Category Archives: ICU

Stuff relevant to patients on ICU

Hyperchloraemia and mortality

Here’s something to add to the pile of data cautioning us to think before we acidify patients with saline. A study in Anesthesia and Analgesia using propensity matching provides retrospective evidence that patients who developed hyperchloremia after noncardiac surgery had worse outcomes.
For more information on why saline isn’t ‘normal’ see: What’s with all the chloride? An assault on salt
Hyperchloremia after noncardiac surgery is independently associated with increased morbidity and mortality: a propensity-matched cohort study
Anesth Analg. 2013 Aug;117(2):412-21
[EXPAND Abstract]


BACKGROUND: The use of normal saline is associated with hyperchloremic metabolic acidosis. In this study, we sought to determine the incidence of acute postoperative hyperchloremia (serum chloride >110 mEq/L) and whether this electrolyte disturbance is associated with an increase in length of hospital stay, morbidity, or 30-day postoperative mortality.

METHODS: Data were retrospectively collected on consecutive adult patients (>18 years of age) who underwent inpatient, noncardiac, nontransplant surgery between January 1, 2003 and December 31, 2008. The impact of postoperative hyperchloremia on patient morbidity and length of hospital stay was examined using propensity-matched and logistic multivariable analysis.

RESULTS: The dataset consisted of 22,851 surgical patients with normal preoperative serum chloride concentration and renal function. Acute postoperative hyperchloremia (serum chloride >110 mmol/L) is quite common, with an incidence of 22%. Patients were propensity-matched based on their likelihood to develop acute postoperative hyperchloremia. Of the 4955 patients with hyperchloremia after surgery, 4266 (85%) patients were matched to patients who had normal serum chloride levels after surgery. These 2 groups were well balanced with respect to all variables collected. The hyperchloremic group was at increased risk of mortality at 30 days postoperatively (3.0% vs 1.9%; odds ratio = 1.58; 95% confidence interval, 1.25-1.98) (relative risk 1.6 or risk increase of 1.1%) and had a longer hospital stay (7.0 days [interquartile range 4.1-12.3] compared with 6.3 [interquartile range 4.0-11.3]) than patients with normal postoperative serum chloride levels. Patients with postoperative hyperchloremia were more likely to have postoperative renal dysfunction. Using all preoperative variables and measured outcome variables in a logistic regression analysis, hyperchloremia remained an independent predictor of 30-day mortality with an odds ratio of 2.05 (95% confidence interval, 1.62-2.59).

CONCLUSION: This retrospective cohort trial demonstrates an association between hyperchloremia and poor postoperative outcome. Additional studies are required to demonstrate a causal relationship between these variables.

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Guidelines for the Management of Heart Failure

Some new guidelines to be aware of are the AHA Guidelines for the Management of Heart Failure. Full text is available free and while comprehensively covering chronic heart failure there is an interesting section on acute decompensated heart failure.
Evidence-based medicine enthusiasts might be interested in recommendations to consider dopamine, nesiritide, and ultrafiltration. These therapies also get a mention in the 2012 European Guidelines. I recommend you review the articles cited in the guidelines to make your own mind up.
Here are a couple of snippets you may find useful:


Snippet from American Guidelines: intravenous loop diuretic doses

“HF patients receiving loop diuretic therapy should receive an initial parenteral dose greater than or equal to their chronic oral daily dose; then dose should be serially adjusted.”


Snippet from European Guidelines: management algorithm for acute heart failure

Click to enlarge

AHF-ESC

2013 ACCF/AHA Guideline for the Management of Heart Failure: Executive Summary
Circulation. 2013 Oct 15;128(16):1810-52 Free Full Text
ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure 2012
Eur Heart J. 2012 Jul;33(14):1787-847 Free Full Text

Avoiding intubation in ARDS with awake ECMO

ECMOillusiconA letter in Intensive Care Medicine by Hoeper and colleagues from Hannover describes a small case series of six ARDS patients with severe hypoxaemia who went straight from non-invasive ventilation to awake veno-venous ECMO. All had single organ failure and four were immunocompromised, the latter factor influencing the decision to try to avoid invasive mechanical ventilation. Four of the six patients survived to hospital discharge. A larger multicentre study is being planned.

Clinical illustration courtesy of Dr Brian Burns

Extracorporeal membrane oxygenation instead of invasive mechanical ventilation in patients with acute respiratory distress syndrome
Intensive Care Med. 2013 Nov;39(11):2056-2057 (no abstract)

How to Be a Hero

Kal-fly-iconI’m not a hero and don’t claim to be, but when I was given this talk to do for the SMACC 2013 conference I researched the topic and realised I’d worked with several of them.
The talk was the toughest I’ve ever given, because I cried while giving it, and knew that it wouldn’t just be the large audience in front of me who would know I was a wuss, but that it was being recorded for many others to find out too!

A full transcript of the talk, the slide set, and links to references from the talk can be found here.

Early surgery for intracerebral haemorrhage

ICHgraphicIconTo operate or not to operate on patients with an intracerebral haematoma? Deep ones can be tricky and risk damage to surrounding brain, so superficial ones may be more likely to benefit.
These patients with superficial lesions were assessed in STICH II, an international prospective randomised controlled trial comparing early surgery with conservative treatment.
Inclusion criteria were strict:

  • spontaneous lobar intracerebral haemorrhage on CT scan (≤1 cm from the cortical surface of the brain) with a volume of between 10 mL and 100 mL
  • within 48 h of onset
  • had a best motor score on the Glasgow Coma Score (GCS) of 5 or 6, and had a best eye score of 2 or more (ie, were conscious at randomisation).

The primary outcome was a Glasgow Outcome Scale-based evaluation of recovery (‘favourable’ vs ‘unfavourable’), which did not significantly differ between groups.
A predefined subgroup of patients with a poorer prognosis (using a score based on age, haematoma size and GCS) may have a better outcome with surgery. Some patients randomised to conservative therapy subsequently underwent delayed surgery. Thanks to appropriate intention-to-treat analysis they would have remained in the conservative treatment group which may have contributed to an underestimation of the benefit of surgery.
So, overall a negative trial, and patients with small lesions and higher GCS scores won’t benefit from surgery. Patients in poorer prognostic groups might benefit, but that remains unproven.
Some other ICH trials to be aware of are Clear III and MISTIE III, which are investigating thrombolytic agents in combination with clot removal, including with minimally invasive techniques.
Early surgery versus initial conservative treatment in patients with spontaneous supratentorial lobar intracerebral haematomas (STICH II): a randomised trial
Lancet. 2013 Aug 3;382(9890):397-408
[EXPAND Abstract]


BACKGROUND: The balance of risk and benefit from early neurosurgical intervention for conscious patients with superficial lobar intracerebral haemorrhage of 10-100 mL and no intraventricular haemorrhage admitted within 48 h of ictus is unclear. We therefore tested the hypothesis that early surgery compared with initial conservative treatment could improve outcome in these patients.

METHODS: In this international, parallel-group trial undertaken in 78 centres in 27 countries, we compared early surgical haematoma evacuation within 12 h of randomisation plus medical treatment with initial medical treatment alone (later evacuation was allowed if judged necessary). An automatic telephone and internet-based randomisation service was used to assign patients to surgery and initial conservative treatment in a 1:1 ratio. The trial was not masked. The primary outcome was a prognosis-based dichotomised (favourable or unfavourable) outcome of the 8 point Extended Glasgow Outcome Scale (GOSE) obtained by questionnaires posted to patients at 6 months. Analysis was by intention to treat. This trial is registered, number ISRCTN22153967.

FINDINGS: 307 of 601 patients were randomly assigned to early surgery and 294 to initial conservative treatment; 298 and 291 were followed up at 6 months, respectively; and 297 and 286 were included in the analysis, respectively. 174 (59%) of 297 patients in the early surgery group had an unfavourable outcome versus 178 (62%) of 286 patients in the initial conservative treatment group (absolute difference 3·7% [95% CI -4·3 to 11·6], odds ratio 0·86 [0·62 to 1·20]; p=0·367).

INTERPRETATION: The STICH II results confirm that early surgery does not increase the rate of death or disability at 6 months and might have a small but clinically relevant survival advantage for patients with spontaneous superficial intracerebral haemorrhage without intraventricular haemorrhage.

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Beta blockade in sepsis

tachy-iconWhat do septic patients need if they remain shocked after fluid resuscitation? Catecholamines right? Let’s stimulate some adrenoceptors and support that circulation!
Sydney’s Prof Myburgh has told us why adrenaline (epinephrine) and noradrenaline (norepinephrine) are the go-to vasoactive choices, and Prof Singer from London likes to remind us about the detrimental effects of these drugs – the pros and cons are listed here. Tachycardia is associated with worse outcomes in sepsis, and the balance of oxygen supply and demand can be difficult to achieve. Beta blocking drugs could reduce tachycardia, but there does seem to be something counter-intuitive about giving both beta-blockers and catecholamines in the same patient. You might expect that beta blockers would cause fall in cardiac output and worsen tissue perfusion.
A small study previously showed possible helpful effects of beta blockers in children with burns. The potential benefits may extend beyond control of heart rate to anti-inflammatory / anti-catabolic effects. A recent publication evaluated beta blockers in adult patients with septic shock, which appears to be a pilot study for an ongoing randomised controlled trial.
They included patients who had been fluid resuscitated and who required noradrenaline, and treated them with a titrated esmolol infusion commenced at 25 mg/hr, with an upper dose limit of 2,000 mg/hr, to maintain a predefined HR range between 80 and 94 beats per minute. Esmolol was chosen because of its half-life of approximately 2 min, so any adverse effects could be rapidly reversed. They examined the macrocirculation using pulmonary artery catheterisation and the microcirculation using sublingual microvascular blood flow imaging.
Most of the patients had pneumonia, and interestingly, all patients received intravenous hydrocortisone (200mg/d) as a continuous infusion.
In this small cohort of patients, they found that titrating the heart rate to less than 95 bpm was associated with maintenance of stroke volume and preservation of microvascular blood flow. Although cardiac output fell because of the lower HR, stroke volume, MAP, and lactate levels were unchanged while noradrenaline requirements were reduced.

Increased vascular reactivity to norepinephrine following nonselective β-blockade is supported by volunteer and animal studies, and postulated mechanisms include:

  • blockade of a peripheral β2-mediated vasodilatory effect of noradrenaline
  • decreased clearance of infused noradrenaline
  • a centrally mediated effect on reflex activity
  • inhibition of vascular endothelial nitric oxide synthase activity

Microvascular Effects of Heart Rate Control With Esmolol in Patients With Septic Shock: A Pilot Study
Crit Care Med. 2013 Sep;41(9):2162-2168
[EXPAND Abstract]

 

OBJECTIVE: β-blocker therapy may control heart rate and attenuate the deleterious effects of β-stimulating catecholamines in septic shock. However, their negative chronotropy and inotropy may potentially lead to an inappropriately low cardiac output, with a subsequent compromise of microvascular blood flow. The purpose of the present pilot study was to investigate the effects of reducing heart rate to less than 95 beats per minute in patients with septic shock using the β-1 adrenoceptor blocker, esmolol, with specific focus on systemic hemodynamics and the microcirculation.

DESIGN: Prospective, observational clinical study.

SETTING: Multidisciplinary ICU at a university hospital.

MEASUREMENTS AND MAIN RESULTS: After 24 hours of initial hemodynamic optimization, 25 septic shock patients with a heart rate greater than or equal to 95 beats per minute and requiring norepinephrine to maintain mean arterial pressure greater than or equal to 65 mm Hg received a titrated esmolol infusion to maintain heart rate less than 95 beats per minute. Sublingual microcirculatory blood flow was assessed by sidestream dark-field imaging. All measurements, including data from right heart catheterization and norepinephrine requirements, were obtained at baseline and 24 hours after esmolol administration. Heart rates targeted between 80 and 94 beats per minute were achieved in all patients. Whereas cardiac index decreased (4.0 [3.5; 5.3] vs 3.1 [2.6; 3.9] L/min/m; p < 0.001), stroke volume remained unchanged (34 [37; 47] vs 40 [31; 46] mL/beat/m; p = 0.32). Microcirculatory blood flow in small vessels increased (2.8 [2.6; 3.0] vs 3.0 [3.0; 3.0]; p = 0.002), while the heterogeneity index decreased (median 0.06 [interquartile range 0; 0.21] vs 0 [0; 0]; p = 0.002). PaO2 and pH increased while PaCO2 decreased (all p < 0.05). Of note, norepinephrine requirements were significantly reduced by selective β-1 blocker therapy (0.53 [0.29; 0.96] vs 0.41 [0.22; 0.79] µg/kg/min; p = 0.03).

CONCLUSIONS: This pilot study demonstrated that heart rate control by a titrated esmolol infusion in septic shock patients was associated with maintenance of stroke volume, preserved microvascular blood flow, and a reduction in norepinephrine requirements.

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Xenon – no bull?

Xenon, an inert ‘noble’ gas with proven anaesthetic properties, has possible neuroprotective properties and appears to be also cardioprotective in this small study of post-cardiac arrest patients. Its high viscosity affects airway resistance, resulting in higher peak pressures and the need for a strategy to avoid gas trapping (ie. longer expiratory times as with asthma). Apparently it’s expensive, but these results suggest further study is warranted.
Feasibility and Cardiac Safety of Inhaled Xenon in Combination With Therapeutic Hypothermia Following Out-of-Hospital Cardiac Arrest
Crit Care Med. 2013 Sep;41(9):2116-24
[EXPAND Abstract]


OBJECTIVES: Preclinical studies reveal the neuroprotective properties of xenon, especially when combined with hypothermia. The purpose of this study was to investigate the feasibility and cardiac safety of inhaled xenon treatment combined with therapeutic hypothermia in out-of-hospital cardiac arrest patients.

DESIGN: An open controlled and randomized single-centre clinical drug trial (clinicaltrials.gov NCT00879892).

SETTING: A multipurpose ICU in university hospital.

PATIENTS: Thirty-six adult out-of-hospital cardiac arrest patients (18-80 years old) with ventricular fibrillation or pulseless ventricular tachycardia as initial cardiac rhythm.

INTERVENTIONS: Patients were randomly assigned to receive either mild therapeutic hypothermia treatment with target temperature of 33°C (mild therapeutic hypothermia group, n = 18) alone or in combination with xenon by inhalation, to achieve a target concentration of at least 40% (Xenon + mild therapeutic hypothermia group, n = 18) for 24 hours. Thirty-three patients were evaluable (mild therapeutic hypothermia group, n = 17; Xenon + mild therapeutic hypothermia group, n = 16).

MEASUREMENTS AND MAIN RESULTS: Patients were treated and monitored according to the Utstein protocol. The release of troponin-T was determined at arrival to hospital and at 24, 48, and 72 hours after out-of-hospital cardiac arrest. The median end-tidal xenon concentration was 47% and duration of the xenon inhalation was 25.5 hours. The frequency of serious adverse events, including inhospital mortality, status epilepticus, and acute kidney injury, was similar in both groups and there were no unexpected serious adverse reactions to xenon during hospital stay. In addition, xenon did not induce significant conduction, repolarization, or rhythm abnormalities. Median dose of norepinephrine during hypothermia was lower in xenon-treated patients (mild therapeutic hypothermia group = 5.30 mg vs Xenon + mild therapeutic hypothermia group = 2.95 mg, p = 0.06). Heart rate was significantly lower in Xenon + mild therapeutic hypothermia patients during hypothermia (p = 0.04). Postarrival incremental change in troponin-T at 72 hours was significantly less in the Xenon + mild therapeutic hypothermia group (p = 0.04).

CONCLUSIONS: Xenon treatment in combination with hypothermia is feasible and has favorable cardiac features in survivors of out-of-hospital cardiac arrest.

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Lowering the BP rapidly in ICH

ICH-iconIn our retrieval service case reviews, one thing that is that sure to generate discussion is what to do about the blood pressure in patients who present with intracranial haemorrhage and hypertension. We don’t want the bleeding to be worsened by higher blood pressure, but we don’t want to decrease cerebral perfusion pressure in patients who have raised intracranial pressure. Consensus guidelines exist for spontaneous intracerebral haemorrhage and subarachnoid haemorrhage, but they’re not based on strong data.
Here’s a study that attempted to provide more information. Intensive lowering to a target systolic of 140 mmHg within 1 hour was compared with lowering to a target of 180 mmHg. There was no significant reduction in the rate of the primary outcome of death or severe disability. The skeptic in me is disappointed there was no placebo arm. An ordinal analysis of modified Rankin scores favoured the intensive BP-lowering intervention, which means this study can be used by both those for and against intensive BP lowering to support their views.
As explained in an accompanying editorial, a number of factors may limit generalisability to Western practice, such as the predominant use of the alpha-blocking agent urapadil in the large numbers of Asian patients, a drug not available in the United States. Future publication of the ATACH-II trial using intravenous nicardipine will shed more light on this topic.
1. Rapid Blood-Pressure Lowering in Patients with Acute Intracerebral Hemorrhage
N Engl J Med. 2013 Jun 20;368(25):2355-65
[EXPAND Abstract]


BACKGROUND: Whether rapid lowering of elevated blood pressure would improve the outcome in patients with intracerebral hemorrhage is not known.

METHODS: We randomly assigned 2839 patients who had had a spontaneous intracerebral hemorrhage within the previous 6 hours and who had elevated systolic blood pressure to receive intensive treatment to lower their blood pressure (with a target systolic level of <140 mm Hg within 1 hour) or guideline-recommended treatment (with a target systolic level of <180 mm Hg) with the use of agents of the physician’s choosing. The primary outcome was death or major disability, which was defined as a score of 3 to 6 on the modified Rankin scale (in which a score of 0 indicates no symptoms, a score of 5 indicates severe disability, and a score of 6 indicates death) at 90 days. A prespecified ordinal analysis of the modified Rankin score was also performed. The rate of serious adverse events was compared between the two groups.

RESULTS: Among the 2794 participants for whom the primary outcome could be determined, 719 of 1382 participants (52.0%) receiving intensive treatment, as compared with 785 of 1412 (55.6%) receiving guideline-recommended treatment, had a primary outcome event (odds ratio with intensive treatment, 0.87; 95% confidence interval [CI], 0.75 to 1.01; P=0.06). The ordinal analysis showed significantly lower modified Rankin scores with intensive treatment (odds ratio for greater disability, 0.87; 95% CI, 0.77 to 1.00; P=0.04). Mortality was 11.9% in the group receiving intensive treatment and 12.0% in the group receiving guideline-recommended treatment. Nonfatal serious adverse events occurred in 23.3% and 23.6% of the patients in the two groups, respectively.

CONCLUSIONS: In patients with intracerebral hemorrhage, intensive lowering of blood pressure did not result in a significant reduction in the rate of the primary outcome of death or severe disability. An ordinal analysis of modified Rankin scores indicated improved functional outcomes with intensive lowering of blood pressure.

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2. Blood pressure in intracerebral hemorrhage–how low should we go?
N Engl J Med. 2013 Jun 20;368(25):2426-7

Clopidogrel and aspirin for TIA

A large Chinese trial compared aspirin alone with combination aspirin / clopidogrel in patients who had had a TIA in the previous 24 hours. 90-day stroke outcome was reduced in the combination therapy group without an apparent increase in haemorrhage.
Clopidogrel with Aspirin in Acute Minor Stroke or Transient Ischemic Attack
N Engl J Med. 2013 Jul 4;369(1):11-19
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Background Stroke is common during the first few weeks after a transient ischemic attack (TIA) or minor ischemic stroke. Combination therapy with clopidogrel and aspirin may provide greater protection against subsequent stroke than aspirin alone.

Methods In a randomized, double-blind, placebo-controlled trial conducted at 114 centers in China, we randomly assigned 5170 patients within 24 hours after the onset of minor ischemic stroke or high-risk TIA to combination therapy with clopidogrel and aspirin (clopidogrel at an initial dose of 300 mg, followed by 75 mg per day for 90 days, plus aspirin at a dose of 75 mg per day for the first 21 days) or to placebo plus aspirin (75 mg per day for 90 days). All participants received open-label aspirin at a clinician-determined dose of 75 to 300 mg on day 1. The primary outcome was stroke (ischemic or hemorrhagic) during 90 days of follow-up in an intention-to-treat analysis. Treatment differences were assessed with the use of a Cox proportional-hazards model, with study center as a random effect.

Results Stroke occurred in 8.2% of patients in the clopidogrel-aspirin group, as compared with 11.7% of those in the aspirin group (hazard ratio, 0.68; 95% confidence interval, 0.57 to 0.81; P<0.001). Moderate or severe hemorrhage occurred in seven patients (0.3%) in the clopidogrel-aspirin group and in eight (0.3%) in the aspirin group (P=0.73); the rate of hemorrhagic stroke was 0.3% in each group.

Conclusions Among patients with TIA or minor stroke who can be treated within 24 hours after the onset of symptoms, the combination of clopidogrel and aspirin is superior to aspirin alone for reducing the risk of stroke in the first 90 days and does not increase the risk of hemorrhage.

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Family presence during resuscitation

CPR-iconFamilies allowed to be present during attempted cardiopulmonary resuscitation had improved psychological outcomes at ninety days.
Adult family members of adult patients were studied in this randomized study from France.
Resuscitation team member stress levels and effectiveness of resuscitation did not appear to be affected by family presence.
Family Presence during Cardiopulmonary Resuscitation
N Engl J Med. 2013 Mar 14;368(11):1008-18
[EXPAND Abstract]


BACKGROUND: The effect of family presence during cardiopulmonary resuscitation (CPR) on the family members themselves and the medical team remains controversial.

METHODS: We enrolled 570 relatives of patients who were in cardiac arrest and were given CPR by 15 prehospital emergency medical service units. The units were randomly assigned either to systematically offer the family member the opportunity to observe CPR (intervention group) or to follow standard practice regarding family presence (control group). The primary end point was the proportion of relatives with post-traumatic stress disorder (PTSD)-related symptoms on day 90. Secondary end points included the presence of anxiety and depression symptoms and the effect of family presence on medical efforts at resuscitation, the well-being of the health care team, and the occurrence of medicolegal claims.

RESULTS: In the intervention group, 211 of 266 relatives (79%) witnessed CPR, as compared with 131 of 304 relatives (43%) in the control group. In the intention-to-treat analysis, the frequency of PTSD-related symptoms was significantly higher in the control group than in the intervention group (adjusted odds ratio, 1.7; 95% confidence interval [CI], 1.2 to 2.5; P=0.004) and among family members who did not witness CPR than among those who did (adjusted odds ratio, 1.6; 95% CI, 1.1 to 2.5; P=0.02). Relatives who did not witness CPR had symptoms of anxiety and depression more frequently than those who did witness CPR. Family-witnessed CPR did not affect resuscitation characteristics, patient survival, or the level of emotional stress in the medical team and did not result in medicolegal claims.

CONCLUSIONS: Family presence during CPR was associated with positive results on psychological variables and did not interfere with medical efforts, increase stress in the health care team, or result in medicolegal conflicts.

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