 36 hours. Her condition then worsened and she was taken back to theatre for a washout of her peritoneal cavity. A number of collections were found and further soiling of her abdomen was evident. Her condition remained the same for the next 12 hours but then started to show an improvement again. She continued to make a good response to treatment over the next 3-4 days. She had another washout at 4 days. She was extubated on day 5 and invasive monitoring and cardiovascular support was no longer needed.

 

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Decompressive Craniotomy in Traumatic Brain Injury

A 20 year-old man was admitted to his local district hospital with a severe head injury following an assault. On arrival in the Emergency Department he was agitated with a reduced conscious level, with evidence of blunt trauma to the head and neck. Prior to intubation, his Glasgow Coma Score (GCS) was recorded as 7 (E1V2M4), and with cervical spine precautions he underwent intubation with subsequent mechanical ventilation and sedation.

An urgent CT brain and cervical spine revealed early evidence of intracerebral contusions with diffuse areas of petechial intracerebral haemorrhage identified. Nasal and maxillary fractures were also seen, with no cervical spine pathology identified. He was transferred to the regional neurological centre for assessment and ongoing management.

On arrival in the Neurosurgical Intensive Care unit the patient underwent insertion of an intracranial pressure monitor revealing an intracranial pressure (ICP) of between 30-35 mmHg. Pupil reactivity was sluggish bilaterally. Sedation was changed to infusions of propofol, fentanyl and midazolam, positioning was optimised with 20 degree head-up tilt, endotracheal tube ties were replaced and targeted mechanical ventilation to EtCO2 4- 4.5kPa. Central venous access was established and an infusion of Noradrenaline was used to target cerebral perfusion pressure to 70mmHg.

Initial medical management stabilised ICP below 25mmHg, but within the next 12 hours this began to rise despite neuromuscular blockade and infusion of hypertonic saline. Further CT imaging revealed progression of the intracerebral contusions with developing oedema. The patient was transferred to the operating theatre for insertion of an external ventricular drain. CSF drainage resulted in an immediate but small improvement in ICP but again over the next 12 hours it began to rise, and decision was made for bifrontal decompressive craniectomy.

Subsequent recovery was slow and was complicated by ventilator-associated pneumonia, a protracted tracheostomy wean and severe agitation. The patient underwent intensive neuro-rehabilitation and had been decannulated, but was left with persistent cognitive impairment, seizures and depression.

What is the rationale for performing decompressive craniotomy in TBI?

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Post Operative Cognitive Deficit after Cardiac Surgery

A middle-aged  man underwent an elective re-do aortic arch replacement for a 6.1cm ascending aortic aneurysm distal to a pre-existing composite graft. Past medical history included a Bentall procedure (metallic aortic valve replacement, aortic root and ascending aorta replacement with coronary re-implantation into the composite graft) 20 years ago. Preoperative echocardiogram showed a well seated AVR and good biventricular function. Drug history included Warfarin (target INR 2-3) and Atenolol.

Anaesthetic induction and re-sternotomy were uneventful. Cerebral oximetry (rSO2) monitoring was utilized in this case. Cardiopulmonary bypass (CPB) was achieved uneventfully and deep hypothermic circulatory arrest (DHCA) was instituted. The patient was cooled to 18°C using CPB and icepacks. Prior to CPB and DHCA being commenced, intravenous thiopentone and methylprednisolone were administered for neuroprotection. Total DHCA time was 40 minutes and selective anterograde perfusion via the right axillary artery (chosen as it is relatively free of atheroma) was employed when rSO2 dropped to <40% and they remained >40% for the remainder of DHCA. Total CPB time was 105 minutes.

Following successful insertion of a new graft, the patient was carefully rewarmed to normothermia and weaned off CPB uneventfully, only requiring minimal vasopressor support. The patient was transferred to the cardiothoracic critical care unit.

After optimization of cardiorespiratory physiology, correcting coagulopathy and maintaining normothermia, with strict avoidance of hyperthermia, the patient was extubated the following day. For the first 48-72 hours postoperatively, delirium was the most active medical issues and this was managed according to conventional treatment. There was no focal upper or lower limb neurology. The patient did not require any other organ system support.

Following resolution of his delirium the patient was discharged to the ward to continue his rehabilitation. Prior to discharge, at approximately postoperative days 7-10, he was complaining of loss of short-term memory, reduced attention span and difficulty with finding words. A neurology review attributed this to cognitive dysfunction but no formal tests were carried out. A neurology clinic follow-up and an outpatient MRI scan were arranged.

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Use of Bicarbonate in Lactic Acidosis

Five days post emergency colorectal surgery, an elderly woman, following a brief period of chest pain a few hours earlier, developed progressive hypotension and tachycardia on the ward. She had a background of hypertension, type 2 diabetes and a chronic left foot ulcer. On examination she was found to be clammy, mottled and peripherally vasoconstricted with a GCS of 15/15. Her abdomen was soft and non-tender. Her initial ECG had showed no ischaemic changes and subsequent ECGs showed only a sinus tachycardia.

Initial blood gas analysis showed a metabolic acidosis (pH 7.21 Lactate 2.8mmol/l, HCO3 11.1mmol/l with a pCO2 of 2.7kPa).  A starting differential diagnosis of a cardiac event, a pulmonary embolism, critical ischaemia or sepsis related to a hip or foot ulcer were made. Urgent orthopaedic and vascular review were obtained, and it was deemed that neither the hip, ulcer or vascular insufficiency were a likely source for the deterioration. Initially it was planned to transfer her for a CTPA, however she became progressively unstable, was no longer fluid responsive, and was intubated on the ward and transferred to the intensive care unit (ICU) for stabilisation.

On arrival on ICU she continued to deteriorate, and in addition to fluid resuscitation required a high dose noradrenaline infusion to maintain her blood pressure. Broad spectrum antibiotics were started, a bedside echocardiogram and blood tests performed and hydrocortisone started. Her metabolic acidosis continued to deteriorate, subsequent arterial blood gas showed a pH 6.91, Lactate of 13.7mmol/l, HCO3 7.7mmol/l, base excess -25mmol/l with a pCO2 of 5.4kPa. It was decided to correct this acidosis with a bicarbonate infusion and initially 200ml of 8.4% was given over an hour, based on correcting half the calculated bicarbonate deficit (bicarbonate deficit (mmol) = base deficit 0.3xbodyweight(kg)1).  The blood gas following this infusion showed improvement in the metabolic acidosis despite the increasing Lactate (pH 7.07, Lac 14.0mmol/l, HCO3 10mmol/l, BE -18.6mmol/l with a pCO2 of 4.85kPa). She continued to deteriorate and the results from her blood tests, troponin and bedside echo suggested a primary myocardial infarction to cause this decline. She was too unstable for primary coronary intervention and her condition continued to deteriorate. She died 6 hours post admission.

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Massive Transfusion in Upper Gastrointestinal Haemorrhage

A 55 year old male presented with acute upper abdominal pain and haematemesis. He had admitted drinking alcohol to excess. Following admission, he had a further significant episode of haematemesis associated with haemorrhagic shock. An emergency oesophagogastrectomy (OGD) was arranged in theatre. His pre-procedure haemoglobin was 60g/L.  OGD revealed large amounts of fresh blood in the stomach, which prevented identification of the bleeding point. The patient had a number of oesophageal varices, attempts were made to band these but this did not stop the bleeding. A partial gastrectomy was undertaken. The patient received a total of 18 units of red blood cells, 14 units of flesh frozen plasma and 2 units of platelets and cryoprecipitate before being taken to Intensive Care intubated and ventilated.

On the Intensive Care Unit he was warmed and repeat blood tests were sent to ensure correction of his coagulopathy. Haemoglobin was recorded as 9.4g/dL and the APTTr was normal. The following day when he was normothermic and cardiovascularly stable he was woken and extubated. He was discharged to the ward the following day.

When should we transfuse in upper gastro-intestinal haemorrhage? Are there any adjunctive therapies that can help?Read More »

Tourniquets in Severe Traumatic Limb Haemorrhage

Tourniquets in Severe Traumatic Limb Haemorrhage

A 30 year old male pedestrian was involved in a road traffic collision with a car travelling at speed. On arrival of the paramedics he was found to be unconscious with evidence of severe blood loss. He also had a partial amputation of his right leg below the knee. The paramedics applied a combat application tourniquet to the thigh, above the injury. He then suffered a cardiorespiratory arrest and CPR was commenced. On arrival in the emergency department his trachea was intubated and he underwent bilateral decompressive thoracostomies. Large bore intra-venous access was secured and two units of packed red cells given by a rapid infusion device. He remained haemodynamically unstable requiring a further six units of red cells and associated blood products to maintain a systolic blood pressure of above 80mmHg. Orthopaedic members of the trauma team were persistently keen to remove the tourniquet in order to prevent distal-neurovascular damage. This request was repeatedly denied and he was transferred rapidly to theatre for definitive control of his ongoing haemorrhage with an exploratory laparotomy. No cause for haemorrhage was found on laparotomy so attention shifted to damage control surgery on his leg in order to try and achieve some haemodynamic stability. Unfortunately to achieve this aim the tourniquet was removed. Bleeding was uncontrollable even with reapplication of the tourniquet and the patient exsanguinated and died.

What are the current recommendations for the use of limb tourniquets in trauma, and what is the evidence base for those recommendations?

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Coiling versus Clipping Subarachnoid Haemorrhages

Coiling versus Clipping Subarachnoid Haemorrhages

A 40 year old female presented with a severe sudden onset headache, and deteriorated in the emergency department with worsening agitation and confusion requiring intubation and ventilation for her own safety. A CT scan diagnosed a Fisher Grade 4 subarachnoid haemorrhage and obstructive hydrocephalus. Clinical presentation was scored as Hunt and Hess grade 4 or World Federation of Neurosurgeons grade 4. The patient was transferred to the local tertiary Neurocritical care unit where an extra-ventricular drain was inserted overnight. The following day the patient underwent coiling of her right middle cerebral artery aneurysm in the radiology suite. A Magnesium infusion and Nimodipine therapy were commenced to reduce the risk of vasospasm. On initial sedation hold she woke up agitated so she had an early tracheostomy placed to allow controlled wake up. She had a straightforward respiratory wean from the ventilator over the next few days. Neurological recovery was good (Glasgow coma score improved to 14/15) and the patient was discharged to the ward for on-going neuro rehabilitation and repatriation to the base hospital.

What are the risks of clipping vs coiling subarachnoid haemorrhages?Read More »