In Dr Jason Nomura’s excellent blog takeokun.com he describes his technique to assist in viewing the needle during in-plane ultrasound guidance for vascular access.
The technique is described as follows:
Obtain a sagittal view of the target vessel
Stabilize the transducer and brace your hand. Then rock the probe to elevate the proximal section.
Place the needle in the center of the probe (usually at the case seam) and under the probe footprint.
Stop rocking the probe so the entire surface is again contacting the skin, the needle tip should be immediately visible.
Advance the needle to the target vessel
Click the image below to go to the site and the demonstration video: The “Ski Lift”: A Technique to Maximize Needle Visualization with the Long-axis Approach for Ultrasound-guided Vascular Access Acad Emerg Med. 2010 Jul;17(7):e83-4
Evidence-based medicine reminds us to beware ‘experts’. However, here’s one self-described expert who talks some sense. Doctor (Doktor?) HJ Priebe from the University Hospital Freiburg in Germany suggests the risk of harm outweighs the risk of benefit from this procedure:
‘Despite the lack of evidence for its effectiveness and evidence for numerous deleterious effects, cricoid pressure is still considered a standard of care during rapid sequence induction, and its application is considered mandatory in patients at high risk for gastric regurgitation. However, by using cricoid pressure, we may well be endangering more lives by causing airway problems than we are saving in the hope of preventing pulmonary aspiration. It is dangerous to consider cricoid pressure to be an effective and reliable measure in reducing the risk of pulmonary aspiration and to become complacent about the many factors that contribute to regurgitation and aspiration. Cricoid pressure is not a substitute for optimal patient preparation. Ensuring optimal positioning and a rapid onset of anesthesia and muscle relaxation to decrease the risk of coughing, straining or retching during the induction of anesthesia are likely more important in the prevention of pulmonary aspiration than cricoid pressure.
‘At the time of Sellick’s description of the technique of cricoid pressure, morbidity and mortality from pulmonary aspiration during the induction of anesthesia in the surgical population in general, and the obstetric population in particular, were of great concern. At that time, the concept of cricoid pressure was highly attractive. However, during the past 48 years, many aspects of anesthetic management have considerably changed, and knowledge has advanced. By today’s standards, cricoid pressure can no longer be considered an evidence-based practice. This is why more and more anesthetists (including myself) no longer apply cricoid pressure.‘
Vielen Dank, Herr Doktor! Cricoid pressure: an expert’s opinion Minerva Anestesiol 2009;75:710-4 – Full text
Just as well really, because these guys show many people don’t know how to do it anyway! Cases were identified in which pressure was mistakenly applied to the thyroid cartilage and even the sternocleidomastoid muscles! Variable application and misapplication of cricoid pressure J Trauma. 2010 Nov;69(5):1182-4
H1N1 Update 16 December 2010 sent from the UK Intensive Care Society
As many of you will already be aware, the predicted second wave of swine flu seems to becoming a reality. The HPA have received information that there has been a rise in the number of confirmed H1N1 cases and has restarted regular teleconferences to discuss the current situation and to disseminate the latest advice and information. The initial teleconference was held last Friday and the first question asked was how many cases have units seen. Although the total numbers were not high, the fact that there are confirmed cases throughout the UK gave support to the decision that hospitals should prepare for an increase in the numbers.
Subsequent updates have confirmed that the case numbers are rising and although not all patients admitted to ICUs with a suspected diagnosis of H1N1 have required mechanical ventilation or had H1N1 confirmed. As of Wednesday this week the numbers of H1N1 related ICU cases had risen to 140. An additional concern is that the number of cases with probable H1N1 referred for ECMO is now 13 and this has resulted in a policy that there should be support for all the centers in the UK who can provide ECMO.
It is still too early to predict what the level escalation is going to be required, but there are real concerns that the combination of adverse weather conditions, the current financial restrictions in the NHS, and an H1N1 peak could place ICUs in a more seriously challenging situation than occurred in the previous outbreak.
For this reason, it is recommended that clinicians should once again have a low threshold for considering the possibility of H1N1 in patients who are referred to intensive care. Trusts should reconvene regular meetings to plan for any necessary expansion of critical care services. It is important that staff have up to date training in the use of personal protection equipment. One of the most important points learned from the first outbreak was that early antiviral therapy can reduce the need for mechanical ventilation and it is recommended that any patients admitted to hospital with a history and symptoms suggestive of an influenza-like illness should be given antiviral therapy.
The following points were made in the HPA–led teleconference on 10 December:
be vigilant: have a low threshold for considering the diagnosis.
start antivirals whenever there is a suspicion of flu (oseltamivir 75or 150 mg bd po).
In patients with resistance or not tolerating NG medication, there is an IV preparation which is currently undergoing clinical trial. GSK produces it (zanamavir) and may provide it on patient-name compassionate grounds.
Use ARDSnet ventilation especially for those with normal lung compliance.
Consider HFO for those with poor compliance
Fluid restrict patients
Consider referral for ECMO early if conventional ventilation is failing. ECMO beds are occupied almost all occupied by ‘flu patients and elective surgery has been curtailed to accomodate them. Surge funding has been agreed for extra ECMO. In cases where conventional ventilation is failing and there are no other options, patients should be referred to Glenfield before seven days of MV.
There will be advice re pregnant women after discussion with the RCOG
In some cases, URT specimens may be negative in severe cases and LRT samples may be needed for the diagnosis.
Point of care testing may have inadequate sensitivity for this strain of H1N1
The current rate is 21.5/100,000.
We aim to provide updates on the ICS website and copy of this document is available to download via http://www.ics.ac.uk/ under ‘Latest News – H1N1 Latest News’.
Update by the Executive Committee of the Intensive Care Society.
Sent from the email of:
Pauline Kemp
Head of Secretariat
Measuring end-tidal carbon dioxide (ET CO2 ) is a practical non-invasive method for detecting pulmonary blood flow, reflecting cardiac output and thereby the quality of CPR. It has also been shown to rise before clinically detectable return of spontaneous circulation (ROSC).
Passive leg raising (PLR) increases venous return and may therefore augment cardiac output and in a cardiac arrest this may be reflected by an elevation in ETCO2.
A Swedish observational study of 126 patients with out of hospital cardiac arrest due to a likely cardiac aetiology underwent tracheal intubation with standardised ventilation and chest compressions (either manually or using the LUCAS device, as part of larger study of mechanical chest compressions according to a cluster design). Patients were stratified to receive either PLR to 20 degrees or no PLR. ETCO2 was measured during CPR, either for 15min, or until the detection of ROSC. Hang on I think that's overdoing it a bit
During PLR, an increase in ETCO2 was found in all 44 patients who received PLR within 15s (p=0.003), 45s (p = 0.002) and 75 s (p = 0.0001). Survival to hospital discharge was 7% among patients with PLR and 1% among those without PLR (p = 0.12). Among patients experiencing ROSC (60 of 126), there was a marked increase in ETCO2 1 min before the detection of a palpable pulse. Passive leg raising during cardiopulmonary resuscitation in out-of-hospital cardiac arrest—Does it improve circulation and outcome? Resuscitation. 2010 Dec;81(12):1615-20
Two dedicated devices for transtracheal oxygen delivery through a cricothyroidotomy needle are available, the ENK Oxygen Flow Modulator (ENK) and the Manujet. Both maintain oxygenation, but the ENK is thought to achieve better ventilation (as previously shown in a pig model) because of a continuous flow that provides CO2 washout between insufflations. Very little is known concerning the lung pressures generated with these 2 devices, so a study using a simulated trachea and artificial lung model sought to determine oxygen flow, tidal volumes, and airway pressures at different occlusion rates and during both simulated partial and complete upper airway obstruction. Manujet
Gas flow and tidal volume were 3 times greater with the Manujet than the ENK (approximately 37 vs 14 L/min and 700 vs 250 mL, respectively) and were not dependent on the respiratory rate. In the absence of ventilation, the ENK delivered a 0.6+/-0.1 L/min constant gas flow. In the totally occluded airway, lung pressures increased to 136 cm H2O after 3 insufflations with the Manujet, whereas the ENK, which has a pressure release vent, generated acceptable pressures at a low respiratory rate (4 breaths/min) (peak pressure at 27.7 +/-0.7 and end-expiratory pressure at 18.8+/- 3.8 cm H2O). When used at a respiratory rate of 12 breaths/min, the ENK generated higher pressures (peak pressure at 95.9 +/- 21.2 and end-expiratory pressure at 51.4+/- 21.4 cm H2O). In the partially occluded airway, lung pressures were significantly greater with the Manujet compared with the ENK, and pressures increased with the respiratory rate with both devices. Finally, the gas flow and tidal volume generated by the Manujet varied proportionally with the driving pressure.
The authors asset that this study confirms:
the absolute necessity of allowing gas exhalation between 2 insufflations and
maintaining low respiratory rates during transtracheal oxygenation.
In the case of total airway obstruction, the ENK may be less deleterious because it has a pressure release vent. Using a Manujet at lower driving pressures may decrease the risk of barotrauma and allow the safe use of higher respiratory rates ENK Oxygen delivery during transtracheal oxygenation: a comparison of two manual devices Anesth Analg. 2010 Oct;111(4):922-4
One infrequently used option for refractory status epilepticus is isoflurane anaesthesia. A report of two cases demonstrates progressive MRI changes suggestive of neurotoxicity, that improved after discontinuation of isoflurane. Impossible to prove cause and effect here, since the both patients had status for weeks and were on multiple anticonvulsant medications, for example lorazepam, fosphenytoin, levetiracetam, valproate, and subsequent infusions of midazolam, pentobarbital, and ketamine. Neither patient recovered beyond a minimally conscious state. This article serves as a reminder that:
Persistent status epilepticus may be associated with a poor neurologic outcome
Some cases are extremely refractory to treatment
Isoflurane is one of many options to try when standard anticonvulsant regimens are failing
Dr WFS Sellers and colleagues describe several cases that demonstrate convincingly a protective effect of intravenous magnesium sulphate against the tachycardia produced by intravenous salbutamol in patients with asthma. This effect was observed both when magnesium was given before and when given after the salbutamol. It was seen in critically ill asthmatic patients and in a volunteer with well-controlled asthma.
Intravenous magnesium sulphate increases atrial contraction time and refractory times. It is used to treat atrial tachyarrhythmias and has a negative chronotropic and dromotropic effect. Intravenous magnesium sulphate prevents intravenous salbutamol tachycardia in asthma Br J Anaesth. 2010 Dec;105(6):869-70
Level 1 evidence is great, but for useful tips that can add options to your resuscitation toolbox there are some great finds in journal letters pages.
Try this one: An apneoic patient requires assisted ventilation in your resuscitation room. Bag-mask ventilation is ineffective. You then notice a mature tracheostomy at the same time that you’re told he had a laryngectomy. How would you ventilate him?
The obvious answer is to intubate the stoma with a size 6.0 tracheal tube or a tracheostomy tube if you have one. However prior to that you could bag-‘mask’ ventilate with a size 2 laryngeal mask airway applied to the stoma, holding the cuff in place with pressure through an index finger.
Such a technique is desribed in the context of an elective anaesthesia case in this month’s Anaesthesia. The LMA cuff provided an effective seal around the stoma, thereby allowing leak-free ventilation.
Stoma ventilation using a paediatric facemask is another option. Tracheostomy ventilation using a laryngeal mask as a ‘bridge to extubation’ Anaesthesia 2010;65(12):1232–1233
A case report of massive obstetric haemorrhage due to placental abruption describes the successful management of haemorrhage associated with a low fibrinogen level with blood products that included fibrinogen concentrate.
Fibrinogen concentrate can be available more quickly than other clotting products as it is rapidly solubilised from an ampoule in 50 ml water and given as a bolus. To raise the plasma fibrinogen concentration by 1 g/l in a 70-kg person, 1000 ml fresh frozen plasma (6 standard UK units), or 260 ml cryoprecipitate (10 standard UK units) will be required. Administration of adequate doses of fresh frozen plasma or cryoprecipitate to treat hypofibrinogenaemia during obstetric haemorrhage will therefore take a substantial amount of time, even with an efficient blood bank and portering system. Fibrinogen concentrate use during major obstetric haemorrhage Anaesthesia 2010;65(12):1229–1230
A previous retrospective study showed its use in a series of surgical and obstetric haemorrhage cases may have been associated with a subsequent decreased need for other blood products. Fibrinogen concentrate substitution therapy in patients with massive haemorrhage and low plasma fibrinogen concentrations Br. J. Anaesth. (2008) 101 (6): 769-773 (Full text)
Another stab at assessing noninvasive ventilation in cardiogenic pulmonary oedema has been made by Italian researchers who compared CPAP with noninvasive pressure support ventilation (nPSV – similar to BiPAP) in a randomised trial of 80 patients. The primary outcome was endotracheal intubation rates. There was no significant difference between the two modalities. This result is in keeping with the much larger 3CPO trial. Continuous Positive Airway Pressure vs. Pressure Support Ventilation in Acute Cardiogenic Pulmonary Edema: A Randomized Trial J Emerg Med. 2010 Nov;39(5):676-84
